Aerie Pharmaceuticals (AERI) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2021	Apr. 29, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-36152
Entity Registrant Name	Aerie Pharmaceuticals, Inc.
Entity Incorporation, State	DE
Entity Tax Identification Number	20-3109565
Entity Address, Street Address	4301 Emperor Boulevard, Suite 400
Entity Address, City	Durham
Entity Address, State	NC
Entity Address, Postal Zip Code	27703
City Area Code	919
Local Phone Number	237-5300
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	AERI
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		46,893,289
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity CIK	0001337553
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 122,695	$ 151,570
Short-term investments	85,509	88,794
Accounts receivable, net	46,150	56,022
Inventory	28,324	27,059
Prepaid expenses and other current assets	10,899	8,310
Total current assets	293,577	331,755
Property, plant and equipment, net	53,283	54,260
Operating lease right-of-use assets	13,241	14,084
Other assets	2,627	1,946
Total assets	362,728	402,045
Current liabilities
Accounts payable	6,520	8,826
Accrued expenses and other current liabilities	82,792	90,723
Operating lease liabilities	4,052	4,923
Total current liabilities	93,364	104,472
Convertible notes, net	216,088	210,373
Deferred revenue, non-current	51,605	50,858
Long-term operating lease liabilities	9,914	10,206
Other non-current liabilities	2,125	2,168
Total liabilities	373,096	378,077
Commitments and contingencies (Note 12)
Stockholders’ (deficit) equity
Preferred stock, $0.001 par value; 15,000,000 shares authorized as of March 31, 2021 and December 31, 2020; none issued and outstanding	0	0
Common stock, $0.001 par value; 150,000,000 shares authorized as of March 31, 2021 and December 31, 2020; 46,893,822 and 46,821,644 shares issued and outstanding as of March 31, 2021 and December 31, 2020, respectively	47	47
Additional paid-in capital	1,110,714	1,103,074
Accumulated other comprehensive loss	(64)	(52)
Accumulated deficit	(1,121,065)	(1,079,101)
Total stockholders’ (deficit) equity	(10,368)	23,968
Total liabilities and stockholders’ (deficit) equity	$ 362,728	$ 402,045

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	15,000,000	15,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	46,893,822	46,821,644
Common stock, shares outstanding (in shares)	46,893,822	46,821,644

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Total revenues, net	$ 22,970	$ 20,341
Costs and expenses:
Cost of goods sold	6,700	6,092
Selling, general and administrative	32,598	36,902
Pre-approval commercial manufacturing	0	2,114
Research and development	17,891	19,173
Total costs and expenses	57,189	64,281
Loss from operations	(34,219)	(43,940)
Other (expense) income, net	(7,714)	(5,222)
Loss before income taxes	(41,933)	(49,162)
Income tax expense (benefit)	31	(33)
Net loss	$ (41,964)	$ (49,129)
Net loss per common share—basic and diluted (in dollars per share)	$ (0.91)	$ (1.07)
Weighted average number of common shares outstanding—basic and diluted (in shares)	46,109,080	45,792,504
Net loss	$ (41,964)	$ (49,129)
Unrealized loss on available-for-sale investments, net	(12)	(28)
Comprehensive loss	(41,976)	(49,157)
Product revenues, net
Total revenues, net	$ 22,970	$ 20,341

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' (Deficit) Equity - USD ($) $ in Thousands	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	ACCUMULATED OTHER COMPREHENSIVE LOSS	ACCUMULATED DEFICIT
Beginning balance (in shares) at Dec. 31, 2019		46,464,669
Beginning balance at Dec. 31, 2019	$ 166,950	$ 46	$ 1,062,996	$ (92)	$ (896,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and warrants (in shares)		5,811
Issuance of common stock upon exercise of stock options and warrants	44		44
Issuance of common stock for restricted stock awards, net (in shares)		5,705
Issuance of common stock for restricted stock awards, net	(1,466)		(1,466)
Stock-based compensation	10,838		10,838
Other comprehensive loss	(28)			(28)
Net loss	(49,129)				(49,129)
Ending balance (in shares) at Mar. 31, 2020		46,476,185
Ending balance at Mar. 31, 2020	127,209	$ 46	1,072,412	(120)	(945,129)
Beginning balance (in shares) at Dec. 31, 2020		46,821,644
Beginning balance at Dec. 31, 2020	$ 23,968	$ 47	1,103,074	(52)	(1,079,101)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and warrants (in shares)	63,370	62,016
Issuance of common stock upon exercise of stock options and warrants	$ 26		26
Issuance of common stock for restricted stock awards, net (in shares)		10,162
Issuance of common stock for restricted stock awards, net	(1,127)		(1,127)
Stock-based compensation	8,741		8,741
Other comprehensive loss	(12)			(12)
Net loss	(41,964)				(41,964)
Ending balance (in shares) at Mar. 31, 2021		46,893,822
Ending balance at Mar. 31, 2021	$ (10,368)	$ 47	$ 1,110,714	$ (64)	$ (1,121,065)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net loss	$ (41,964)	$ (49,129)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	1,499	1,591
Amortization and accretion	7,408	6,585
Stock-based compensation	8,749	10,529
Other non-cash	1,116	(39)
Changes in operating assets and liabilities
Accounts receivable, net	9,872	(4,587)
Inventory	(1,052)	1,048
Prepaid, current and other assets	(4,286)	(2,410)
Accounts payable, accrued expenses and other current liabilities	(10,297)	(3,952)
Operating lease liabilities	(1,846)	(1,458)
Deferred revenue	747	0
Net cash used in operating activities	(30,054)	(41,822)
Cash flows from investing activities
Purchase of available-for-sale investments	(25,236)	(15,834)
Proceeds from sales and maturities of investments	28,288	50,557
Purchase of property, plant and equipment	(772)	(1,240)
Net cash provided by investing activities	2,280	33,483
Cash flows from financing activities
Payments related to issuance of stock for stock-based compensation arrangements, net	(1,101)	(1,422)
Net cash used in financing activities	(1,101)	(1,422)
Net change in cash and cash equivalents	(28,875)	(9,761)
Cash and cash equivalents, at beginning of period	151,570	143,940
Cash and cash equivalents, at end of period	122,695	134,179
Non-cash investing and financing activities
Purchase of property, plant and equipment	$ 182	$ 254

