Clearside Biomedical (CLSD) 10-K 11 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 07, 2022	Jun. 30, 2021
Cover [Abstract]
Entity Registrant Name	Clearside Biomedical, Inc.
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Trading Symbol	CLSD
Document Type	10-K
Entity Central Index Key	0001539029
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		60,147,618
Entity Public Float			$ 227,700,000
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Entity File Number	001-37783
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-2437375
Entity Address, Address Line One	900 North Point Parkway
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Alpharetta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30005
City Area Code	678
Local Phone Number	270-3631
Document Annual Report	true
Document Transition Report	false
Documents Incorporated by Reference	Portions of the Company’s definitive proxy statement, to be filed pursuant to Regulation 14A under the Securities Exchange Act of 1934, for its 2022 Annual Meeting of Stockholders are incorporated by reference in Part III of the Form 10-K.
Auditor Name	Ernst & Young LLP
Auditor Location	Atlanta, Georgia
Auditor Firm ID	42

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 30,436	$ 17,287
Accounts receivable	10,000
Prepaid expenses	921	722
Other current assets	779	109
Total current assets	42,136	18,118
Property and equipment, net	238	416
Operating lease right-of-use asset	369	528
Restricted cash	160	260
Total assets	42,903	19,322
Current liabilities:
Accounts payable	941	1,997
Accrued liabilities	3,312	1,582
Current portion of long-term debt		991
Current portion of operating lease liabilities	387	373
Deferred revenue		5,000
Total current liabilities	4,640	9,943
Operating lease liabilities	288	616
Total liabilities	4,928	10,559
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized and no shares issued at December 31, 2020 and 2019
Common stock, $0.001 par value; 100,000,000 shares authorized at December 31, 2021 and 2020; 59,722,930 and 51,860,941 shares issued and outstanding at December 31, 2021 and 2020, respectively	60	52
Additional paid-in capital	293,406	264,578
Accumulated deficit	(255,491)	(255,867)
Total stockholders’ equity	37,975	8,763
Total liabilities and stockholders’ equity	$ 42,903	$ 19,322

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares, issued	59,722,930	51,860,941
Common stock, shares outstanding	59,722,930	51,860,941

Statements of Operations

Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
License and other revenue	$ 29,575	$ 7,894	$ 2,173
Type of Revenue [Extensible List]	us-gaap:LicenseMember	us-gaap:LicenseMember	us-gaap:LicenseMember
Operating expenses:
Research and development	$ 18,537	$ 15,073	$ 15,658
General and administrative	11,665	10,756	16,819
Total operating expenses	30,202	25,829	32,477
Loss from operations	(627)	(17,935)	(30,304)
Other income	1,003	0	0
Other expense	0	275	466
Net income (loss)	$ 376	$ (18,210)	$ (30,770)
Net income (loss) per share of common stock - basic and diluted	$ 0.01	$ (0.39)	$ (0.81)
Weighted average shares outstanding - basic	58,491,986	46,506,540	38,170,830
Weighted average shares outstanding - diluted	59,906,602	46,506,540	38,170,830

Statement of Stockholders' Equi

Statement of Stockholders' Equity (Deflicit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In-Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2018	$ 23,620	$ 32	$ 230,475	$ (206,887)
Beginning balance, shares at Dec. 31, 2018		32,119,227
Issuance of common shares under at-the-market sales agreement	10,319	$ 9	10,310
Issuance of common shares under at-the-market sales agreement, shares		8,976,940
Issuance of common shares under private placement	3,324	$ 3	3,321
Issuance of common shares under private placement, shares		3,178,367
Issuance of common shares under employee stock purchase plan	45		45
Issuance of common shares under employee stock purchase plan, shares		52,476
Exercise of stock options	7		7
Exercise of stock options, shares		16,362
Vesting and settlement of restricted stock units, shares		70,000
Share-based compensation expense	4,612		4,612
Net income (loss)	(30,770)			(30,770)
Ending balance at Dec. 31, 2019	11,157	$ 44	248,770	(237,657)
Ending balance, shares at Dec. 31, 2019		44,413,372
Issuance of common shares under at-the-market sales agreement	11,958	$ 6	11,952
Issuance of common shares under at-the-market sales agreement, shares		6,176,415
Issuance of common shares under employee stock purchase plan	31		31
Issuance of common shares under employee stock purchase plan, shares		35,359
Exercise of stock options	227	$ 2	225
Exercise of stock options, shares		254,466
Vesting and settlement of restricted stock units, shares		981,329
Share-based compensation expense	3,600		3,600
Net income (loss)	(18,210)			(18,210)
Ending balance at Dec. 31, 2020	8,763	$ 52	264,578	(255,867)
Ending balance, shares at Dec. 31, 2020		51,860,941
Issuance of common shares under at-the-market sales agreement	12,205	$ 3	12,202
Issuance of common shares under at-the-market sales agreement, shares		2,891,419
Issuance of common shares under a direct registered offering	11,078	$ 4	11,074
Issuance of common shares under a direct registered offering, shares		4,209,050
Issuance of common shares under employee stock purchase plan	111		111
Issuance of common shares under employee stock purchase plan, shares		65,481
Exercise of stock options	388	$ 1	387
Exercise of stock options, shares		280,771
Vesting and settlement of restricted stock units, shares		415,268
Share-based compensation expense	5,054		5,054
Net income (loss)	376			376
Ending balance at Dec. 31, 2021	$ 37,975	$ 60	$ 293,406	$ (255,491)
Ending balance, shares at Dec. 31, 2021		59,722,930

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income (loss)	$ (376)	$ (18,210)	$ (30,770)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation	178	180	211
Share-based compensation expense	5,054	3,600	4,612
Gain on extinguishment of debt	(998)	0	0
Non-cash interest expense	0	59	163
Accretion of debt discount	0	129	67
Loss on disposal of fixed assets	0	0	63
Amortization and accretion on available-for-sale investments, net	0	0	(115)
Changes in operating assets and liabilities:
Accounts receivable, prepaid expenses and other current assets	(10,869)	1,893	(558)
Other assets and liabilities	(155)	(140)	(159)
Accounts payable and accrued liabilities	681	(631)	(5,582)
Deferred revenue	(5,000)	0	5,000
Net cash used in operating activities	(10,733)	(13,120)	(27,068)
Investing activities
Maturities of available-for-sale-investments	0	0	32,950
Acquisition of property and equipment	0	(55)	(25)
Net cash (used in) provided by investing activities	0	(55)	32,925
Financing activities
Proceeds from at-the-market sales agreement, net of issuance costs	12,205	11,958	10,319
Proceeds from registered direct offering, net of issuance costs	11,078	0	0
Proceeds from private placement, net of issuance costs	0	0	3,324
Proceeds from shares issued under employee stock purchase plan	111	31	45
Proceeds from exercise of stock options	388	227	7
Proceeds from issuance of long-term debt	0	991	0
Principal payments made on long-term debt	0	(5,340)	(5,000)
Net cash provided by financing activities	23,782	7,867	8,695
Net increase (decrease) in cash, cash equivalents and restricted cash	13,049	(5,308)	14,552
Cash, cash equivalents and restricted cash, beginning of period	17,647	22,955	8,403
Cash, cash equivalents and restricted cash, end of period	30,696	17,647	22,955
Supplemental disclosure
Interest paid	0	524	843
Forgiveness of PPP Loan and accrued interest	998	0	0
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	30,436	17,287	22,595
Restricted cash ($100 as of December 31, 2021 is recorded in other current assets)	260	360	360
Cash, cash equivalents and restricted cash, end of period	$ 30,696	$ 17,647	$ 22,955

Statements of Cash Flows (Paren

Statements of Cash Flows (Parenthetical) $ in Thousands	Dec. 31, 2021USD ($)
Statement Of Cash Flows [Abstract]
Restricted cash in other current assets	$ 100

