0001397702-23-000067 | 10-Q | XBRL Viewer

Fair Value Measurements

9 Months Ended

Sep. 30, 2023

4. Fair Value Measurements

The Company measures certain financial assets and liabilities at fair value on a recurring basis, including cash equivalents and investments. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. A three-tier fair value hierarchy is established as a basis for considering such assumptions and for inputs used in the valuation methodologies in measuring fair value:

•Level 1 – quoted prices in active markets are identical assets and liabilities;

•Level 2 – observable inputs other than quoted prices in active markets for identical assets and liabilities;

•Level 3 – unobservable inputs.

Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The Company’s investments are classified within Level 1 of the fair value hierarchy include money market funds valued using quoted market prices and U.S. treasury bills valued using broker or dealer quotations with reasonable levels of price transparency. Investments classified within Level 2 include commercial paper, which are valued using model-based valuation techniques, and corporate bonds/notes, U.S. government securities and agency bonds/notes, which are valued based upon quoted market prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active for which all significant inputs are observable in the market or can be corroborated by observable market data for substantially the full term of the assets.

The following tables set forth by level within the fair value hierarchy the Company’s assets that are reported at fair value as of September 30, 2023 and December 31, 2022, using the inputs defined above (in thousands):



	September 30, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	29,156	$	—	$	—	$	29,156
U.S. treasury bills		7,844		—		—		7,844
Commercial paper		—		38,689		—		38,689
Corporate bonds/notes		—		34,017		—		34,017
U.S. government securities		—		7,990		—		7,990
Agency bonds/notes		—		79,481		—		79,481
	$	37,000	$	160,177	$	—	$	197,177



	December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	55,158	$	—	$	—	$	55,158
U.S. treasury bills		19,776		—		—		19,776
Commercial paper		—		48,875		—		48,875
Corporate bonds/notes		—		1,515		—		1,515
U.S. government securities		—		83,270		—		83,270
Asset-backed securities		—		1,996		—		1,996
Agency notes		—		2,884		—		2,884
	$	74,934	$	138,540	$	—	$	213,474

There were no transfers between fair value hierarchy levels during the three and nine months ended September 30, 2023 and 2022.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Commitments and Contingencies (Operating Lease Maturities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Commitments and Contingencies [Abstract]
2023	$ 496
2024	1,991
2025	2,130
2026	2,255
2027 and Thereafter	4,459
Total lease payments	11,331
Less: imputed interest	(1,995)
Present value of lease liabilities	$ 9,336	$ 7,842

Long-term Debt

9 Months Ended

Sep. 30, 2023

Long-term Debt [Abstract]

Long-term Debt

6. Long-term Debt

In May 2022, the Company entered into a Loan and Security Agreement, or Loan Agreement, with Oxford Finance LLC and its agents, or Oxford Finance, which provides for a $225,000,000 loan facility, comprised of a $25,000,000 secured revolving credit facility and a $200,000,000 secured term loan facility. The term loans are available in three tranches. The first $75,000,000 tranche of term loans was available at closing in May 2022. A second tranche of $75,000,000 of term loans is available through December 31, 2024. A third tranche of $50,000,000 would be available through December 31, 2024 so long as, at the time of draw, the Company has consolidated trailing 12-month revenues equal to at least 90% of the sum of the outstanding term loans plus the amount of any requested third tranche term loans.

Upon request of the Company, the revolving credit facility will be increased from $25,000,000 to $50,000,000. The revolving loans are available subject to a borrowing base equal to 85% of eligible receivables plus 50% of eligible inventory, up to the lesser of 40% of the borrowing base or $10,000,000, in the case of eligible inventory.

The revolving loans and the term loans mature on May 1, 2027. The principal amount of outstanding revolving loans, together with accrued and unpaid interest, is due on the maturity date. The term loans begin to amortize in equal monthly installments beginning on July 1, 2026. As the Company achieved a specified consolidated trailing twelve-month revenue target, it has the option to extend the first amortization date for the term loans to July 1, 2027. Such election may be made no earlier than June 30, 2023 and no later than thirty (30) days prior to July 1, 2026. If the Company exercises this option, then the maturity date for both the revolving loans and the term loans will be May 1, 2028.

The revolving loans accrue interest at the greater of 1-month Secured Overnight Financing Rate (SOFR), or the Index Rate, and 0.85%, plus a margin of 3.00%. The term loans accrue interest at the greater of the Index Rate and 0.85%, plus a margin of 5.00%. The Index Rate is capped at 2.50% for purposes of the Loan Agreement. Interest on both revolving loans and term loans is payable monthly in arrears. The Company may borrow, prepay and reborrow revolving loans, without premium or penalty. The term loans once repaid or prepaid may not be reborrowed. Term loans may be prepaid in full, or in part in increments of $10,000,000. The Company is required to pay a prepayment fee of 3.0% for prepayments of term loans made in the first year after closing, 2.0% for prepayments of term loans made in the second year after closing, 1.0% for prepayments of term loans made in the third year after closing and no prepayment fees thereafter. Upon the earlier of prepayment or maturity of the term loans, the Company is required to pay a fee of 5.0% of the aggregate original principal amount of the funded term loans, which fee increases to 6.75% if the Company exercises its option to extend the amortization date and maturity date. The Company is also obligated to pay other customary fees for a loan facility of this size and type.

Also in May 2022, the Company borrowed the first $75,000,000 tranche of the term loan and used a portion of the proceeds to pay off and terminate the prior term loan agreement with Stifel Bank totaling $49,181,000, which included a final interest payment of $181,000. The Company recognized a loss on debt extinguishment of $245,000 in connection with the early termination of its prior term loan agreement with Stifel Bank. The Success Fee Agreement obligation, of $367,500, survives the Stifel Bank debt repayment and terminates on October 29, 2025.

Obligations under the Loan Agreement are secured by substantially all of the Company’s assets. The Loan Agreement requires the Company to maintain consolidated trailing twelve-month revenues of at least 75% of the outstanding principal amount of the term loans, measured as of the last day of each fiscal quarter; or if the revenue target is not achieved, the Company must have maintained unrestricted cash and cash equivalents (net of outstanding revolving loans) subject to control agreements in favor of Oxford Finance equal to at least 50% of the outstanding principal amount of the term loans. Additionally, the Loan Agreement contains customary affirmative and negative covenants, including covenants limiting the Company’s ability and the ability of the Company’s subsidiaries to, among other things, dispose of assets, effect certain mergers, incur debt, grant liens, pay dividends and distributions on capital stock, make investments and acquisitions, and enter into transactions with affiliates, in each case subject to customary exceptions for a loan facility of this size and type.

The events of default under the Loan Agreement include, among others, payment defaults, material misrepresentations, breaches of covenants, cross defaults with certain other material indebtedness, bankruptcy and insolvency events, and judgment defaults. The occurrence of an event of default could result in the acceleration of the Company’s obligations under the Loan Agreement, the termination of the lender’s commitments, a 5% increase in the applicable rate of interest and the exercise by the lender of other rights and remedies provided for under the Loan Agreement.

As of September 30, 2023, the aggregate outstanding principal balance under the term loan facility was $75,000,000 with the variable interest rate capped at the maximum rate of 7.50%, and no amounts were outstanding under the revolving credit facility of the Loan Agreement. As of September 30, 2023, the Company was in compliance with all applicable financial covenants.

Future payments under the Oxford Finance term loan agreement as of September 30, 2023 are as follows (in thousands):



Period Ending December 31:	Amount
2023	$	1,437
2024		5,719
2025		5,703
2026		45,699
2027		34,517
		93,075
Add: Accretion of closing fees		1,126
		94,201
Less: Amount representing interest		(18,075)
Less: Amount representing debt discount and debt issuance costs		(762)
Present value of minimum payments	$	75,364

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

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+ Details

Recent Accounting Pronouncements	9 Months Ended
Sep. 30, 2023
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	3. Recent Accounting Pronouncements The Company has considered all recent accounting pronouncements that have not yet been adopted and believe there are none that could potentially have a material impact on the Company’s financial statements and related disclosures.

Recent Accounting Pronouncements

9 Months Ended

Sep. 30, 2023

Recent Accounting Pronouncements [Abstract]

Recent Accounting Pronouncements

3. Recent Accounting Pronouncements

The Company has considered all recent accounting pronouncements that have not yet been adopted and believe there are none that could potentially have a material impact on the Company’s financial statements and related disclosures.

