Chiasma (CHMA) 10-K 4 Mar 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 26, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Entity Interactive Data Current	Yes
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Registrant Name	Chiasma, Inc.
Entity Central Index Key	0001339469
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity File Number	001-37500
Entity Tax Identification Number	76-0722250
Entity Incorporation, State or Country Code	DE
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		57,843,577
Entity Public Float			$ 195,166,166
Trading Symbol	CHMA
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, $0.01 par value
Entity Address, Address Line One	140 Kendrick Street, Building C East
Entity Address, City or Town	Needham
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02494
City Area Code	617
Local Phone Number	928-5300
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE The registrant intends to file a definitive proxy statement pursuant to Regulation 14A within 120 days of the end of the fiscal year ended December 31, 2020. Portions of such definitive proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 15,462	$ 27,855
Marketable securities	119,959	64,520
Accounts receivable	538
Inventory	10,955
Prepaid expenses and other current assets	6,444	3,881
Total current assets	153,358	96,256
Property and equipment, net	534	334
Other assets	1,883	2,236
Restricted cash	20,563
Total assets	176,338	98,826
Current liabilities
Accounts payable	4,240	3,253
Accrued expenses	11,858	7,576
Other current liabilities	633	546
Total current liabilities	16,731	11,375
Deferred royalty obligation	63,548
Long-term liabilities	4,274	1,682
Total liabilities	84,553	13,057
Commitments and Contingencies (Note 15)
Stockholders’ equity:
Common stock, $0.01 par value; authorized 125,000,000 shares at December 31, 2020 and December 31, 2019; issued and outstanding 57,815,596 shares at December 31, 2020 and 42,078,416 shares at December 31, 2019	578	421
Preferred stock, $0.01 par value; authorized 5,000,000 shares; none outstanding
Additional paid-in capital	438,920	358,245
Accumulated other comprehensive income		37
Accumulated deficit	(347,713)	(272,934)
Total stockholders’ equity	91,785	85,769
Total liabilities and stockholders' equity	$ 176,338	$ 98,826

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	57,815,596	42,078,416
Common stock, shares outstanding	57,815,596	42,078,416
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Product revenue, net	$ 1,106
Cost of goods sold	61
Gross profit	1,045
Operating expenses:
Selling, general and administrative	44,892	$ 15,122	$ 9,974
Research and development	26,802	22,457	22,362
Total operating expenses	71,694	37,579	32,336
Loss from operations	(70,649)	(37,579)	(32,336)
Interest and other income, net	1,826	1,543	1,044
Interest expense	(5,872)
Loss before income taxes	(74,695)	(36,036)	(31,292)
Provision (benefit) for income taxes	84	284	(31)
Net loss	$ (74,779)	$ (36,320)	$ (31,261)
Earnings per share
Basic	$ (1.43)	$ (1.06)	$ (1.28)
Diluted	$ (1.43)	$ (1.06)	$ (1.28)
Weighted-average shares outstanding:
Basic	52,234,945	34,204,284	24,399,706
Diluted	52,234,945	34,204,284	24,399,706

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (74,779)	$ (36,320)	$ (31,261)
Other comprehensive income (loss):
Unrealized gain (loss) on available for sale securities, net	(37)	53	43
Total other comprehensive income (loss):	(37)	53	43
Comprehensive loss	$ (74,816)	$ (36,267)	$ (31,218)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2017	$ 62,474	$ 244	$ 267,642	$ (59)	$ (205,353)
Beginning balance, shares at Dec. 31, 2017		24,381,605
Stock-based compensation	2,730		2,730
Exercise of stock options	37	$ 1	36
Exercise of stock options, shares		74,515
Additional paid-in capital on account of vested portion of restricted stock	101		101
Other comprehensive income (loss)	43			43
Net loss	(31,261)				(31,261)
Ending balance at Dec. 31, 2018	34,124	$ 245	270,509	(16)	(236,614)
Ending balance, shares at Dec. 31, 2018		24,456,120
Stock-based compensation	3,270		3,270
Exercise of stock options	50	$ 2	48
Exercise of stock options, shares		192,711
Issuance of common stock in follow-on offerings, net	84,576	$ 174	84,402
Issuance of common stock in follow-on offering, net, shares		17,429,585
Additional paid-in capital on account of vested portion of restricted stock	16		16
Other comprehensive income (loss)	53			53
Net loss	(36,320)				(36,320)
Ending balance at Dec. 31, 2019	85,769	$ 421	358,245	37	(272,934)
Ending balance, shares at Dec. 31, 2019		42,078,416
Stock-based compensation	5,074		5,074
Exercise of stock options	$ 279	$ 2	277
Exercise of stock options, shares	207,416	207,416
Issuance of common stock and pre-funded warrants in follow-on offerings, net	$ 75,479	$ 151	75,328
Issuance of common stock and pre-funded warrants in follow-on offering, net , shares		15,125,000
Issuance of common stock from cashless warrant exercise		$ 4	(4)
Issuance of common stock from cashless warrant exercise, shares		404,764
Other comprehensive income (loss)	(37)			$ (37)
Net loss	(74,779)				(74,779)
Ending balance at Dec. 31, 2020	$ 91,785	$ 578	$ 438,920		$ (347,713)
Ending balance, shares at Dec. 31, 2020		57,815,596

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities:
Net loss	$ (74,779)	$ (36,320)	$ (31,261)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	172	55	88
Stock-based compensation	5,020	3,270	2,730
Accretion on marketable securities, net	(6)	(515)	(440)
Non-cash lease expense	509	319
Amortization of debt discount and issuance costs	330
Change in fair value of embedded derivative liability	(1,200)
Provision (benefit) for deferred income taxes	(4)	(22)	16
Non-cash interest expense			5
Loss on disposal of property and equipment		29
Changes in operating assets and liabilities:
Accounts receivable	(538)
Inventory	(10,901)
Prepaid expenses and other current assets	(2,364)	(1,420)	471
Insurance recovery (Note 15)		18,288
Accounts payable and accrued expenses	6,167	111	4,349
Settlement liability (Note 15)		(18,750)
Other assets	(289)	(107)	9
Other current and long-term liabilities	2,557	50	(58)
Net cash used in operating activities	(75,326)	(35,012)	(24,091)
Investing Activities:
Purchase of marketable securities	(145,341)	(99,726)	(38,010)
Maturities of marketable securities	89,871	64,376	62,227
Purchases of property and equipment	(372)	(307)	(6)
Net cash provided by (used in) investing activities	(55,842)	(35,657)	24,211
Financing Activities:
Proceeds from the issuance of common stock and pre- funded warrants, net	75,479	84,576
Exercise of stock options	279	50	37
Payments under license termination agreement			(1,700)
Proceeds from short-term borrowing		1,675
Payments of short-term borrowing	(838)	(837)
Proceeds from deferred royalty obligation, net	64,418
Net cash provided by (used in) financing activities	139,338	85,464	(1,663)
Net increase (decrease) in cash, cash equivalents and restricted cash	8,170	14,795	(1,543)
Cash, cash equivalents and restricted cash, beginning of year	27,855	13,060	14,603
Cash, cash equivalents and restricted cash, end of year	36,025	27,855	13,060
Reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets
Cash and cash equivalents	15,462	27,855	13,060
Restricted cash	20,563
Cash, cash equivalents and restricted cash, end of year	36,025	27,855	13,060
Supplemental disclosures of cash flow information:
Cash paid for interest on deferred royalty obligation	17
Cash paid for income taxes	$ 188	$ 380	$ 333