The Company

The Company	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	The Company Aerie Pharmaceuticals, Inc. (“Aerie”), with its wholly-owned subsidiaries, Aerie Distribution, Inc., Aerie Pharmaceuticals Limited, Aerie Pharmaceuticals Ireland Limited and Avizorex Pharma S.L. (“Aerie Distribution,” “Aerie Limited,” “Aerie Ireland Limited” and “Avizorex,” respectively, together with Aerie, the “Company”), is an ophthalmic pharmaceutical company focused on the discovery, development and commercialization of first-in-class therapies for the treatment of patients with open-angle glaucoma, ocular surface diseases and retinal diseases. The Company has its principal executive offices in Durham, North Carolina, and operates as one business segment. U.S Commercial Products The Company has developed and commercialized two U.S. Food and Drug Administration (“FDA”) approved products, Rhopressa ® (netarsudil ophthalmic solution) 0.02% (“Rhopressa ® ”) and Rocklatan ® (netarsudil/ latanoprost ophthalmic solution) 0.02%/0.005% (“Rocklatan ® ”), which are sold in the United States and comprise its glaucoma franchise. Rhopressa ® is a once-daily eye drop designed to reduce elevated intraocular pressure (“IOP”) in patients with open-angle glaucoma or ocular hypertension. Rocklatan ® is a once-daily fixed-dose combination of Rhopressa ® and latanoprost, the most widely-prescribed drug for the treatment of patients with open-angle glaucoma. The Company is commercializing Rhopressa ® , which was launched in the United States in April 2018, and Rocklatan ® , which was launched in the United States in May 2019. Outside the United States In addition to actively promoting Rhopressa ® and Rocklatan ® in the United States, the Company’s strategy also includes developing business opportunities outside of the United States including the successful commercialization of Rhopressa ® and Rocklatan ® in Europe, Japan and other regions . At present, the Company has a development and commercialization partner for Japan and certain other Asian countries, and is evaluating potential collaborators for Europe and other regions. Rhopressa ® and Rocklatan ® will be marketed under the names Rhokiinsa ® and Roclanda ® , respectively, if ultimately commercialized in Europe. In Europe, Rhokiinsa ® and Roclanda ® were granted a Centralised Marketing Authorisation (“Centralised MA”) by the European Commission (“EC”) in November 2019 and January 2021, respectively. In April 2021, Roclanda ® received marketing authorisation from the Medicines and Healthcare Products Regulatory Agency (“MHRA”) in Great Britain. As the EC decision was received after the end of the Brexit transition period, the Company was required to complete a further administrative step in order to obtain authorisation in Great Britain, which has now been granted. The Company reported positive interim topline 90-day efficacy data in September 2020 for the Phase 3b clinical trial for Roclanda ® , named Mercury 3, a six-month efficacy and safety trial designed to compare Roclanda ® to Ganfort ® , a fixed-dose combination product marketed in Europe of bimatoprost (a prostaglandin analog), and timolol (a beta blocker). As a result of the positive Mercury 3 results, discussions are underway with third parties, who have expressed interest in a commercialization partnership in and potentially beyond Europe, while the Company has been simultaneously preparing on its own for pricing discussions in Germany. In Japan, the Company entered into a Collaboration and License Agreement (the “Santen Agreement”) with Santen Pharmaceuticals Co., Ltd. (“Santen”) in October 2020 to advance its clinical development and ultimately commercialize Rhopressa ® and Rocklatan ® in Japan and eight other countries in Asia. See Note 3 for additional information. The Company initiated a Rhopressa ® Phase 3 clinical trial in December 2020, the first of three expected Phase 3 clinical trials in Japan. Clinical trials for Rocklatan ® in Japan have not yet begun. Glaucoma Product Manufacturing The Company has a sterile fill production facility in Athlone, Ireland, for the production of its FDA approved products and clinical supplies. The Company received FDA approval to produce Rocklatan ® and Rhopressa ® at the Athlone manufacturing plant for commercial distribution in the United States in January 2020 and September 2020, respectively. The manufacturing plant began manufacturing commercial supplies of Rocklatan ® during the first quarter of 2020 and Rhopressa ® in the third quarter of 2020 for distribution to the United States. Shipments of commercial supply of Rocklatan ® and Rhopressa ® from the Athlone manufacturing plant to the United States commenced in the third quarter of 2020 and in the fourth quarter of 2020, respectively. The Athlone manufacturing plant has also manufactured clinical supplies of Rhopressa ® for the Phase 3 clinical trials in Japan. Product Candidates and Pipeline The Company is furthering the development of its product candidates focused on dry eye and retinal diseases, particularly AR-15512, AR-1105, AR-13503 SR and AR-14034 SR, described below. The Company acquired Avizorex, a Spanish ophthalmic pharmaceutical company, developing therapeutics for the treatment of dry eye disease, in late 2019. The active ingredient in AR-15512 is a potent and selective agonist of the TRPM8 ion channel, a cold sensor and osmolarity sensor that regulates tear production and blink rate. In addition, activating the TRPM8 receptor may reduce ocular discomfort by promoting a cooling sensation. The Investigational New Drug Application (“IND”) for AR-15512 eye drop for dry eye became effective in September 2020, allowing Aerie to initiate clinical studies in the treatment of dry eye. The Company is currently testing two concentrations of AR-15512 in an ongoing 90-day Phase 2b clinical trial with 360 subjects, which could potentially be considered pivotal. The Company initiated this now fully enrolled clinical trial, named COMET-1, in October 2020 and a topline readout is expected in the third quarter of 2021. The Company is currently developing three sustained-release implants focused on retinal diseases, AR-1105, AR-13503 SR and AR-14034 SR. In July 2020, the Company completed a Phase 2 clinical trial for AR-1105, a dexamethasone steroid implant, in patients with macular edema due to retinal vein occlusion (“RVO”). Also, in July 2020, the Company reported topline results of the Phase 2 clinical trial for AR-1105 indicating sustained efficacy of up to six months, an important achievement in validating the capabilities of Aerie’s sustained release platform. The Company is in the process of meeting with regulatory agencies in order to harmonize development plans across both Europe and the United States and continues to evaluate next steps regarding clinical and regulatory pathways for Phase 3 clinical trials along with commercialization prospects in both markets. The Company is also developing AR-13503, a Rho kinase (“ROCK”) and Protein kinase C inhibitor that is the active ingredient in the AR-13503 sustained-release implant. The IND for AR-13503 SR became effective in April 2019, allowing the Company to initiate human studies in the treatment of wet age-related macular degeneration (age-related macular degeneration, “AMD”) and diabetic macular edema (“DME ”). The Company initiated a first-in-human clinical safety study for AR-13503 SR in the third quarter of 2019 . The Company expects to complete the dose escalation safety evaluation with the current implant design for AR-13503 SR in the first quarter of 2022. The preclinical stage sustained-release implant AR-14034 SR, is being designed to deliver the active ingredient axitinib, a potent small molecule pan-VEGF receptor inhibitor. AR-14034 SR has the potential to provide a duration of effect of approximately one year with a once per-year injection. It may potentially be used to treat DME, wet AMD and related diseases of the retina. IND-enabling preclinical studies are underway and the Company anticipates filing an IND for AR-14034 SR with the FDA in the second half of 2022. Liquidity The Company commenced generating product revenues related to the sales in the United States of Rhopressa ® in the second quarter of 2018 and Rocklatan ® in the second quarter of 2019. The Company’s activities prior to the commercial launch of Rhopressa ® had primarily consisted of developing product candidates, raising capital and performing research and development activities. The Company has incurred losses and experienced negative operating cash flows since inception. The Company had previously funded its operations primarily through the sale of equity securities and issuance of convertible notes prior to generating product revenues. In September 2019, the Company issued an aggregate principal amount of $316.25 million of 1.50% convertible senior notes due 2024 (the “Convertible Notes”) (Note 10). Further, in October 2020, the Company entered into the Santen Agreement, pursuant to which Santen paid an upfront payment of $50.0 million (Note 3). The Company expects to incur ongoing operating losses until such a time when Rhopressa ® or Rocklatan ® or any current or future product candidates or future product candidates, if approved, generate sufficient cash flows for the Company to achieve profitability. Accordingly, the Company may be required to obtain further funding through debt or equity offerings or other sources. Adequate additional funding may not be available to the Company on acceptable terms, or at all. If the Company is unable to raise capital when needed or on acceptable terms, it may be forced to delay, reduce or eliminate its research and development programs or commercialization and manufacturing efforts.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation The Company’s interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). In the opinion of management, the Company has made all necessary adjustments, which include normal recurring adjustments necessary for a fair statement of the Company’s condensed consolidated financial position and results of operations for the interim periods presented. Certain information and disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes for the year ended December 31, 2020 included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on February 26, 2021. The results for the three months ended March 31, 2021 are not necessarily indicative of the results to be expected for a full year, any other interim periods or any future year or period. Principles of Consolidation The interim condensed consolidated financial statements include the accounts of Aerie and its wholly-owned subsidiaries. All intercompany accounts, transactions and profits have been eliminated in consolidation. Use of Estimates The preparation of condensed consolidated 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 condensed consolidated financial statements and reported amounts of income and expenses during the reporting periods. Significant items subject to such estimates and assumptions include revenue recognition, acquisitions, stock-based compensation and fair value measurements. On March 11, 2020, the World Health Organization declared the coronavirus (“COVID-19”) outbreak a pandemic. The full extent to which COVID-19 will directly or indirectly impact the Company’s business, results of operations and financial condition, including net product revenue, cost and expenses, reserves and allowances, manufacturing and clinical trials, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat it, as well as the economic impact on eye-care professionals, patients, third parties and markets. Actual results could differ from the Company’s estimates. Adoption of New Accounting Standards In December 2019, the Financial Accounting Standards Board (“FASB”) issued 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 guidance was effective for the Company beginning on January 1, 2021 and prescribes different transition methods for the various provisions. The adoption of ASU 2019-12 did not have a material impact on the Company’s consolidated financial statements and disclosures. Recent Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”) to address the complexity associated with applying GAAP to certain financial instruments with characteristics of liabilities and equity. This ASU includes amendments to the guidance on convertible instruments and the derivative scope exception for contracts in an entity’s own equity. ASU 2020-06 also simplifies the accounting for convertible instruments, which includes eliminating the cash conversion accounting model for convertible instruments. Additionally, ASU 2020-06 will require entities to use the “if-converted” method when calculating diluted earnings per share for convertible instruments. The guidance is effective for the Company beginning on January 1, 2022 and prescribes different transition methods for the various provisions. The Company is currently evaluating the impact of ASU 2020-06 on its consolidated financial statements and disclosures. Net Loss per Common Share Basic net loss per common share (“Basic EPS”) is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share (“Diluted EPS”) gives effect to all dilutive potential shares of common stock outstanding during this period. For Diluted EPS, net loss used in calculating Basic EPS may be adjusted for certain items related to the dilutive securities. For all periods presented, Aerie’s potential common stock equivalents have been excluded from the computation of Diluted EPS as their inclusion would have had an anti-dilutive effect. The potential common stock equivalents that have been excluded from the computation of Diluted EPS consist of the following: THREE MONTHS ENDED 2021 2020 Outstanding stock options 8,720,368 8,701,163 Stock purchase warrants — 4,500 Non-vested restricted stock awards and performance share units 714,005 633,865 Non-vested restricted stock units 95,238 30,938 Total 9,529,611 9,370,466