The Company

The Company	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
The Company	1. The Company Clearside Biomedical, Inc. (the “Company”) is a biopharmaceutical company focused on revolutionizing the delivery of therapies to the back of the eye through the suprachoroidal space (SCS). Incorporated in the State of Delaware on May 26, 2011 , the Company has its corporate headquarters in Alpharetta, Georgia. The Company’s activities since inception have primarily consisted of developing product and technology rights, raising capital and performing research and development activities. The Company has no current source of revenue to sustain present activities, and does not expect to generate meaningful revenue until and unless the Company's licensees successfully commercialize XIPERE, its other licensees receive regulatory approval and successfully commercialize such licensees' product candidates or the Company commercializes its product candidates either on its own or with a third party. The Company is subject to a number of risks and uncertainties similar to those of other life science companies at a similar stage of development, including, among others, the need to obtain adequate additional financing, successful development efforts including regulatory approval of products, compliance with government regulations, successful commercialization of potential products, protection of proprietary technology and dependence on key individuals. Liquidity The Company had cash and cash equivalents of $ 30.4 million as of December 31, 2021. On January 6, 2021, the Company entered into a securities purchase agreement with certain institutional purchasers that purchased 4.2 million shares of its common stock in a registered direct offering at a price of $ 2.851 per share. The Company raised net proceeds of $ 11.1 million after deducting offering expenses. During the year ended December 31, 2021, the Company sold 2.9 million shares of its common stock for net proceeds of $ 12.2 million under its at-the-market agreement with Cowen and Company, LLC. In August 2021, the Company entered into an amendment to the Arctic Vision License Agreement (as defined in Note 10 - License and Other Agreements) to expand the territories covered by the license to include India and the ASEAN Countries (Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand, and Vietnam). In September 2021, the Company entered into a second amendment to the Arctic Vision License Agreement to expand the territories covered by the license to include Australia and New Zealand. The Company received an aggregate of $ 3.0 million in consideration for the expansion of the licensed territory. On October 25, 2021, the Company announced that the U.S. Food and Drug Administration (the "FDA") approved XIPERE (triamcinolone acetonide injectable suspension) for the treatment of macular edema associated with uveitis, a form of eye inflammation. The Company received an aggregate of $ 9.0 million in milestone payments related to the approval of XIPERE from Arctic Vision (Hong Kong) Limited and Bausch + Lomb. In addition, in January 2022, the Company received a $ 10.0 million milestone payment from Bausch upon completion of pre-launch activities for XIPERE. The $ 10.0 million was recorded as revenue in the fourth quarter of 2021 and is included in accounts receivable as of December 31, 2021. Bausc h expects to launch XIPERE in the United States in the first quarter of 2022. In April 2020, we entered into a loan agreement with Silicon Valley Bank under the terms of which Silicon Valley bank loaned us $ 1.0 million, or the PPP Loan, pursuant to the Paycheck Protection Program, or PPP, under the Coronavirus Aid, Relief, and Economic Security Act, or CARES Act. In accordance with the requirements of the CARES Act, we used the proceeds primarily for payroll costs and other eligible expenses. The CARES Act and the PPP provide a mechanism for forgiveness of up to the full amount borrowed. On January 11, 2021, we received notification from Silicon Valley Bank that the PPP loan was forgiven in full, including approximately $ 7,000 of accrued interest. The Company has funded its operations primarily through the proceeds from public offerings of its common stock, sales of convertible preferred stock and the issuance of long-term debt. The Company will continue to need to obtain additional financing to fund future operations, including completing the development, partnering and potential commercialization of its primary product candidates. The Company will need to obtain financing to conduct additional trials for the regulatory approval of its product candidates if requested by regulatory bodies, and completing the development of any product candidates that might be acquired. If such products were to receive regulatory approval, the Company would need to obtain additional financing to prepare for the potential commercialization of its product candidates, if the Company decides to commercialize the products on its own. The Company has suffered recurring losses and negative cash flows from operations since inception and anticipates incurring additional losses until such time, if ever, that it can obtain generate significant revenue from commercializing its first approved product, XIPERE (triamcinolone acetonide suprachoroidal injectable suspension formulated for administration to the back of the eye), with its licensees. In the absence of product or other revenues, the amount, timing, nature or source of which cannot be predicted, the Company’s losses will continue as it conducts its research and development activities. Based on its current plans and forecasted expenses, the Company expects that its cash and cash equivalents as of the filing date, March 11, 2022, will enable it to fund its planned operating expenses and capital expenditure requirements into the second quarter of 2023. The Company has based this estimate on assumptions that may prove to be wrong, and it could exhaust its capital resources sooner than expected.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Basis of Presentation The Company’s financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of income and expenses during the reporting periods. Significant items subject to such estimates and assumptions include revenue recognition, the accounting for useful lives to calculate depreciation and amortization, clinical trial expense accruals, share-based compensation expense and income tax valuation allowance. Actual results could differ from these estimates. Effects of COVID-19 The COVID-19 pandemic is expected to continue to result in a global slowdown of economic activity. Estimates and assumptions about future events and their effects cannot be determined with certainty and therefore require the exercise of judgment. As of the date of issuance of these financial statements, the Company is not aware of any specific event or circumstance that would require it to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. These estimates may change as new events occur and additional information is obtained and are recognized in the consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to the financial statements. Revenue Recognition The Company recognizes revenue from its contracts with customers under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC Topic 606”). The Company’s primary revenue arrangements are license agreements which typically include upfront payments, regulatory and commercial milestone payments and royalties based on future product sales. The arrangements may also include payments for the Company’s SCS Microinjector devices as well as payments for assistance and oversight of the customer’s use of the Company’s technology. In determining the amount of revenue to be recognized under these agreements, the Company performs the following steps: (i) identifies the promised goods and services to be transferred in the contract, (ii) identifies the performance obligations, (iii) determines the transaction price, (iv) allocates the transaction price to the performance obligations and (v) recognizes revenue as the performance obligations are satisfied. The Company receives payments from its customers based on billing schedules established in each contract. Up-front and other payments may require deferral of revenue recognition to a future period until the Company performs its obligations under the arrangement. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment. Property and Equipment, Net Property and equipment is recorded at historical cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets, or for leasehold improvement the lesser of the useful life or remaining lease term. Repairs and maintenance are expensed when incurred. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is included in the determination of net income. Debt Discount All debt discounts are recorded against the related debt obligation and are amortized using the effective interest rate method over the term of the underlying debt obligation and reflected in interest expense. Income Taxes Deferred tax assets or liabilities are recorded for temporary differences between financial statement and tax basis of assets and liabilities, using enacted rates in effect for the year in which the differences are expected to reverse. A valuation allowance is recorded if it is more likely than not that a deferred tax asset will not be realized. The Company has provided a full valuation allowance on its deferred tax assets, which primarily consist of cumulative net operating losses for the period from May 26, 2011 (inception) to December 31, 2020. Due to its history of operating losses since inception and losses expected to be incurred in the foreseeable future, a full valuation allowance was considered necessary. Liabilities for uncertain tax positions are recognized based on a two-step process. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. Once it is determined that the position meets the recognition threshold, the second step requires estimating and measuring the largest amount of tax benefit that is more likely than not to be realized upon ultimate settlement. The difference between the amount of recognizable tax benefit and the total amount of tax benefit from positions filed or to be filed with the tax authorities is recorded as a liability for uncertain tax benefits. Research and Development Costs Research and development costs are charged to expense as incurred and include: • employee-related expenses, including salaries, benefits, travel and share-based compensation expense for research and development personnel; • expenses incurred under agreements with contract research organizations, contract manufacturing organizations and consultants that conduct preclinical studies and clinical trials; • costs associated with preclinical and clinical development activities; • costs associated with submitting regulatory approval applications for the Company’s product candidates; • costs associated with training physicians on the suprachoroidal injection procedure and educating and providing them with appropriate product candidate information; • costs associated with technology and intellectual property licenses; • costs for the Company’s research and development facility; and • depreciation expense for assets used in research and development activities. Costs for certain development activities, such as clinical trial activities, are recognized based on an evaluation of the estimated total costs for the clinical trial, progress to completion of specific tasks, using data such as patient enrollment, pass through expenses, clinical site activations, data from the clinical sites or information provided to the Company by its vendors on their actual costs incurred. Payments for these activities are based on the terms of the individual contracts and any subsequent amendments, which may differ from the patterns of costs incurred, and are reflected in the financial statements as prepaid or accrued expenses. Share-Based Compensation Compensation cost related to share-based awards granted to employees, directors and consultants is measured based on the estimated fair value of the award at the grant date. The fair value of restricted stock units granted is measured based on the market value of the Company’s common stock on the date of grant. Share-based compensation costs are expensed on a straight-line basis over the relevant vesting period. Compensation cost related to shares purchased through the Company’s employee stock purchase plan, which is considered compensatory, is based on the estimated fair value of the shares on the offering date, including consideration of the discount and the look back period. The Company estimates the fair value of the shares using a Black-Scholes option pricing model. Compensation expense is recognized over the six-month withholding period prior to the purchase date. All share-based compensation costs are recorded in general and administrative or research and development costs in the statements of operations based upon the underlying employees’ roles within the Company. Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with an original term of three months or less at the date of purchase. Restricted Cash The Company is required to maintain a stand-by letter of credit as a security deposit for its facility lease in Alpharetta, Georgia. The Company’s bank requires the Company to maintain a restricted cash balance to serve as collateral for the letter of credit issued to the landlord by the bank. As of December 31, 2021, the restricted cash balance was invested in a commercial money market account. The current portion of the restricted cash is recorded in other current assets and the long-term portion is recorded in restricted cash. Concentration of Credit Risk Arising From Cash Deposits in Excess of Insured Limits The Company maintains its cash in bank deposits that at times may exceed federally insured limits. The Company has not experienced any loss in such accounts. The Company believes it is not exposed to any significant risks with respect to its cash balances. Recent Accounting Pronouncements In December 2019, the FASB issued Accounting Standards Update ("ASU") 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which simplifies the accounting for income taxes by removing certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new ASU also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates. These changes aim to improve the overall usefulness of disclosures to financial statement users and reduce unnecessary costs to companies when preparing the disclosures. The Company adopted ASU 2019-12 on January 1, 2021, and the adoption did not have a material impact on its financial statements and related disclosures.

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Property and Equipment, Net	3. Property and Equipment, Net Property and equipment, net consisted of the following (dollar amounts in thousands): Estimated December 31, 2021 2020 Furniture and fixtures 5 $ 337 $ 337 Machinery and equipment 5 176 176 Computer equipment 3 13 13 Leasehold improvements Lesser of or 667 667 Total property and equipment 1,193 1,193 Less: Accumulated depreciation ( 955 ) ( 777 ) Property and equipment, net $ 238 $ 416

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2021
Payables And Accruals [Abstract]
Accrued Liabilities	4. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): December 31, 2021 2020 Accrued research and development $ 1,083 $ 234 Accrued employee costs 1,854 1,132 Accrued professional fees 30 56 Accrued expense 345 160 $ 3,312 $ 1,582

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Long-Term Debt	5. Long-Term Debt Loan and Security Agreements On May 14, 2018, the Company entered into a second amended and restated loan and security agreement (the “2 nd A&R Loan Agreement”) with Silicon Valley Bank (“SVB”), MidCap Funding III Trust and MidCap Financial Trust (together, “MidCap” and collectively with SVB, the “Lenders”). The 2 nd A&R Loan Agreement provided for new term loans of up to $ 20.0 million, with a floating interest rate equal to 6.50 % plus the greater of (i) the 30-day U.S. LIBOR , as reported in the Wall Street Journal on the last business day of the month the immediately precedes the month in which the interest will accrue, or (ii) 1.89 %. The 2 nd A&R Loan Agreement included, among other things, the ability of the Lenders to accelerate the payment of the term loan in the event of a material adverse change and restrictions on the Company’s ability to sell, assign, license, transfer or otherwise dispose of its assets, including intellectual property assets, without the prior written consent of the Lenders. The Company borrowed an initial tranche of $ 10.0 million on May 14, 2018, of which $ 7.0 million was used to repay all amounts outstanding under a prior loan agreement, including fees associated with the final payment. The prepayment fees were waived. Of the remaining $ 10.0 million available under the 2 nd A&R loan agreement, the Company elected not to draw $ 5.0 million and the other $ 5.0 million was not available for draw . On October 18, 2019, the Company entered into an amendment to the 2 nd A&R Loan Agreement with the Lenders. Pursuant to the amendment, the Company repaid $ 5.0 million of the outstanding principal balance of the $ 10.0 million term loan. The Company did not pay any final payment or termination fees in connection with the $5.0 million prepayment. In addition, the Company and the Lenders agreed to modify the term loan repayment schedule. As amended, the term loan repayment schedule provided for interest only payments through October 31, 2020, followed by consecutive equal monthly payments of principal and interest in arrears continuing through the maturity date of October 1, 2022 . The Company had the option to prepay the outstanding balance in full, subject to a prepayment fee. A final payment of 5.50 % of the aggregate borrowed amount was due at maturity of the loan on October 1, 2022, or upon the prepayment of the facility or the acceleration of amounts due under the facility as a result of an event of default. The term loans under the 2 nd A&R loan agreement were secured by substantially all of the Company’s assets. On May 7, 2020, due to various restrictions and other limiting covenants of the 2 nd A&R Loan Agreement, the Company prepaid in full the outstanding $ 5.0 million principal balance, plus $ 0.3 million reflecting the final payment fee and accrued interest. The prepayment fees were waived by the Lenders. Interest expense on the borrowings under the loan agreements described above was $ 147,000 and $ 804,000 for the years ended December 31, 2020 and 2019, respectively. Accretion of the scheduled final payment was $ 59,000 and $ 163,000 for the years ended December 31, 2020 and 2019, respectively. Accretion of the deferred closing costs was $ 129,000 and $ 67,000 for the years ended December 31, 2020 and 2019, respectively.