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. Nature of Business Chiasma, Inc. is a commercial-stage are focused on developing and commercializing oral therapies to improve the lives of patients who face challenges associated with their existing treatments for rare and serious chronic disease. Employing our proprietary Transient Permeability Enhancer technology platform, we seek to develop oral medications that are currently available only as injections. On June 26, 2020, we received approval from the U.S. Food and Drug Administration (“FDA”) of our oral octreotide capsules product candidate, MYCAPSSA, for long-term maintenance treatment in acromegaly patients who have responded to and tolerated treatment with octreotide or lanreotide. We commenced our U.S. commercial launch of MYCAPSSA in September 2020. Acromegaly is a rare and debilitating condition that results in the body’s production of excess growth hormone. Octreotide is an analog of somatostatin, a natural inhibitor of growth hormone secretion. Octreotide capsules have been granted orphan designation in the United States and the European Union for the treatment of acromegaly. We conducted an international Phase 3 clinical trial, referred to as MPOWERED, of oral octreotide capsules for the maintenance treatment of adult patients with acromegaly to support regulatory approval in the European Union by the European Medicines Agency (“EMA”). The MPOWERED trial was a global, randomized, open-label and active-controlled 15-month trial initially designed to enroll up to 150 patients. The EMA requested that a minimum of 80 patients who are responders to octreotide capsules per the protocol following the six-month In April 2019, we completed an underwritten public offering of we completed a follow-on public offering of common stock in which we In April 2020, we entered into an Open Market Sales Agreement (“ATM Agreement”) for “at the market offerings” with Jefferies LLC (“Jefferies”), under which we may offer and sell from time to time, shares of our common stock having an aggregate offering price of up to $60.0 million through Jefferies, acting as our sales agent or principal. To date, we have not sold any common stock under the ATM Agreement. In April 2020, we entered into a Revenue Interest Financing Agreement (the “Revenue Interest Financing Agreement”) with Healthcare Royalty Partners IV, L.P. (“HCR”) for up to $75.0 million. As of September 30, 2020, we have received aggregate proceeds of $65.0 million, less certain transaction expenses (see Note 9). In July 2020, we completed an underwritten public offering of 15,125,000 shares of common stock and pre-funded warrants (the “Pre-Funded Warrants”) to purchase an aggregate of 5,000,000 shares of common stock. The public offering price was $4.00 per share of common stock. We received aggregate net proceeds of approximately $75.5 million after deducting underwriting fees and offering expenses. The Pre-Funded Warrants are immediately exercisable at an exercise price per share of $0.0001. We have incurred substantial operating losses since inception, and we expect our operating losses and negative operating cash flows to continue for the foreseeable future. We are heavily dependent on the commercial success of MYCAPSSA in the United States and the regulatory approval and subsequent commercial success of MYCAPSSA in the European Union, both of which may never occur. We plan to invest in our U.S. commercial launch and the manufacturing of octreotide capsules for market consumption including capsules as a treatment for acromegaly in the European Union. We currently expect our existing cash, cash equivalents and marketable securities to fund our operations for at least one year after the date these consolidated financial statements are issued. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support our cost structure. We plan to continue to fund our losses from operations and capital funding needs from existing balances of cash, cash equivalents and marketable securities and potentially through additional equity financings. We may also opportunistically consider license and collaboration agreements with potential partners or convertible debt financing to the extent such sources are identified and available. If our anticipated U.S. revenues are insufficient to fund our operations to attaining and sustaining profitability, additional financing may be required. Such financing, if required, may not be available on a timely basis on terms acceptable to us, or at all. If we are not able to secure adequate additional funding when required, we may be forced to make reductions in spending, extend payment terms with suppliers, suspend or curtail our development opportunities, or it may negatively impact our ability to adequately fund or delay our potential commercial preparations or launch readiness outside the United States if the MPOWERED trial results are positive and MYCAPSSA is approved by the EMA. Any of these actions could materially harm our business, results of operations and future prospects. Failure to successfully commercialize octreotide capsules in acromegaly will prevent us from achieving profitability and positive cash flows, which could raise significant concerns about our continued viability as a business.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Principles of Consolidation and Basis of Presentation The accompanying consolidated financial statements include the accounts of Chiasma, Inc. and its subsidiaries and are prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and are stated in U.S. dollars. The consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities in the ordinary course of business. All intercompany balances and transactions have been eliminated in consolidation. Use of estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes during the reporting period. We base these estimates and assumptions on historical experience when available, and on various factors that we believe to be reasonable under the specific circumstances. Significant estimates relied upon in preparing the accompanying consolidated financial statements include, but are not limited to, recognition of product revenues, accounting for stock-based compensation, income taxes, the fair value of embedded derivative and our deferred royalty obligation and accounting for certain accruals. We assess the above estimates on an ongoing basis; however, actual results could materially differ from those estimates. Cash Equivalents Cash equivalents consist of highly liquid instruments which mature within three months or less from the date of purchase. Marketable Securities Our investments primarily consist of commercial paper and corporate and government debt securities. These marketable securities are classified as available-for-sale, and as such, are reported at fair value on our consolidated balance sheets. Unrealized holding gains and losses are reported within accumulated other comprehensive income as a separate component of stockholders’ equity. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion, together with interest on securities, are included in interest and other income, net, on our consolidated statements of operations. If a decline in the fair value of a marketable security below our cost basis is determined to be other than temporary, such marketable security is written down to its estimated fair value as a new cost basis and the amount of the write-down is included in earnings as an impairment charge. The cost of securities sold is based on the specific identification method. Accounts Receivable Our accounts receivable consist of amounts due from one specialty pharmacy (the “customer”) for sales of MYCAPSSA and which have standard payments terms. We extend credit to our customer based on our evaluation of the customer’s financial condition. Accounts receivable are stated at amounts due net of applicable prompt pay discounts and other adjustments. We assess the need for an allowance for doubtful accounts by considering a number of factors, including the length of time trade accounts receivable are past due and the customer’s ability to pay its obligation. Based on a review of these factors, as of December 31 , 2020, we determined that an allowance for doubtful accounts was not required. Concentrations of credit risk Financial instruments that potentially subject us to significant concentration of credit risk consist primarily of cash, cash equivalents, marketable securities, and accounts receivable. During the year ended December 31, 2020, one customer comprised 100% of our accounts receivable and product revenues. We routinely maintain deposits in financial institutions in excess of government insured limits. Management believes that we are not exposed to significant credit risk as our deposits are held at financial institutions that management believes to be of high credit quality and we have not experienced any significant losses in these deposits. We regularly invest excess operating cash in deposits with major financial institutions and money market funds and in notes issued by the U.S. government, as well as in fixed income investments and bond funds, both of which can be readily purchased and sold using established markets. We believe that the market risk arising from our holdings of these financial instruments is mitigated based on the fact that many of these securities are either government backed or of high credit rating. Inventory Prior to FDA approval of MYCAPSSA, all costs related to the manufacturing of MYCAPSSA that could potentially be available to support the planned U.S. commercial launch were charged to research and development expense in the period incurred. Generally, inventory may be capitalized if it is probable that future revenues will be generated from the sale of the inventory and that these revenues will exceed the cost of the inventory. Through the FDA approval date of MYCAPSSA, we expensed all of our manufacturing costs due to the high risk inherent in drug development and uncertainty as to whether MYCAPSSA would be approved. We began to capitalize our manufacturing-related costs to inventory starting July 1, 2020. We capitalize the costs to manufacture our products incurred after regulatory approval when, based on our judgment, future commercialization is considered probable and the future economic benefit is expected to be realized. In connection therewith, we value our inventories at the lower of cost or estimated net realizable value. We determine the cost of our inventories, which includes amounts related to active pharmaceutical ingredient (“API”), and other raw materials, third party manufacturing costs and other overhead costs, on a first-in, first-out basis. Inventories that may be used for either research and development or commercial sale are classified as inventory until the material is consumed or otherwise allocated for research and development. If the material is intended to be used for research and development, it is expensed as research and development once that determination is made. On a quarterly basis, we review inventory quantities on hand and analyze the provision for excess and obsolete inventory based primarily on remaining product shelf life and our estimated sales forecast which is based on anticipated future demand. We build demand forecasts by considering factors such as, but not limited to, overall market potential, market share, market acceptance, and patient usage. Our estimates of future product demand may prove to be imprecise and changes in estimates will result in a change to the provision required for excess and obsolete inventory. Accordingly, any significant unanticipated changes in demand could have a significant impact on the value of our inventory and results of operations. Foreign currency translation We use the U.S. dollar as our functional currency. Monetary assets and liabilities denominated in foreign currency are re-measured at current rates and non-monetary assets denominated in foreign currency are recorded at historical exchange rates. Realized and unrealized exchange gains or losses from transactions and re-measurement adjustments are reflected in other income, net, in the accompanying consolidated statements of operations. Comprehensive income (loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Other than reported net income, comprehensive income (loss) includes unrealized gains and losses on available for sale securities, which are disclosed in the accompanying consolidated statements of comprehensive income (loss). There were no reclassifications out of comprehensive income (loss) for the years ended December 31, 2020, 2019 or 2018. Segment information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, our Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. We view our operations and manage our business in one operating segment. Other assets Other assets consist of right of use assets, long-term restricted deposits, prepayments, and deferred tax assets. Restricted cash Restricted cash consists of $20.0 million that we are required to maintain in securitized cash and investment accounts under the Revenue Interest Financing Agreement, interest-bearing money market accounts held as security deposits against bank guarantees, and amounts related to our co-pay assistance program. Property and equipment Property and equipment are stated at cost, net of accumulated depreciation and amortization. Expenditures for maintenance and repairs are charged to operations as incurred, whereas major betterments are capitalized as additions to property and equipment. Depreciation and amortization are recorded using the straight-line method over the estimated useful lives of the assets, as follows: Asset Category Estimated Useful Lives Computer equipment and software 3 years Office furniture and equipment 7—17 years (mainly 7) Machinery and equipment 5 — 7 years Leasehold improvements The lesser of lease term or estimated useful lives Impairment of long-lived assets We review long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. When such events occur, we compare the carrying amounts of the assets to their undiscounted expected future cash flows the assets are expected to generate and to be recognized. The amount of impairment loss to be recognized is the excess of the carrying value over the fair value of the related asset. We did not record any impairments during the years ended December 31, 2020, 2019 and 2018. Deferred Royalty Obligation We treat the deferred royalty obligation, as discussed further in Note 9, as a debt obligation, amortized under the effective interest rate method over the estimated life of the agreement. We recognize interest expense thereon using the effective rate, which is based on our current estimates of future revenues over the life of the arrangement. In connection therewith, we periodically assess our expected revenues using internal projections, impute interest on the carrying value of the deferred royalty obligation, and record interest expense using the effective interest rate. To the extent our estimates of future revenues are greater or less than previous estimates or the estimated timing of such payments is materially different than previous estimates, we will account for any such changes by adjusting the effective interest rate on a prospective basis, with a corresponding impact to the reclassification of our deferred royalty obligation between short- and long-term. The assumptions used in determining the expected repayment term of the deferred royalty obligation and amortization period of the issuance costs requires that we make estimates that could impact the short-term and long-term classification of such costs, as well as the period over which such costs will be amortized. Revenue Recognition In accordance with accounting guidance for revenue recognition, we recognize revenue when a customer obtains control of promised goods or services, in an amount that reflects the consideration which we expect to receive in exchange for those goods or services. To determine revenue recognition for arrangements that we determine to be within the scope of such guidance, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. We only apply the five-step model to contracts when it is probable that we will collect the consideration we are entitled to in exchange for the goods or services that we transfer to the customer. For a further discussion of accounting for net product revenue see Note 3 . Research and development Research and development costs are expensed as incurred. Research and development costs include payroll and personnel expense, consulting costs, external contract research and development expenses, raw materials, drug product manufacturing costs, and allocated overhead including depreciation and amortization, rent, and utilities. Research and development costs that are paid in advance of performance are capitalized as a prepaid expense and amortized over the service period as the services are provided. Clinical trial costs Clinical trial costs are a component of research and development expenses. We accrue and expense clinical trial activities performed by third parties on an evaluation of the progress to completion of specific tasks using data such as hours spent in performance of services, patient enrollment, clinical site activation, and other information provided to us by our vendors. We make estimates of our clinical trial accrued expenses as of each balance sheet date in our financial statements based on facts and circumstances known to us. If timelines or contracts are modified based upon changes in the clinical trial protocol or scope of work to be performed, we assess our estimates of accrued expenses accordingly. Patent costs Patent costs are expensed as incurred as their realization is uncertain. These costs are classified as general and administrative in the accompanying consolidated statements of operations. Advertising and Product Promotion Costs Advertising and product promotion costs are included in selling, general and administrative expenses and were $5.3 million during the year ended December 31, 2020. We did not incur any advertising and promotion costs in the years ended December 31, 2019 and 2018, respectively. Advertising and product promotion costs are expensed as incurred. Stock-based compensation We account for all stock-based compensation to employees and nonemployees based on their fair values on the date of grant. For stock-based awards with only service conditions, we recognize compensation on a straight-line basis over the requisite service period, which is usually the vesting period of the award, net of any actual forfeitures. We determine the fair value of stock options by using the Black-Scholes option pricing model. This model requires the input of several assumptions such as the expected option term, the expected risk-free interest rate over the expected option term, the expected volatility of our stock price over the expected option term, and the expected dividend yield over the expected option term. The computation of expected volatility is based on an average historical share price volatility based on an analysis of reported data for a peer group of comparable publicly traded companies, which were selected based upon industry similarities. The interest rate for periods within the expected term of the award is based on the U.S. Treasury risk-free interest rate in effect at the time of grant. The expected lives of the options were estimated using the simplified method. Income taxes The consolidated financial statements reflect provisions for federal, state, local and foreign income taxes. Deferred tax assets and liabilities represent future tax consequences of temporary differences between the financial statement carrying amounts and the tax basis of assets and liabilities and for loss carryforwards using enacted tax rates expected to be in effect in the years in which the differences reverse. A valuation allowance is recorded when it is more likely than not that some or all of the deferred tax assets will not be realized. We determine whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, none of the benefit attributable to the position is recognized. The tax benefit to be recognized for any tax position that meets the more likely than not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency. We account for interest and penalties related to uncertain tax positions as part of our other expenses in the accompanying consolidated financial statements. Leases We determine if an arrangement is a lease at inception. We have operating leases for our office spaces and certain automobiles. Right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use asset also includes direct costs incurred and is reduced by lease incentives. Lease agreements with lease and non-lease components are accounted for separately. As our leases do not provide an implicit rate, we use an estimated incremental borrowing rate based on the information available at the commencement date in determining the present value of future payments. We recognize operating lease expense on a straight-line basis over the lease term. Contingent liabilities In the normal course of business, we are subject to proceedings, lawsuits, and other claims and assessments. We assess the likelihood of any adverse judgments or outcomes to these matters as well as potential ranges of probable losses. A determination of the amount of reserves required, if any, for these contingencies is made after careful analysis of each individual issue. The required reserves may change in the future due to new developments in each matter or changes in approach such as a change in settlement strategy in dealing with these matters. We record charges for the losses we anticipate incurring in connection with litigation and claims against us when we conclude a loss is probable and we can reasonably estimate these losses. Earnings per share We compute basic earnings per share by dividing net loss by the weighted average number of common shares outstanding for the period. We compute diluted earnings per common share after giving consideration to all potentially dilutive common shares, including stock options and warrants outstanding during the period, except where the effect of such non-participating securities would be antidilutive. Recently issued accounting pronouncements In June 2016, the Financial Accounting Standards Board issued new guidance which will require more timely recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. The new guidance requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. The new guidance also requires enhanced disclosures regarding significant estimates and judgments used in estimating credit losses. On January 1, 2020, we adopted this standard. The adoption of this standard did not have a material impact on our consolidated financial statements.