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Product Revenues Net product revenues for the three months ended March 31, 2021 and 2020 were generated from sales of Rhopressa ® and Rocklatan ® , the Company’s glaucoma franchise products, which were commercially launched in the United States in April 2018 and May 2019, respectively. Aerie’s customers include a limited number of national and select regional wholesalers (the “distributors”). For the three months ended March 31, 2021, three distributors accounted for 36%, 30% and 33% of total revenues, respectively. For the three months ended March 31, 2020, three distributors accounted for 37%, 33% and 28% of total revenues, respectively. Product affordability for the patient drives consumer acceptance, and this is generally managed through coverage by third-party payers, such as government or private healthcare insurers and pharmacy benefit managers (“Third-party Payers”) and such product may be subject to rebates and discounts payable directly to those Third-party Payers. Product revenue is recorded net of trade discounts, allowances, rebates, chargebacks, estimated returns and other incentives, discussed below. These reserves are classified as either reductions of accounts receivable or as current liabilities. Amounts billed or invoiced are included in accounts receivable, net on the condensed consolidated balance sheets. The Company did not have any contract assets (unbilled receivables) as of March 31, 2021 or December 31, 2020, as customer invoicing generally occurs before or at the time of revenue recognition. The Company did not have any contract liabilities as of March 31, 2021 or December 31, 2020, as the Company did not receive payments in advance of fulfilling its performance obligations to its customers. The Company calculates its net product revenue based on the wholesale acquisition cost that the Company charges its distributors for Rhopressa ® and Rocklatan ® less provisions for (i) trade discounts and allowances, such as discounts for prompt payment and distributor fees, (ii) estimated rebates to Third-party Payers, estimated payments for Medicare Part D prescription drug program coverage gap (commonly called the “donut hole”), patient co-pay program coupon utilization, chargebacks and other discount programs and (iii) reserves for expected product returns. Provisions for revenue reserves reduced product reve nues by $50.8 million and $43.6 million in aggregate for the three months ended March 31, 2021 and 2020, respectively, a significant portion of which related to commercial and Medicare Part D rebates. Trade Discounts and Allowances : The Company generally provides discounts on sales of Rhopressa ® and Rocklatan ® to its distributors for prompt payment and pays fees for distribution services and for certain data that distributors provide to the Company. The Company expects its distributors to earn these discounts and fees, and accordingly deducts the full amount of these discounts and fees from its gross product revenues at the time such revenues are recognized. Rebates, Chargebacks and Other Discounts : The Company contracts with Third-party Payers for coverage and reimbursement of Rhopressa ® and Rocklatan ® . The Company estimates the rebates and chargebacks it expects to be obligated to provide to Third-party Payers and deducts these estimated amounts from its gross product revenue at the time the revenue is recognized. The Company estimates the rebates and chargebacks that it expects to be obligated to provide to Third-party Payers based upon (i) the Company's contracts and negotiations with these Third-party Payers, (ii) estimates regarding the payer mix for Rhopressa ® and Rocklatan ® based on third-party data and utilization, (iii) inventory held by distributors and (iv) estimates of inventory held at the retail channel. Other discounts include the Company’s co-pay assistance coupon programs for commercially-insured patients meeting certain eligibility requirements. The calculation of the accrual for co-pay assistance is based on an estimate of claims and the cost per claim that the Company expects to pay associated with product that has been recognized as revenue. Product Returns : The Company estimates the amount of Rhopressa ® and Rocklatan ® that will be returned and deducts these estimated amounts from its gross revenue at the time the revenue is recognized. The Company currently estimates product returns based on historical information regarding returns of Rhopressa ® and Rocklatan ® as well as historical industry information regarding rates for comparable pharmaceutical products and product portfolios, the estimated remaining shelf life of Rhopressa ® and Rocklatan ® shipped to distributors, and contractual agreements with the Company's distributors intended to limit the amount of inventory they maintain. Reporting from the distributors includes distributor sales and inventory held by distributors, which provides the Company with visibility into the distribution channel to determine when the product would be eligible to be returned. Santen Collaboration and License Agreement In October 2020, Aerie Ireland Limited entered into a Collaboration and License Agreement with Santen Pharmaceutical Co., Ltd., a Japanese pharmaceutical company dedicated to ophthalmology that carries out research, development, marketing and sales of pharmaceuticals, over-the-counter products and medical devices. Pursuant to the Santen Agreement, Aerie Ireland Limited granted to Santen the exclusive right to develop, manufacture, market and commercialize Rhopressa ® and Rocklatan ® (the “Licensed Products”) in Japan, South Korea, Indonesia, Malaysia, Philippines, Singapore, Thailand, Vietnam and Taiwan (such jurisdictions collectively, the “Territories”). The Company is the sole manufacturer of the Licensed Products for Santen. Under the Santen Agreement, Aerie Ireland Limited granted Santen a first right of negotiation for the rights to the Licensed Products in any Asian countries other than the Territories. Under the Santen Agreement, Santen made an upfront payment to Aerie Ireland Limited of $50.0 million (the “Upfront Payment”) and Aerie Ireland Limited will earn various development milestones of up to $39.0 million and sales milestones of up to $60.0 million upon the achievement of certain events. In addition, Santen will pay Aerie Ireland Limited a royalty in excess of 25% of the Licensed Products’ net sales, such consideration consisting of the cost of products supplied to Santen from Aerie Ireland Limited and a royalty for the Company’s intellectual property. Santen will be responsible for sales, marketing and pricing decisions relating to the Licensed Products. Santen is also responsible for all development and commercialization costs and activities related to the Licensed Products in the Territories, except that Aerie Ireland Limited shares 50% of the costs related to conducting the first Rhopressa ® Phase 3 clinical trial in Japan, which commenced in the fourth quarter of 2020. The term of the Santen Agreement varies on a country-by-country basis in the Territory until the later of (i) the expiration of the last to expire valid patent claim covering the Licensed Product and (ii) 12 years from the date of the first commercial sale of each Licensed Products under a New Drug Application approval, marketing authorization or the equivalent. The Santen Agreement may be terminated by either Aerie Ireland Limited or Santen upon the other party’s material breach or bankruptcy or insolvency. Aerie Ireland Limited may also terminate the Santen Agreement upon a patent challenge by Santen, and Santen may terminate the Santen Agreement in its discretion if, following marketing authorization for Rhopressa ® in Japan, Santen reasonably determines that the Licensed Products are not commercially viable in the Territory (effective upon 180 days’ prior written notice). In addition, in the event that patents are issued that may prevent the commercialization of the Licensed Products, Santen would have the right to terminate the Santen Agreement and require Aerie Ireland Limited’s repayment of up to approximately 85% of the Upfront Payment, all development milestone payments and 50% of the development expenses incurred by Santen. In the event of termination, the Licensed Products in the applicable Territories will revert to the Company. Deferred revenue, non-current as of March 31, 2021 and December 31, 2020 was $51.6 million and $50.9 million, respectively, and included the Upfront Payment as well as Santen’s portion of shared costs related to conducting the first Rhopressa ® Phase 3 clinical trial in Japan, which commenced in the fourth quarter of 2020. While the Company determined that the license was a right to use the Company’s intellectual property and as of the effective date of the Santen Agreement, the Company had provided all necessary information to Santen to benefit from the license and the license term had begun, revenue was not recognized upon satisfaction of the performance obligation due to the uncertainty around potential termination in the event that patents are issued that may prevent the commercialization of the Licensed Products. The Company will recognize the Upfront Payment, and any other potential future development milestones and sales milestones, when it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. The Company will re-evaluate the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur.