- Definition

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

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+ Details

Stock-Based Compensation Plans (Summary of Shares Available for Issuance) (Details) - 2019 Equity Incentive Plan [Member]	9 Months Ended
	Sep. 30, 2023 shares
Shares Available for Grant
Beginning balance (in shares)	2,209,072
Authorized (in shares)	1,534,238
Allowance for Performance Stock Units for overperformance (in shares)	(99,350)
Granted/Awarded (in shares)	(1,531,871)
Canceled (in shares)	57,460
Ending balance (in shares)	2,169,549

Condensed Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
Condensed Statements of Cash Flows - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net loss	$ (42,732)	$ (42,396)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	2,040	1,465
Stock-based compensation expense	29,284	17,478
Accretion of discounts on investments, net	(5,280)	(338)
Amortization of debt discount and debt issuance costs	173	160
Amortization of right-of-use asset	821	766
Non-cash interest expense	600	823
Loss on extinguishment of debt		245
Loss on disposal of property and equipment	144	175
Change in accounts receivable allowances	45	(3)
Provision for excess and obsolete inventories	23	5
Changes in assets and liabilities:
Accounts receivable	(3,816)	(5,184)
Inventories	(2,796)	(2,446)
Prepaid expenses and other current assets	(353)	(1,132)
Other assets	(253)	(52)
Accounts payable	2,477	1,665
Accrued liabilities	(2,808)	(744)
Other liabilities	(1,130)	(344)
Net cash used in operating activities	(23,561)	(29,857)
Cash flows from investing activities
Purchases of property and equipment	(1,054)	(3,438)
Purchases of investments	(148,842)	(53,679)
Proceeds from maturity of investments	144,300
Net cash used in investing activities	(5,596)	(57,117)
Cash flows from financing activities
Proceeds from issuance of common stock	2,832	3,067
Proceeds from long-term debt		75,000
Principal repayment of debt		(49,000)
Payments of debt issuance costs		(1,086)
Payments of deferred offering costs		(9)
Net cash provided by financing activities	2,832	27,972
Net change in cash, cash equivalents and restricted cash	(26,325)	(59,002)
Cash, cash equivalents and restricted cash, beginning of period	55,513	110,463
Cash, cash equivalents and restricted cash, end of period	29,188	51,461
Supplemental disclosure of cash flow information
Cash paid for interest	4,364	2,383
Noncash investing and financing activities:
Accounts payable and accrued liabilities for purchases of property and equipment	71	176
Right-of-use asset obtained in exchange for lease obligation	$ 2,504	903
Unpaid debt issuance costs		3
Unpaid deferred offering costs		$ 162

Balance Sheet Components

9 Months Ended

Sep. 30, 2023

Balance Sheet Components [Abstract]

Balance Sheet Components

5. Balance Sheet Components

Investments

The fair value of the Company’s cash equivalents and available-for-sale investments as of September 30, 2023 and December 31, 2022 are as follows (in thousands):


	September 30, 2023
			Gross Unrealized				Estimated
	Amortized Cost		Gains		Losses		Fair Value
Money market funds	$	29,156	$	—	$	—	$	29,156
U.S. treasury bills		7,844		—		—		7,844
Commercial paper		38,689		—		—		38,689
Corporate bonds/notes		34,110		—		(93)		34,017
U.S. government securities		7,991		—		(1)		7,990
Agency bonds/notes		79,671		1		(191)		79,481
	$	197,461	$	1	$	(285)	$	197,177
Classified as:
Cash equivalents							$	29,156
Short-term investments								163,673
Long-term investments								4,348
							$	197,177


	December 31, 2022
			Gross Unrealized				Estimated
	Amortized Cost		Gains		Losses		Fair Value
Money market funds	$	55,158	$	—	$	—	$	55,158
U.S. treasury bills		19,772		4		—		19,776
Commercial paper		48,875		—		—		48,875
Corporate bonds/notes		1,528		—		(13)		1,515
U.S. government securities		83,432		2		(164)		83,270
Asset-backed securities		2,000		—		(4)		1,996
Agency notes		2,876		8		—		2,884
	$	213,641	$	14	$	(181)	$	213,474
Classified as:
Cash equivalents							$	55,158
Short-term investments								158,316
							$	213,474

‎

The following table summarizes the fair value of the Company’s cash equivalents, and available-for-sale investments classified by maturity as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30,		December 31,
	2023		2022
Amounts maturing within one year	$	192,829	$	213,474
Amounts maturing after one year through two years		4,348		—
	$	197,177	$	213,474

Available-for-sale investments held as of September 30, 2023 had a weighted average days to maturity of 205 days.

The following table presents the Company’s available-for-sale investments that were in an unrealized loss position as of September 30, 2023 and December 31, 2022 (in thousands):


	September 30, 2023				December 31, 2022
	Less than 12 months				Less than 12 months
Assets:	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U.S. treasury bills	$	2,949	$	—	$	—	$	—
Corporate bonds/notes		33,744		(93)		1,490		(13)
U.S. government securities		7,985		(1)		73,329		(164)
Asset-backed securities		—		—		1,994		(4)
Agency bonds/notes		72,827		(191)		—		—
	$	117,505	$	(285)	$	76,813	$	(181)

Inventories

Components of inventories were as follows (in thousands):


	September 30,		December 31,
	2023		2022
Raw materials	$	6,394	$	4,913
Finished products		15,672		14,380
	$	22,066	$	19,293

As of September 30, 2023 and December 31, 2022, there were no work-in-process inventories.

Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):



	September 30,		December 31,
	2023		2022
Accrued payroll and related expenses	$	12,890	$	15,216
Operating lease liability		1,700		1,844
Accrued royalty expense		1,034		973
Accrued professional services		221		781
Accrued travel expenses		814		775
Provision for sales returns		534		540
Accrued interest payable		502		519
Deferred revenue		120		253
Accrued clinical expenses		341		249
Accrued other expenses		772		815
Total	$	18,928	$	21,965

Commitments and Contingencies

9 Months Ended

Sep. 30, 2023

Commitments and Contingencies [Abstract]

Commitments and Contingencies

7. Commitments and Contingencies

Operating Lease and Rights-of-Use

The Company’s operating lease obligation at its corporate headquarters in California consists of leased office, laboratory, and manufacturing space under a non-cancellable operating lease that expires in October 2027. In May 2023, the Company extended the lease term for an additional three years and recorded an additional $2,504,000 right-of-use asset and lease liability from the remeasurement. The lease agreement includes a renewal provision allowing the Company to extend this lease for an additional period of five years.

The Company’s non-cancelable operating lease obligation at its facility in Minnesota consists of additional office, laboratory and manufacturing space and expires in November 2029. The lease agreement includes a renewal provision allowing the Company to extend this lease for two additional five year terms.

Balance sheet information as of September 30, 2023 and December 31, 2022 consists of the following (in thousands):


	September 30,		December 31,
Operating Lease:	2023		2022
Operating lease right-of-use assets in other non-current assets	$	6,765	$	5,081
Operating lease liabilities in accrued liabilities	$	1,700	$	1,844
Operating lease liabilities in other liabilities		7,636		5,998
Total operating lease liabilities	$	9,336	$	7,842

The following table summarizes the Company’s operating lease payments as of September 30, 2023 (in thousands):



Period Ending December 31:	Amount
2023	$	496
2024		1,991
2025		2,130
2026		2,255
2027 and thereafter		4,459
Total lease payments	$	11,331
Less: imputed interest		(1,995)
Present value of lease liabilities	$	9,336

Purchase Obligations

Purchase obligations consist of agreements to purchase goods and services entered into in the ordinary course of business. As of September 30, 2023, the Company had non-cancellable purchase obligations to suppliers of $18,320,000. In addition, the Company has minimum purchase commitments under its amended supply agreement with Cordis from July 2024 through February 2029 which require a specified minimum volume commitment based on the actual units purchased during the prior year period from July 1 through June 30, with the unit purchase price dependent upon annual volume during the same prior year period.

Indemnification

In the normal course of business, the Company enters into contracts and agreements with suppliers and other parties that contain a variety of representations and warranties and may provide for indemnification of the counterparty. The Company’s exposure under these agreements is unknown because it involves claims that may be made against it in the future but have not yet been made. To date, the Company has not been subject to any claims or been required to defend any action related to its indemnification obligations.

The Company indemnifies each of its directors and officers for certain events or occurrences, subject to certain limits, while the director or officer is or was serving at the Company’s request in such capacity, as permitted under Delaware law and in accordance with its certificate of incorporation and bylaws. The term of the indemnification period lasts as long as a director or officer may be subject to any proceeding arising out of acts or omissions of such director or officer in such capacity. The maximum amount of potential future indemnification is unlimited; however, the Company currently holds director and officer liability insurance. The Company believes that the fair value of these indemnification obligations is minimal. Accordingly, the Company has not recognized any liabilities relating to these obligations as of September 30, 2023.

Contingencies

The Company is not involved in any pending legal proceedings that it believes could have a material adverse effect on its financial condition, results of operations or cash flows. From time to time, the Company may pursue litigation to assert its legal rights and such litigation may be costly and divert the efforts and attention of its management and technical personnel which could adversely affect its business. The Company accrues a liability for such matters when it is probable that future expenditures will be made, and such expenditures can be reasonably estimated. There were no contingent liabilities requiring accrual as of September 30, 2023 and December 31, 2022.