Product Revenue, Net

Product Revenue, Net	12 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Product Revenue, Net	3. Product Revenue, Net We began selling MYCAPSSA in September 2020. We currently sell MYCAPSSA in the United States to a specialty pharmacy, which dispenses the product directly to patients. We recognize revenue when the customer obtains control of the product, which occurs at a point in time, when delivery of the product has occurred. Revenue Reserves for Variable Consideration Revenue from sales of MYCAPSSA are recorded at the net sales price, which is the amount of consideration we expect to receive in exchange for transferring the product to a customer (“transaction price”). This transaction price for product sales includes variable consideration for which reserves are established and which may result from discounts, returns, chargebacks, rebates, co-pay or co-insurance assistance and other allowances that are offered within contracts with our customer and payors. We estimate the amount of variable consideration that should be included in the transaction price under the expected value method for all sales deductions other than trade discounts, which are estimated under the most likely amount method. These provisions represent our best estimate of the amount of consideration to which we are entitled. Actual amounts of consideration ultimately received may differ from these estimates. If actual results in the future vary from our estimates, we will adjust these estimates, which would affect net product revenue and earnings in the period such changes in estimates become known. Trade Discounts and Specialty Pharmacy Fees : we provide customary discounts to our customer for prompt payment, the terms for which are explicitly stated in our contract with such customer. We record these discounts as a reduction of revenue with a corresponding reduction to accounts receivable. In addition, we also pay fees for data and distribution services from our specialty pharmacy. We have determined that such fees are not for a distinct good or service and, accordingly, are being recorded as a reduction of product revenue and a component of accrued expenses. Government Rebates: We are subject to discount obligations under state Medicaid programs, Medicare, and other government programs. Additionally, in the future we may contract with various private payor organizations, primarily insurance companies and pharmacy benefit managers, for the payment of rebates with respect to utilization of MYCAPSSA. Provisions for government rebates are based on the estimated amount of rebates and incentives to be claimed on the related sales from the period. These reserves are recorded in the same period in which the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability that is included in accrued expenses in our consolidated balance sheet. For Medicare, we must also estimate the number of patients in the prescription drug coverage gap for whom we will owe an additional liability under the Medicare Part D program. Our liability for these rebates currently consists of estimates of claims that we have not yet received associated with product that has been recognized as revenue. Other Incentives/Patient Assistance Programs: Product Returns : We offer customers a limited right of return for unopened damaged or defective product, and, under certain circumstances, for unopened product for a limited time before its expiration date. We estimate the amount of product revenues that may be returned by customers and record this estimate as a reduction of revenue in the period in which the related product revenue is recognized. We currently estimate our provision for sales returns based on our expectations and adjust the transaction price with such estimate at the time of sale to our customer. Once sufficient history has been collected for product returns, we will utilize that history to inform our estimate assumption. The following table summarizes activity in each of the above product revenue allowances and reserve categories for year ended December 31, 2020: Discounts and Fees Rebates and Other Incentives Returns Total ($ in thousands) Balance, January 1, 2020 $ — $ — $ — $ — Provision 80 142 1 223 Payments or credits (64 ) (12 ) — (76 ) Balance, December 31, 2020 $ 16 $ 130 $ 1 $ 147

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments All Other Investments [Abstract]
Investments	4. Investments Our investments consisted of the following as of December 31, 2020 and 2019: As of December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value ($ in thousands) Money market funds $ 29,392 $ — $ — $ 29,392 Corporate notes 11,347 — (1 ) 11,346 Commercial paper 98,030 8 (8 ) 98,030 U.S. treasury securities 12,582 1 — 12,583 Total $ 151,351 $ 9 $ (9 ) $ 151,351 As of December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value ($ in thousands) Money market funds $ 23,012 $ — $ — $ 23,012 Corporate notes 45,584 20 — 45,604 Commercial paper 20,899 17 — 20,916 Total $ 89,495 $ 37 $ — $ 89,532 As of December 31, 2020, we consider the unrealized losses in our investment portfolio to be temporary in nature and not due to credit losses. We have the ability to hold such investments until recovery of the fair value. We utilize the specific identification method in computing realized gains and losses. We had no realized gains and losses on our available-for-sale securities for the years ended December 31, 2020, 2019 or 2018. The fair values of our investments by classification in our consolidated balance sheets as of December 31, 2020 and 2019 were as follows: As of December 31, 2020 2019 ($ in thousands) Cash and cash equivalents $ 10,829 $ 25,012 Marketable securities 119,959 64,520 Restricted cash 20,563 — Total $ 151,351 $ 89,532 Cash and cash equivalents in the table above exclude cash of $4.6 million and $2.8 million as of December 31, 2020 and 2019, respectively. The contractual maturity dates of all of our investments are less than one year.

Fair Value Measurements and Fai

Fair Value Measurements and Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements and Fair Value of Financial Instruments	5. Fair Value Measurements and Fair Value of Financial Instruments Certain assets and liabilities are reported at fair value on a recurring basis. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. The fair value accounting guidance requires that assets and liabilities carried at fair value be classified and disclosed in one of the following three categories: Level 1— Quoted prices in active markets for identical assets or liabilities that we have the ability to access at the measurement date. Level 2— Inputs other than quoted prices in active markets that are observable for the asset or liability, either directly or indirectly. Level 3— Inputs that are unobservable for the asset or liability. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by us in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The following tables summarize the fair value measurements of our financial instruments as of December 31, 2020 and 2019: Fair Value Measurements at December 31, 2020 Description Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Financial assets ($ in thousands) Cash equivalents and restricted cash: Money market funds $ 29,392 $ — $ — $ 29,392 Commercial paper — 2,000 — 2,000 Total cash equivalents and restricted cash $ 29,392 $ 2,000 $ — $ 31,392 Marketable securities: U.S. treasury securities $ — $ 12,583 $ — $ 12,583 Corporate notes — 11,346 — 11,346 Commercial paper — 96,030 — 96,030 Total marketable securities $ — $ 119,959 $ — $ 119,959 Total $ 29,392 $ 121,959 $ — $ 151,351 Financial liabilities Derivative liabilities $ — $ — $ 1,900 $ 1,900 Fair Value Measurements at December 31, 2019 Description Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Financial assets ($ in thousands) Cash equivalents: Money market funds $ 23,012 $ — $ — $ 23,012 Corporate notes — 2,000 — 2,000 Total cash equivalents $ 23,012 $ 2,000 $ — $ 25,012 Marketable securities: Corporate notes $ — $ 43,604 $ — $ 43,604 Commercial paper — 20,916 — 20,916 Total marketable securities $ — $ 64,520 $ — $ 64,520 Total $ 23,012 $ 66,520 $ — $ 89,532 Our cash equivalents and restricted cash are composed of money market funds, as well as U.S. treasury securities, corporate notes and commercial paper with maturity dates of 90 days or less from the date of purchase. We measure these investments at fair value. The fair value of cash equivalents and restricted cash held in money market funds is determined based on Level 1 inputs. Items classified as Level 2 within the valuation hierarchy consist of U.S. treasury securities, corporate notes and commercial paper. We estimate the fair values of these marketable securities by taking into consideration valuations obtained from independent pricing services, which normally derive security prices from recently reported trades for identical or similar securities, making adjustments based upon other significant observable market transactions. At the end of each reporting period, we perform quantitative and qualitative analysis of prices received from third parties to determine whether prices are reasonable estimates of fair value. After completing our analysis, we did not adjust or override any fair value measurements provided by our pricing services as of December 31, 2020 or 2019. In certain cases where there is limited activity or less transparency around inputs to valuation, the related assets or liabilities are classified as Level 3. We recorded derivative liabilities associated with our deferred royalty obligation, as discussed further in Note 9. These derivative liabilities are measured at fair value using an option pricing Monte Carlo simulation model and is included as a component of the deferred royalty obligation. The embedded derivative liabilities are subject to remeasurement at the end of each reporting period, with changes in fair value recognized as a component of interest and other income, net. The assumptions used in the option pricing Monte Carlo simulation model include: (1) the expected net sales of MYCAPSSA; (2) our risk-adjusted discount rate that includes a company specific risk premium; (3) our cost of debt; (4) volatility; (5) the probability and timing of a change in control occurring during the term of the instrument; and (6) the probability and timing of an event of default during the term of the instrument. We did not have any Level 3 assets or liabilities being measured at fair value on a recurring basis as of December 31, 2019 . The following table sets forth a summary of the changes in the fair value of the embedded derivative liabilities for the year ended December 31, 2020: ($ in thousands) Fair Value Measurement of Embedded Derivative using Significant Unobservable Inputs (Level 3) Balance, January 1, 2020 $ — Additions during the period 3,100 Change in fair value during the period (1,200 ) Balance, December 31, 2020 $ 1,900

Inventory

Inventory	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventory	6. Inventory Our inventory of MYCAPSSA consisted of the following as of December 31, 2020: ($ in thousands) December 31, 2020 Raw materials and supplies $ 6,786 Work in process 3,857 Finished goods 312 Total inventory $ 10,955

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property and Equipment	7. Property and Equipment Property and equipment consisted of the following as of December 31, 2020 and 2019: As of December 31, 2020 2019 ($ in thousands) Computer equipment and software $ 553 $ 431 Office furniture and equipment 358 108 Machinery and equipment 115 115 Property and equipment, at cost 1,026 654 Less accumulated depreciation (492 ) (320 ) Property and equipment, net $ 534 $ 334 Depreciation expense was $0.2 million, $0.1 million and $0.1 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued Expenses	8. Accrued Expenses Accrued expenses consisted of the following as of December 31, 2020 and 2019: As of December 31, 2020 2019 ($ in thousands) Accrued payroll and employee benefits $ 4,900 $ 1,872 Accrued selling, general, administrative and other expenses 3,830 1,485 Accrued research and development expenses 3,128 4,219 Total accrued expenses $ 11,858 $ 7,576