Investments

Investments	3 Months Ended
	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Investments	Investments Cash, cash equivalents and investments as of March 31, 2021 included the following: (in thousands) AMORTIZED GROSS GROSS FAIR Cash and cash equivalents: Cash and cash equivalents $ 122,695 $ 122,695 Total cash and cash equivalents $ 122,695 $ — $ — $ 122,695 Investments: Commercial paper (due within 1 year) $ 42,942 $ 1 $ (41) $ 42,902 Corporate bonds (due within 1 year) 42,631 — (24) 42,607 Total investments $ 85,573 $ 1 $ (65) $ 85,509 Total cash, cash equivalents and investments $ 208,268 $ 1 $ (65) $ 208,204 Cash, cash equivalents and investments as of December 31, 2020 included the following: GROSS GROSS AMORTIZED UNREALIZED UNREALIZED FAIR (in thousands) COST GAINS LOSSES VALUE Cash and cash equivalents: Cash and cash equivalents $ 151,570 $ — $ — $ 151,570 Total cash and cash equivalents $ 151,570 $ — $ — $ 151,570 Investments: Commercial paper (due within 1 year) 44,122 5 (23) 44,104 Corporate bonds (due within 1 year) 44,724 3 (37) 44,690 Total investments $ 88,846 $ 8 $ (60) $ 88,794 Total cash, cash equivalents and investments $ 240,416 $ 8 $ (60) $ 240,364 Interest income earned on the Company’s cash, cash equivalents and investments was $0.1 million and $1.1 million for the three months ended March 31, 2021 and 2020, respectively. Realized gains or losses were immaterial during the three months ended March 31, 2021 and 2020. As of March 31, 2021, the Company had no equity securities. As of December 31, 2020, the fair value of the equity securities held at the end of the period was $1.3 million. For the three months ended March 31, 2021, the Company had $1.0 million of losses on equity securities sold during the period.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following tables summarize the fair value of financial assets and liabilities that are measured at fair value and the classification by level of input within the fair value hierarchy: FAIR VALUE MEASUREMENTS AS OF MARCH 31, 2021 (in thousands) LEVEL 1 LEVEL 2 LEVEL 3 TOTAL Cash and cash equivalents: Cash and cash equivalents $ 122,695 $ 122,695 Total cash and cash equivalents: $ 122,695 $ — $ — $ 122,695 Investments: Commercial paper $ 42,902 42,902 Corporate bonds 42,607 42,607 Total investments $ — $ 85,509 $ — $ 85,509 Total cash, cash equivalents and investments: $ 122,695 $ 85,509 $ — $ 208,204 FAIR VALUE MEASUREMENTS AS OF DECEMBER 31, 2020 (in thousands) LEVEL 1 LEVEL 2 LEVEL 3 TOTAL Cash and cash equivalents: Cash and cash equivalents $ 151,570 $ — $ — $ 151,570 Total cash and cash equivalents: $ 151,570 $ — $ — $ 151,570 Investments: Commercial paper $ — $ 44,104 $ — $ 44,104 Corporate bonds — 44,690 — 44,690 Total investments $ — $ 88,794 $ — $ 88,794 Total cash, cash equivalents and investments: $ 151,570 $ 88,794 $ — $ 240,364 The fair value of the Convertible Notes, which differs from their carrying value, is influenced by interest rates, stock price and stock price volatility and is determined by prices observed in market trading. The market for trading of the Convertible Notes is not considered to be an active market and therefore the estimate of fair value is based on Level 2 inputs. The estimated fair value of the Convertible Notes was $332.9 million at March 31, 2021. There were no transfers between the different levels of the fair value hierarchy during the three months ended March 31, 2021 and 2020.

Inventory

Inventory	3 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory consists of the following: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Raw materials $ 2,695 $ 1,875 Work-in-process 22,365 21,648 Finished goods 3,264 3,536 Total inventory $ 28,324 $ 27,059 For the three months ended March 31, 2021 and 2020, $4.4 million and $3.5 million, respectively, of idle capacity cost associated with the Company’s Athlone manufacturing plant was recorded to costs of goods sold. The idle capacity results from the manufacturing plant having commenced operations earlier in 2020 and not having yet reached full capacity.

Property, Plant and Equipment,

Property, Plant and Equipment, Net	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net Property, plant and equipment, net consists of the following: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Manufacturing equipment $ 21,822 $ 21,705 Laboratory equipment 8,391 7,948 Furniture and fixtures 1,681 1,681 Software, computer and other equipment 7,838 7,836 Leasehold improvements 30,433 30,178 Construction-in-progress 1,243 1,481 Property, plant and equipment 71,408 70,829 Less: Accumulated depreciation (18,125) (16,569) Property, plant and equipment, net $ 53,283 $ 54,260

Leases

Leases	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Leases	Leases The Company has operating leases for corporate offices, research and development facilities, and a fleet of vehicles. The properties primarily relate to the Company’s principal executive office and research facility located in Durham, North Carolina, regulatory, commercial support and other administrative activities located in Irvine, California, and clinical, finance and legal operations located in Bedminster, New Jersey. The Durham, North Carolina, facility consists of approximately 61,000 square feet of laboratory and office space under leases that expire between January 2022 and June 2024 and the Irvine, California, location consists of approximately 37,300 square feet of office space under a lease that expires in January 2022. The Bedminster, New Jersey, location consists of approximately 34,000 square feet of office space under a lease that expires in October 2029. There are also small offices in Ireland, the United Kingdom and Japan. The Company is leasing approximately 30,000 square feet of interior floor space for its manufacturing plant in Athlone, Ireland. The Company is reasonably certain it will remain in the lease through the end of its lease term in 2037, however, the Company is permitted to terminate the lease as early as September 2027. The Company’s operating leases have remaining lease terms of approximately 1 year to 16 years, some of which include options to extend the leases. Balance sheet information related to leases was as follows: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Operating Leases Operating lease right-of-use assets $ 13,241 $ 14,084 Operating lease liabilities $ 4,052 $ 4,923 Long-term operating lease liabilities 9,914 10,206 Total operating lease liabilities $ 13,966 $ 15,129

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2021
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Accrued expenses and other current liabilities: Accrued compensation and benefits $ 9,653 $ 15,207 Accrued consulting and professional fees 3,215 2,645 Accrued research and development (1) 3,821 2,222 Accrued revenue reserves (2) 61,472 66,552 Accrued other (3) 4,631 4,097 Total accrued expenses and other current liabilities $ 82,792 $ 90,723 (1) Comprised primarily of accruals related to fees for investigative sites, contract research organizations and other service providers that assist in conducting preclinical research studies and clinical trials. (2) Comprised primarily of accruals related to commercial and government rebates as well as returns. (3) Comprised primarily of accruals related to interest payable as well as other business-related expenses.