CARES Act Paycheck Protection P

CARES Act Paycheck Protection Program Loan	12 Months Ended
	Dec. 31, 2021
Extraordinary And Unusual Items [Abstract]
CARES Act Paycheck Protection Program Loan	6 . CARES Act Paycheck Protection Program Loan On April 20, 2020, the Company entered into a loan agreement with SVB (the “PPP Lender”) under the terms of which the PPP Lender made a loan to the Company in an aggregate principal amount of $ 1.0 million (the “PPP Loan”) pursuant to the Paycheck Protection Program (the “PPP”) under the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”). The PPP Loan was evidenced by a promissory note (the “Note”) containing the terms and conditions for repayment of the PPP Loan. Under the terms of the Note and the PPP Loan, interest accrued on the outstanding principal amount at the rate of 1.0 % per annum. The term of the Note was until April 2022 , with the Company obligated to make equal monthly payments of principal and interest, beginning in November 2020 and continuing until the maturity date. The CARES Act and the PPP provide a mechanism for forgiveness of up to the full amount borrowed. On January 11, 2021, the Company was notified by the PPP Lender that the PPP Loan had been forgiven in full, including approximately $ 7,000 of accrued interest. In accordance with ASC 405-20, Extinguishment of Liabilities , the income from the forgiveness of the amount borrowed and the accrued interest was recognized in the statement of operations in other income as a gain on extinguishment of debt.

Preferred and Common Stock

Preferred and Common Stock	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Preferred and Common Stock	7. Preferred and Common Stock The Company’s amended and restated certificate of incorporation authorizes the Company to issue 10,000,000 shares of $ 0.001 par value of preferred stock. As of December 31, 2021 and 2020, there were 10,000,000 shares of preferred stock authorized, no ne of which were issued and outstanding. The Company’s amended and restated certificate of incorporation authorizes the Company to issue 100,000,000 shares of $ 0.001 par value common stock. As of December 31, 2021 and 2020, there were 59,722,930 and 51,860,941 shares of common stock outstanding, respectively.

Common Stock Warrants

Common Stock Warrants	12 Months Ended
	Dec. 31, 2021
Common Stock Warrants [Abstract]
Common Stock Warrants	8. Common Stock Warrants In September 2016, in connection with a loan agreement, the Company issued warrants to the lenders to purchase up to 29,796 shares of common stock at a price per share of $ 10.74 . The warrants are fully exercisable and expire in September 2026 , or earlier upon the occurrence of specified mergers or acquisitions of the Company. The warrants were recorded in equity at the time of issuance and had a remaining life of 4.75 years as of December 31, 2021.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	9. Share-Based Compensation Stock Options In January 2016, the Company’s board of directors adopted and approved the Clearside Biomedical, Inc. 2016 Equity Incentive Plan (the “2016 Plan”) which became effective on June 1, 2016. The 2016 Plan provides for the grant of share-based awards to employees, directors and consultants of the Company. The 2016 Plan provides for the grant of incentive stock options to employees, and for the grant of nonqualified stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights, performance stock awards and other forms of stock compensation to the Company’s employees, directors, and non-employee third parties. The number of shares of common stock reserved for issuance under the 2016 Plan will automatically increase on January 1 each year, through January 1, 2026, by 4 % of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares as may be determined by the Company’s board of directors. At December 31, 2021, under the 2016 Plan, options to purchase 5,378,247 shares of the Company’s common stock were outstanding at a weighted average price of $ 4.13 per share and 382,788 shares remained available for future grant. As of January 1, 2022, the number of shares of common stock that may be issued under the 2016 Plan was automatically increased by 2,388,917 shares, representing 4 % of the total number of shares of common stock outstanding on December 31, 2021, increasing the number of shares of common stock available for issuance under the 2016 Plan as of that date to 2,771,705 shares. As a result of the adoption of the 2016 Plan, no further grants may be made under the Company’s 2011 Stock Incentive Plan (the “2011 Plan”). The 2011 Plan provided for the grant of share-based awards to employees, directors and consultants of the Company. At December 31, 2021, options to purchase 366,845 shares of the Company’s common stock were outstanding under the 2011 Plan at a weighted average exercise price of $ 2.94 per share. The Company has granted stock option awards to employees, directors and consultants. The total share-based compensation expense recognized is reflected in the statements of operations as follows (in thousands): Year Ended 2021 2020 2019 Research and development $ 1,570 $ 1,183 $ 1,379 General and administrative 1,985 1,574 2,728 Total $ 3,555 $ 2,757 $ 4,107 Share-based compensation is accounted for in accordance with the provisions of ASC 718, Compensation-Stock Compensation . The estimated fair value of options granted is determined as of the date of grant using the Black-Scholes option pricing model. The resulting fair value is recognized ratably over the requisite service period, which is generally the vesting period of the awards. The following table sets forth the weighted average assumptions utilized in the Black-Scholes option pricing model to calculate the fair value of the underlying common stock for the years ended December 31, 2021, 2020 and 2019. Year Ended 2021 2020 2019 Expected term (years) 7.00 7.00 7.00 Expected stock price volatility 101.43 % 108.13 % 109.49 % Risk-free interest rate 0.75 % 1.52 % 2.49 % Expected dividend yield 0.00 % 0.00 % 0.00 % Expected term (in years): The Company utilized the simplified method as prescribed by ASC 718, as the Company does not have sufficient historical exercise and post-vesting termination data to provide a reasonable basis upon which to estimate the expected term of stock options granted to employees. Risk-free interest rate : The risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected time to a possible liquidity event. Expected dividend yield : The Company has not paid and does not anticipate paying any dividends in the foreseeable future. Expected stock price volatility : The Company calculates expected volatility based on the historical volatility of its common stock. Forfeitures: The Company records forfeitures as they occur. The following table summarizes the activity related to stock options during the year ended December 31, 2021: Weighted Number of Average Shares Exercise Price Options outstanding at December 31, 2020 4,248,193 $ 3.95 Granted 1,794,906 3.93 Exercised ( 280,771 ) 1.38 Options outstanding at December 31, 2021 5,762,328 4.07 Options exercisable at December 31, 2020 2,355,900 4.96 Options exercisable at December 31, 2021 3,148,502 4.59 The following table provides additional information about the Company’s stock options that were outstanding and exercisable at December 31, 2021 (aggregate intrinsic values in thousands): Weighted Weighted Weighted Average Weighted Average Average Aggregate Remaining Average Aggregate Remaining Exercise Options Exercise Intrinsic Contractual Options Exercise Intrinsic Contractual Price Outstanding Price Value Life (Years) Exercisable Price Value Life (Years) $ 0.00 - $ 2.99 2,334,392 7.25 1,572,297 7.03 $ 3.00 - $ 6.99 2,776,850 7.83 933,870 5.51 $ 7.00 - $ 8.99 449,308 5.16 444,933 5.15 $ 9.00 - $ 20.84 201,778 5.76 197,402 5.75 5,762,328 $ 4.07 $ 2,469 7.32 3,148,502 $ 4.59 $ 1,880 6.23 As of December 31, 2021, the Company had $ 5.6 million of unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted average period of 2.6 years. The weighted average fair values of all stock options granted for the years ended December 31, 2021, 2020 and 2019 was $ 3.24 per share, $ 1.97 per share and $ 1.09 per share, respectively. The intrinsic value is calculated as the difference between the fair market value and the exercise price per share of the stock options. The fair market value per share of common stock as of December 31, 2021 was $ 2.75 , which was the closing sale price of the Company’s common stock on the Nasdaq Global Market on that date. Restricted Stock Units The Company has granted restricted stock units (“RSUs”) to employees under the 2016 Plan. The shares underlying the RSU awards have vesting terms of four years from the date of grant, subject to the employees’ continuous service and subject to accelerated vesting in specified circumstances. The fair value of the RSUs granted is measured based on the market value of the Company’s common stock on the date of grant and is recognized ratably over the requisite service period, which is generally the vesting period of the awards. The total share-based compensation expense related to RSUs is reflected in the statements of operations as follows (in thousands): Year Ended 2021 2020 2019 Research and development $ 723 $ 375 $ 177 General and administrative 715 427 306 Total $ 1,438 $ 802 $ 483 The following table summarizes the activity related to RSUs during the year ended December 31, 2021: Weighted Average Number of Grant Date Shares Fair Value Non-vested RSUs outstanding at December 31, 2020 767,271 $ 1.78 Granted 965,344 4.01 Vested ( 415,268 ) 1.27 Non-vested RSUs outstanding at December 31, 2021 1,317,347 3.58 As of December 31, 2021, the Company had $ 3.5 million of unrecognized compensation expense related to the RSUs, which amount is expected to be recognized over a weighted average period of 2.9 years. Employee Stock Purchase Plan In January 2016, the Company’s board of directors adopted and approved the Clearside Biomedical, Inc. 2016 Employee Stock Purchase Plan (the “2016 ESPP”) which became effective on June 1, 2016. The 2016 ESPP permits employees to purchase shares of the Company’s common stock through payroll deductions up to 15 % of their earnings. The number of shares reserved for issuance under the 2016 ESPP will automatically increase on January 1 of each year, through January 1, 2026, by the lesser of (i) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (ii) 454,545 shares of common stock or (iii) a lesser number of shares as may be determined by the Company’s board of directors . The Company’s board of directors elected not to increase the shares reserved for issuance on January 1, 2022. The number of shares of common stock available for issuance under the 2016 ESPP as of December 31, 2021 was 505,491 shares. The 2016 ESPP is considered a compensatory plan and the fair value of the discount and the look-back period are estimated using the Black-Scholes option pricing model and expense is recognized over the six-month withholding period prior to the purchase date. During the years ended December 31, 2021, 2020 and 2019, the Company issued 65,481 , 35,359 and 52,476 shares, respectively, of common stock purchased under the 2016 ESPP. The share-based compensation expense recognized for the 2016 ESPP is reflected in the statements of operations and comprehensive loss as follows (in thousands): Year Ended 2021 2020 2019 Research and development $ 41 $ 19 $ 11 General and administrative 20 22 9 Total $ 61 $ 41 $ 20