Deferred Royalty Obligation

Deferred Royalty Obligation	12 Months Ended
	Dec. 31, 2020
Deferred Royalty Obligation [Abstract]
Deferred Royalty Obligation	9. Deferred Royalty Obligation In April 2020, we entered into the Revenue Interest Financing Agreement with HCR whereby HCR will receive payments from us at a tiered percentage (the “Applicable Tiered Percentage”) of future net revenues of MYCAPSSA and any of our other future products, including worldwide net product sales and upfront payments and milestones received from third parties under license agreements (the “Revenue Interests”). Under the terms of the agreement, we received $25.0 million, less certain transaction expenses, from HCR in April 2020 and an additional $25.0 million in July 2020 following the FDA approval of MYCAPSSA. In September 2020 HCR’s rights to receive the Revenue Interests shall terminate on the date on which HCR has received payments equal to 195% of the funded portion of the Investment Amount including the aggregate of all payments made to HCR as of such date, unless the Revenue Interest Financing Agreement is terminated earlier. If HCR has not received payments equal to the 195% of the funded portion of the Investment Amount by the ten-year anniversary of the initial closing date and no event of default has occurred or is ongoing, among other things, we shall pay HCR an amount equal to the funded portion of the Investment Amount plus a specific annual rate of return in the low to mid-teens less payments previously received. If a change of control of the Company occurs, we must immediately repay HCR the total amount actually funded (including unfunded amounts conditionally eligible to be funded) plus a change of control premium, the amount of which is variable up to 95% based on timing and circumstances of such change of control. Upon the occurrence of an event of default, including the withdrawal, suspension or other termination of the FDA approval of MYCAPSSA as a treatment for acromegaly that continues for 60 days that prevents us from marketing MYCAPSSA, HCR may accelerate payments due under the agreement to the . If HCR has not received 60% of the funded portion of the Investment Amount by September 30, 2023 or 100% of the funded portion of the Investment Amount by September 30, 2024, we must make cash payments sufficient to gross HCR up to such minimum amounts. Further, the Revenue Interest Financing Agreement requires us to maintain a minimum of $20.0 million in securitized cash and investment accounts, which we recorded as restricted cash in the consolidated balance sheet, during any quarter that the trailing four quarters of net revenue of MYCAPSSA is below a certain threshold. Our obligations under the Revenue Interest Financing Agreement are secured by a first priority perfected security interest in all of our Chiasma, Inc. cash and cash equivalents (as defined in the Revenue Interest Financing Agreement), all present and future net revenues of MYCAPSSA and all MYCAPSSA-related assets. We have evaluated the terms of the deferred royalty obligation and concluded that the features of the Investment Amount are similar to those of a debt instrument. Accordingly, we have accounted for the transaction as long-term debt. We have evaluated the terms of the debt and determined that the repayment upon a change of control of up to 195% of the funded portion of the Investment Amount, less any payments made to date, is an embedded derivative that requires bifurcation from the debt instrument and fair value recognition. In addition, we have determined that the repayment upon an event of default of 195% of the funded portion of the Investment Amount, less any payments made to date, upon an event of default is an embedded derivative that requires bifurcation from the debt instrument and fair value recognition. We determine the fair value of the derivatives using an option pricing Monte Carlo simulation model taking into account the probability and timing of a change of control and an event of default occurring and potential repayment amounts and timing of such payments that would result under various scenarios, as further described in Note 5. The embedded derivative liabilities were recorded at fair value of $3.1 million at inception, with the remaining proceeds received from HCR allocated to the carrying value of the debt resulting in a debt discount that will be amortized over the estimated term of the obligation using the effective interest method. The aggregate fair value of the embedded derivative as of December 31, 2020 is $1.9 million and is presented in deferred royalty obligation in the consolidated balance sheet. We remeasure the embedded derivative to fair value each reporting period until the termination of the Revenue Interest Financing Agreement. Such changes in fair value are recorded as interest and other income, net in the consolidated statement of operations. The effective interest rate as of December 31, 2020 was approximately 17%. In connection with the deferred royalty obligation, we incurred debt issuance costs totaling $0.6 million during the year ended December 31, 2020. Debt issuance costs have been netted against the deferred royalty obligation and are being amortized over the estimated term of the obligation using the effective interest method, adjusted on a prospective basis for changes in the underlying assumptions and inputs. The assumptions used in determining the expected repayment term of the deferred royalty obligation and amortization period of the issuance costs requires that we make estimates that could impact the short- and long-term classification of these costs, as well as the period over which these costs will be amortized. The carrying value of the deferred royalty obligation was $63.5 million as of December 31, 2020. The fair value of the deferred royalty obligation was $82.1 million as of December 31, 2020 and was measured using Level 3 inputs. The estimated fair value was calculated using an option pricing Monte Carlo simulation model with inputs consistent with those used in determining the embedded derivative values as described in Note 5 .

Earnings per Share of Common St

Earnings per Share of Common Stock	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings per Share of Common Stock	10. Earnings per Share of Common Stock We include or outstanding shares of common stock and Pre-Funded Warrants in our calculation of the basic weighted-average shares outstanding. We include the Pre-Funded Warrants as their exercise price of $0.0001 per share is negligible and they are fully vested and exercisable at any time after the original issuance date. All other common stock warrants outstanding and stock options have been excluded from the computation of diluted weighted-average shares outstanding because such securities would have an anti-dilutive impact due to net losses reported during the years ended December 31, 2020, 2019 and 2018. Since we have reported a net loss for the years ended December 31, 2020, 2019 and 2018, diluted net loss per share is the same as basic net loss per share for those periods.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Warrants	11. Warrants A summary of our common stock warrants activity for the year ended December 31, 2020 is presented below. Description Exercise Price Expiration Date Balance, December 31, 2019 Warrants Issued Warrants Exercised Balance, December 31, 2020 October 2012 Warrants $ 0.0910 10/22/2022 829,686 — (205,321 ) 624,365 March 2013 Warrants $ 0.0910 3/28/2022 829,686 — (205,321 ) 624,365 December 2014 Warrants $ 9.1320 12/16/2024 923,527 — — 923,527 February 2015 Warrants $ 9.1320 12/16/2024 984,116 — — 984,116 July 2020 Pre-Funded Warrants $ 0.0001 No expiration — 5,000,000 — 5,000,000 3,567,015 5,000,000 (410,642 ) 8,156,373 As described in Note 1, in July 2020 in connection with an underwritten public offering, we issued Pre-Funded Warrants to purchase an aggregate of 5,000,000 shares of common stock which are immediately exercisable at an exercise price per share of $0.0001.

Stock Incentive Plan

Stock Incentive Plan	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Incentive Plan	12. Stock Incentive Plan In 2008, our Board of Directors adopted the 2008 Stock Incentive Plan (the “2008 Plan”), which provided for the grant of incentive stock options, nonqualified stock options, and restricted stock to our employees, directors, and nonemployees up to 3,547,741 shares of common stock. Option awards expire 10 years from the grant date and generally vest over four years In July 2015, we approved the 2015 Stock Option and Incentive Plan (the “2015 Plan”), which became effective upon our IPO. The 2015 Plan allows the grant of incentive stock options, nonqualified stock options, restricted stock, and other stock-based awards to employees, directors, and nonemployees of Chiasma up to 3,566,296 shares of common stock. In connection with the adoption of the 2015 Plan, no further option grants are permitted under the 2008 Plan and any expirations, cancellations, or terminations under the previous plan are available for issuance under the 2015 Plan. On January 1, 2021 and 2020, the number of shares reserved and available for issuance under the 2015 Stock Plan increased by 2,312,623 and 1,683,136 shares of common stock, respectively, pursuant to a provision in the 2015 Stock Plan that provides that the number of shares reserved and available for issuance will automatically increase each January 1, beginning on January 1, 2016, by 4% of the number of shares of common stock issued and outstanding on the immediately preceding December 31 or such lesser number as determined by the compensation committee of the Board of Directors. As of December 31, 2020, the total number of shares authorized for stock award plans is 9,775,418 of which 1,033,460 remain available for grant. There are 8,378,060 stock options outstanding as of December 31, 2020. The fair value of each stock option issued was estimated at the date of grant using the Black-Scholes option model with the following weighted-average assumptions: For the Years Ended December 31, 2020 2019 2018 Expected volatility 85 % 97 % 77 % Expected term (years) 6.2 6.0 6.2 Risk-free interest rate 0.93 % 1.93 % 2.72 % Expected dividend yield 0 % 0 % 0 % A summary of option activity as of December 31, 2020 and the year then ended is presented below: Number of Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2019 6,489,692 $ 5.01 7.3 $ 8,166,882 Granted 2,307,500 $ 4.63 Exercised (207,416 ) $ 1.35 Forfeited / Expired (211,716 ) $ 5.47 Outstanding, December 31, 2020 8,378,060 $ 4.98 7.2 $ 5,611,109 Exercisable, December 31, 2020 4,774,332 $ 4.98 6.0 $ 4,634,332 Vested and expected to vest, December 31, 2020 8,378,060 $ 4.98 7.2 $ 5,611,109 The weighted-average grant date per-share fair value of stock options granted during 2020, 2019 and 2018 was $3.32, $4.79 and $1.06, respectively. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2020, 2019 and 2018 was approximately $0.7 million, $1.0 million and $0.2 million, respectively. At December 31, 2020, there was $12.2 million of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted-average period of 3.0 years. Stock-based compensation expense for 2020, 2019 and 2018 consisted of the following: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) General and administrative $ 4,082 $ 2,243 $ 1,412 Research and development 938 1,027 1,318 Total $ 5,020 $ 3,270 $ 2,730 Stock-based compensation of $54,000 was capitalized into inventory for the year ended December 31, 2020. Stock-based compensation capitalized into inventory is recognized as cost of goods sold when the related product is sold. During 2015, two directors exercised options to purchase an aggregate of 122,644 shares of common stock of which 116,258 of the shares were issued as restricted stock as they were exercised prior to full vesting. The proceeds from the issuance of the restricted stock was historically presented as a liability within the consolidated balance sheet, since we had the right to repurchase the unvested portion of the restricted stock following termination of the services of their holder. The liability was released to additional paid-in capital per the original vesting schedule of the options. The restricted shares fully vested during the year ended December 31, 2019.