Debt

Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Debt	Debt Convertible Notes In September 2019, the Company issued an aggregate principal amount of $316.25 million of Convertible Notes to qualified institutional buyers pursuant to Rule 144A of the Securities Act of 1933, as amended. The Convertible Notes, governed by an indenture between the Company and a trustee, are senior, unsecured obligations and do not include financial and operating covenants nor any restrictions on the payments of dividends, the incurrence of indebtedness or the issuance or repurchase of securities by Aerie or any of its subsidiaries. Interest on the Convertible Notes is payable semi-annually in cash in arrears at a rate of 1.50% per annum on April 1 and October 1 of each year, which began on April 1, 2020. The Convertible Notes will mature on October 1, 2024 unless they are redeemed, repurchased or converted prior to such date. Prior to April 1, 2024, the Convertible Notes will be convertible at the option of holders only during certain periods and upon satisfaction of certain conditions. On and after April 1, 2024, the Convertible Notes will be convertible at the option of the holders any time until the close of business on the second scheduled trading day immediately preceding the maturity date. Upon conversion, the Convertible Notes may be settled in shares of Aerie common stock, cash or a combination, thereof, at the Company's election. The Company intends to settle the principal and interest amounts of the Convertible Notes in cash, and therefore, the Company currently would not expect the conversion to have a dilutive effect on the Company’s earnings per share, as applicable. However, the Company is currently evaluating the impact of ASU 2020-06 on its consolidated financial statements and disclosures, in which the Company will soon no longer be eligible to use the treasury stock method to reflect the shares underlying the Convertible Notes in the Company’s dilutive earnings per share. See Note 2 for additional information. The Convertible Notes have an initial conversion rate of 40.04 shares of Aerie common stock per $1,000 principal amount of the Convertible Notes, which will be subject to customary anti-dilution adjustments in certain circumstances. This represents an initial effective conversion price of approximately $24.98 per share, which represents a premium of approximately 35% to the $18.50 per share closing price of Aerie common stock on September 4, 2019, the date the Company priced the offering. The Company may redeem all or any portion of the Convertible Notes, at its option, on or after October 3, 2022, at a cash redemption price equal to 100% of the principal amount of the Convertible Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, but only if the last reported sale price of Aerie common stock exceeds 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately before the date the Company provides written notice of redemption; and the trading day immediately before the notice is sent. Holders of Convertible Notes may require the Company to repurchase their Convertible Notes upon the occurrence of certain events that constitute a fundamental change under the indenture governing the Convertible Notes at a fundamental change repurchase price equal to 100% of the principal amount thereof, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. During the three months ended March 31, 2021, the conditions allowing holders of the Convertible Notes to elect to convert had not been met. As of March 31, 2021, the if-converted value of the Convertible Notes did not exceed the principal amount of the Convertible Notes. The estimated fair value of the liability component of the Convertible Notes at the time of issuance was $187.9 million, and was determined based on a discounted cash flow analysis and a binomial lattice model. The valuation required the use of Level 3 unobservable inputs and subjective assumptions, including but not limited to the stock price volatility and bond yield. The effective interest rate on the liability component was 10.5% for the period from the date of issuance through March 31, 2021. The equity component of the Convertible Notes was recognized at issuance and represents the difference between the principal amount of the Convertible Notes and the fair value of the liability component of the Convertible Notes at issuance. The equity component was approximately $128.4 million at the time of issuance and its fair value is not remeasured as long as it continues to meet the conditions for equity classification. In connection with the issuance of the Convertible Notes, the Company incurred debt issuance costs of $9.2 million for the three months ended December 31, 2019. In accordance with ASC Topic 470, Debt , these costs were allocated to debt and equity components in proportion to the allocation of proceeds. Issuance costs of $5.5 million were recorded as debt issuance costs in the net carrying value of Convertible Notes. The debt issuance costs are amortized on an effective interest basis over the term of the Convertible Notes. The remaining issuance costs of $3.7 million were recorded as additional paid-in capital, net with the equity component and such amounts are not subject to amortization. The following table summarizes the carrying value of the Convertible Notes as of March 31, 2021: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Gross proceeds $ 316,250 $ 316,250 Unamortized debt discount (96,083) (101,565) Unamortized issuance costs (4,079) (4,312) Carrying value $ 216,088 $ 210,373 The following table summarizes the interest expense recognized related to the Convertible Notes: THREE MONTHS ENDED (in thousands) 2021 2020 Stated interest $ 1,186 $ 1,193 Amortized debt discount 5,482 4,971 Amortized issuance costs 232 211 Interest Expense $ 6,900 $ 6,375 Separately, in September 2019 the Company entered into privately negotiated capped call options with financial institutions. The capped call options cover, subject to customary anti-dilution adjustments, the number of shares of Aerie common stock that initially underlie the Convertible Notes. The cap price of the capped call options is $37.00 per share of Aerie common stock, representing a premium of 100% above the closing price of $18.50 per share of Aerie common stock on September 4, 2019, and is subject to certain adjustments under the terms of the capped call options. The capped call options are generally intended to reduce or offset potential dilution to Aerie common stock upon conversion of the Convertible Notes with such reduction and/ or offset, as the case may be, subject to a cap based on the cap price. The Company paid a total of $32.9 million in premiums for the capped call options, which was recorded as additional paid-in capital, using a portion of the gross proceeds from the issuance and sale of the Convertible Notes. The capped call options are excluded from diluted earnings per share because the impact would be anti-dilutive.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense for options granted, restricted stock awards (“RSAs”), RSAs with non-market performance and service conditions (“PSAs”), restricted stock units (“RSUs”) and stock appreciation rights (“SARs”) is reflected in the condensed consolidated statements of operations and comprehensive loss as follows: THREE MONTHS ENDED (in thousands) 2021 2020 Cost of goods sold $ 507 $ 497 Selling, general and administrative 6,255 6,908 Pre-approval commercial manufacturing — 294 Research and development 1,987 2,830 Total $ 8,749 $ 10,529 Equity Plans The Company maintains three equity compensation plans, the 2005 Aerie Pharmaceutical Stock Plan (the “2005 Plan”), the 2013 Omnibus Incentive Plan (the “2013 Equity Plan”), which was amended and restated as the Aerie Pharmaceuticals, Inc. Second Amended and Restated Omnibus Incentive Plan (the “Second Amended and Restated Equity Plan”), as described below, and the Aerie Pharmaceuticals, Inc. Inducement Award Plan (the “Inducement Award Plan”), as described below. The 2005 Plan, the Second Amended and Restated Equity Plan and the Inducement Award Plan are referred to collectively as the “Plans.” The 2005 Plan was frozen in 2013 and no additional awards have been or will be made under the 2005 Plan. On June 7, 2018, Aerie’s stockholders approved the adoption of the Second Amended and Restated Equity Plan to increase the number of shares issuable under the Plan by 4,500,000. The Second Amended and Restated Equity Plan provides for the granting of up to 10,229,068 equity awards in respect of Aerie common stock. On December 7, 2016, Aerie’s Board of Directors approved the Inducement Award Plan which provides for the granting of up to 418,000 equity awards in respect of common stock of Aerie and was subsequently amended during the year ended December 31, 2017 to increase the equity awards that may be issued by an additional 874,500 shares. On December 5, 2019, the Inducement Award Plan was further amended by the Company’s Board of Directors to increase the number of shares issuable under the plan by 100,000 shares. Awards granted under the Inducement Award Plan are intended to qualify as employment inducement awards under NASDAQ Listing Rule 5635(c)(4). Options to Purchase Common Stock The following table summarizes the stock option activity under the Plans: NUMBER OF WEIGHTED AVERAGE WEIGHTED AGGREGATE Options outstanding at December 31, 2020 8,588,614 $ 27.36 Granted 421,280 17.50 Exercised (63,370) 0.76 Canceled (226,156) 38.78 Options outstanding at March 31, 2021 8,720,368 $ 26.78 5.9 $ 23,551 Options exercisable at March 31, 2021 6,464,439 $ 26.66 4.9 $ 21,828 As of March 31, 2021, the Company had $39.2 million of unrecognized compensation expense related to options granted under its equity plans. This expense is expected to be recognized over a weighted average period of 2.1 years as of March 31, 2021. Restricted Stock Awards The following table summarizes the RSA, including PSA, activity under the Plans: NUMBER OF WEIGHTED AVERAGE Non-vested RSAs at December 31, 2020 809,527 $ 29.03 Granted 94,132 17.61 Vested (160,259) 44.62 Canceled (29,395) 23.86 Non-vested RSAs at March 31, 2021 714,005 $ 24.23 As of March 31, 2021, the Company had $15.0 million of unrecognized compensation expense related to unvested RSAs. This expense is expected to be recognized over the weighted average period of 2.4 years as of March 31, 2021. The vesting of the RSAs is time and service based with terms of one Restricted Stock Units The following table summarizes the RSU activity under the Plans: NUMBER OF WEIGHTED AVERAGE Non-vested RSUs at December 31, 2020 107,182 $ 14.43 Granted 1,407 19.18 Vested (11,035) 19.25 Canceled (2,316) 14.34 Non-vested RSUs at March 31, 2021 95,238 $ 13.95 As of March 31, 2021, the associated unrecognized compensation expense totaled $2.1 million. This expense is expected to be recognized over the weighted average period of 2.6 years as of March 31, 2021. Stock Appreciation Rights The following table summarizes the SAR activity under the Plans: NUMBER OF WEIGHTED AVERAGE WEIGHTED AGGREGATE SARs outstanding at December 31, 2020 212,044 $ 32.28 Granted 5,000 18.68 Canceled (13,801) 28.43 SARs outstanding at March 31, 2021 203,243 $ 32.20 3.3 $ 280 SARs exercisable at March 31, 2021 66,546 $ 45.16 2.5 $ 3 Holders of the SARs are entitled under the terms of the Plans to receive cash payments calculated based on the excess of Aerie’s common stock price over the exercise price in their award; consequently, these awards are accounted for as liability-classified awards and the Company measures compensation cost based on their estimated fair value at each reporting date, net of actual forfeitures, if any.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and ContingenciesThe Company may periodically become subject to legal proceedings and claims arising in connection with its business. The Company is not a party to any known litigation, is not aware of any material unasserted claims and does not have contingency reserves established for any litigation liabilities.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). In the opinion of management, the Company has made all necessary adjustments, which include normal recurring adjustments necessary for a fair statement of the Company’s condensed consolidated financial position and results of operations for the interim periods presented. Certain information and disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes for the year ended December 31, 2020 included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on February 26, 2021. The results for the three months ended March 31, 2021 are not necessarily indicative of the results to be expected for a full year, any other interim periods or any future year or period.
Principles of Consolidation	Principles of Consolidation The interim condensed consolidated financial statements include the accounts of Aerie and its wholly-owned subsidiaries. All intercompany accounts, transactions and profits have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of condensed consolidated 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 condensed consolidated financial statements and reported amounts of income and expenses during the reporting periods. Significant items subject to such estimates and assumptions include revenue recognition, acquisitions, stock-based compensation and fair value measurements. On March 11, 2020, the World Health Organization declared the coronavirus (“COVID-19”) outbreak a pandemic. The full extent to which COVID-19 will directly or indirectly impact the Company’s business, results of operations and financial condition, including net product revenue, cost and expenses, reserves and allowances, manufacturing and clinical trials, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat it, as well as the economic impact on eye-care professionals, patients, third parties and markets. Actual results could differ from the Company’s estimates.
Adoption of New Accounting Standards and Recent Accounting Pronouncements	Adoption of New Accounting Standards In December 2019, the Financial Accounting Standards Board (“FASB”) issued 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 guidance was effective for the Company beginning on January 1, 2021 and prescribes different transition methods for the various provisions. The adoption of ASU 2019-12 did not have a material impact on the Company’s consolidated financial statements and disclosures. Recent Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”) to address the complexity associated with applying GAAP to certain financial instruments with characteristics of liabilities and equity. This ASU includes amendments to the guidance on convertible instruments and the derivative scope exception for contracts in an entity’s own equity. ASU 2020-06 also simplifies the accounting for convertible instruments, which includes eliminating the cash conversion accounting model for convertible instruments. Additionally, ASU 2020-06 will require entities to use the “if-converted” method when calculating diluted earnings per share for convertible instruments. The guidance is effective for the Company beginning on January 1, 2022 and prescribes different transition methods for the various provisions. The Company is currently evaluating the impact of ASU 2020-06 on its consolidated financial statements and disclosures.
Net Loss per Common Share	Net Loss per Common Share Basic net loss per common share (“Basic EPS”) is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share (“Diluted EPS”) gives effect to all dilutive potential shares of common stock outstanding during this period. For Diluted EPS, net loss used in calculating Basic EPS may be adjusted for certain items related to the dilutive securities. For all periods presented, Aerie’s potential common stock equivalents have been excluded from the computation of Diluted EPS as their inclusion would have had an anti-dilutive effect.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Schedule of Computation of Diluted EPS	The potential common stock equivalents that have been excluded from the computation of Diluted EPS consist of the following: THREE MONTHS ENDED 2021 2020 Outstanding stock options 8,720,368 8,701,163 Stock purchase warrants — 4,500 Non-vested restricted stock awards and performance share units 714,005 633,865 Non-vested restricted stock units 95,238 30,938 Total 9,529,611 9,370,466