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s net deferred income tax assets consist of the following (in thousands): December 31, 2021 2020 2019 Deferred tax asset (liability): Net operating loss carryforwards $ 53,966 $ 51,414 $ 46,305 Non-deductible accrued expenses 469 263 422 Right-of-use asset ( 96 ) ( 132 ) ( 138 ) Lease liability 176 247 264 Deferred revenue — 1,247 — Stock compensation expense 2,768 2,044 1,472 Depreciation differences ( 44 ) ( 82 ) ( 94 ) Federal tax credits 9,012 8,015 7,249 State tax credits 342 381 623 Disallowed interest expense — 7 99 Charitable contributions 6 — 4 Valuation allowance ( 66,599 ) ( 63,404 ) ( 56,206 ) Net deferred tax asset $ — $ — $ — A reconciliation of the statutory tax rates and the effective tax rates is as follows: Year Ended December 31, 2021 2020 2019 U.S. federal tax rate 21.00 % 21.00 % 21.00 % State tax rate ( 599.32 ) 14.28 — Permanent difference ( 3.15 ) 1.42 ( 1.33 ) Tax credit ( 253.97 ) 2.89 2.06 Valuation allowance 847.82 ( 39.66 ) ( 21.73 ) ASC 740-10 ( 3.19 ) ( 0.26 ) — Adjustment to prior year tax provision ( 13.16 ) — — Other 3.97 — — 0.00 % ( 0.33 )% 0.00 % Certain items of income and expense are not reported in tax returns and financial statements in the same year. The tax effect of such temporary differences is reported as deferred income taxes. The measurement of deferred tax assets is reduced, if necessary, by the amount of any tax benefit that, based on available evidence, is not expected to be realized. The Company establishes a valuation allowance for deferred tax assets for which realization is not likely. As of each reporting date, management considers new evidence, both positive and negative, that could affect its view of the future realization of deferred tax assets. At December 31, 2021, the Company had a valuation allowance of $ 66.6 million recorded against the benefit of certain deferred tax assets. The valuation allowance was primarily related to federal and state net operating loss ("NOL") carryforwards that, in the judgment of management, are not more likely than not to be realized. In assessing the recoverability of the Company’s deferred tax assets, management considered, among other things, its deferred tax liabilities, its historical earnings and losses, projections of future income, and tax-planning strategies available to the Company in the relevant jurisdiction. The Company will release this valuation allowance when management determines that it is more likely than not that its deferred tax asset will be realized. At December 31, 2021, the Company had income tax NOL carryforwards for federal and state purposes of $ 234.4 million and $ 75.6 million, respectively. The Company has recorded a deferred tax asset for both federal and state NOL carryforwards of $ 49.2 million and $ 4.8 million, respectively. If not utilized, the federal NOL carryforwards will begin to expire beginning in 2031 , and the state NOL carryforwards will begin to expire at various dates beginning in 2027 . Additionally, under the 2017 Tax Cuts and Jobs Act, federal net operating losses incurred in 2018 and beyond may be carried forward indefinitely. However, the deductibility of such federal net operating losses is limited beginning in 2021. Certain states have also adopted the indefinite carryforward period beginning with the 2018 tax year, but state conformity varies state by state. Liabilities for uncertain tax positions are recognized based on a two-step process. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. Once it is determined that the position meets the recognition threshold, the second step requires the Company to estimate and measure the largest amount of tax benefit that is more likely than not to be realized upon ultimate settlement. The difference between the amount of recognizable tax benefit and the total amount of tax benefit from positions filed or to be filed with the tax authorities is recorded as a liability for uncertain tax benefits. The following is a rollforward of the Company’s uncertain tax positions (in thousands): Year Ended December 31, 2021 2020 Balance of uncertain tax positions at the beginning of the year $ 7,568 $ 2,903 Gross increases - tax positions in prior period — 4,665 Gross decreases - tax positions in prior period ( 12 ) — Gross decreases - settlements with taxing authorities ( 36 ) — Balance of uncertain tax positions at the end of the year $ 7,520 $ 7,568 As of December 31, 2021 and 2020, there was $ 7.5 million and $ 7.6 million, respectively, of unrecognized tax benefit that if recognized would be in the form of a net operating loss carryforward, which is expected to require a full valuation allowance based on present circumstances. The Company reversed $ 48,000 of previously recorded unrecognized tax expenses for the year 2021. The Company recognizes accrued interest related to unrecognized tax expenses and penalties as income tax expense. No significant amounts of interest or penalties have been recorded as of December 31, 2021. Ownership changes, as defined by Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”), may limit the amount of net operating losses that a company may utilize to offset future taxable income and taxes payable. Pursuant to Section 382 of the Code, an ownership change occurs when the stock ownership of 5% stockholders increases by more than 50% over a testing period of three years. It is possible that the Company has undergone an ownership change as defined by Section 382 of the Code or that the Company may undergo such a change in the future. Any such ownership change may limit the Company’s ability to utilize net operating losses. The Company is subject to taxation in the United States and certain state jurisdictions. As of December 31, 2021, the Company’s tax returns for 2018, 2019 and 2020 are subject to full examination by the tax authorities. As of December 31, 2021, the Company is generally no longer subject to state or local examinations by tax authorities for years before 2018, except to the extent of NOLs generated in prior years claimed on a tax return.

Commitment and Contingencies

Commitment and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies Lease Commitment Summary The Company leases its facilities and some of its equipment under noncancelable operating lease arrangements that expire at various dates through 2023. In November 2016, the Company signed an office lease agreement to lease approximately 20,000 square feet of office space in Alpharetta, Georgia for its corporate headquarters. The lease agreement is for a six and one-half year term with a renewal option for one additional five-year term. Rental payments are $ 35,145 per month subject to an increase of 3 % per year. Operating lease cost under this lease is recognized on a straight-line basis over the term of the lease. In addition, the lease agreement requires payment of the pro-rata share of the annual operating expenses associated with the premises. In August 2018, the Company signed an office lease agreement to lease approximately 3,500 square feet of office space in Berkeley, California for its commercial operations. The lease agreement was for a two-year term with a renewal option for an additional one-year term. The Company did not exercise the renewal option for the Berkeley lease and terminated the lease on December 15, 2019 , with no further payments due. The termination of the lease did not have a material impact on the Company’s statements of operations. Operating lease cost under this lease was recognized on a straight-line basis over the term of the lease. The Company also paid a pro-rata share of the annual operating expenses associated with the premises. The Company’s operating leases included on the balance sheet are as follows (in thousands): December 31, Operating lease right-of-use asset $ 369 Liabilities Current portion of operating lease liabilities $ 387 Operating lease liabilities 288 Total operating lease liabilities $ 675 The Company recognizes a right-of-use asset for the right to use the underlying asset for the lease term, and a lease liability, which represents the present value of the Company’s obligation to make payments over the lease term. The renewal option is not included in the calculation of the right-of-use asset and the lease liabilities as the Company has not yet determined if the Alpharetta, Georgia lease will be renewed. The present value of the lease payments is calculated using an incremental borrowing rate as the Company’s leases do not provide an implicit interest rate. At December 31, 2021, the Company’s incremental borrowing rate was 11.0 % and the remaining lease term was 1.75 years. Minimum lease payments were as follows at December 31, 2021 (in thousands): Year ending December 31, 2022 $ 407 2023 316 Total minimum lease payments 723 Less imputed interest ( 48 ) Total operating lease liabilities $ 675 Equipment leases with an initial term of 12 months or less are not recorded with operating lease liabilities. The Company recognizes expense for these leases on a straight-line basis over the lease term. The equipment leases were deemed to be immaterial. Operating lease cost was $ 247,000 for each of the years ended December 31, 2021 and 2020, and $ 393,000 for the year ended 2019. Variable lease cost was $ 95,000 for each of the years ended December 31, 2021 and 2020, and $ 83,000 for the year ended 2019. Short-term lease cost was $ 8,000 , $ 12,000 and $ 20,000 for the years ended December 31, 2021, 2020 and 2019, respectively. Contract Service Providers In the course of the Company’s normal business operations, it has agreements with contract service providers to assist in the performance of its research and development, clinical research and manufacturing. Substantially all of these contracts are on an as needed basis. In May 2018, the Company entered into a manufacturing supply agreement (the “Supply Agreement”), with Gerresheimer Regensburg GmbH, a company incorporated under the laws of Germany (“Gerresheimer”). Gerresheimer will manufacture and supply the Company’s proprietary SCS Microinjector. The Company will provide Gerresheimer with a rolling forecast schedule of its projected purchase orders for at least the next four calendar quarters. The Supply Agreement contains an initial five-year term that will automatically renew for successive periods of three years , unless terminated by either party at least 12 months prior to the end of the applicable term.