License Agreement

License Agreement	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
License Agreement	13. License Agreement In December 2012, we signed a license agreement with F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. (collectively “Roche”), which was effective in January 2013, and granted Roche an exclusive, non-transferable license to our intellectual property related to octreotide capsules. In July 2014, Roche terminated the license agreement. Subsequent to the termination, we purchased from Roche API supplies to continue the development and manufacturing of octreotide capsules as well as Roche’s proposed trade name for octreotide capsules for an aggregate amount of $5.1 million payable in three equal annual installments of $1.7 million beginning in 2016. We made the final $1.7 million annual payment in March 2018. Roche has no remaining rights to octreotide capsules and we retain all rights to octreotide capsules and all related intellectual property. We have no further financial or operational obligations to Roche.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes Our loss before provision (benefit) for income taxes for the years ended December 31, 2020, 2019 and 2018 consisted of the following: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) Domestic $ (75,102 ) $ (36,407 ) $ (31,477 ) Foreign 407 371 185 Total $ (74,695 ) $ (36,036 ) $ (31,292 ) The components of income tax provision (benefit) consisted of the following for the years ended December 31, 2020, 2019 and 2018: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) Current provision for income taxes: U.S. $ 61 $ 18 $ 12 Foreign 27 288 (59 ) Total current provision for income taxes 88 306 (47 ) Deferred tax provision (benefit) - foreign (4 ) (22 ) 16 Total deferred provision (benefit) for income taxes (4 ) (22 ) 16 Total provision (benefit) for income taxes $ 84 $ 284 $ (31 ) A reconciliation setting forth the differences between our effective tax rates and the U.S. federal statutory tax rate is as follows: For the Years Ended December 31, 2020 2019 2018 U.S. federal tax provision at statutory rate 21.0 % 21.0 % 21.0 % State and local tax, net of federal benefit 6.2 % 5.6 % 5.3 % Foreign rate differences 0.0 % 0.1 % 0.2 % Non-deductible foreign stock compensation (0.1 %) (0.3 %) (0.4 %) Effect of other permanent differences (0.1 %) (0.5 %) (0.3 %) Uncertain tax positions 0.1 % (0.4 %) 0.2 % Change in valuation allowance (2.4 %) (26.1 %) (26.0 %) Section 382 limitation of net operating loss (24.9 %) 0.0 % 0.0 % Other adjustments 0.0 % (0.2 %) 0.1 % Effective tax rate (0.1 %) (0.8 %) 0.1 % 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 and for tax carryforwards. Significant components of our deferred tax assets and liabilities as of December 31, 2020 and 2019 are as follows: As of December 31, 2020 2019 ($ in thousands) Deferred tax assets: Federal and state net operating loss carryforwards $ 55,220 $ 54,269 Intangible and other related assets 439 379 Accrued expenses 29 710 Stock compensation 3,505 2,180 Lease liability 244 325 Other 168 18 Total deferred tax assets 59,605 57,881 Deferred tax liabilities: Right of use asset (209 ) (291 ) Total deferred tax liabilities (209 ) (291 ) Valuation allowance (59,358 ) (57,560 ) Net deferred tax assets $ 38 $ 30 When realization of a deferred tax asset is more likely than not to occur, the benefit related to the deductible temporary differences attributable to operations is recognized as a reduction of income tax expense. Valuation allowances are provided against deferred tax assets when, based on all available evidence, it is considered more likely than not that some portion or all of the recorded deferred tax assets will not be realized in future periods. We cannot be certain that future U.S. taxable income will be sufficient to realize our deferred tax assets. Accordingly, a full valuation allowance has been provided against our U.S. net deferred tax assets. The valuation allowance increased by $1.8 million and $9.4 million in 2020 and 2019, respectively. The increases in 2020 and 2019 were primarily the result of an increase in net operating loss (“NOL”) carryforwards. At December 31, 2020, we had U.S. Federal and state NOL carryforwards totaling approximately $288.6 million and $234.4 million, respectively, that expire at various dates through 2038 with the exception of the Federal NOLs generated after December 31, 2017 of approximately $132.8 million which have an unlimited carryover period. At December 31, 2020, we had no Israeli NOL carryforwards. Under Section 382 of the Internal Revenue Code of 1986, as amended, substantial changes in our ownership may limit the amount of NOL carryforwards that can be utilized annually in the future to offset our U.S. Federal taxable income. Specifically, this limitation may arise in the event of a cumulative change in our ownership of more than 50% within any three-year period. We have determined that we experienced an ownership change for purposes of Section 382 in August 2005, May 2008, February 2015, and July 2020. These ownership changes resulted in annual limitations to the amount of NOL carryforwards that can be utilized to offset future taxable income, if any, at the U.S. Federal level. The annual limit is approximately $1.1 million for 2020, and each year thereafter. As a result of these Section 382 ownership changes, approximately $96.7 million of our Federal NOLs will expire unutilized. If we perform a Section 382 study in the future and conclude that have in fact undergone an ownership change, our NOL carryforwards may be substantially limited. The 2017 Tax Reform Act allowed us to receive our U.S. Federal alternative minimum tax credit carryforward in the form of a refund beginning in 2019 that we expected would go utilized. Accordingly, we recorded a receivable $0.5 million for the U.S. Federal alternative minimum tax credit refund in the accompanying consolidated balance sheet as of December 31, 2019. We received the refund during the year ended December 31, 2020. Our Israeli subsidiary has been recognized as a research and development company by the Head of the Israeli Administration of Industrial Research and Development and is entitled to tax benefits by virtue of the “beneficiary enterprise” status granted to part of its business activities under the Israeli Law for the Encouragement of Capital Investments 1959. The tax benefits include reduced tax rates on the research and development portion of its income during the first ten years of the benefit period (commenced in 2008). We benefit from a 16% tax rate for its income derived from research and development activities. Our tax rate on income from non-research and development activities is 23.0%. The continued application of the tax benefits is subject to certain conditions as defined by Israeli law. As part of the transition tax provision, we have a deemed repatriation of all of our undistributed earnings as of December 31, 2019. However, our subsidiary’s earnings, if distributed, would still be subject to local withholding tax and state income taxes. The subsidiary has undistributed earnings of approximately $ 2.0 million as of December 31, 2020 , which is considered to be permanently reinvested in the operations of the subsidiary. If the earnings were to be distributed to the U.S. parent, they would be subject to Israeli withholding and state income tax liabilities. The unrecognized deferred tax liability is approximately $ 0.2 million. We file U.S. federal, various state and Israeli income tax returns. The associated tax filings remain subject to examination by applicable tax authorities for a certain length of time following the tax year to which those filings relate. As we are in a loss carry-forward position, we are generally subject to U.S. Federal and state examinations for all years for which the Company generated losses that are included in the available losses carried forward to the current period. As of December 31, 2020, a summary of the tax years that remain subject to examination in our taxing jurisdictions is as follows: United States 2003 and forward Israel 2016 and forward We have reviewed the tax positions taken, or to be taken, in our tax returns for all tax years currently open to examination by a taxing authority. We have recorded minimal interest or penalties related to uncertain tax positions. We remain subject to examination until the statute of limitations expires for each respective tax jurisdiction. The statute of limitations will be open with respect to these tax positions until 2021. A reconciliation of the beginning and ending amount of our unrecognized tax benefits is as follows: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) Uncertain tax position at the beginning of year $ 568 $ 391 $ 471 Additions for uncertain tax positions of prior year 43 177 — Reductions for settlements with taxing authorities (72 ) — — Reductions for lapses of the applicable statutes of limitations — — (80 ) Uncertain tax position at the end of the year $ 539 $ 568 $ 391 On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was signed into law. The CARES act included several income tax provisions such as the ability to carryback NOLs generated after December 31, 2017 and before January 1, 2021 and a temporary increase to the annual IRC Section 163(j) limitation. The income tax provisions included in the CARES act did not have a material impact on our income tax provision for the year ended December 31, 2020.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	15. Commitments and Contingencies Manufacturing Commitments As of December 31, 2020, we had outstanding manufacturing commitments, including the acquisition of API, in the aggregate amount of $20.3 million, of which $17.8 million, is expected to be incurred in 2021 with the remaining to be incurred throughout 2022. The payments on these orders will occur following the deliveries of the API or completion of the manufacturing services. Legal Proceedings On June 9, 2016, Chiasma, Inc. and certain of our current and former officers were named as defendants in a purported federal securities class action lawsuit filed in the United States District Court for the District of Massachusetts, styled Gerneth v. Chiasma, Inc., et al . An amended complaint was filed by the lead plaintiff on February 10, 2017 challenging our statements regarding our first Phase 3 clinical trial methodology and results, and our ability to obtain FDA approval for octreotide capsules, in violation of Sections 11 and 15 of the Securities Act of 1933. The amended complaint added as defendants current and former members of our board of directors, as well as the investment banks that underwrote our initial public offering on July 15, 2015. The plaintiff sought an unspecified amount of compensatory damages on behalf of himself and members of a putative shareholder class, including interest and reasonable costs and expenses incurred in litigating the action, and any other relief the court determines is appropriate. The defendants filed a motion to dismiss the amended complaint on March 27, 2017 and o approval of the settlement. The litigation insurance settlement recovery and litigation settlement liability were settled during the three months ended June 30, 2019.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	16. Leases We have operating leases for our office spaces and certain automobiles which are recognized as right of use assets and lease liabilities. For the Years Ended December 31, 2020 2019 ($ in thousands) The components of lease expense were as follows: Operating lease expense $ 675 $ 366 Supplemental cash flow information related to leases was as follows: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 662 $ 219 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 122 $ 1,690 For the year ended December 31, 2018, we recognized rent expense of $0.2 million. Our operating lease right-of-use assets are recorded within other assets on our consolidated balance sheets. As of December 31, 2020 2019 ($ in thousands) Supplemental balance sheet information related to leases was as follows: Operating lease right-of-use assets $ 985 $ 1,371 Other current liabilities $ 633 $ 465 Long-term liabilities 480 1,036 Total operating lease liabilities $ 1,113 $ 1,501 Weighted average remaining lease term - operating leases 21 Months 31 Months Weighted average discount rate - operating leases 10.9 % 10.8 % Future lease payments under noncancelable leases as of December 31, 2020 are as follows: ($ in thousands) 2021 $ 726 2022 497 2023 7 Total future minimum lease payments 1,230 Less: imputed interest (117 ) Total $ 1,113

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	17. Related Party Transactions In August 2014, we signed a consulting agreement, which was most recently amended in March 2018, with one of our investors and a representative of this investor to serve as our head of clinical. Payments for services rendered by the head of clinical were $0.1 million, $0.3 million and $0.3 million for the years ended December 31, 2020, 2019, and 2018, respectively. Related to this consulting agreement, there was $35,000 and $0.1 million of accrued liabilities as of December 31, 2020 and 2019, respectively, recorded in our consolidated balance sheets.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2020
Postemployment Benefits [Abstract]
Employee Benefit Plans	18. Employee Benefit Plans Pursuant to the Israeli Severance Pay Law 1963, Israeli employees are entitled to severance pay equal to one month’s salary for each year of employment, or a portion thereof. The employees of Chiasma (Israel) Ltd. are included under Section 14 of the Severance Pay Law, under which these employees are entitled to monthly deposits, which relieve us from future obligations under this law. As a result, no assets or liabilities are recorded in the accompanying consolidated balance sheets. In addition, we make mandated monthly contributions to an Israeli government retirement benefit plan for our Israeli employees. We provide a 401(k) profit-sharing plan covering eligible U.S. employees to make tax deferred contributions, a portion of which are matched by us. All matching contributions and participant contributions vest immediately. During the years ended December 31, 2020, 2019, and 2018, we recorded expenses of $0.4 million, $0.2 million and $0.2 million, respectively, related to these employee benefit plans.