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of Cash, Cash Equivalents and Investments	Cash, cash equivalents and investments as of March 31, 2021 included the following: (in thousands) AMORTIZED GROSS GROSS FAIR Cash and cash equivalents: Cash and cash equivalents $ 122,695 $ 122,695 Total cash and cash equivalents $ 122,695 $ — $ — $ 122,695 Investments: Commercial paper (due within 1 year) $ 42,942 $ 1 $ (41) $ 42,902 Corporate bonds (due within 1 year) 42,631 — (24) 42,607 Total investments $ 85,573 $ 1 $ (65) $ 85,509 Total cash, cash equivalents and investments $ 208,268 $ 1 $ (65) $ 208,204 Cash, cash equivalents and investments as of December 31, 2020 included the following: GROSS GROSS AMORTIZED UNREALIZED UNREALIZED FAIR (in thousands) COST GAINS LOSSES VALUE Cash and cash equivalents: Cash and cash equivalents $ 151,570 $ — $ — $ 151,570 Total cash and cash equivalents $ 151,570 $ — $ — $ 151,570 Investments: Commercial paper (due within 1 year) 44,122 5 (23) 44,104 Corporate bonds (due within 1 year) 44,724 3 (37) 44,690 Total investments $ 88,846 $ 8 $ (60) $ 88,794 Total cash, cash equivalents and investments $ 240,416 $ 8 $ (60) $ 240,364

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value Measurements	The following tables summarize the fair value of financial assets and liabilities that are measured at fair value and the classification by level of input within the fair value hierarchy: FAIR VALUE MEASUREMENTS AS OF MARCH 31, 2021 (in thousands) LEVEL 1 LEVEL 2 LEVEL 3 TOTAL Cash and cash equivalents: Cash and cash equivalents $ 122,695 $ 122,695 Total cash and cash equivalents: $ 122,695 $ — $ — $ 122,695 Investments: Commercial paper $ 42,902 42,902 Corporate bonds 42,607 42,607 Total investments $ — $ 85,509 $ — $ 85,509 Total cash, cash equivalents and investments: $ 122,695 $ 85,509 $ — $ 208,204 FAIR VALUE MEASUREMENTS AS OF DECEMBER 31, 2020 (in thousands) LEVEL 1 LEVEL 2 LEVEL 3 TOTAL Cash and cash equivalents: Cash and cash equivalents $ 151,570 $ — $ — $ 151,570 Total cash and cash equivalents: $ 151,570 $ — $ — $ 151,570 Investments: Commercial paper $ — $ 44,104 $ — $ 44,104 Corporate bonds — 44,690 — 44,690 Total investments $ — $ 88,794 $ — $ 88,794 Total cash, cash equivalents and investments: $ 151,570 $ 88,794 $ — $ 240,364

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consists of the following: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Raw materials $ 2,695 $ 1,875 Work-in-process 22,365 21,648 Finished goods 3,264 3,536 Total inventory $ 28,324 $ 27,059

Property, Plant and Equipment_2

Property, Plant and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, plant and equipment, net consists of the following: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Manufacturing equipment $ 21,822 $ 21,705 Laboratory equipment 8,391 7,948 Furniture and fixtures 1,681 1,681 Software, computer and other equipment 7,838 7,836 Leasehold improvements 30,433 30,178 Construction-in-progress 1,243 1,481 Property, plant and equipment 71,408 70,829 Less: Accumulated depreciation (18,125) (16,569) Property, plant and equipment, net $ 53,283 $ 54,260

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Schedule of Operating Lease Assets And Liabilities	Balance sheet information related to leases was as follows: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Operating Leases Operating lease right-of-use assets $ 13,241 $ 14,084 Operating lease liabilities $ 4,052 $ 4,923 Long-term operating lease liabilities 9,914 10,206 Total operating lease liabilities $ 13,966 $ 15,129

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Accrued expenses and other current liabilities: Accrued compensation and benefits $ 9,653 $ 15,207 Accrued consulting and professional fees 3,215 2,645 Accrued research and development (1) 3,821 2,222 Accrued revenue reserves (2) 61,472 66,552 Accrued other (3) 4,631 4,097 Total accrued expenses and other current liabilities $ 82,792 $ 90,723 (1) Comprised primarily of accruals related to fees for investigative sites, contract research organizations and other service providers that assist in conducting preclinical research studies and clinical trials. (2) Comprised primarily of accruals related to commercial and government rebates as well as returns. (3) Comprised primarily of accruals related to interest payable as well as other business-related expenses.