License and Other Agreements

License and Other Agreements	12 Months Ended
	Dec. 31, 2021
License And Other Agreement [Abstract]
License and Other Agreements	12. License and Other Agreements Bausch + Lomb On October 22, 2019, the Company entered into a License Agreement (as amended, the "Bausch License Agreement") with Bausch + Lomb, a division of Bausch Health Companies, Inc. (“Bausch”). Pursuant to the Bausch License Agreement, the Company has granted an exclusive license to Bausch to develop, manufacture, distribute, promote, market and commercialize XIPERE using the Company’s proprietary SCS Microinjector (the “Device”), as well as specified other steroids, corticosteroids and NSAIDs in combination with the Device (“Other Products,” and together with XIPERE, the “Products”), subject to specified exceptions, in the United States and Canada (the “Territory”) for the treatment of ophthalmology indications, including non-infectious uveitis. Pursuant to the Bausch License Agreement, Bausch paid the Company an upfront payment of $ 5.0 million (the “Upfront Payment”) in October 2019. In October 2021, the FDA approved XIPERE. The Company received $ 5.0 million from Bausch as a result of the approval. In December 2021, $ 10.0 million was recorded upon completion of pre-launch activities for XIPERE and payment was received in January 2022. In addition, Bausch has agreed to pay up to an aggregate of $ 55.0 million in additional milestone payments upon the achievement of (i) specified regulatory approvals for specified additional indications of XIPERE and (ii) specified levels of annual net sales (as defined in the Bausch License Agreement). Further, during the applicable royalty term, the Company will also be entitled to receive tiered royalties at increasing percentages, from the high-teens to twenty percent, based on XIPERE achieving certain annual net sales thresholds in the Territory, in each case subject to reductions in specified circumstances; provided that the Company will not receive any royalties on the first $ 45.0 million of cumulative net sales of all products in the Territory. Bausch launched XIPERE in the United States in the first quarter of 2022. The Company was responsible for all development expenses for XIPERE in the Territory until the Company's New Drug Application ("NDA") was approved by the FDA, subject to specified exceptions, as well as manufacturing costs in connection with the NDA. The Company was also responsible for all clinical and development expenses conducted to satisfy the FDA’s requests in the complete response letter issued on October 18, 2019 related to the NDA and any subsequent complete response letter related to the NDA (the “CRL-related expenses”). Following FDA approval of XIPERE, Bausch is responsible for all such expenses. Due to the refund provisions in the License Agreement, the Upfront Payment was included on the balance sheet as deferred revenue as of December 31, 2020 and 2019. The refund provisions lapsed upon FDA approval of XIPERE and the $ 5.0 million was recognized as revenue in the fourth quarter of 2021. REGENXBIO, Inc . On August 29, 2019, the Company entered into an option and license agreement with REGENXBIO, Inc. (“REGENXBIO”) pursuant to which the Company granted REGENXBIO an exclusive option to enter into a commercial license agreement (the “Option”), which grants REGENXBIO an exclusive, worldwide and sublicensable license to the Company’s SCS Microinjector for the delivery of adeno-associated virus-based gene therapies for the treatment of wet age-related macular degeneration, diabetic retinopathy and other conditions for which anti-vascular endoth elial growth factor treatment is currently the standard of care. REGENXBIO exercised the Option in October 2019 and paid the Company an option fee equal to $ 2.0 million, less a credit of $ 0.5 million previously received under a technology access agreement. In addition, REGENXBIO has agreed to pay the Company up to an aggregate of $ 31.0 million in milestone payments upon the achievement of specified development milestones and up to an aggregate of $ 102.0 million in sales-based milestone payments, as well as mid-single digit royalties on net sales of products using the SCS Microinjector during the royalty term. In September 2020, the Company received $ 3.0 milli on in milestone payments under the Option. Arctic Vision (Hong Kong) Limited On March 10, 2020, the Company entered into a License Agreement (the “License Agreement”) with Arctic Vision (Hong Kong) Limited (“Arctic Vision”). Pursuant to the License Agreement, the Company has granted an exclusive license to Arctic Vision to develop, distribute, promote, market and commercialize XIPERE, subject to specified exceptions in China, Hong Kong, Macau, Taiwan and South Korea (the “Arctic Territory”). Under the terms of the License Agreement, neither party may commercialize XIPERE in the other party’s territory. Arctic Vision has agreed to use commercially reasonably efforts to pursue development and commercialization of XIPERE for indications associated with uveitis in the Arctic Territory. In addition, upon receipt of the Company’s consent, Arctic Vision will have the right, but not the obligation, to develop and commercialize XIPERE for additional indications in the Arctic Territory. Pursuant to the License Agreement, Arctic Vision paid the Company an upfront payment of $ 4.0 million in March 2020. In December 2021, the Company received a milestone paym ent of $ 4.0 million following the receipt of FDA approval of XIPERE in the United States. In addition, Arctic Vision has agreed to pay the Company up to $ 22.5 million in development and sales milestones. Further, dur ing the applicable royalty term, the Company will also be entitled to receive tiered royalties of ten to twelve percent of net sales based on achieving certain annual net sales thresholds in the Arctic Territory, subject to customary reductions, payable on a product-by-product and country-by-country basis, commencing at launch in such country and lasting until the latest of (i) the date that all valid claims within the licensed patent rights covering XIPERE have expired, (ii) the date of the loss of marketing or regulatory exclusivity of XIPERE in a given country, or (iii) ten years from the first commercial sale of XIPERE in a given country. In August 2021, the Company entered into an amendment to the Arctic Vision License Agreement to expand the territories covered by the license to include India and the ASEAN Countries (Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand, and Vietnam). In September 2021, the Company entered into a second amendment to the Arctic Vision License Agreement to expand the Arctic Territory to include Australia and New Zealand. The Company received an aggregate of $ 3.0 million in consideration for the expansion of the Arctic Territory. Other The Company periodically enters into short-term agreements with other customers to evaluate the potential use of its proprietary SCS Microinjector with third-party product candidates for the treatment of various diseases. Funds received from these agreements are recognized as revenue over the term of the agreement. The Company recorded $ 13,000 , $ 200,000 and $ 105,000 of revenue from these agreements during the years ended December 31, 2021, 2020 and 2019, respectively.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	13. Fair Value Measurements The Company’s material financial instruments at December 31, 2021 and 2020, consisted primarily of cash and cash equivalents and at December 31, 2020, also included long-term debt. The fair value of cash and cash equivalents, other current assets and accounts payable approximate their respective carrying values due to the short-term nature of these instruments and are classified as Level 1 in the fair value hierarchy. The fair value of long-term debt approximates the carrying value due to variable interest rates that correspond to market rates and is classified as Level 1 in the fair value hierarchy There were no significant transfers between Levels 1, 2 and 3 during the years ended December 31, 2021 and 2020.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	14. Net Income (Loss) Per Share Basic net income (loss) per share is calculated by dividing the net income (loss) by the weighted average number of shares of common stock outstanding for the period, without consideration of the dilutive effect of potential common stock equivalents. Diluted net income (loss) per share gives effect to all dilutive potential shares of common stock outstanding during this period. For periods in which the Company incurred net losses, common stock equivalents were excluded which included stock options, unvested restricted stock and stock purchase warrants, have been excluded from the computation of diluted net loss per share as their inclusion would have the effect of reducing the net loss per share. Therefore, the denominator used to calculate both basic and diluted net loss per share is the same in all periods presented. Year Ended December 31, 2021 2020 2019 Net income (loss) - basic and diluted $ 376 $ ( 18,210 ) $ ( 30,770 ) Weighted average shares - basic 58,491,986 46,506,540 38,170,830 Effect of dilutive securities: Stock options 1,058,134 — — Restricted stock 342,943 — — ESPP 13,539 — — Weighted average shares - diluted 59,906,602 46,506,540 38,170,830 Net income (loss) per share - basic $ 0.01 $ ( 0.39 ) $ ( 0.81 ) Net income (loss) per share - diluted $ 0.01 $ ( 0.39 ) $ ( 0.81 ) The Company’s potential common stock equivalents that have been excluded from the computation of diluted net income (loss) per share for all periods presented because of their antidilutive effect consisted of the following: Year Ended 2021 2020 2019 Outstanding stock options 4,704,194 4,248,193 4,104,450 Non-vested restricted stock units 974,404 767,271 1,269,300 Stock purchase warrants 29,796 29,796 29,796 5,708,394 5,045,260 5,403,546

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of income and expenses during the reporting periods. Significant items subject to such estimates and assumptions include revenue recognition, the accounting for useful lives to calculate depreciation and amortization, clinical trial expense accruals, share-based compensation expense and income tax valuation allowance. Actual results could differ from these estimates.
Effects of COVID-19	Effects of COVID-19 The COVID-19 pandemic is expected to continue to result in a global slowdown of economic activity. Estimates and assumptions about future events and their effects cannot be determined with certainty and therefore require the exercise of judgment. As of the date of issuance of these financial statements, the Company is not aware of any specific event or circumstance that would require it to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. These estimates may change as new events occur and additional information is obtained and are recognized in the consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to the financial statements.
Revenue Recognition	Revenue Recognition The Company recognizes revenue from its contracts with customers under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC Topic 606”). The Company’s primary revenue arrangements are license agreements which typically include upfront payments, regulatory and commercial milestone payments and royalties based on future product sales. The arrangements may also include payments for the Company’s SCS Microinjector devices as well as payments for assistance and oversight of the customer’s use of the Company’s technology. In determining the amount of revenue to be recognized under these agreements, the Company performs the following steps: (i) identifies the promised goods and services to be transferred in the contract, (ii) identifies the performance obligations, (iii) determines the transaction price, (iv) allocates the transaction price to the performance obligations and (v) recognizes revenue as the performance obligations are satisfied. The Company receives payments from its customers based on billing schedules established in each contract. Up-front and other payments may require deferral of revenue recognition to a future period until the Company performs its obligations under the arrangement. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less.
Segment Information	Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment.
Property and Equipment, Net	Property and Equipment, Net Property and equipment is recorded at historical cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets, or for leasehold improvement the lesser of the useful life or remaining lease term. Repairs and maintenance are expensed when incurred. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is included in the determination of net income.
Debt Discount	Debt Discount All debt discounts are recorded against the related debt obligation and are amortized using the effective interest rate method over the term of the underlying debt obligation and reflected in interest expense.
Income Taxes	Income Taxes Deferred tax assets or liabilities are recorded for temporary differences between financial statement and tax basis of assets and liabilities, using enacted rates in effect for the year in which the differences are expected to reverse. A valuation allowance is recorded if it is more likely than not that a deferred tax asset will not be realized. The Company has provided a full valuation allowance on its deferred tax assets, which primarily consist of cumulative net operating losses for the period from May 26, 2011 (inception) to December 31, 2020. Due to its history of operating losses since inception and losses expected to be incurred in the foreseeable future, a full valuation allowance was considered necessary. Liabilities for uncertain tax positions are recognized based on a two-step process. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. Once it is determined that the position meets the recognition threshold, the second step requires estimating and measuring the largest amount of tax benefit that is more likely than not to be realized upon ultimate settlement. The difference between the amount of recognizable tax benefit and the total amount of tax benefit from positions filed or to be filed with the tax authorities is recorded as a liability for uncertain tax benefits.
Research and Development Costs	Research and Development Costs Research and development costs are charged to expense as incurred and include: • employee-related expenses, including salaries, benefits, travel and share-based compensation expense for research and development personnel; • expenses incurred under agreements with contract research organizations, contract manufacturing organizations and consultants that conduct preclinical studies and clinical trials; • costs associated with preclinical and clinical development activities; • costs associated with submitting regulatory approval applications for the Company’s product candidates; • costs associated with training physicians on the suprachoroidal injection procedure and educating and providing them with appropriate product candidate information; • costs associated with technology and intellectual property licenses; • costs for the Company’s research and development facility; and • depreciation expense for assets used in research and development activities. Costs for certain development activities, such as clinical trial activities, are recognized based on an evaluation of the estimated total costs for the clinical trial, progress to completion of specific tasks, using data such as patient enrollment, pass through expenses, clinical site activations, data from the clinical sites or information provided to the Company by its vendors on their actual costs incurred. Payments for these activities are based on the terms of the individual contracts and any subsequent amendments, which may differ from the patterns of costs incurred, and are reflected in the financial statements as prepaid or accrued expenses.
Share-Based Compensation	Share-Based Compensation Compensation cost related to share-based awards granted to employees, directors and consultants is measured based on the estimated fair value of the award at the grant date. The fair value of restricted stock units granted is measured based on the market value of the Company’s common stock on the date of grant. Share-based compensation costs are expensed on a straight-line basis over the relevant vesting period. Compensation cost related to shares purchased through the Company’s employee stock purchase plan, which is considered compensatory, is based on the estimated fair value of the shares on the offering date, including consideration of the discount and the look back period. The Company estimates the fair value of the shares using a Black-Scholes option pricing model. Compensation expense is recognized over the six-month withholding period prior to the purchase date. All share-based compensation costs are recorded in general and administrative or research and development costs in the statements of operations based upon the underlying employees’ roles within the Company.
Cash Equivalents	Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with an original term of three months or less at the date of purchase.
Restricted Cash	Restricted Cash The Company is required to maintain a stand-by letter of credit as a security deposit for its facility lease in Alpharetta, Georgia. The Company’s bank requires the Company to maintain a restricted cash balance to serve as collateral for the letter of credit issued to the landlord by the bank. As of December 31, 2021, the restricted cash balance was invested in a commercial money market account. The current portion of the restricted cash is recorded in other current assets and the long-term portion is recorded in restricted cash.
Concentration of Credit Risk Arising From Cash Deposits in Excess of Insured Limits	Concentration of Credit Risk Arising From Cash Deposits in Excess of Insured Limits The Company maintains its cash in bank deposits that at times may exceed federally insured limits. The Company has not experienced any loss in such accounts. The Company believes it is not exposed to any significant risks with respect to its cash balances.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In December 2019, the FASB issued Accounting Standards Update ("ASU") 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which simplifies the accounting for income taxes by removing certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new ASU also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates. These changes aim to improve the overall usefulness of disclosures to financial statement users and reduce unnecessary costs to companies when preparing the disclosures. The Company adopted ASU 2019-12 on January 1, 2021, and the adoption did not have a material impact on its financial statements and related disclosures.