Interest and Other Income, net

Interest and Other Income, net	12 Months Ended
	Dec. 31, 2020
Interest And Other Income [Abstract]
Interest and Other Income, net	19. Interest and Other Income, net Interest and other income, net is as follows: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) (Loss) / gain on foreign currency transactions, net $ (42 ) $ (75 ) $ 37 Interest income 668 1,554 1,007 Change in fair value of derivative liabilities 1,200 — — Other income — 64 — Total $ 1,826 $ 1,543 $ 1,044

Quarterly Financial Data (unaud

Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (unaudited)	20. Quarterly Financial Data (unaudited) Three Months Ended March 31, 2020 June 30, 2020 September 30, 2020 December 31, 2020 ($ in thousands, except for per share data) Loss from operations $ (15,707 ) $ (20,337 ) $ (17,432 ) $ (17,173 ) Net loss (15,386 ) (21,128 ) (18,457 ) (19,808 ) Earnings per share Basic $ (0.36 ) $ (0.50 ) $ (0.30 ) $ (0.32 ) Diluted $ (0.36 ) $ (0.50 ) $ (0.30 ) $ (0.32 ) Three Months Ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 ($ in thousands, except for per share data) Loss from operations $ (8,921 ) $ (8,166 ) $ (8,226 ) $ (12,266 ) Net loss (8,750 ) (7,840 ) (7,683 ) (12,047 ) Earnings per share Basic $ (0.36 ) $ (0.25 ) $ (0.20 ) $ (0.29 ) Diluted $ (0.36 ) $ (0.25 ) $ (0.20 ) $ (0.29 )

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation The accompanying consolidated financial statements include the accounts of Chiasma, Inc. and its subsidiaries and are prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and are stated in U.S. dollars. The consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities in the ordinary course of business. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes during the reporting period. We base these estimates and assumptions on historical experience when available, and on various factors that we believe to be reasonable under the specific circumstances. Significant estimates relied upon in preparing the accompanying consolidated financial statements include, but are not limited to, recognition of product revenues, accounting for stock-based compensation, income taxes, the fair value of embedded derivative and our deferred royalty obligation and accounting for certain accruals. We assess the above estimates on an ongoing basis; however, actual results could materially differ from those estimates.
Cash Equivalents	Cash Equivalents Cash equivalents consist of highly liquid instruments which mature within three months or less from the date of purchase.
Marketable Securities	Marketable Securities Our investments primarily consist of commercial paper and corporate and government debt securities. These marketable securities are classified as available-for-sale, and as such, are reported at fair value on our consolidated balance sheets. Unrealized holding gains and losses are reported within accumulated other comprehensive income as a separate component of stockholders’ equity. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion, together with interest on securities, are included in interest and other income, net, on our consolidated statements of operations. If a decline in the fair value of a marketable security below our cost basis is determined to be other than temporary, such marketable security is written down to its estimated fair value as a new cost basis and the amount of the write-down is included in earnings as an impairment charge. The cost of securities sold is based on the specific identification method.
Accounts Receivable	Accounts Receivable Our accounts receivable consist of amounts due from one specialty pharmacy (the “customer”) for sales of MYCAPSSA and which have standard payments terms. We extend credit to our customer based on our evaluation of the customer’s financial condition. Accounts receivable are stated at amounts due net of applicable prompt pay discounts and other adjustments. We assess the need for an allowance for doubtful accounts by considering a number of factors, including the length of time trade accounts receivable are past due and the customer’s ability to pay its obligation. Based on a review of these factors, as of December 31 , 2020, we determined that an allowance for doubtful accounts was not required.
Concentrations of credit risk	Concentrations of credit risk Financial instruments that potentially subject us to significant concentration of credit risk consist primarily of cash, cash equivalents, marketable securities, and accounts receivable. During the year ended December 31, 2020, one customer comprised 100% of our accounts receivable and product revenues. We routinely maintain deposits in financial institutions in excess of government insured limits. Management believes that we are not exposed to significant credit risk as our deposits are held at financial institutions that management believes to be of high credit quality and we have not experienced any significant losses in these deposits. We regularly invest excess operating cash in deposits with major financial institutions and money market funds and in notes issued by the U.S. government, as well as in fixed income investments and bond funds, both of which can be readily purchased and sold using established markets. We believe that the market risk arising from our holdings of these financial instruments is mitigated based on the fact that many of these securities are either government backed or of high credit rating.
Inventory	Inventory Prior to FDA approval of MYCAPSSA, all costs related to the manufacturing of MYCAPSSA that could potentially be available to support the planned U.S. commercial launch were charged to research and development expense in the period incurred. Generally, inventory may be capitalized if it is probable that future revenues will be generated from the sale of the inventory and that these revenues will exceed the cost of the inventory. Through the FDA approval date of MYCAPSSA, we expensed all of our manufacturing costs due to the high risk inherent in drug development and uncertainty as to whether MYCAPSSA would be approved. We began to capitalize our manufacturing-related costs to inventory starting July 1, 2020. We capitalize the costs to manufacture our products incurred after regulatory approval when, based on our judgment, future commercialization is considered probable and the future economic benefit is expected to be realized. In connection therewith, we value our inventories at the lower of cost or estimated net realizable value. We determine the cost of our inventories, which includes amounts related to active pharmaceutical ingredient (“API”), and other raw materials, third party manufacturing costs and other overhead costs, on a first-in, first-out basis. Inventories that may be used for either research and development or commercial sale are classified as inventory until the material is consumed or otherwise allocated for research and development. If the material is intended to be used for research and development, it is expensed as research and development once that determination is made. On a quarterly basis, we review inventory quantities on hand and analyze the provision for excess and obsolete inventory based primarily on remaining product shelf life and our estimated sales forecast which is based on anticipated future demand. We build demand forecasts by considering factors such as, but not limited to, overall market potential, market share, market acceptance, and patient usage. Our estimates of future product demand may prove to be imprecise and changes in estimates will result in a change to the provision required for excess and obsolete inventory. Accordingly, any significant unanticipated changes in demand could have a significant impact on the value of our inventory and results of operations.
Foreign currency translation	Foreign currency translation We use the U.S. dollar as our functional currency. Monetary assets and liabilities denominated in foreign currency are re-measured at current rates and non-monetary assets denominated in foreign currency are recorded at historical exchange rates. Realized and unrealized exchange gains or losses from transactions and re-measurement adjustments are reflected in other income, net, in the accompanying consolidated statements of operations.
Comprehensive income (loss)	Comprehensive income (loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Other than reported net income, comprehensive income (loss) includes unrealized gains and losses on available for sale securities, which are disclosed in the accompanying consolidated statements of comprehensive income (loss). There were no reclassifications out of comprehensive income (loss) for the years ended December 31, 2020, 2019 or 2018.
Segment information	Segment information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, our Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. We view our operations and manage our business in one operating segment.
Other assets	Other assets Other assets consist of right of use assets, long-term restricted deposits, prepayments, and deferred tax assets.
Restricted Cash	Restricted cash Restricted cash consists of $20.0 million that we are required to maintain in securitized cash and investment accounts under the Revenue Interest Financing Agreement, interest-bearing money market accounts held as security deposits against bank guarantees, and amounts related to our co-pay assistance program.
Property and equipment	Property and equipment Property and equipment are stated at cost, net of accumulated depreciation and amortization. Expenditures for maintenance and repairs are charged to operations as incurred, whereas major betterments are capitalized as additions to property and equipment. Depreciation and amortization are recorded using the straight-line method over the estimated useful lives of the assets, as follows: Asset Category Estimated Useful Lives Computer equipment and software 3 years Office furniture and equipment 7—17 years (mainly 7) Machinery and equipment 5 — 7 years Leasehold improvements The lesser of lease term or estimated useful lives
Impairment of long-lived assets	Impairment of long-lived assets We review long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. When such events occur, we compare the carrying amounts of the assets to their undiscounted expected future cash flows the assets are expected to generate and to be recognized. The amount of impairment loss to be recognized is the excess of the carrying value over the fair value of the related asset. We did not record any impairments during the years ended December 31, 2020, 2019 and 2018.
Deferred Royalty Obligation	Deferred Royalty Obligation We treat the deferred royalty obligation, as discussed further in Note 9, as a debt obligation, amortized under the effective interest rate method over the estimated life of the agreement. We recognize interest expense thereon using the effective rate, which is based on our current estimates of future revenues over the life of the arrangement. In connection therewith, we periodically assess our expected revenues using internal projections, impute interest on the carrying value of the deferred royalty obligation, and record interest expense using the effective interest rate. To the extent our estimates of future revenues are greater or less than previous estimates or the estimated timing of such payments is materially different than previous estimates, we will account for any such changes by adjusting the effective interest rate on a prospective basis, with a corresponding impact to the reclassification of our deferred royalty obligation between short- and long-term. The assumptions used in determining the expected repayment term of the deferred royalty obligation and amortization period of the issuance costs requires that we make estimates that could impact the short-term and long-term classification of such costs, as well as the period over which such costs will be amortized.
Revenue Recognition	Revenue Recognition In accordance with accounting guidance for revenue recognition, we recognize revenue when a customer obtains control of promised goods or services, in an amount that reflects the consideration which we expect to receive in exchange for those goods or services. To determine revenue recognition for arrangements that we determine to be within the scope of such guidance, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. We only apply the five-step model to contracts when it is probable that we will collect the consideration we are entitled to in exchange for the goods or services that we transfer to the customer. For a further discussion of accounting for net product revenue see Note 3 .
Research and development	Research and development Research and development costs are expensed as incurred. Research and development costs include payroll and personnel expense, consulting costs, external contract research and development expenses, raw materials, drug product manufacturing costs, and allocated overhead including depreciation and amortization, rent, and utilities. Research and development costs that are paid in advance of performance are capitalized as a prepaid expense and amortized over the service period as the services are provided.
Clinical trial costs	Clinical trial costs Clinical trial costs are a component of research and development expenses. We accrue and expense clinical trial activities performed by third parties on an evaluation of the progress to completion of specific tasks using data such as hours spent in performance of services, patient enrollment, clinical site activation, and other information provided to us by our vendors. We make estimates of our clinical trial accrued expenses as of each balance sheet date in our financial statements based on facts and circumstances known to us. If timelines or contracts are modified based upon changes in the clinical trial protocol or scope of work to be performed, we assess our estimates of accrued expenses accordingly.
Patent costs	Patent costs Patent costs are expensed as incurred as their realization is uncertain. These costs are classified as general and administrative in the accompanying consolidated statements of operations.
Advertising and Product Promotion Costs	Advertising and Product Promotion Costs Advertising and product promotion costs are included in selling, general and administrative expenses and were $5.3 million during the year ended December 31, 2020. We did not incur any advertising and promotion costs in the years ended December 31, 2019 and 2018, respectively. Advertising and product promotion costs are expensed as incurred.
Stock-based compensation	Stock-based compensation We account for all stock-based compensation to employees and nonemployees based on their fair values on the date of grant. For stock-based awards with only service conditions, we recognize compensation on a straight-line basis over the requisite service period, which is usually the vesting period of the award, net of any actual forfeitures. We determine the fair value of stock options by using the Black-Scholes option pricing model. This model requires the input of several assumptions such as the expected option term, the expected risk-free interest rate over the expected option term, the expected volatility of our stock price over the expected option term, and the expected dividend yield over the expected option term. The computation of expected volatility is based on an average historical share price volatility based on an analysis of reported data for a peer group of comparable publicly traded companies, which were selected based upon industry similarities. The interest rate for periods within the expected term of the award is based on the U.S. Treasury risk-free interest rate in effect at the time of grant. The expected lives of the options were estimated using the simplified method.
Income taxes	Income taxes The consolidated financial statements reflect provisions for federal, state, local and foreign income taxes. Deferred tax assets and liabilities represent future tax consequences of temporary differences between the financial statement carrying amounts and the tax basis of assets and liabilities and for loss carryforwards using enacted tax rates expected to be in effect in the years in which the differences reverse. A valuation allowance is recorded when it is more likely than not that some or all of the deferred tax assets will not be realized. We determine whether it is more likely than not that a tax position will be sustained upon examination. If it is not more likely than not that a position will be sustained, none of the benefit attributable to the position is recognized. The tax benefit to be recognized for any tax position that meets the more likely than not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the contingency. We account for interest and penalties related to uncertain tax positions as part of our other expenses in the accompanying consolidated financial statements.
Leases	Leases We determine if an arrangement is a lease at inception. We have operating leases for our office spaces and certain automobiles. Right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use asset also includes direct costs incurred and is reduced by lease incentives. Lease agreements with lease and non-lease components are accounted for separately. As our leases do not provide an implicit rate, we use an estimated incremental borrowing rate based on the information available at the commencement date in determining the present value of future payments. We recognize operating lease expense on a straight-line basis over the lease term.
Contingent liabilities	Contingent liabilities In the normal course of business, we are subject to proceedings, lawsuits, and other claims and assessments. We assess the likelihood of any adverse judgments or outcomes to these matters as well as potential ranges of probable losses. A determination of the amount of reserves required, if any, for these contingencies is made after careful analysis of each individual issue. The required reserves may change in the future due to new developments in each matter or changes in approach such as a change in settlement strategy in dealing with these matters. We record charges for the losses we anticipate incurring in connection with litigation and claims against us when we conclude a loss is probable and we can reasonably estimate these losses.
Earnings Per Share	Earnings per share We compute basic earnings per share by dividing net loss by the weighted average number of common shares outstanding for the period. We compute diluted earnings per common share after giving consideration to all potentially dilutive common shares, including stock options and warrants outstanding during the period, except where the effect of such non-participating securities would be antidilutive.
Recently Issued Accounting Pronouncements	Recently issued accounting pronouncements In June 2016, the Financial Accounting Standards Board issued new guidance which will require more timely recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. The new guidance requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. The new guidance also requires enhanced disclosures regarding significant estimates and judgments used in estimating credit losses. On January 1, 2020, we adopted this standard. The adoption of this standard did not have a material impact on our consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives of Assets	Depreciation and amortization are recorded using the straight-line method over the estimated useful lives of the assets, as follows: Asset Category Estimated Useful Lives Computer equipment and software 3 years Office furniture and equipment 7—17 years (mainly 7) Machinery and equipment 5 — 7 years Leasehold improvements The lesser of lease term or estimated useful lives