Condensed Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Preferred stock, $0.001 par value
Preferred shares (in USD per share)	$ 0.001	$ 0.001
Preferred shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, $0.001 par value
Common stock, par value (in USD per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	38,907,789	38,355,972
Shares outstanding (in shares)	38,907,789	38,355,972

Balance Sheet Components (Available-for-Sale Investments in Unrealized Loss Position) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 months	$ 117,505	$ 76,813
Unrealized Loss, Less than 12 months	(285)	(181)
US Treasury Bills [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 months	2,949
Corporate Bonds/Notes [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 months	33,744	1,490
Unrealized Loss, Less than 12 months	(93)	(13)
U.S. Government Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 months	7,985	73,329
Unrealized Loss, Less than 12 months	(1)	(164)
Asset-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 months		1,994
Unrealized Loss, Less than 12 months		$ (4)
Agency bonds/notes [Member]
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 months	72,827
Unrealized Loss, Less than 12 months	$ (191)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

+ Details

Long-term Debt (Narrative) (Details) - USD ($)	1 Months Ended	9 Months Ended
Long-term Debt (Narrative) (Details) - USD ($)	May 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Subsequent Event [Line Items]
Loss on debt extinguishment			$ (245,000)
Oxford Finance [Member]
Subsequent Event [Line Items]
Debt. Default, Rate Increase		5.00%
Secured Debt [Member] \| Stifel Bank [Member]
Subsequent Event [Line Items]
Facility amount	$ 200,000,000
Term Loan [Member]
Subsequent Event [Line Items]
Percentage of revenue for debt repayment		90.00%
Term Loan [Member] \| Stifel Bank [Member]
Subsequent Event [Line Items]
Repayment of outstanding loan amount	49,181,000
Debt interest	181,000
Loss on debt extinguishment	245,000
Term Loan [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Percentage of prepayment fees		3.00%
Percentage of prepayment fees in second year		2.00%
Percentage of prepayment fees in third year		1.00%
Percent aggregate original principal amount		5.00%
Term loan prepaid in increments		$ 10,000,000
Loan Facility [Member] \| Stifel Bank [Member]
Subsequent Event [Line Items]
Facility fee	367,500,000
Debt Instrument, Fee Amount	$ 367,500,000
Letter of Credit [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Aggregate outstanding principal balance		$ 75,000,000
Annual interest rate		7.50%
Secured Revolving Credit Facility [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Annual interest rate		2.50%
Maturity date		May 01, 2027
Percent of borrowing base of eligible receivables		85.00%
Percent of eligible inventory		50.00%
Percent of borrowing base in case eligible inventory		40.00%
Borrowing base amount in case eligible inventory		$ 10,000,000
Debt instrument margin rate	5.00%
Secured Revolving Credit Facility [Member] \| Index Rate [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Variable interest rate	0.85%	0.85%
Debt instrument margin rate		3.00%
Secured Revolving Credit Facility [Member] \| Secured Debt [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Facility amount	$ 25,000,000
Secured Revolving Credit Facility [Member] \| Term Loan [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Facility amount	25,000,000	$ 50,000,000
Loan Agreement [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Facility amount	$ 225,000,000
Loan Agreement [Member] \| Term Loan [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Percentage of revenue for debt repayment	75.00%
Percent aggregate original principal amount	50.00%
Term Loan, First Tranche [Member] \| Term Loan [Member]
Subsequent Event [Line Items]
Debt, face amount	$ 75,000,000
Term Loan, Second Tranche [Member] \| Term Loan [Member]
Subsequent Event [Line Items]
Debt, face amount	75,000,000
Term Loan, Third Tranche [Member] \| Term Loan [Member]
Subsequent Event [Line Items]
Debt, face amount	$ 50,000,000
Maximum [Member] \| Secured Term Loan Facility [Member] \| Oxford Finance [Member]
Subsequent Event [Line Items]
Percent aggregate original principal amount		6.75%

Organization

9 Months Ended

Sep. 30, 2023

Organization [Abstract]

Organization

1. Organization

The Company

Silk Road Medical, Inc., or the Company, has developed a technologically advanced, minimally-invasive solution for patients with carotid artery disease who are at risk for stroke. The Company's portfolio of products enable a procedure referred to as transcarotid artery revascularization, or TCAR, that combines the benefits of endovascular techniques and surgical principles. The Company manufactures and sells in the United States its portfolio of TCAR products which are designed to provide direct access to the carotid artery, effective reduction in stroke risk throughout the procedure, and long-term restraint of carotid plaque.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2023

Summary of Significant Accounting Policies [Abstract]

Basis of Preparation

The accompanying financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America, or U.S. GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or SEC, regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and accordingly the condensed balance sheet as of December 31, 2022, and related disclosures, have been derived from the audited financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. These unaudited condensed financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for the fair statement of the Company’s condensed financial information. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results to be expected for the year ending December 31, 2023 or for any other interim period or for any other future year.

The accompanying interim unaudited condensed financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2022 included in the Company's annual report on Form 10-K filed with the SEC on February 28, 2023.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts and disclosures reported in the financial statements. Management uses judgment when making estimates related to provisions for accounts receivable and excess and obsolete inventories, the valuation of deferred tax assets, the reserves for sales returns, and stock-based compensation. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately differ from these estimates and assumptions.

Fair Value of Financial Instruments

The Company has evaluated the estimated fair value of its financial instruments as of September 30, 2023 and December 31, 2022. The carrying amounts of certain of the Company’s financial instruments, which include accounts receivable, accounts payable and accrued liabilities approximate their respective fair values because of the short-term nature of these instruments. Management believes that its debt bears interest at the prevailing market rates for instruments with similar characteristics (Level 2 within the fair value hierarchy); accordingly, the carrying value of this instrument approximates its fair value.

Cash, Cash Equivalents and Restricted Cash

The Company considers all highly liquid investments with an original maturity of three months or less at the time of purchase to be cash equivalents. Cash equivalents are recorded at fair value, based on quoted market prices. As of

September 30, 2023 and December 31, 2022, the Company’s cash equivalents were entirely comprised of investments in money market funds.

Restricted cash as of December 31, 2022 consisted of a letter of credit of $155,000, representing collateral for the Company's facility lease in California. The Company had no restricted cash as of September 30, 2023.

Investments

Short-term investments consist of debt securities classified as available-for-sale and have original maturities greater than 90 days, but less than one year as of the balance sheet date. Long-term investments have maturities greater than one year as of the balance sheet date. All investments are recorded at fair value based on the fair value hierarchy. Unrealized gains and losses, deemed temporary in nature, are reported as a separate component of accumulated other comprehensive income (loss). Realized gains and losses are included in earnings and are derived based on the specific-identification method for determining the costs of investments sold and were insignificant for the three and nine months ended September 30, 2023 and 2022. Amortization of premiums and accretion of discounts are reported as a component of interest income.

A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the corresponding establishment of a new cost basis for the investment. The Company evaluates the securities in an unrealized loss position for expected credit losses by considering factors such as historical experience, market data, issuer-specific factors, current economic conditions and credit ratings. The Company did not recognize any credit losses on its available-for-sale securities during the three and nine months ended September 30, 2023 and 2022.

Concentration of Credit Risk, and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to credit risk consist of cash and cash equivalents, investments and accounts receivable to the extent of the amounts recorded on the balance sheet. Cash, cash equivalents, and investments are deposited in financial institutions which, at times, may be in excess of federally insured limits. Cash equivalents are invested in highly rated money market funds. The Company invests in a variety of financial instruments, such as, but not limited to, commercial paper, corporate bonds/notes, U.S. government securities, U.S. treasury bills, agency bonds/notes and, by policy, limits the amount of credit exposure with any one financial institution or commercial issuer. The Company has not experienced any material losses on its deposits of cash and cash equivalents or investments during the three and nine months ended September 30, 2023 and 2022.

As of September 30, 2023 and December 31, 2022, a portion of the Company’s cash and cash equivalents was maintained with Silicon Valley Bank, a division of First Citizens Bank, or SVB, and exceeded federally insured limits. Substantially all of the Company’s cash equivalents and investments reside in a custodial account held by a third party, in which SVB Asset Management is the advisor. On March 10, 2023, SVB was shut down and placed under receivership with the Federal Deposit Insurance Corporation, or FDIC, by the California Department of Financial Protection and Innovation. On March 26, 2023, the FDIC announced it had entered into a purchase and assumption agreement with First Citizens Bank & Trust Company under which all of SVB’s deposits were assumed. As of the issuance date of these financial statements, the Company has not experienced any losses on its deposits and all of the Company’s cash deposited with SVB has been accessible to the Company.