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (dollar amounts in thousands): Estimated December 31, 2021 2020 Furniture and fixtures 5 $ 337 $ 337 Machinery and equipment 5 176 176 Computer equipment 3 13 13 Leasehold improvements Lesser of or 667 667 Total property and equipment 1,193 1,193 Less: Accumulated depreciation ( 955 ) ( 777 ) Property and equipment, net $ 238 $ 416

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2021
Payables And Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): December 31, 2021 2020 Accrued research and development $ 1,083 $ 234 Accrued employee costs 1,854 1,132 Accrued professional fees 30 56 Accrued expense 345 160 $ 3,312 $ 1,582

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Summary of Share-based Compensation Expense	The Company has granted stock option awards to employees, directors and consultants. The total share-based compensation expense recognized is reflected in the statements of operations as follows (in thousands): Year Ended 2021 2020 2019 Research and development $ 1,570 $ 1,183 $ 1,379 General and administrative 1,985 1,574 2,728 Total $ 3,555 $ 2,757 $ 4,107
Weighted Average Assumptions Used in Black-Scholes Option Pricing Model to Calculate Fair Value of Underlying Common Stock	The following table sets forth the weighted average assumptions utilized in the Black-Scholes option pricing model to calculate the fair value of the underlying common stock for the years ended December 31, 2021, 2020 and 2019. Year Ended 2021 2020 2019 Expected term (years) 7.00 7.00 7.00 Expected stock price volatility 101.43 % 108.13 % 109.49 % Risk-free interest rate 0.75 % 1.52 % 2.49 % Expected dividend yield 0.00 % 0.00 % 0.00 %
Summary of Activity Related to Stock Options	The following table summarizes the activity related to stock options during the year ended December 31, 2021: Weighted Number of Average Shares Exercise Price Options outstanding at December 31, 2020 4,248,193 $ 3.95 Granted 1,794,906 3.93 Exercised ( 280,771 ) 1.38 Options outstanding at December 31, 2021 5,762,328 4.07 Options exercisable at December 31, 2020 2,355,900 4.96 Options exercisable at December 31, 2021 3,148,502 4.59
Additional Information about the Stock Option Outstanding and Exercisable	The following table provides additional information about the Company’s stock options that were outstanding and exercisable at December 31, 2021 (aggregate intrinsic values in thousands): Weighted Weighted Weighted Average Weighted Average Average Aggregate Remaining Average Aggregate Remaining Exercise Options Exercise Intrinsic Contractual Options Exercise Intrinsic Contractual Price Outstanding Price Value Life (Years) Exercisable Price Value Life (Years) $ 0.00 - $ 2.99 2,334,392 7.25 1,572,297 7.03 $ 3.00 - $ 6.99 2,776,850 7.83 933,870 5.51 $ 7.00 - $ 8.99 449,308 5.16 444,933 5.15 $ 9.00 - $ 20.84 201,778 5.76 197,402 5.75 5,762,328 $ 4.07 $ 2,469 7.32 3,148,502 $ 4.59 $ 1,880 6.23
2016 Employee Stock Purchase Plan
Summary of Share-based Compensation Expense	The share-based compensation expense recognized for the 2016 ESPP is reflected in the statements of operations and comprehensive loss as follows (in thousands): Year Ended 2021 2020 2019 Research and development $ 41 $ 19 $ 11 General and administrative 20 22 9 Total $ 61 $ 41 $ 20
Restricted Stock Units (RSUs)
Summary of Share-based Compensation Expense	The total share-based compensation expense related to RSUs is reflected in the statements of operations as follows (in thousands): Year Ended 2021 2020 2019 Research and development $ 723 $ 375 $ 177 General and administrative 715 427 306 Total $ 1,438 $ 802 $ 483
Summary of the Activity Related to RSUs	The following table summarizes the activity related to RSUs during the year ended December 31, 2021: Weighted Average Number of Grant Date Shares Fair Value Non-vested RSUs outstanding at December 31, 2020 767,271 $ 1.78 Granted 965,344 4.01 Vested ( 415,268 ) 1.27 Non-vested RSUs outstanding at December 31, 2021 1,317,347 3.58

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Net Deferred Tax Assets	Significant components of the Company’s net deferred income tax assets consist of the following (in thousands): December 31, 2021 2020 2019 Deferred tax asset (liability): Net operating loss carryforwards $ 53,966 $ 51,414 $ 46,305 Non-deductible accrued expenses 469 263 422 Right-of-use asset ( 96 ) ( 132 ) ( 138 ) Lease liability 176 247 264 Deferred revenue — 1,247 — Stock compensation expense 2,768 2,044 1,472 Depreciation differences ( 44 ) ( 82 ) ( 94 ) Federal tax credits 9,012 8,015 7,249 State tax credits 342 381 623 Disallowed interest expense — 7 99 Charitable contributions 6 — 4 Valuation allowance ( 66,599 ) ( 63,404 ) ( 56,206 ) Net deferred tax asset $ — $ — $ —
Schedule of Statutory and Effective Income Tax Rate Reconciliation	A reconciliation of the statutory tax rates and the effective tax rates is as follows: Year Ended December 31, 2021 2020 2019 U.S. federal tax rate 21.00 % 21.00 % 21.00 % State tax rate ( 599.32 ) 14.28 — Permanent difference ( 3.15 ) 1.42 ( 1.33 ) Tax credit ( 253.97 ) 2.89 2.06 Valuation allowance 847.82 ( 39.66 ) ( 21.73 ) ASC 740-10 ( 3.19 ) ( 0.26 ) — Adjustment to prior year tax provision ( 13.16 ) — — Other 3.97 — — 0.00 % ( 0.33 )% 0.00 %
Summary of Activity Related to Uncertain Tax Positions	The following is a rollforward of the Company’s uncertain tax positions (in thousands): Year Ended December 31, 2021 2020 Balance of uncertain tax positions at the beginning of the year $ 7,568 $ 2,903 Gross increases - tax positions in prior period — 4,665 Gross decreases - tax positions in prior period ( 12 ) — Gross decreases - settlements with taxing authorities ( 36 ) — Balance of uncertain tax positions at the end of the year $ 7,520 $ 7,568

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Operating Leases Included on the Balance Sheet	The Company’s operating leases included on the balance sheet are as follows (in thousands): December 31, Operating lease right-of-use asset $ 369 Liabilities Current portion of operating lease liabilities $ 387 Operating lease liabilities 288 Total operating lease liabilities $ 675
Future Minimum Commitments Due Under Non-Cancelable Operating Leases	Minimum lease payments were as follows at December 31, 2021 (in thousands): Year ending December 31, 2022 $ 407 2023 316 Total minimum lease payments 723 Less imputed interest ( 48 ) Total operating lease liabilities $ 675

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Year Ended December 31, 2021 2020 2019 Net income (loss) - basic and diluted $ 376 $ ( 18,210 ) $ ( 30,770 ) Weighted average shares - basic 58,491,986 46,506,540 38,170,830 Effect of dilutive securities: Stock options 1,058,134 — — Restricted stock 342,943 — — ESPP 13,539 — — Weighted average shares - diluted 59,906,602 46,506,540 38,170,830 Net income (loss) per share - basic $ 0.01 $ ( 0.39 ) $ ( 0.81 ) Net income (loss) per share - diluted $ 0.01 $ ( 0.39 ) $ ( 0.81 )
Potential Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share	The Company’s potential common stock equivalents that have been excluded from the computation of diluted net income (loss) per share for all periods presented because of their antidilutive effect consisted of the following: Year Ended 2021 2020 2019 Outstanding stock options 4,704,194 4,248,193 4,104,450 Non-vested restricted stock units 974,404 767,271 1,269,300 Stock purchase warrants 29,796 29,796 29,796 5,708,394 5,045,260 5,403,546