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Convertible Debt	The following table summarizes the carrying value of the Convertible Notes as of March 31, 2021: (in thousands) MARCH 31, 2021 DECEMBER 31, 2020 Gross proceeds $ 316,250 $ 316,250 Unamortized debt discount (96,083) (101,565) Unamortized issuance costs (4,079) (4,312) Carrying value $ 216,088 $ 210,373
Schedule of Interest Expense of Convertible Debt	The following table summarizes the interest expense recognized related to the Convertible Notes: THREE MONTHS ENDED (in thousands) 2021 2020 Stated interest $ 1,186 $ 1,193 Amortized debt discount 5,482 4,971 Amortized issuance costs 232 211 Interest Expense $ 6,900 $ 6,375

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense for options granted, restricted stock awards (“RSAs”), RSAs with non-market performance and service conditions (“PSAs”), restricted stock units (“RSUs”) and stock appreciation rights (“SARs”) is reflected in the condensed consolidated statements of operations and comprehensive loss as follows: THREE MONTHS ENDED (in thousands) 2021 2020 Cost of goods sold $ 507 $ 497 Selling, general and administrative 6,255 6,908 Pre-approval commercial manufacturing — 294 Research and development 1,987 2,830 Total $ 8,749 $ 10,529
Schedule of Stock Options Activity	The following table summarizes the stock option activity under the Plans: NUMBER OF WEIGHTED AVERAGE WEIGHTED AGGREGATE Options outstanding at December 31, 2020 8,588,614 $ 27.36 Granted 421,280 17.50 Exercised (63,370) 0.76 Canceled (226,156) 38.78 Options outstanding at March 31, 2021 8,720,368 $ 26.78 5.9 $ 23,551 Options exercisable at March 31, 2021 6,464,439 $ 26.66 4.9 $ 21,828
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	The following table summarizes the RSA, including PSA, activity under the Plans: NUMBER OF WEIGHTED AVERAGE Non-vested RSAs at December 31, 2020 809,527 $ 29.03 Granted 94,132 17.61 Vested (160,259) 44.62 Canceled (29,395) 23.86 Non-vested RSAs at March 31, 2021 714,005 $ 24.23 The following table summarizes the RSU activity under the Plans: NUMBER OF WEIGHTED AVERAGE Non-vested RSUs at December 31, 2020 107,182 $ 14.43 Granted 1,407 19.18 Vested (11,035) 19.25 Canceled (2,316) 14.34 Non-vested RSUs at March 31, 2021 95,238 $ 13.95
Schedule of Stock Appreciation Rights	The following table summarizes the SAR activity under the Plans: NUMBER OF WEIGHTED AVERAGE WEIGHTED AGGREGATE SARs outstanding at December 31, 2020 212,044 $ 32.28 Granted 5,000 18.68 Canceled (13,801) 28.43 SARs outstanding at March 31, 2021 203,243 $ 32.20 3.3 $ 280 SARs exercisable at March 31, 2021 66,546 $ 45.16 2.5 $ 3

The Company (Details)

The Company (Details)	3 Months Ended
	Mar. 31, 2021Segmentproduct	Oct. 31, 2020USD ($)	Sep. 30, 2019USD ($)
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Number of operating segments | Segment	1
Number of FDA approved products | product	2
Collaborative Arrangement
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Upfront payment receivable		$ 50,000,000
Convertible notes
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Principal amount			$ 316,250,000
Interest rate			1.50%

Significant Accounting Polici_4

Significant Accounting Policies - Antidilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	9,529,611	9,370,466
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	8,720,368	8,701,163
Stock purchase warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	0	4,500
Non-vested restricted stock awards and performance share units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	714,005	633,865
Non-vested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	95,238	30,938

Revenue Recognition (Details)

Revenue Recognition (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Oct. 31, 2020USD ($)Segment	Mar. 31, 2021USD ($)distributor	Mar. 31, 2020USD ($)distributor	Dec. 31, 2020USD ($)
Disaggregation of Revenue [Line Items]
Provisions for revenue reserves to reduce product revenues to product revenues, net		$ 50,800	$ 43,600
Deferred revenue, non-current		$ 51,605		$ 50,858
Collaborative Arrangement
Disaggregation of Revenue [Line Items]
Upfront payment receivable	$ 50,000
Contingent payments receivable upon achievement of development and regulatory milestones (up to)	39,000
Contingent payments receivable upon achievement of commercial milestones (up to)	$ 60,000
Royalty percentage (in excess of)	25.00%
Company's share of clinical trial costs, percentage	50.00%
Collaborative agreement expiration, period after first commercial sale of product	12 years
Collaborative agreement, termination by counterparty, effective after written notice period | Segment	180
Repayment of upfront payment upon termination, percentage	85.00%
Reimbursement of development expenses upon termination, percentage	50.00%
Customer Concentration Risk | Sales Revenue, Net | Rhopressa and Rocklatan
Disaggregation of Revenue [Line Items]
Number of distributors | distributor		3	3
Customer Concentration Risk | Sales Revenue, Net | Rhopressa and Rocklatan | Distributor One
Disaggregation of Revenue [Line Items]
Concentration risk percentage		36.00%	37.00%
Customer Concentration Risk | Sales Revenue, Net | Rhopressa and Rocklatan | Distributor Two
Disaggregation of Revenue [Line Items]
Concentration risk percentage		30.00%	33.00%
Customer Concentration Risk | Sales Revenue, Net | Rhopressa and Rocklatan | Distributor Three
Disaggregation of Revenue [Line Items]
Concentration risk percentage		33.00%	28.00%

Investments - Summary of Cash,

Investments - Summary of Cash, Cash Equivalents and Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Cash and cash equivalents:
AMORTIZED COST	$ 122,695	$ 151,570	$ 134,179	$ 143,940
GROSS UNREALIZED GAINS	0	0
GROSS UNREALIZED LOSSES	0	0
FAIR VALUE	122,695	151,570
Investments:
AMORTIZED COST	85,573	88,846
GROSS UNREALIZED GAINS	1	8
GROSS UNREALIZED LOSSES	(65)	(60)
FAIR VALUE	85,509	88,794
Total cash, cash equivalents and investments, Amortized Cost	208,268	240,416
Total cash, cash equivalents and investments, Gross Unrealized Gains	1	8
Total cash, cash equivalents and investments, Gross Unrealized Losses	(65)	(60)
Total cash, cash equivalents and investments, Fair Value	208,204	240,364
Cash and cash equivalents
Cash and cash equivalents:
AMORTIZED COST	122,695	151,570
GROSS UNREALIZED GAINS		0
GROSS UNREALIZED LOSSES		0
FAIR VALUE	122,695	151,570
Commercial paper (due within 1 year)
Investments:
AMORTIZED COST	42,942	44,122
GROSS UNREALIZED GAINS	1	5
GROSS UNREALIZED LOSSES	(41)	(23)
FAIR VALUE	42,902	44,104
Corporate bonds (due within 1 year)
Investments:
AMORTIZED COST	42,631	44,724
GROSS UNREALIZED GAINS	0	3
GROSS UNREALIZED LOSSES	(24)	(37)
FAIR VALUE	$ 42,607	$ 44,690

Investments - Additional Inform

Investments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Interest income	$ 100,000	$ 1,100,000
Fair value	0		$ 1,300,000
Investment losses on equity securities	$ 1,000,000

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 122,695	$ 151,570
Debt securities, available-for-sale	85,509	88,794
Total investments	85,509	88,794
Total cash, cash equivalents and investments	208,204	240,364
LEVEL 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	122,695	151,570
Total investments	0	0
Total cash, cash equivalents and investments	122,695	151,570
LEVEL 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Total investments	85,509	88,794
Total cash, cash equivalents and investments	85,509	88,794
LEVEL 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Total investments	0	0
Total cash, cash equivalents and investments	0	0
Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	122,695	151,570
Cash and cash equivalents | LEVEL 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	122,695	151,570
Cash and cash equivalents | LEVEL 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		0
Cash and cash equivalents | LEVEL 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	42,902	44,104
Commercial paper | LEVEL 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale		0
Commercial paper | LEVEL 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	42,902	44,104
Commercial paper | LEVEL 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale		0
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	42,607	44,690
Corporate bonds | LEVEL 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale		0
Corporate bonds | LEVEL 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale	42,607	44,690
Corporate bonds | LEVEL 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available-for-sale		$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Millions	Mar. 31, 2021USD ($)
LEVEL 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Estimated fair value of the convertible notes	$ 332.9

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 2,695		$ 1,875
Work-in-process	22,365		21,648
Finished goods	3,264		3,536
Total inventory	28,324		$ 27,059
Idle capacity	$ 4,400	$ 3,500

Property, Plant and Equipment_3

Property, Plant and Equipment, Net - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 71,408	$ 70,829
Less: Accumulated depreciation	(18,125)	(16,569)
Property, plant and equipment, net	53,283	54,260
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	21,822	21,705
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,391	7,948
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,681	1,681
Software, computer and other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7,838	7,836
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	30,433	30,178
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,243	$ 1,481

Leases - Narrative (Details)