The Company’s accounts receivable are due from a variety of hospitals and medical centers in the United States. As of September 30, 2023 and December 31, 2022, no customer represented 10% or more of the Company’s accounts receivable. For the three and nine months ended September 30, 2023 and 2022, there were no customers that represented 10% or more of revenue.

The Company provides for uncollectible amounts when specific credit problems are identified. In doing so, the Company analyzes historical bad debt trends, customer credit worthiness, current economic trends and changes in customer payment patterns when evaluating the adequacy of the allowance for expected credit losses on customer accounts.

The Company manufactures certain of its commercial products in-house. Certain of the Company’s product components and sub-assemblies continue to be manufactured by sole suppliers, the most significant of which is the ENROUTE

Transcarotid Stent System, manufactured by Cordis Corporation, or Cordis. Disruption in component or sub-assembly supply from these manufacturers or from in-house production would have a negative impact on the Company’s financial position and results of operations.

The Company is subject to certain risks, including that its devices may not be approved or cleared for marketing by governmental authorities or be successfully marketed. There can be no assurance that the Company’s products will achieve widespread adoption in the marketplace, nor can there be any assurance that existing devices or any future devices can be developed or manufactured at an acceptable cost and with appropriate performance characteristics. The Company is also subject to risks common to companies in the medical device industry, including, but not limited to, new technological innovations, competition, dependence upon government and third-party payers to provide adequate coverage and reimbursement, dependence on key personnel and suppliers, protection of proprietary technology, product liability claims, and compliance with government regulations.

Existing or future devices developed by the Company may require approvals or clearances from the U.S. Food and Drug Administration, or FDA, or international regulatory agencies. In addition, in order to continue the Company’s operations, compliance with various federal and state laws is required. If the Company were denied or delayed in receiving such approvals or clearances, it may be necessary to adjust operations to align with the Company’s currently approved portfolio. If clearance for the products in the current portfolio were withdrawn by the FDA, this would have a material adverse impact on the Company.

Leases

The Company accounts for its leasing arrangements in accordance with Accounting Standards Codification, or ASC 842, “Leases.” The Company considers if an arrangement is a lease at inception if it obtains the right to control the use of an identified asset under a leasing arrangement with an initial term greater than twelve months. The Company determines whether a contract conveys the right to control the use of an identified asset for a period of time if the contract contains both the right to obtain substantially all of the economic benefits from the use of the identified asset and the right to direct the use of the identified asset. The Company also evaluates the nature of each lease to determine whether it is an operating or financing lease and recognizes the right-of-use asset and lease liabilities based on the present value of future minimum lease payments over the expected lease term. The Company’s leases do not generally contain an implicit interest rate and therefore the Company uses the incremental borrowing rate it would expect to pay to borrow on a similar collateralized basis over a similar term in order to determine the present value of its lease payments. The Company considers renewal options in the determination of the lease term if the option to renew is reasonably certain. Variable lease costs represent payments that are dependent on usage, a rate or index. Variable lease costs, which consists primarily of taxes, insurance and common area maintenance costs, are expensed as incurred. The Company elected to account for contracts that contain lease and non-lease components as a single component, consistent with its historical practice. The Company does not have any finance leases.

Revenue Recognition

The Company recognizes revenue in accordance with ASC Topic 606, "Revenue from Contracts with Customers." Under ASC 606, revenue is recognized when a customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services.

The Company’s revenue is generated from the sale of its products to hospitals and medical centers in the United States through direct sales representatives. Revenue is recognized when obligations under the terms of a contract with customers are satisfied, which occurs with the transfer of control of the Company’s products to its customers, either upon shipment of the product or delivery of the product to the customer. The Company’s products are readily available for usage as soon as the customer possesses it. Upon receipt, the customer controls the economic benefits of the product, has significant risks and rewards, and the legal title. The Company has present right to payment; therefore, the transfer of control is deemed to happen at a point in time. Revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring the goods. The Company is entitled to the total consideration for the products ordered by customers as product pricing is fixed according to the terms of customer contracts and payment terms are short.

As of September 30, 2023 and December 31, 2022, the Company recorded $298,000 and $148,000, respectively, of unbilled receivables, which are included in accounts receivable, net on the condensed balance sheet, as the Company has an unconditional right to payment as of the end of the applicable period.

The Company excludes taxes assessed by governmental authorities on revenue-producing transactions from the measurement of the transaction price. Costs associated with product sales, which include commissions and royalties, are expensed when incurred because the expense is incurred at a point in time and the amortization period is less than one year. Commissions are recorded as selling expense and royalties are recorded as cost of goods sold in the condensed statements of operations and comprehensive loss.

The Company accepts product returns at its discretion or if the product is defective as manufactured. The Company establishes estimated provisions for returns based on historical experience and considers other factors that it believes could significantly impact its expected returns, which provisions are classified within accrued liabilities on the condensed balance sheet. The Company elected to expense shipping and handling costs as incurred and includes them in the cost of goods sold. In those cases where the Company bills shipping and handling costs to customers, it will classify the amounts billed as a component of revenue.

Cost of Goods Sold

The Company manufactures certain of its portfolio of TCAR products at its California and Minnesota facilities and purchases other products from third party manufacturers. Cost of goods sold consists primarily of costs related to materials, components and sub-assemblies, manufacturing overhead costs, direct labor, scrap, product rework, reserves for excess, obsolete and non-sellable inventories as well as distribution-related expenses. A significant portion of the Company’s cost of goods sold currently consists of manufacturing overhead costs. These overhead costs include the cost of quality control, material procurement, inventory control, facilities, equipment and operations supervision and management. Cost of goods sold also includes depreciation expense for production equipment and certain direct costs such as shipping costs and royalties. The Company entered into the lease for its additional facility in Minnesota in May 2021 and did not begin commercial production of the ENROUTE Neuroprotection System until the third quarter of 2022. During this time, the Company experienced additional overhead expenses related to its investment in the start-up phase of its manufacturing capacity expansion, which were recorded as a period expense.

Stock-Based Compensation

Stock–Based Compensation

The Company accounts for stock-based compensation in accordance with Financial Accounting Standards Board, or FASB, ASC 718, "Compensation-Stock Compensation." ASC 718 requires the recognition of compensation expense, using a fair-value based method, for costs related to all share-based payments including stock options, restricted stock units, performance stock units, and shares issued under its employee stock purchase plan. ASC 718 requires companies to estimate the fair value of all share-based payment option awards on the date of grant using an option pricing model. The fair value of stock options is recognized over the period during which an optionee is required to provide services in exchange for the option award, known as the requisite service period (usually the vesting period), on a straight-line basis. The Company accounts for option forfeitures as they occur.

The Company accounts for stock-based compensation for restricted stock units at their fair value, based on the closing market price of the Company’s common stock on the date of grant. These costs are recognized on a straight-line basis over the requisite service period, which is usually the vesting period.

The Company accounts for stock-based compensation for performance stock units with market-based conditions at their fair value on the date of the award using the Monte Carlo simulation model. These costs are recognized over the requisite service period, which is usually the vesting period, regardless of the likelihood of achievement of the market-based performance criteria.

The Company accounts for stock-based compensation for its employee stock purchase plan based on the estimated fair value of the options on the date of grant. The Company estimates the grant date fair value using an option pricing model for each purchase period. These costs are recognized on a straight-line basis over the offering period.

Income Taxes

The Company accounts for income taxes under the liability method, whereby deferred tax assets and liabilities are determined based on the difference between the condensed financial statements and tax bases of assets and liabilities using the enacted tax rates in effect for the year in which the differences are expected to affect taxable income. A valuation allowance is established when necessary to reduce deferred tax assets to the amounts expected to be realized. As the Company has historically incurred operating losses, it has established a full valuation allowance against its net deferred tax assets, and there is no provision for income taxes.

The Company also follows the provisions of ASC 740-10, "Accounting for Uncertainty in Income Taxes." ASC 740-10 prescribes a comprehensive model for the recognition, measurement, presentation and disclosure in financial statements of any uncertain tax positions that have been taken or expected to be taken on a tax return. No liability related to uncertain tax positions is recorded on the condensed financial statements. It is the Company's policy to include penalties and interest expense related to income taxes as part of the provision for income taxes.

Comprehensive Loss

Comprehensive loss consists of net loss and changes in unrealized gains and losses on investments classified as available-for-sale. For the three and nine months ended September 30, 2023 and 2022, the Company’s unrealized gains and losses on available-for-sale investments represent the only component of other comprehensive loss that are excluded from the reported net loss and that are presented in the condensed statements of operations and comprehensive loss. Accumulated other comprehensive income (loss) is presented in the accompanying condensed balance sheets as a component of stockholders' equity.