The Company - Additional Inform

The Company - Additional Information (Details) - USD ($)	Oct. 25, 2021	Jan. 11, 2021	Jan. 06, 2021	Jan. 31, 2022	Apr. 30, 2020	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2021
Entity incorporation date							May 26, 2011
Cash and cash equivalents						$ 30,436,000	$ 30,436,000	$ 17,287,000	$ 22,595,000
Net proceeds after deducting offering expenses							$ 11,078,000	0	0
Aggregate milestone payments from the licensees	$ 9,000,000
Interest expense on borrowings								$ 147,000	$ 804,000
PPP Loan [Member]
Proceeds from Loan					$ 1,000,000
Interest expense on borrowings		$ 7,000
Arctic Vision Limited | License Arrangement
Consideration received from expansion of business										$ 3,000,000
Bausch Health Ireland Limited
Aggregate milestone payments from the licensees				$ 10,000,000		10,000,000
Common Stock
Purchase of common stock by institutional purchasers									3,178,367
Private Placement | Common Stock
Purchase of common stock by institutional purchasers			4,200,000
Purchase price per share			$ 2.851
Net proceeds after deducting offering expenses			$ 11,100,000
At-the-market Sales Agreement | Cowen and Company LLC | Common Stock
Number of shares sold under facility							2,900,000
Net proceeds from issuance of stock						$ 12,200,000	$ 12,200,000

Significant Accounting Polici_3

Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021NumberOfSegment
Accounting Policies [Abstract]
Number of operating segments	1

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment	$ 1,193	$ 1,193
Less: Accumulated depreciation	(955)	(777)
Property and equipment, net	238	416
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	$ 337	337
Estimated Useful Lives (Years)	5 years
Machinery and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	$ 176	176
Estimated Useful Lives (Years)	5 years
Computer Equipment
Property Plant And Equipment [Line Items]
Total property and equipment	$ 13	13
Estimated Useful Lives (Years)	3 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment	$ 667	$ 667
Estimated Useful Lives (Years)	Lesser ofuseful life orremaininglease term

Accrued Liabilities - Schedule

Accrued Liabilities - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued research and development	$ 1,083	$ 234
Accrued employee costs	1,854	1,132
Accrued professional fees	30	56
Accrued expense	345	160
Accrued liabilities, current	$ 3,312	$ 1,582

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details) - USD ($)	May 07, 2020	Oct. 18, 2019	May 14, 2018	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Interest expense on borrowings					$ 147,000	$ 804,000
Accretion of scheduled final payment					59,000	163,000
Accretion of deferred closing costs					$ 129,000	$ 67,000
Second Amended and Restated Loan and Security Agreement
Debt Instrument [Line Items]
Debt instrument, principal balance payment	$ 5,000,000
Debt Instrument, Final Payment, Interest	$ 300,000
Third Amended And Restated Loan And Security Agreement
Debt Instrument [Line Items]
Debt instrument, payment terms				On October 18, 2019, the Company entered into an amendment to the 2nd A&R Loan Agreement with the Lenders. Pursuant to the amendment, the Company repaid $5.0 million of the outstanding principal balance of the $10.0 million term loan. The Company did not pay any final payment or termination fees in connection with the $5.0 million prepayment. In addition, the Company and the Lenders agreed to modify the term loan repayment schedule. As amended, the term loan repayment schedule provided for interest only payments through October 31, 2020, followed by consecutive equal monthly payments of principal and interest in arrears continuing through the maturity date of October 1, 2022
Silicon Valley Bank, MidCap Funding III Trust and MidCap Financial Trust | Second Amended and Restated Loan and Security Agreement
Debt Instrument [Line Items]
Fixed interest rate			6.50%
Variable interest rate			1.89%
Debt instrument, description of variable rate basis				30-day U.S. LIBOR
Line of credit facility, maximum borrowing capacity			$ 20,000,000
Long term debt			10,000,000
Line of credit facility, remaining borrowing capacity description				Of the remaining $10.0 million available under the 2nd A&R loan agreement, the Company elected not to draw $5.0 million and the other $5.0 million was not available for draw
Line of credit facility remaining borrowing capacity not available for withdraw			5,000,000
Line of credit facility, remaining borrowing capacity			5,000,000
Silicon Valley Bank, MidCap Funding III Trust and MidCap Financial Trust | Second Amended and Restated Loan and Security Agreement, Initial Tranche
Debt Instrument [Line Items]
Long term debt			10,000,000
Silicon Valley Bank , MidCap Funding XII Trust and MidCap Financial Trust | First Amended and Restated Loan and Security Agreement | Final Payment
Debt Instrument [Line Items]
Repayment of outstanding amount under the loan agreement including fees			$ 7,000,000
Silicon Valley Bank , MidCap Funding XII Trust and MidCap Financial Trust | Third Amended And Restated Loan And Security Agreement
Debt Instrument [Line Items]
Long term debt		$ 10,000,000
Repayment of outstanding amount under the loan agreement including fees		$ 5,000,000
Loans held-for-sale, maturity date		Oct. 1, 2022
Final payment during maturity, percentage				5.50%

CARES Act Paycheck Protection_2

CARES Act Paycheck Protection Program Loan - Additional Information (Details) - USD ($)	Jan. 11, 2021	Apr. 20, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021
Short Term Debt [Line Items]
Current portion of long-term debt			$ 991,000
Interest expense on borrowings			$ 147,000	$ 804,000
PPP Loan
Short Term Debt [Line Items]
Interest expense on borrowings	$ 7,000
PPP Loan | Silicon Valley Bank
Short Term Debt [Line Items]
Aggregate principal amount		$ 1,000,000
Interest rate on outstanding principal amount		1.00%
Note, Maturity date		Apr. 30, 2022

Preferred and Common Stock - Ad

Preferred and Common Stock - Additional Information (Detail) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	100,000,000	100,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares outstanding	59,722,930	51,860,941

Common Stock Warrants - Additio

Common Stock Warrants - Additional Information (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2021
Maximum [Member]
Class Of Warrant Or Right [Line Items]
Number of stock that can be purchased by each warrant	29,796
Convertible Stock Warrant
Class Of Warrant Or Right [Line Items]
Class of warrant Exercise	$ 10.74
Warrants expiration term	2026-09
Weighted average remaining life of warrants		4 years 9 months

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 01, 2021	Jan. 31, 2016	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
2016 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual increase of common stock reserved for issuance	4.00%
Increase in common stock for future issuance, shares	2,388,917
Shares common stock reserved for issuance	2,771,705
2016 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation arrangement description			The number of shares reserved for issuance under the 2016 ESPP will automatically increase on January 1 of each year, through January 1, 2026, by the lesser of (i) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (ii) 454,545 shares of common stock or (iii) a lesser number of shares as may be determined by the Company’s board of directors
Shares common stock reserved for issuance			505,491
Employee payroll deductions, percent		15.00%
Addition of common stock shares reserved for future issuance		454,545
Issuance of common shares under employee stock purchase plan, shares			65,481	35,359	52,476
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares grants			1,794,906
Option to purchase common stock shares outstanding			5,762,328	4,248,193
Weighted average exercise price			$ 4.07	$ 3.95
Unrecognized compensation expense related to unvested stock options			$ 5.6
Expected to be recognized over a weighted average period			2 years 7 months 6 days
Weighted-average fair values granted			$ 3.24	$ 1.97	$ 1.09
Fair market value per share of common stock			$ 2.75
Stock Options | 2016 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation arrangement description			The number of shares of common stock reserved for issuance under the 2016 Plan will automatically increase on January 1 each year, through January 1, 2026, by 4% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares as may be determined by the Company’s board of directors.
Annual increase of common stock reserved for issuance			4.00%
Option to purchase common stock shares outstanding			5,378,247
Weighted average exercise price			$ 4.13
Shares available for future grant			382,788
Stock Options | 2011 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares grants			0
Option to purchase common stock shares outstanding			366,845
Weighted average exercise price			$ 2.94
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected to be recognized over a weighted average period			2 years 10 months 24 days
Unrecognized compensation expense related to the RSUs			$ 3.5

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
2016 Employee Stock Purchase Plan
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 61	$ 41	$ 20
2016 Employee Stock Purchase Plan | Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	41	19	11
2016 Employee Stock Purchase Plan | General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	20	22	9
Stock Options
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	3,555	2,757	4,107
Stock Options | Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	1,570	1,183	1,379
Stock Options | General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	1,985	1,574	2,728
Restricted Stock Units (RSUs)
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	1,438	802	483
Restricted Stock Units (RSUs) | Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	723	375	177
Restricted Stock Units (RSUs) | General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 715	$ 427	$ 306

Share-Based Compensation - Weig

Share-Based Compensation - Weighted Average Assumptions Used in Black-Scholes Option Pricing Model to Calculate Fair Value of Underlying Common Stock (Details) - Stock Options	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Expected term (years)	7 years	7 years	7 years
Expected stock price volatility	101.43%	108.13%	109.49%
Risk-free interest rate	0.75%	1.52%	2.49%
Expected dividend yield	0.00%	0.00%	0.00%

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Activity Related to Stock Options (Details) - Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Options outstanding, Beginning balance	4,248,193
Number of Shares, Granted	1,794,906
Number of Shares, Exercised	(280,771)
Number of Shares, Options outstanding, Ending balance	5,762,328	4,248,193
Number of Shares, Options exercisable	3,148,502	2,355,900
Weighted Average Exercise Price, Options outstanding, Beginning balance	$ 3.95
Weighted Average Exercise Price, Granted	3.93
Weighted Average Exercise Price, Exercised	1.38
Weighted Average Exercise Price, Options outstanding, Ending balance	4.07	$ 3.95
Weighted Average Exercise Price, Options exercisable	$ 4.59	$ 4.96