Leases - Narrative (Details)	3 Months Ended
	Mar. 31, 2021ft²
Minimum
Operating Leased Assets [Line Items]
Term of contract	1 year
Maximum
Operating Leased Assets [Line Items]
Term of contract	16 years
North Carolina
Operating Leased Assets [Line Items]
Area of interior floor space (in sqft)	61,000
California
Operating Leased Assets [Line Items]
Area of interior floor space (in sqft)	37,300
New Jersey
Operating Leased Assets [Line Items]
Area of interior floor space (in sqft)	34,000
Ireland
Operating Leased Assets [Line Items]
Area of interior floor space (in sqft)	30,000

Leases - Schedule of Operating

Leases - Schedule of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Operating Leases
Operating lease right-of-use assets	$ 13,241	$ 14,084
Operating lease liabilities	4,052	4,923
Long-term operating lease liabilities	9,914	10,206
Total operating lease liabilities	$ 13,966	$ 15,129

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accrued expenses and other current liabilities:
Accrued compensation and benefits	$ 9,653	$ 15,207
Accrued consulting and professional fees	3,215	2,645
Accrued research and development expenses	3,821	2,222
Accrued revenue reserves	61,472	66,552
Accrued other	4,631	4,097
Total accrued expenses and other current liabilities	$ 82,792	$ 90,723

Debt - Convertible Notes (Detai

Debt - Convertible Notes (Details)	Sep. 04, 2019$ / shares	Sep. 30, 2019USD ($)$ / shares$ / unit	Mar. 31, 2021USD ($)d	Dec. 31, 2019USD ($)	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio	0.04004
Debt instrument trading days | d			20
Debt instrument consecutive trading day | d			30
Premiums for capped call options		$ 32,900,000
Call Option
Debt Instrument [Line Items]
Capped price (in dollars per share) | $ / unit		37
Premium of cap price as a percentage of closing price		100.00%
COMMON STOCK
Debt Instrument [Line Items]
Closing stock price (in dollars per share) | $ / shares	$ 18.50	$ 18.50
Convertible notes
Debt Instrument [Line Items]
Principal amount		$ 316,250,000
Interest rate		1.50%
Convertible notes | Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Principal amount			$ 316,250,000		$ 316,250,000
Debt instrument, convertible conversion price (in dollars per share) | $ / shares	$ 24.98
Stock price trigger, premium on closing price (as a percent)	35.00%
Redemption price (as a percent)			100.00%
Stock price trigger (as a percent)			130.00%
Equity component of convertible debt			$ 128,400,000
Debt issuance costs incurred				$ 9,200,000
Debt issuance costs, net			4,079,000	$ 5,500,000	$ 4,312,000
Debt issuance costs related with equity component of convertible debt			3,700,000
Convertible notes | Convertible Senior Notes Due 2024 | LEVEL 3
Debt Instrument [Line Items]
Convertible notes fair value of liability component			$ 187,900,000
Convertible notes fair value of liability component, effective interest rate percentage			10.50%

Debt - Reconciliation of Conver

Debt - Reconciliation of Convertible Debt (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Debt Instrument [Line Items]
Carrying value	$ 216,088,000	$ 210,373,000
Convertible notes
Debt Instrument [Line Items]
Gross proceeds				$ 316,250,000
Convertible Senior Notes Due 2024 | Convertible notes
Debt Instrument [Line Items]
Gross proceeds	316,250,000	316,250,000
Unamortized debt discount	(96,083,000)	(101,565,000)
Unamortized issuance costs	(4,079,000)	(4,312,000)	$ (5,500,000)
Carrying value	$ 216,088,000	$ 210,373,000

Debt - Interest Expense of Conv

Debt - Interest Expense of Convertible Notes (Details) - Convertible notes - Convertible Senior Notes Due 2024 - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Stated interest	$ 1,186	$ 1,193
Amortized debt discount	5,482	4,971
Amortized issuance costs	232	211
Interest Expense	$ 6,900	$ 6,375

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-based Compensation Expense for Options Granted and Restricted Stock as Reflected in the Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 8,749	$ 10,529
Cost of goods sold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	507	497
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	6,255	6,908
Pre-approval commercial manufacturing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	0	294
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,987	$ 2,830

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)planshares	Dec. 31, 2017shares	Dec. 05, 2019shares	Jun. 07, 2018shares	Dec. 07, 2016shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity compensation plans | plan	3
Additional awards granted (in shares)	421,280
Outstanding stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense | $	$ 39.2
Weighted-average remaining vesting period	2 years 1 month 6 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested awards | $	$ 15
Weighted-average of remaining vesting period	2 years 4 months 24 days
Granted (in shares)	94,132
Non-vested shares cancelled and replaced (in shares)	29,395
Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based awards, vesting period	1 year
Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based awards, vesting period	4 years
Restricted Stock With Non-Market Performance Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		98,817
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested awards | $	$ 2.1
Weighted-average of remaining vesting period	2 years 7 months 6 days
Granted (in shares)	1,407
Non-vested shares cancelled and replaced (in shares)	2,316
2005 Aerie Pharmaceutical Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional awards granted (in shares)	0
2013 Omnibus incentive plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards (in shares)	10,229,068			4,500,000
Inducement Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards (in shares)		874,500	100,000		418,000

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock Options Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares
NUMBER OF SHARES
Beginning balance (in shares) | shares	8,588,614
Granted (in shares) | shares	421,280
Exercised (in shares) | shares	(63,370)
Canceled (in shares) | shares	(226,156)
Ending balance (in shares) | shares	8,720,368
Options exercisable (in shares) | shares	6,464,439
WEIGHTED AVERAGE EXERCISE PRICE
Beginning balance (in dollars per share) | $ / shares	$ 27.36
Granted (in dollars per share) | $ / shares	17.50
Exercised (in dollars per share) | $ / shares	0.76
Canceled (in dollars per share) | $ / shares	38.78
Ending balance (in dollars per share) | $ / shares	26.78
Options exercisable (in dollars per share) | $ / shares	$ 26.66
WEIGHTED AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)
Options outstanding (in years)	5 years 10 months 24 days
Options exercisable (in years)	4 years 10 months 24 days
AGGREGATE INTRINSIC VALUE
Options outstanding | $	$ 23,551
Options exercisable | $	$ 21,828

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Activity (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Restricted Stock
NUMBER OF SHARES
Beginning balance (in shares) | shares	809,527
Granted (in shares) | shares	94,132
Vested (in shares) | shares	(160,259)
Canceled (in shares) | shares	(29,395)
Ending balance (in shares) | shares	714,005
WEIGHTED AVERAGE FAIR VALUE PER SHARE
Beginning balance (in dollars per share) | $ / shares	$ 29.03
Granted (in dollars per share) | $ / shares	17.61
Vested (in dollars per share) | $ / shares	44.62
Canceled (in dollars per share) | $ / shares	23.86
Ending balance (in dollars per share) | $ / shares	$ 24.23
Non-vested restricted stock units
NUMBER OF SHARES
Beginning balance (in shares) | shares	107,182
Granted (in shares) | shares	1,407
Vested (in shares) | shares	(11,035)
Canceled (in shares) | shares	(2,316)
Ending balance (in shares) | shares	95,238
WEIGHTED AVERAGE FAIR VALUE PER SHARE
Beginning balance (in dollars per share) | $ / shares	$ 14.43
Granted (in dollars per share) | $ / shares	19.18
Vested (in dollars per share) | $ / shares	19.25
Canceled (in dollars per share) | $ / shares	14.34
Ending balance (in dollars per share) | $ / shares	$ 13.95

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock Appreciation Rights (Details) - Stock Appreciation Rights (SARs) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares
NUMBER OF SHARES
Beginning balance (in shares) | shares	212,044
Granted (in shares) | shares	5,000
Canceled (in shares) | shares	(13,801)
Ending balance (in shares) | shares	203,243
Stock exercisable (in shares) | shares	66,546
WEIGHTED AVERAGE EXERCISE PRICE
Beginning balance (in dollars per share) | $ / shares	$ 32.28
Granted (in dollars per share) | $ / shares	18.68
Canceled (in dollars per share) | $ / shares	28.43
Ending balance (in dollars per share) | $ / shares	32.20
Stock exercisable (in dollars per share) | $ / shares	$ 45.16
WEIGHTED AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)
Stock outstanding (in years)	3 years 3 months 18 days
Stock exercisable (in years)	2 years 6 months
AGGREGATE INTRINSIC VALUE
Stock outstanding | $	$ 280
Stock exercisable | $	$ 3