Net Loss per Share

Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding during the period, without consideration for potential dilutive common shares. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, common stock options, restricted stock units and performance stock units are considered to be potentially dilutive securities. Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share as the inclusion of all potential dilutive common shares would have been anti-dilutive.

Net loss per share was determined as follows (in thousands, except share and per share data):


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2023		2022		2023		2022
Net loss	$	(12,788)	$	(10,319)	$	(42,732)	$	(42,396)
Weighted average common stock outstanding used to compute net loss per share, basic and diluted		38,865,011		35,303,958		38,722,012		35,157,840
Net loss per share, basic and diluted	$	(0.33)	$	(0.29)	$	(1.10)	$	(1.21)

The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted average shares outstanding because such securities have an antidilutive impact due to the Company's net loss:



	September 30,
	2023	2022
Common stock options	3,645,243	4,023,518
Restricted stock units and performance stock units	2,498,989	1,147,820
	6,144,232	5,171,338

Segment and Geographical Information

The Company operates and manages its business as one reportable and operating segment. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. Primarily all of the Company’s long-lived assets are based in the United States. Long-lived assets are comprised of property and equipment. All of the Company’s revenue was in the United States for the three and nine months ended September 30, 2023 and 2022, based on the shipping location of the external customer.

Balance Sheet Components (Schedule of Inventory) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Balance Sheet Components [Abstract]
Raw materials	$ 6,394	$ 4,913
Finished products	15,672	14,380
Inventory, gross	$ 22,066	$ 19,293

Long-term Debt (Future Payment Under the Term Loan) (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Long-term Debt [Abstract]
2023	$ 1,437
2024	5,719
2025	5,703
2026	45,699
2027	34,517
Long-term debt, gross before accretion of closing fees	93,075
Add: Accretion of closing fees	1,126
Long-Term Debt, Gross, After Accretion Of Closing Fees	94,201
Less: Amount representing interest	(18,075)
Less: Amount representing debt discount and debt issuance costs	(762)
Present value of minimum payments	$ 75,364

Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2023	Oct. 31, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-38847
Entity Registrant Name	SILK ROAD MEDICAL, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-8777622
Entity Address, Address Line One	1213 Innsbruck Dr.
Entity Address, City or Town	Sunnyvale
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94089
City Area Code	408
Local Phone Number	720-9002
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	SILK
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		38,945,496
Entity Central Index Key	0001397702
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

Summary of Significant Accounting Policies (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) segment	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Summary of Significant Accounting Policies [Abstract]
Unbilled receivables	$ 298,000		$ 298,000		$ 148,000
Provision for income taxes	0		0
Liability for uncertain tax positions	0		$ 0
Number of reportable segments \| segment			1
Number of operating segments \| segment			1
Available-for-sale securities, credit losses	0	$ 0	$ 0	$ 0
Restricted cash	$ 0		$ 0		$ 155,000

Stock-Based Compensation Plans (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Mar. 31, 2023	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expensed not yet recognized		$ 10,302
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance		100.00%
ISO and NSO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise threshold as a percentage of fair value of shares		10.00%
Option term		10 years
Vesting term		4 years
ISO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise threshold as a percentage of fair value of shares		100.00%
NSO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise threshold as a percentage of fair value of shares		85.00%
2019 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expensed not yet recognized, period for recognition		1 month 20 days
Common Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of options exercised		$ 7,842
Compensation expensed not yet recognized, period for recognition		1 year 10 months 17 days
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term		2 years 9 months 18 days
Unrecognized compensation costs of unvested RSUs		$ 77,791
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		1,412,623
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	99,350	99,350
Expected volatility		61.20%
Risk-free interest rate		0.38%
Dividend yield		0.00%
Performance Stock Units [Member] \| Benchmark [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility		62.30%
Risk-free interest rate		4.58%
Maximum [Member] \| ISO and NSO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise threshold as a percentage of fair value of shares		110.00%
2019 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance (in shares)		7,952,134
Unrecognized compensation costs related to the ESPP		$ 136
2019 Equity Incentive Plan [Member] \| Common Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock under employee stock purchase plan (in shares)		318,126
Shares available for future issuance (in shares)		1,504,289
2019 Equity Incentive Plan [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term		4 years
2019 Equity Incentive Plan [Member] \| Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term		3 years
2019 Equity Incentive Plan [Member] \| Maximum [Member] \| Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Performance	200.00%

Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2023

Summary of Significant Accounting Policies [Abstract]

Schedule of Net Loss Per Share Determination


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2023		2022		2023		2022
Net loss	$	(12,788)	$	(10,319)	$	(42,732)	$	(42,396)
Weighted average common stock outstanding used to compute net loss per share, basic and diluted		38,865,011		35,303,958		38,722,012		35,157,840
Net loss per share, basic and diluted	$	(0.33)	$	(0.29)	$	(1.10)	$	(1.21)

Schedule of Potentially Dilutive Securities Outstanding Excluded from Diluted Weighted Average Shares Outstanding



	September 30,
	2023	2022
Common stock options	3,645,243	4,023,518
Restricted stock units and performance stock units	2,498,989	1,147,820
	6,144,232	5,171,338

Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 2023

Balance Sheet Components [Abstract]

Fair Value of the Available-For-Sale Investments


	September 30, 2023
			Gross Unrealized				Estimated
	Amortized Cost		Gains		Losses		Fair Value
Money market funds	$	29,156	$	—	$	—	$	29,156
U.S. treasury bills		7,844		—		—		7,844
Commercial paper		38,689		—		—		38,689
Corporate bonds/notes		34,110		—		(93)		34,017
U.S. government securities		7,991		—		(1)		7,990
Agency bonds/notes		79,671		1		(191)		79,481
	$	197,461	$	1	$	(285)	$	197,177
Classified as:
Cash equivalents							$	29,156
Short-term investments								163,673
Long-term investments								4,348
							$	197,177


	December 31, 2022
			Gross Unrealized				Estimated
	Amortized Cost		Gains		Losses		Fair Value
Money market funds	$	55,158	$	—	$	—	$	55,158
U.S. treasury bills		19,772		4		—		19,776
Commercial paper		48,875		—		—		48,875
Corporate bonds/notes		1,528		—		(13)		1,515
U.S. government securities		83,432		2		(164)		83,270
Asset-backed securities		2,000		—		(4)		1,996
Agency notes		2,876		8		—		2,884
	$	213,641	$	14	$	(181)	$	213,474
Classified as:
Cash equivalents							$	55,158
Short-term investments								158,316
							$	213,474

Fair Value of Cash Equivalents, Short-Term and Long-Term Equivalents


	September 30,		December 31,
	2023		2022
Amounts maturing within one year	$	192,829	$	213,474
Amounts maturing after one year through two years		4,348		—
	$	197,177	$	213,474

Available-For-Sale Investments in Unrealized Loss Position


	September 30, 2023				December 31, 2022
	Less than 12 months				Less than 12 months
Assets:	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U.S. treasury bills	$	2,949	$	—	$	—	$	—
Corporate bonds/notes		33,744		(93)		1,490		(13)
U.S. government securities		7,985		(1)		73,329		(164)
Asset-backed securities		—		—		1,994		(4)
Agency bonds/notes		72,827		(191)		—		—
	$	117,505	$	(285)	$	76,813	$	(181)

Schedule of Inventories


	September 30,		December 31,
	2023		2022
Raw materials	$	6,394	$	4,913
Finished products		15,672		14,380
	$	22,066	$	19,293

Schedule of Accrued Liabilities



	September 30,		December 31,
	2023		2022
Accrued payroll and related expenses	$	12,890	$	15,216
Operating lease liability		1,700		1,844
Accrued royalty expense		1,034		973
Accrued professional services		221		781
Accrued travel expenses		814		775
Provision for sales returns		534		540
Accrued interest payable		502		519
Deferred revenue		120		253
Accrued clinical expenses		341		249
Accrued other expenses		772		815
Total	$	18,928	$	21,965

- Definition

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-9

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

+ Details

Balance Sheet Components (Accrued Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Balance Sheet Components [Abstract]
Accrued payroll and related expenses	$ 12,890	$ 15,216
Operating lease liability	1,700	1,844
Accrued royalty expense	1,034	973
Accrued professional services	221	781
Accrued travel expenses	814	775
Provision for sales returns	534	540
Accrued interest payable	502	519
Deferred revenue	120	253
Accrued clinical expenses	341	249
Accrued other expenses	772	815
Total	$ 18,928	$ 21,965

Summary of Significant Accounting Policies (Schedule of Potentially Dilutive Securities Not Included in Calculation of Earnings per Share) (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	6,144,232	5,171,338
Common Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3,645,243	4,023,518
Restricted Stock Units and Performance Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,498,989	1,147,820