Product Revenue, Net (Tables)

Product Revenue, Net (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Schedule Of Product Revenue And Allowances	The following table summarizes activity in each of the above product revenue allowances and reserve categories for year ended December 31, 2020: Discounts and Fees Rebates and Other Incentives Returns Total ($ in thousands) Balance, January 1, 2020 $ — $ — $ — $ — Provision 80 142 1 223 Payments or credits (64 ) (12 ) — (76 ) Balance, December 31, 2020 $ 16 $ 130 $ 1 $ 147

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments All Other Investments [Abstract]
Schedule of Investments	Our investments consisted of the following as of December 31, 2020 and 2019: As of December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value ($ in thousands) Money market funds $ 29,392 $ — $ — $ 29,392 Corporate notes 11,347 — (1 ) 11,346 Commercial paper 98,030 8 (8 ) 98,030 U.S. treasury securities 12,582 1 — 12,583 Total $ 151,351 $ 9 $ (9 ) $ 151,351 As of December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value ($ in thousands) Money market funds $ 23,012 $ — $ — $ 23,012 Corporate notes 45,584 20 — 45,604 Commercial paper 20,899 17 — 20,916 Total $ 89,495 $ 37 $ — $ 89,532
Schedule of Fair Value of Investments	The fair values of our investments by classification in our consolidated balance sheets as of December 31, 2020 and 2019 were as follows: As of December 31, 2020 2019 ($ in thousands) Cash and cash equivalents $ 10,829 $ 25,012 Marketable securities 119,959 64,520 Restricted cash 20,563 — Total $ 151,351 $ 89,532

Fair Value Measurements and F_2

Fair Value Measurements and Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements of Company's Financial Instruments	The following tables summarize the fair value measurements of our financial instruments as of December 31, 2020 and 2019: Fair Value Measurements at December 31, 2020 Description Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Financial assets ($ in thousands) Cash equivalents and restricted cash: Money market funds $ 29,392 $ — $ — $ 29,392 Commercial paper — 2,000 — 2,000 Total cash equivalents and restricted cash $ 29,392 $ 2,000 $ — $ 31,392 Marketable securities: U.S. treasury securities $ — $ 12,583 $ — $ 12,583 Corporate notes — 11,346 — 11,346 Commercial paper — 96,030 — 96,030 Total marketable securities $ — $ 119,959 $ — $ 119,959 Total $ 29,392 $ 121,959 $ — $ 151,351 Financial liabilities Derivative liabilities $ — $ — $ 1,900 $ 1,900 Fair Value Measurements at December 31, 2019 Description Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Financial assets ($ in thousands) Cash equivalents: Money market funds $ 23,012 $ — $ — $ 23,012 Corporate notes — 2,000 — 2,000 Total cash equivalents $ 23,012 $ 2,000 $ — $ 25,012 Marketable securities: Corporate notes $ — $ 43,604 $ — $ 43,604 Commercial paper — 20,916 — 20,916 Total marketable securities $ — $ 64,520 $ — $ 64,520 Total $ 23,012 $ 66,520 $ — $ 89,532
Summary of the changes in the fair value of the embedded derivative liabilities	The following table sets forth a summary of the changes in the fair value of the embedded derivative liabilities for the year ended December 31, 2020: ($ in thousands) Fair Value Measurement of Embedded Derivative using Significant Unobservable Inputs (Level 3) Balance, January 1, 2020 $ — Additions during the period 3,100 Change in fair value during the period (1,200 ) Balance, December 31, 2020 $ 1,900

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	Our inventory of MYCAPSSA consisted of the following as of December 31, 2020: ($ in thousands) December 31, 2020 Raw materials and supplies $ 6,786 Work in process 3,857 Finished goods 312 Total inventory $ 10,955

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Summary of Property and Equipment	Property and equipment consisted of the following as of December 31, 2020 and 2019: As of December 31, 2020 2019 ($ in thousands) Computer equipment and software $ 553 $ 431 Office furniture and equipment 358 108 Machinery and equipment 115 115 Property and equipment, at cost 1,026 654 Less accumulated depreciation (492 ) (320 ) Property and equipment, net $ 534 $ 334

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following as of December 31, 2020 and 2019: As of December 31, 2020 2019 ($ in thousands) Accrued payroll and employee benefits $ 4,900 $ 1,872 Accrued selling, general, administrative and other expenses 3,830 1,485 Accrued research and development expenses 3,128 4,219 Total accrued expenses $ 11,858 $ 7,576

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Summary of common stock warrants activity	A summary of our common stock warrants activity for the year ended December 31, 2020 is presented below. Description Exercise Price Expiration Date Balance, December 31, 2019 Warrants Issued Warrants Exercised Balance, December 31, 2020 October 2012 Warrants $ 0.0910 10/22/2022 829,686 — (205,321 ) 624,365 March 2013 Warrants $ 0.0910 3/28/2022 829,686 — (205,321 ) 624,365 December 2014 Warrants $ 9.1320 12/16/2024 923,527 — — 923,527 February 2015 Warrants $ 9.1320 12/16/2024 984,116 — — 984,116 July 2020 Pre-Funded Warrants $ 0.0001 No expiration — 5,000,000 — 5,000,000 3,567,015 5,000,000 (410,642 ) 8,156,373

Stock Incentive Plan (Tables)

Stock Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Fair Value Calculation of Option Granted	The fair value of each stock option issued was estimated at the date of grant using the Black-Scholes option model with the following weighted-average assumptions: For the Years Ended December 31, 2020 2019 2018 Expected volatility 85 % 97 % 77 % Expected term (years) 6.2 6.0 6.2 Risk-free interest rate 0.93 % 1.93 % 2.72 % Expected dividend yield 0 % 0 % 0 %
Summary of Stock Option Activity	A summary of option activity as of December 31, 2020 and the year then ended is presented below: Number of Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2019 6,489,692 $ 5.01 7.3 $ 8,166,882 Granted 2,307,500 $ 4.63 Exercised (207,416 ) $ 1.35 Forfeited / Expired (211,716 ) $ 5.47 Outstanding, December 31, 2020 8,378,060 $ 4.98 7.2 $ 5,611,109 Exercisable, December 31, 2020 4,774,332 $ 4.98 6.0 $ 4,634,332 Vested and expected to vest, December 31, 2020 8,378,060 $ 4.98 7.2 $ 5,611,109
Schedule of Stock-based Compensation	Stock-based compensation expense for 2020, 2019 and 2018 consisted of the following: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) General and administrative $ 4,082 $ 2,243 $ 1,412 Research and development 938 1,027 1,318 Total $ 5,020 $ 3,270 $ 2,730

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Summary of loss before provision (benefit) for income taxes	Our loss before provision (benefit) for income taxes for the years ended December 31, 2020, 2019 and 2018 consisted of the following: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) Domestic $ (75,102 ) $ (36,407 ) $ (31,477 ) Foreign 407 371 185 Total $ (74,695 ) $ (36,036 ) $ (31,292 )
Summary of Components of Income Tax Provision (Benefit)	The components of income tax provision (benefit) consisted of the following for the years ended December 31, 2020, 2019 and 2018: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) Current provision for income taxes: U.S. $ 61 $ 18 $ 12 Foreign 27 288 (59 ) Total current provision for income taxes 88 306 (47 ) Deferred tax provision (benefit) - foreign (4 ) (22 ) 16 Total deferred provision (benefit) for income taxes (4 ) (22 ) 16 Total provision (benefit) for income taxes $ 84 $ 284 $ (31 )
Summary of Differences Between Effective Tax Rates and U.S. Federal Statutory Tax	A reconciliation setting forth the differences between our effective tax rates and the U.S. federal statutory tax rate is as follows: For the Years Ended December 31, 2020 2019 2018 U.S. federal tax provision at statutory rate 21.0 % 21.0 % 21.0 % State and local tax, net of federal benefit 6.2 % 5.6 % 5.3 % Foreign rate differences 0.0 % 0.1 % 0.2 % Non-deductible foreign stock compensation (0.1 %) (0.3 %) (0.4 %) Effect of other permanent differences (0.1 %) (0.5 %) (0.3 %) Uncertain tax positions 0.1 % (0.4 %) 0.2 % Change in valuation allowance (2.4 %) (26.1 %) (26.0 %) Section 382 limitation of net operating loss (24.9 %) 0.0 % 0.0 % Other adjustments 0.0 % (0.2 %) 0.1 % Effective tax rate (0.1 %) (0.8 %) 0.1 %
Schedule of Components of Deferred Tax Assets and Liabilities	Significant components of our deferred tax assets and liabilities as of December 31, 2020 and 2019 are as follows: As of December 31, 2020 2019 ($ in thousands) Deferred tax assets: Federal and state net operating loss carryforwards $ 55,220 $ 54,269 Intangible and other related assets 439 379 Accrued expenses 29 710 Stock compensation 3,505 2,180 Lease liability 244 325 Other 168 18 Total deferred tax assets 59,605 57,881 Deferred tax liabilities: Right of use asset (209 ) (291 ) Total deferred tax liabilities (209 ) (291 ) Valuation allowance (59,358 ) (57,560 ) Net deferred tax assets $ 38 $ 30
Summary of Tax Years that Remain Subject to Examination	As of December 31, 2020, a summary of the tax years that remain subject to examination in our taxing jurisdictions is as follows: United States 2003 and forward Israel 2016 and forward
Reconciliation of Beginning and Ending Amount of Uncertain Tax Position	A reconciliation of the beginning and ending amount of our unrecognized tax benefits is as follows: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) Uncertain tax position at the beginning of year $ 568 $ 391 $ 471 Additions for uncertain tax positions of prior year 43 177 — Reductions for settlements with taxing authorities (72 ) — — Reductions for lapses of the applicable statutes of limitations — — (80 ) Uncertain tax position at the end of the year $ 539 $ 568 $ 391