Share-Based Compensation - Ad_2

Share-Based Compensation - Additional Information about the Stock Option Outstanding and Exercisable (Details) - Stock Options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding	5,762,328	4,248,193
Weighted Average Exercise Price	$ 4.07	$ 3.95
Aggregate Intrinsic Value	$ 2,469
Weighted Average Remaining Contractual Life (Years)	7 years 3 months 25 days
Options Exercisable	3,148,502	2,355,900
Weighted Average Exercise Price	$ 4.59	$ 4.96
Aggregate Intrinsic Value	$ 1,880
Weighted Average Remaining Contractual Life (Years)	6 years 2 months 23 days
$0.00 - $2.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range Limit	$ 0
Exercise Price Upper Range Limit	$ 2.99
Options Outstanding	2,334,392
Weighted Average Remaining Contractual Life (Years)	7 years 3 months
Options Exercisable	1,572,297
Weighted Average Remaining Contractual Life (Years)	7 years 10 days
$3.00 - $6.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range Limit	$ 3
Exercise Price Upper Range Limit	$ 6.99
Options Outstanding	2,776,850
Weighted Average Remaining Contractual Life (Years)	7 years 9 months 29 days
Options Exercisable	933,870
Weighted Average Remaining Contractual Life (Years)	5 years 6 months 3 days
$7.00 - $8.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range Limit	$ 7
Exercise Price Upper Range Limit	$ 8.99
Options Outstanding	449,308
Weighted Average Remaining Contractual Life (Years)	5 years 1 month 28 days
Options Exercisable	444,933
Weighted Average Remaining Contractual Life (Years)	5 years 1 month 24 days
$9.00 - $20.84
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range Limit	$ 9
Exercise Price Upper Range Limit	$ 20.84
Options Outstanding	201,778
Weighted Average Remaining Contractual Life (Years)	5 years 9 months 3 days
Options Exercisable	197,402
Weighted Average Remaining Contractual Life (Years)	5 years 9 months

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of the Activity Related to RSUs (Details) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Non-vested units outstanding, Number of Shares, Beginning balance | shares	767,271
Number of Shares, Granted | shares	965,344
Number of Shares, Vested | shares	(415,268)
Non-vested units outstanding, Number of Shares, Ending balance | shares	1,317,347
Non-vested units outstanding, Weighted Average Grant Date Fair Value, Beginning balance | $ / shares	$ 1.78
Weighted Average Grant Date Fair Value, Granted | $ / shares	4.01
Weighted Average Grant Date Fair Value, Vested | $ / shares	1.27
Non-vested units outstanding, Weighted Average Grant Date Fair Value, Ending balance | $ / shares	$ 3.58

Income Taxes - Schedule of Net

Income Taxes - Schedule of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred tax asset (liability)
Net operating loss carryforwards	$ 53,966	$ 51,414	$ 46,305
Non-deductible accrued expenses	469	263	422
Right-of-use asset	(96)	(132)	(138)
Lease liability	176	247	264
Deferred revenue		1,247
Stock compensation expense	2,768	2,044	1,472
Depreciation differences	(44)	(82)	(94)
Disallowed interest expense		7	99
Charitable contributions	6		4
Valuation allowance	(66,599)	(63,404)	(56,206)
Net deferred tax asset	0	0	0
Federal
Deferred tax asset (liability)
Net operating loss carryforwards	49,200
Tax credits	9,012	8,015	7,249
State
Deferred tax asset (liability)
Net operating loss carryforwards	4,800
Tax credits	$ 342	$ 381	$ 623

Schedule of Statutory and Effec

Schedule of Statutory and Effective Income Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
U.S. federal tax rate	21.00%	21.00%	21.00%
State tax rate	(599.32%)	14.28%
Permanent difference	(3.15%)	1.42%	(1.33%)
Tax credit	(253.97%)	2.89%	2.06%
Valuation allowance	847.82%	(39.66%)	(21.73%)
ASC 740-10	(3.19%)	(0.26%)
Adjustment to prior year tax provision	(13.16%)
Other	3.97%
Total income tax provision (benefit)	0.00%	(0.33%)	0.00%

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Line Items]
Deferred tax assets, valuation allowance	$ 66,599,000	$ 63,404,000	$ 56,206,000
Deferred tax assets, net operating loss carryforwards	53,966,000	51,414,000	$ 46,305,000
Unrecognized tax benefits that would affect the effective tax rate if recognized	7,500,000	$ 7,600,000
Unrecognized tax expenses	48,000
Unrecognized tax benefits, income tax penalties expense	$ 0
Operating loss carryforwards, limitations on use	Ownership changes, as defined by Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”), may limit the amount of net operating losses that a company may utilize to offset future taxable income and taxes payable. Pursuant to Section 382 of the Code, an ownership change occurs when the stock ownership of 5% stockholders increases by more than 50% over a testing period of three years. It is possible that the Company has undergone an ownership change as defined by Section 382 of the Code or that the Company may undergo such a change in the future. Any such ownership change may limit the Company’s ability to utilize net operating losses.
Federal
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 234,400,000
Deferred tax assets, net operating loss carryforwards	$ 49,200,000
Federal | Earliest Tax Year
Income Tax Disclosure [Line Items]
Operating loss carryforwards expiration period	2031
State
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 75,600,000
Deferred tax assets, net operating loss carryforwards	$ 4,800,000
State | Earliest Tax Year
Income Tax Disclosure [Line Items]
Operating loss carryforwards expiration period	2027

Summary of Activity Related to

Summary of Activity Related to Uncertain Tax Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Summary of activity related to uncertain tax positions
Balance of uncertain tax positions at the beginning of the year	$ 7,568	$ 2,903
Gross increases - tax positions in prior period		4,665
Gross decreases - tax positions in prior period	(12)
Gross decreases - settlements with taxing authorities	(36)
Balance of uncertain tax positions at the end of the year	$ 7,520	$ 7,568

Commitment and Contingencies -

Commitment and Contingencies - Additional Information (Details)	1 Months Ended			12 Months Ended
	Aug. 31, 2018USD ($)ft²	May 31, 2018	Nov. 30, 2016USD ($)ft²	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Commitment And Contingencies [Line Items]
Lessee, operating lease, option to extend, description				The renewal option is not included in the calculation of the right-of-use asset and the lease liabilities as the Company has not yet determined if the Alpharetta, Georgia lease will be renewed.
Incremental borrowing rate				11.00%
Operating lease, remaining lease term				1 year 9 months
Operating Lease, Cost				$ 247,000	$ 247,000	$ 393,000
Variable Lease, Cost				95,000	95,000	83,000
Short-term Lease, Cost				$ 8,000	$ 12,000	$ 20,000
Manufacturing Supply Agreement | Gerresheimer Regensburg GmbH
Commitment And Contingencies [Line Items]
Initial term of agreement		5 years
Renewal term of agreement		3 years
GEORGIA
Commitment And Contingencies [Line Items]
Area of office leased | ft²			20,000
Operating lease agreement term			6 years 6 months
Operating lease agreement renewal option term			5 years
Minimum monthly lease payments			$ 35,145
Percentage of increase per year			3.00%
CALIFORNIA
Commitment And Contingencies [Line Items]
Area of office leased | ft²	3,500
Operating lease agreement term	2 years
Operating lease agreement renewal option term	1 year
Lease termination date	Dec. 15, 2019
Operating lease liability payments due	$ 0

Commitment and Contingencies _2

Commitment and Contingencies - Operating Leases Included on the Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Operating lease right-of-use asset	$ 369	$ 528
Liabilities
Current portion of operating lease liabilities	387	373
Operating lease liabilities	288	$ 616
Total operating lease liabilities	$ 675

Commitment and Contingencies _3

Commitment and Contingencies - Future Minimum Commitments Due Under Non-Cancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2021USD ($)
Commitments And Contingencies Disclosure [Abstract]
2022	$ 407
2023	316
Total minimum lease payments	723
Less imputed interest	(48)
Total operating lease liabilities	$ 675

License and Other Agreements -

License and Other Agreements - Additional Information (Detail) - USD ($)	Mar. 10, 2020	Oct. 22, 2019	Dec. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Oct. 31, 2019	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Research And Development Arrangement Contract To Perform For Others [Line Items]
Deferred revenue									$ 5,000,000
Revenue								29,575,000	7,894,000	$ 2,173,000
Other Agreement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Revenue								13,000	$ 200,000	$ 105,000
License Arrangement | REGENXBIO, Inc.
Research And Development Arrangement Contract To Perform For Others [Line Items]
Option fee paid						$ 2,000,000
Proceeds from option fee previously received						500,000
Milestone payments						31,000,000
Sales-based milestone payments						$ 102,000,000
Milestone payments received					$ 3,000,000
Bausch Health Ireland Limited
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment		$ 5,000,000
Bausch Health Ireland Limited | Upfront Payment
Research And Development Arrangement Contract To Perform For Others [Line Items]
Deferred revenue			5,000,000				5,000,000	5,000,000
Bausch Health Ireland Limited | XIPERE [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Pre-launch milestone payments								10,000,000
First cumulative net sales of products								$ 45,000
Revenue							$ 5,000,000
Bausch Health Ireland Limited | XIPERE [Member] | Maximum [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Additional milestone payments		$ 55,000,000
Arctic Vision Limited | Maximum [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Threshold percentage of sales for tiered royalties	12.00%
Arctic Vision Limited | Minimum [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Threshold percentage of sales for tiered royalties	10.00%
Arctic Vision Limited | License Arrangement
Research And Development Arrangement Contract To Perform For Others [Line Items]
Consideration received for territory expansion				$ 3,000,000
Arctic Vision Limited | License Arrangement | Upfront Payment
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment	$ 4,000,000
Arctic Vision Limited | License Arrangement | Maximum [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Development milestone payments	$ 22,500,000
Arctic Vision Limited | XIPERE [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone payments			$ 4,000,000

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Significant transfers between Levels 1, 2 and 3	$ 0	$ 0

Net Income (Loss) Per Share - S

Net Income (Loss) Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Net income (loss) - basic and diluted	$ 376	$ (18,210)	$ (30,770)
Weighted average shares - basic	58,491,986	46,506,540	38,170,830
Effect of dilutive securities:
Weighted average shares outstanding - diluted	59,906,602	46,506,540	38,170,830
Net income (loss) per share - basic	$ 0.01	$ (0.39)	$ (0.81)
Net income (loss) per share - diluted	$ 0.01	$ (0.39)	$ (0.81)
Stock Options [Member]
Effect of dilutive securities:
Weighted Average Number Diluted Shares Outstanding Adjustment	1,058,134
Restricted Stock [Member]
Effect of dilutive securities:
Weighted Average Number Diluted Shares Outstanding Adjustment	342,943
ESPP [Member]
Effect of dilutive securities:
Weighted Average Number Diluted Shares Outstanding Adjustment	13,539

Net Loss Per Share - Potential

Net Loss Per Share - Potential Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,708,394	5,045,260	5,403,546
Outstanding Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	4,704,194	4,248,193	4,104,450
Non-vested Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	974,404	767,271	1,269,300
Stock Purchase Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	29,796	29,796	29,796