Fair Value Measurements (Details) - Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 197,177	$ 213,474
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	29,156	55,158
US Treasury Bills [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	7,844	19,776
Commercial Papers [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	38,689	48,875
Corporate Bonds/Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	34,017	1,515
U.S. Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	7,990	83,270
Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		1,996
Agency bonds/notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	79,481	2,884
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	37,000	74,934
Level 1 [Member] \| Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	29,156	55,158
Level 1 [Member] \| US Treasury Bills [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	7,844	19,776
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	160,177	138,540
Level 2 [Member] \| Commercial Papers [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	38,689	48,875
Level 2 [Member] \| Corporate Bonds/Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	34,017	1,515
Level 2 [Member] \| U.S. Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	7,990	83,270
Level 2 [Member] \| Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		1,996
Level 2 [Member] \| Agency bonds/notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 79,481	$ 2,884

401(k) Plan	9 Months Ended
401(k) Plan	Sep. 30, 2023
401(k) Plan [Abstract]
401(k) Plan	9. 401(k) Plan The Company has a qualified retirement plan under section 401(k) of the Internal Revenue Code, or the IRC, under which participants may contribute up to 90% of their eligible compensation, subject to maximum deferral limits specified by the IRC. The Company may make a discretionary matching contribution to the 401(k) plan and may make a discretionary employer contribution to each eligible employee each year. Effective January 2022, the Company matched employees' contributions to the 401(k) plan at 50% of the first 6% of compensation deferred to the 401(k) plan. The Company's matching contributions were $519,000 and $352,000 for the three months ended September 30, 2023 and 2022, respectively, and $1,734,000 and $1,394,000 for the nine months ended September 30, 2023 and 2022, respectively.

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2023

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Preparation

Use of Estimates

Fair Value of Financial Instruments

Cash, Cash Equivalents and Restricted Cash

September 30, 2023 and December 31, 2022, the Company’s cash equivalents were entirely comprised of investments in money market funds.

Investments

Concentration of Credit Risk, and Other Risks and Uncertainties

Leases

Revenue Recognition

Cost of Goods Sold

Stock–Based Compensation

Income Taxes

Comprehensive Loss

Net Loss per Share

Net loss per share was determined as follows (in thousands, except share and per share data):


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2023		2022		2023		2022
Net loss	$	(12,788)	$	(10,319)	$	(42,732)	$	(42,396)
Weighted average common stock outstanding used to compute net loss per share, basic and diluted		38,865,011		35,303,958		38,722,012		35,157,840
Net loss per share, basic and diluted	$	(0.33)	$	(0.29)	$	(1.10)	$	(1.21)



	September 30,
	2023	2022
Common stock options	3,645,243	4,023,518
Restricted stock units and performance stock units	2,498,989	1,147,820
	6,144,232	5,171,338

Segment and Geographical Information

401(k) Plan (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
401(k) Plan (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
401(k) Plan [Abstract]
Percentage employee contribution			90.00%
Employer discretionary contribution	$ 519	$ 352	$ 1,734	$ 1,394
Employer contribution match percentage			50.00%
Percent of matching contribution of the employee's pay			6.00%

Stock-Based Compensation Plans (Summary of Stock Option Activity) (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Number of Shares
Beginning balance (in shares) \| shares	3,839,858
Options granted (in shares) \| shares	19,898
Options exercised (in shares) \| shares	(195,708)
Options cancelled (in shares) \| shares	(18,805)
Ending balance (in shares) \| shares	3,645,243	3,839,858
Vested and exercisable (in shares) \| shares	3,088,087
Vested and expect to vest (in shares) \| shares	3,645,243
Weighted Average Exercise Price
Beginning balance (in USD per share) \| $ / shares	$ 24.22
Options granted (in USD per share) \| $ / shares	33.57
Options exercised (in USD per share) \| $ / shares	7.53
Options cancelled (in USD per share) \| $ / shares	48.84
Ending balance (in USD per share) \| $ / shares	25.04	$ 24.22
Vested and exercisable (in USD per share) \| $ / shares	21.96
Vested and expected to vest (in USD per share) \| $ / shares	$ 25.04
Weighted Average Remaining Contractual Term (in Years)
Awards outstanding	5 years 9 months 10 days	6 years 4 months 28 days
Vested and exercisable	5 years 4 months 17 days
Vested and expected to vest	5 years 9 months 10 days
Aggregate Intrinsic Value (in thousands)
Awards outstanding \| $	$ 11,810	$ 112,755
Vested and exercisable \| $	11,810
Vested and expected to vest \| $	$ 11,810

Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 29,188	$ 55,358
Short-term investments	163,673	158,316
Accounts receivable, net	21,779	18,007
Inventories	22,066	19,293
Prepaid expenses and other current assets	4,277	3,924
Total current assets	240,983	254,898
Long-term investments	4,348
Property and equipment, net	8,337	9,372
Restricted cash	0	155
Other non-current assets	7,196	5,260
Total assets	260,864	269,685
Current liabilities:
Accounts payable	5,094	2,523
Accrued liabilities	18,928	21,965
Total current liabilities	24,022	24,488
Long-term debt	75,364	74,596
Other liabilities	8,336	6,726
Total liabilities	107,722	105,810
Commitments and contingencies (Note 7)
Stockholders' equity:
Preferred stock, $0.001 par value Shares authorized: 5,000,000 at September 30, 2023 and December 31, 2022 Shares issued and outstanding: none at September 30, 2023 and December 31, 2022
Common stock, $0.001 par value Shares authorized: 100,000,000 at September 30, 2023 and December 31, 2022 Shares issued and outstanding: 38,907,789 and 38,355,972 at September 30, 2023 and December 31, 2022, respectively	39	38
Additional paid-in capital	539,831	507,715
Accumulated other comprehensive loss	(284)	(166)
Accumulated deficit	(386,444)	(343,712)
Total stockholders’ equity	153,142	163,875
Total liabilities and stockholders’ equity	$ 260,864	$ 269,685

Stock-Based Compensation Plans (Summary of Stock-Based Compensation) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 10,247	$ 6,339	$ 29,284	$ 17,478
Cost of Goods Sold [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	437	303	1,272	802
Research and Development Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	1,965	1,392	5,540	3,763
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 7,845	$ 4,644	$ 22,472	$ 12,913

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2023

Commitments and Contingencies [Abstract]

Balance Sheet Information


	September 30,		December 31,
Operating Lease:	2023		2022
Operating lease right-of-use assets in other non-current assets	$	6,765	$	5,081
Operating lease liabilities in accrued liabilities	$	1,700	$	1,844
Operating lease liabilities in other liabilities		7,636		5,998
Total operating lease liabilities	$	9,336	$	7,842

Operating Lease Maturities



Period Ending December 31:	Amount
2023	$	496
2024		1,991
2025		2,130
2026		2,255
2027 and thereafter		4,459
Total lease payments	$	11,331
Less: imputed interest		(1,995)
Present value of lease liabilities	$	9,336

Condensed Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Beginning balance (in shares) at Dec. 31, 2021	34,980,896
Beginning balance at Dec. 31, 2021	$ 35	$ 367,907	$ (288,702)		$ 79,240
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options		168			168
Exercise of stock options (in shares)	35,453
Issuance of common stock upon vesting of restricted stock units (in shares)	57,253
Stock-based compensation		4,978			4,978
Net loss			(16,679)		(16,679)
Ending balance (in shares) at Mar. 31, 2022	35,073,602
Ending balance at Mar. 31, 2022	$ 35	373,053	(305,381)		67,707
Beginning balance (in shares) at Dec. 31, 2021	34,980,896
Beginning balance at Dec. 31, 2021	$ 35	367,907	(288,702)		79,240
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss					(42,396)
Ending balance (in shares) at Sep. 30, 2022	35,381,085
Ending balance at Sep. 30, 2022	$ 35	388,452	(331,098)	$ (191)	57,198
Beginning balance (in shares) at Mar. 31, 2022	35,073,602
Beginning balance at Mar. 31, 2022	$ 35	373,053	(305,381)		67,707
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options		322			322
Exercise of stock options (in shares)	55,941
Issuance of common stock upon vesting of restricted stock units (in shares)	13,075
Issuance of common stock under employee stock purchase plan		1,239			1,239
Issuance of common stock under employee stock purchase plan (in shares)	50,551
Stock-based compensation		6,161			6,161
Net loss			(15,398)		(15,398)
Unrealized gain (loss) on investments, net				(2)	(2)
Ending balance (in shares) at Jun. 30, 2022	35,193,169
Ending balance at Jun. 30, 2022	$ 35	380,775	(320,779)	(2)	60,029
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options		1,338			1,338
Exercise of stock options (in shares)	161,924
Issuance of common stock upon vesting of restricted stock units (in shares)	25,992
Stock-based compensation		6,339			6,339
Net loss			(10,319)		(10,319)
Unrealized gain (loss) on investments, net				(189)	(189)
Ending balance (in shares) at Sep. 30, 2022	35,381,085
Ending balance at Sep. 30, 2022	$ 35	388,452	(331,098)	(191)	57,198
Beginning balance (in shares) at Dec. 31, 2022	38,355,972
Beginning balance at Dec. 31, 2022	$ 38	507,715	(343,712)	(166)	163,875
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options		1,110			1,110
Exercise of stock options (in shares)	144,474
Issuance of common stock upon vesting of restricted stock units	$ 1				1
Issuance of common stock upon vesting of restricted stock units (in shares)	207,995
Stock-based compensation		8,838			8,838
Net loss			(16,460)		(16,460)
Unrealized gain (loss) on investments, net				249	249
Ending balance (in shares) at Mar. 31, 2023	38,708,441
Ending balance at Mar. 31, 2023	$ 39	517,663	(360,172)	83	157,613
Beginning balance (in shares) at Dec. 31, 2022	38,355,972
Beginning balance at Dec. 31, 2022	$ 38	507,715	(343,712)	(166)	$ 163,875
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)					195,708
Net loss					$ (42,732)
Ending balance (in shares) at Sep. 30, 2023	38,907,789
Ending balance at Sep. 30, 2023	$ 39	539,831	(386,444)	(284)	153,142
Beginning balance (in shares) at Mar. 31, 2023	38,708,441
Beginning balance at Mar. 31, 2023	$ 39	517,663	(360,172)	83	157,613
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options		232			232
Exercise of stock options (in shares)	32,483
Issuance of common stock upon vesting of restricted stock units (in shares)	19,400
Issuance of common stock under employee stock purchase plan		1,359			1,359
Issuance of common stock under employee stock purchase plan (in shares)	51,956
Stock-based compensation		10,199			10,199
Net loss			(13,484)		(13,484)
Unrealized gain (loss) on investments, net				(414)	(414)
Ending balance (in shares) at Jun. 30, 2023	38,812,280
Ending balance at Jun. 30, 2023	$ 39	529,453	(373,656)	(331)	155,505
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options		131			131
Exercise of stock options (in shares)	18,751
Issuance of common stock upon vesting of restricted stock units (in shares)	76,758
Stock-based compensation		10,247			10,247
Net loss			(12,788)		(12,788)
Unrealized gain (loss) on investments, net				47	47
Ending balance (in shares) at Sep. 30, 2023	38,907,789
Ending balance at Sep. 30, 2023	$ 39	$ 539,831	$ (386,444)	$ (284)	$ 153,142

Long-term Debt (Tables)

9 Months Ended

Sep. 30, 2023

Long-term Debt [Abstract]

Future Payment Under the Term Loan



Period Ending December 31:	Amount
2023	$	1,437
2024		5,719
2025		5,703
2026		45,699
2027		34,517
		93,075
Add: Accretion of closing fees		1,126
		94,201
Less: Amount representing interest		(18,075)
Less: Amount representing debt discount and debt issuance costs		(762)
Present value of minimum payments	$	75,364

Stock-Based Compensation Plans (Tables)

9 Months Ended

Sep. 30, 2023

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Shares Available for Issuance


		Number of Shares
Balances, December 31, 2022		2,209,072
Authorized		1,534,238
Allowance for Performance Stock Units for overperformance		(99,350)
Granted/Awarded		(1,531,871)
Cancelled		57,460
Balances, September 30, 2023		2,169,549

Summary of Stock Option Activity


	Options Outstanding
	Number of	Weighted Average		Weighted Average ‎Remaining ‎Contractual Term		Aggregate ‎ Intrinsic
	Shares	Exercise Price		(Years)		Value
Balances, December 31, 2022	3,839,858	$	24.22		6.41	$	112,755
Options granted	19,898		33.57
Options exercised	(195,708)		7.53
Options cancelled	(18,805)		48.84
Balances, September 30, 2023	3,645,243	$	25.04		5.78	$	11,810
Vested and exercisable at September 30, 2023	3,088,087	$	21.96		5.38	$	11,810
Vested and expected to vest at September 30, 2023	3,645,243	$	25.04		5.78	$	11,810

Summary of Stock-Based Compensation


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2023		2022		2023		2022
Cost of goods sold	$	437	$	303	$	1,272	$	802
Research and development expenses		1,965		1,392		5,540		3,763
Selling, general and administrative expenses		7,845		4,644		22,472		12,913
	$	10,247	$	6,339	$	29,284	$	17,478

Restricted Stock Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Stock Unit Activity


	Number of ‎Restricted ‎Stock Units		Weighted Average ‎Grant Date ‎Fair Value
Balances, December 31, 2022		1,122,356	$	42.70
Awards granted		1,412,623		28.76
Awards vested		(304,153)		41.83
Awards canceled		(38,655)		43.19
Balances, September 30, 2023		2,192,171	$	33.83
Expected to vest at September 30, 2023		2,192,171	$	33.83

Performance Stock Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Stock Unit Activity


	Number of Performance Stock Units		Weighted Average Grant Date Fair Value
Balances, December 31, 2022		207,468	$	77.12
Awards granted		99,350		69.40
Awards vested		—		—
Awards canceled		—		—
Balances, September 30, 2023		306,818	$	74.62
Expected to vest at September 30, 2023		306,818	$	74.62

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-1D

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147480483/718-10-35-3

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-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Balance Sheet Components (Fair Value of Cash Equivalents, Short-Term and Long-Term Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Balance Sheet Components [Abstract]
Amounts maturing within one year	$ 192,829	$ 213,474
Amounts maturing after one year through two years	4,348
Total	$ 197,177	$ 213,474

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2023

Fair Value Measurements [Abstract]

Financial Liabilities Measure on a Recurring Basis



	September 30, 2023
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	29,156	$	—	$	—	$	29,156
U.S. treasury bills		7,844		—		—		7,844
Commercial paper		—		38,689		—		38,689
Corporate bonds/notes		—		34,017		—		34,017
U.S. government securities		—		7,990		—		7,990
Agency bonds/notes		—		79,481		—		79,481
	$	37,000	$	160,177	$	—	$	197,177



	December 31, 2022
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	55,158	$	—	$	—	$	55,158
U.S. treasury bills		19,776		—		—		19,776
Commercial paper		—		48,875		—		48,875
Corporate bonds/notes		—		1,515		—		1,515
U.S. government securities		—		83,270		—		83,270
Asset-backed securities		—		1,996		—		1,996
Agency notes		—		2,884		—		2,884
	$	74,934	$	138,540	$	—	$	213,474

Balance Sheet Components (Narrative) (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Balance Sheet Components [Abstract]
Weighted average days to maturity	205 days
Work-in-process inventories	$ 0	$ 0

Balance Sheet Components (Fair Value of Available-For-Sale Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 197,461	$ 213,641
Gross Unrealized Gains	1	14
Gross Unrealized Losses	(285)	(181)
Estimated Fair Value	197,177	213,474
Cash equivalents	29,156	55,158
Short-term investments	163,673	158,316
Long-term Investments	4,348
Total	197,177	213,474
Money Market Funds [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29,156	55,158
Estimated Fair Value	29,156	55,158
US Treasury Bills [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,844	19,772
Gross Unrealized Gains		4
Estimated Fair Value	7,844	19,776
Commercial Paper [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	38,689	48,875
Estimated Fair Value	38,689	48,875
Corporate Bonds/Notes [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	34,110	1,528
Gross Unrealized Losses	(93)	(13)
Estimated Fair Value	34,017	1,515
U.S. Government Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,991	83,432
Gross Unrealized Gains		2
Gross Unrealized Losses	(1)	(164)
Estimated Fair Value	7,990	83,270
Asset-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		2,000
Gross Unrealized Losses		(4)
Estimated Fair Value		1,996
Agency bonds/notes [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	79,671	2,876
Gross Unrealized Gains	1	8
Gross Unrealized Losses	(191)
Estimated Fair Value	$ 79,481	$ 2,884

Commitments and Contingencies (Balance Sheet Information) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Commitments and Contingencies [Abstract]
Operating lease right-of-use assets in other non-current assets	$ 6,765	$ 5,081
Operating lease liabilities in accrued liabilities	1,700	1,844
Operating lease liabilities in other liabilities	7,636	5,998
Total operating lease liabilities	$ 9,336	$ 7,842

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2023
Insider Trading Arrangements [Line Items]
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accounting Policies (Schedule of Net Loss Per Share Determination) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Summary of Significant Accounting Policies [Abstract]
Net loss	$ (12,788)	$ (10,319)	$ (42,732)	$ (42,396)
Weighted average common stock outstanding used to compute net loss per share, basic (in shares)	38,865,011	35,303,958	38,722,012	35,157,840
Weighted average common stock outstanding used to compute net loss per share, diluted (in shares)	38,865,011	35,303,958	38,722,012	35,157,840
Net loss per share, basic	$ (0.33)	$ (0.29)	$ (1.10)	$ (1.21)
Net loss per share, diluted	$ (0.33)	$ (0.29)	$ (1.10)	$ (1.21)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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+ Details

Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Condensed Statements of Operations and Comprehensive Loss [Abstract]
Revenue	$ 44,435	$ 37,374	$ 129,864	$ 98,567
Cost of goods sold	12,050	9,308	37,580	26,897
Gross profit	32,385	28,066	92,284	71,670
Operating expenses:
Research and development	10,047	8,471	31,260	27,249
Selling, general and administrative	36,009	28,821	105,923	83,795
Total operating expenses	46,056	37,292	137,183	111,044
Loss from operations	(13,671)	(9,226)	(44,899)	(39,374)
Interest income	2,617	617	7,339	751
Interest expense	(1,732)	(1,714)	(5,137)	(3,366)
Loss on debt extinguishment				(245)
Other income (expense), net	(2)	4	(35)	(162)
Net loss	(12,788)	(10,319)	(42,732)	(42,396)
Other comprehensive loss:
Unrealized gain (loss) on investments, net	47	(189)	(118)	(191)
Other comprehensive loss	47	(189)	(118)	(191)
Net loss and comprehensive loss	$ (12,741)	$ (10,508)	$ (42,850)	$ (42,587)
Net loss per share, basic	$ (0.33)	$ (0.29)	$ (1.10)	$ (1.21)
Net loss per share, diluted	$ (0.33)	$ (0.29)	$ (1.10)	$ (1.21)
Weighted average common shares used to compute net loss per share, basic	38,865,011	35,303,958	38,722,012	35,157,840
Weighted average common shares used to compute net loss per share, diluted	38,865,011	35,303,958	38,722,012	35,157,840

Stock-Based Compensation Plans (Summary of Stock Unit Activity) (Details) - $ / shares	1 Months Ended	9 Months Ended
	Mar. 31, 2023	Sep. 30, 2023
Restricted Stock Units [Member]
Number of Stock Units
Beginning balance (in shares)		1,122,356
Stock granted (in shares)		1,412,623
Stock vested (in shares)		(304,153)
Stock forfeited (in shares)		(38,655)
Ending balance (in shares)		2,192,171
Expected to vest (in shares)		2,192,171
Weighted Average Grant Date Fair Value
Beginning balance (in USD per share)		$ 42.70
Stock granted (in USD per share)		28.76
Stock vested (in USD per share)		41.83
Stock forfeited (in USD per share)		43.19
Ending balance (in USD per share)		33.83
Expected to vest (in USD per share)		$ 33.83
Performance Stock Units [Member]
Number of Stock Units
Beginning balance (in shares)		207,468
Stock granted (in shares)	99,350	99,350
Ending balance (in shares)		306,818
Expected to vest (in shares)		306,818
Weighted Average Grant Date Fair Value
Beginning balance (in USD per share)		$ 77.12
Stock granted (in USD per share)		69.40
Ending balance (in USD per share)		74.62
Expected to vest (in USD per share)		$ 74.62

Stock-Based Compensation Plans

9 Months Ended

Sep. 30, 2023

Stock-Based Compensation Plans [Abstract]

Stock-Based Compensation Plans

8. Stock-Based Compensation Plans

As of September 30, 2023, the Company has reserved 7,952,134 shares of common stock for issuance under the 2019 Equity Incentive Plan, or the 2019 Plan.

A summary of the shares available for issuance under the 2019 Plan is as follows:


		Number of Shares
Balances, December 31, 2022		2,209,072
Authorized		1,534,238
Allowance for Performance Stock Units for overperformance		(99,350)
Granted/Awarded		(1,531,871)
Cancelled		57,460
Balances, September 30, 2023		2,169,549

The exercise price of Incentive Stock Options, or ISOs, and Non-Statutory Stock Options, or NSOs, shall not be less than 100% and 85%, respectively, of the estimated fair value of the shares on the date of grant as determined by the Board of Directors. The exercise price of ISOs and NSOs granted to a 10% stockholder shall not be less than 110% of the estimated fair value of the shares on the date of grant as determined by the Board of Directors. To date, options have a term of ten years and generally vest over four years from the date of grant.

Stock option activity under the Company’s 2007 Stock Option Plan, 2015 Equity Incentive Plan and 2019 Plan is set forth below:


	Options Outstanding
	Number of	Weighted Average		Weighted Average ‎Remaining ‎Contractual Term		Aggregate ‎ Intrinsic
	Shares	Exercise Price		(Years)		Value
Balances, December 31, 2022	3,839,858	$	24.22		6.41	$	112,755
Options granted	19,898		33.57
Options exercised	(195,708)		7.53
Options cancelled	(18,805)		48.84
Balances, September 30, 2023	3,645,243	$	25.04		5.78	$	11,810
Vested and exercisable at September 30, 2023	3,088,087	$	21.96		5.38	$	11,810
Vested and expected to vest at September 30, 2023	3,645,243	$	25.04		5.78	$	11,810

The aggregate intrinsic value of options exercised during the nine months ended September 30, 2023 was $7,842,000. The aggregate intrinsic value was calculated as the difference between the exercise prices of the underlying options and the estimated fair value of the common stock on the date of exercise.

Restricted Stock Units

Restricted stock units, or RSUs, are granted under the 2019 Plan and generally vest over four years in annual equal increments. A summary of RSU activity for the nine months ended September 30, 2023 is as follows:


	Number of ‎Restricted ‎Stock Units		Weighted Average ‎Grant Date ‎Fair Value
Balances, December 31, 2022		1,122,356	$	42.70
Awards granted		1,412,623		28.76
Awards vested		(304,153)		41.83
Awards canceled		(38,655)		43.19
Balances, September 30, 2023		2,192,171	$	33.83
Expected to vest at September 30, 2023		2,192,171	$	33.83

Performance Stock Units

Performance stock units, or PSUs, are granted under the 2019 Plan and generally vest over three years. A summary of PSU activity for the nine months ended September 30, 2023 is as follows:


	Number of Performance Stock Units		Weighted Average Grant Date Fair Value
Balances, December 31, 2022		207,468	$	77.12
Awards granted		99,350		69.40
Awards vested		—		—
Awards canceled		—		—
Balances, September 30, 2023		306,818	$	74.62
Expected to vest at September 30, 2023		306,818	$	74.62

The number of awards granted in the table above and the number of shares expected to vest as of September 30, 2023 reflects the performance and vesting of PSUs at 100% of the target value of shares granted.

2019 Employee Stock Purchase Plan

As of September 30, 2023, 318,126 shares of common stock have been issued to employees participating in the 2019 Employee Stock Purchase Plan, or the ESPP, and 1,504,289 shares were available for future issuance under the ESPP.

Stock-Based Compensation

In March 2023, the Company awarded an aggregate of 99,350 PSUs, assuming target performance. Up to one-third of the target award can be earned and vested at the end of each of the one-year and two-year performance measurement periods based on the total stockholder return, or TSR, of the Company’s common stock price relative to a group of peer companies, and up to 200% of the target award at the end of the three year performance measurement period. The fair value of the PSUs was estimated using the Monte Carlo simulation model and the following assumptions: peer companies volatility of 62.3%, Company volatility of 61.2%, risk-free interest rate of 4.58%, correlation with index of 0.38, and dividend yield of 0%.

The following table summarizes the total stock-based compensation expense included in the condensed statements of operations and comprehensive loss for all periods presented (in thousands):


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2023		2022		2023		2022
Cost of goods sold	$	437	$	303	$	1,272	$	802
Research and development expenses		1,965		1,392		5,540		3,763
Selling, general and administrative expenses		7,845		4,644		22,472		12,913
	$	10,247	$	6,339	$	29,284	$	17,478

As of September 30, 2023, there was total unrecognized compensation costs of $10,302,000 related to stock options expected to be recognized over a period of approximately 1.88 years, a total of $77,791,000 of unrecognized compensation costs related to unvested RSUs and PSUs expected to be recognized over a period of approximately 2.80 years and $136,000 of unrecognized compensation costs related to the ESPP, which the Company will recognize over 0.14 years.

Commitments and Contingencies (Narrative) (Details) - USD ($)	1 Months Ended	9 Months Ended
	May 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Lessee, Lease, Description [Line Items]
Purchase obligation		$ 18,320,000
Indemnification obligations, liability recognized		0
Contingent liabilities requiring accrual		0		$ 0
Additional extended lease period	3 years
Right-of-use asset obtained in exchange for lease obligation	$ 2,504,000	$ 2,504,000	$ 903,000
Headquarters [Member]
Lessee, Lease, Description [Line Items]
Renewal term		5 years
Additional Office, Laboratory And Manufacturing Space [Member]
Lessee, Lease, Description [Line Items]
Renewal term		5 years