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Summary of Operations in Leased Facilities	For the Years Ended December 31, 2020 2019 ($ in thousands) The components of lease expense were as follows: Operating lease expense $ 675 $ 366 Supplemental cash flow information related to leases was as follows: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 662 $ 219 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 122 $ 1,690 As of December 31, 2020 2019 ($ in thousands) Supplemental balance sheet information related to leases was as follows: Operating lease right-of-use assets $ 985 $ 1,371 Other current liabilities $ 633 $ 465 Long-term liabilities 480 1,036 Total operating lease liabilities $ 1,113 $ 1,501 Weighted average remaining lease term - operating leases 21 Months 31 Months Weighted average discount rate - operating leases 10.9 % 10.8 %
Schedule of Future Lease Payments Under Noncancelable Leases	Future lease payments under noncancelable leases as of December 31, 2020 are as follows: ($ in thousands) 2021 $ 726 2022 497 2023 7 Total future minimum lease payments 1,230 Less: imputed interest (117 ) Total $ 1,113

Interest and Other Income, net

Interest and Other Income, net (Tables)	12 Months Ended
	Dec. 31, 2020
Interest And Other Income [Abstract]
Summary of Interest and Other Income, Net	Interest and other income, net is as follows: For the Years Ended December 31, 2020 2019 2018 ($ in thousands) (Loss) / gain on foreign currency transactions, net $ (42 ) $ (75 ) $ 37 Interest income 668 1,554 1,007 Change in fair value of derivative liabilities 1,200 — — Other income — 64 — Total $ 1,826 $ 1,543 $ 1,044

Quarterly Financial Data (una_2

Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	Three Months Ended March 31, 2020 June 30, 2020 September 30, 2020 December 31, 2020 ($ in thousands, except for per share data) Loss from operations $ (15,707 ) $ (20,337 ) $ (17,432 ) $ (17,173 ) Net loss (15,386 ) (21,128 ) (18,457 ) (19,808 ) Earnings per share Basic $ (0.36 ) $ (0.50 ) $ (0.30 ) $ (0.32 ) Diluted $ (0.36 ) $ (0.50 ) $ (0.30 ) $ (0.32 ) Three Months Ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 ($ in thousands, except for per share data) Loss from operations $ (8,921 ) $ (8,166 ) $ (8,226 ) $ (12,266 ) Net loss (8,750 ) (7,840 ) (7,683 ) (12,047 ) Earnings per share Basic $ (0.36 ) $ (0.25 ) $ (0.20 ) $ (0.29 ) Diluted $ (0.36 ) $ (0.25 ) $ (0.20 ) $ (0.29 )

Nature of Business - Additional

Nature of Business - Additional Information (Detail) $ / shares in Units, $ in Millions	1 Months Ended					9 Months Ended	12 Months Ended
	Jul. 31, 2020USD ($)$ / sharesshares	Apr. 30, 2020USD ($)	Aug. 31, 2019USD ($)$ / sharesshares	Apr. 30, 2019USD ($)$ / sharesshares	Jul. 31, 2018Patient	Sep. 30, 2020USD ($)	Dec. 31, 2020SubsidiaryPatient$ / shares
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of subsidiaries owned by the company | Subsidiary							2
Stock issued during period, shares, new issues | shares | shares			10,166,427	7,263,158
Shares issued, price per share | $ / shares | $ / shares			$ 5.50	$ 4.75
Proceeds from issuance of common stock			$ 52.3	$ 32.2
Pre Funded Warrant [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares	5,000,000
Proceeds from Pre Funded Warrants	$ 75.5
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares	$ 0.0001						$ 0.0001
Common stock and Pre-Funded Warrants [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Stock issued during period, shares, new issues | shares | shares	15,125,000
Shares issued, price per share | $ / shares | $ / shares	$ 4
Jeffries LLC ("Jeffries") [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Maximum proceeds of sales of common stock under sales agreement		$ 60
Healthcare Royalty Partners IV, L.P. ("HCR") [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Maximum proceeds under investment agreement		$ 75
Healthcare Royalty Partners IV, L.P. ("HCR") [Member] | First And Second Tranche [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Proceeds from investment						$ 65
MPOWERED Trial [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
First trial period for adult acromegaly patients expected to randomize					6 months
Additional trial period for adult acromegaly patients expected to randomize					9 months
MPOWERED Trial [Member] | Maximum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Trial period for adult acromegaly patients expected to enroll							15 months
Number of adult acromegaly patients expected to enroll in trial | Patient							150
MPOWERED Trial [Member] | Minimum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of adult acromegaly patients expect to randomize | Patient					80

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)Segment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Reclassifications out of comprehensive income (loss)	$ 0	$ 0	$ 0
Number of operating segments | Segment	1
Restricted cash	$ 20,563,000
Impairment of long-lived assets	0	0	0
Selling, General and Administrative Expenses [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Advertising and product promotion costs	5,300,000	$ 0	$ 0
Securitized Cash and Investment Accounts [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Restricted cash	$ 20,000,000
Customer One [Member] | Accounts Receivable [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	100.00%
Customer One [Member] | Product Revenue [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	100.00%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Assets (Detail)	12 Months Ended
	Dec. 31, 2020
Computer Equipment And Software [Member]
Property and equipment [Line Items]
Estimated useful lives	3 years
Office Furniture and Equipment [Member] | Minimum [Member]
Property and equipment [Line Items]
Estimated useful lives	7 years
Office Furniture and Equipment [Member] | Maximum [Member]
Property and equipment [Line Items]
Estimated useful lives	17 years
Machinery and equipment [Member] | Minimum [Member]
Property and equipment [Line Items]
Estimated useful lives	5 years
Machinery and equipment [Member] | Maximum [Member]
Property and equipment [Line Items]
Estimated useful lives	7 years
Leasehold Improvements
Property and equipment [Line Items]
Estimated useful lives	The lesser of lease term or estimated useful lives

Product Revenue, Net - Schedule

Product Revenue, Net - Schedule Of Product Revenue And Allowances (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Revenue From Contract With Customer [Abstract]
Provision	$ 80
Payments or credits	(64)
Balance, December 31, 2020	16
Provision	142
Payments or credits	(12)
Balance, December 31, 2020	130
Provision	1
Balance, December 31, 2020	1
Provision	223
Payments or credits	(76)
Balance, December 31, 2020	$ 147

Investments - Schedule of Inves

Investments - Schedule of Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Gain (Loss) on Securities [Line Items]
Amortized Cost	$ 151,351	$ 89,495
Gross Unrealized Gains	9	37
Gross Unrealized Losses	(9)
Estimated Fair Value	151,351	89,532
Money Market Funds [Member]
Gain (Loss) on Securities [Line Items]
Amortized Cost	29,392	23,012
Estimated Fair Value	29,392	23,012
Corporate Notes [Member]
Gain (Loss) on Securities [Line Items]
Amortized Cost	11,347	45,584
Gross Unrealized Gains		20
Gross Unrealized Losses	(1)
Estimated Fair Value	11,346	45,604
Commercial Paper [Member]
Gain (Loss) on Securities [Line Items]
Amortized Cost	98,030	20,899
Gross Unrealized Gains	8	17
Gross Unrealized Losses	(8)
Estimated Fair Value	98,030	$ 20,916
U.S. treasury securities [Member]
Gain (Loss) on Securities [Line Items]
Amortized Cost	12,582
Gross Unrealized Gains	1
Estimated Fair Value	$ 12,583

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investments All Other Investments [Abstract]
Realized gains and losses on available-for-sale securities	$ 0	$ 0	$ 0
Cash excluded from cash and cash equivalents	$ 4,600,000	$ 2,800,000
Contractual maturity period of investments	1 year

Investments - Schedule of Fair

Investments - Schedule of Fair Value of Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Net Investment Income [Line Items]
Fair values of investments	$ 151,351	$ 89,532
Cash and Cash Equivalents [Member]
Net Investment Income [Line Items]
Fair values of investments	10,829	25,012
Marketable Securities [Member]
Net Investment Income [Line Items]
Fair values of investments	119,959	$ 64,520
Restricted Cash [Member]
Net Investment Income [Line Items]
Fair values of investments	$ 20,563

Fair Value Measurements and F_3

Fair Value Measurements and Fair Value of Financial Instruments - Fair Value Measurements of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash equivalents and restricted cash:
Total cash equivalents and restricted cash	$ 31,392
Cash equivalents:
Total cash equivalents		$ 25,012
Marketable securities:
Total marketable securities	151,351	89,532
Total	151,351	89,532
Financial liabilities
Derivative liabilities	1,900
Money Market Funds [Member]
Cash equivalents and restricted cash:
Total cash equivalents and restricted cash	29,392
Cash equivalents:
Total cash equivalents		23,012
Commercial Paper [Member]
Cash equivalents and restricted cash:
Total cash equivalents and restricted cash	2,000
Marketable securities:
Total marketable securities	96,030	20,916
U.S. treasury securities [Member]
Marketable securities:
Total marketable securities	12,583
Corporate Notes [Member]
Cash equivalents:
Total cash equivalents		2,000
Marketable securities:
Total marketable securities	11,346	43,604
Marketable Securities [Member]
Marketable securities:
Total marketable securities	119,959	64,520
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Cash equivalents and restricted cash:
Total cash equivalents and restricted cash	29,392
Cash equivalents:
Total cash equivalents		23,012
Marketable securities:
Total	29,392	23,012
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Money Market Funds [Member]
Cash equivalents and restricted cash:
Total cash equivalents and restricted cash	29,392
Cash equivalents:
Total cash equivalents		23,012
Significant Other Observable Inputs (Level 2) [Member]
Cash equivalents and restricted cash:
Total cash equivalents and restricted cash	2,000
Cash equivalents:
Total cash equivalents		2,000
Marketable securities:
Total	121,959	66,520
Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper [Member]
Cash equivalents and restricted cash:
Total cash equivalents and restricted cash	2,000
Marketable securities:
Total marketable securities	96,030	20,916
Significant Other Observable Inputs (Level 2) [Member] | U.S. treasury securities [Member]
Marketable securities:
Total marketable securities	12,583
Significant Other Observable Inputs (Level 2) [Member] | Corporate Notes [Member]
Cash equivalents:
Total cash equivalents		2,000
Marketable securities:
Total marketable securities	11,346	43,604
Significant Other Observable Inputs (Level 2) [Member] | Marketable Securities [Member]
Marketable securities:
Total marketable securities	119,959	$ 64,520
Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities
Derivative liabilities	$ 1,900

Fair Value Measurements and F_4

Fair Value Measurements and Fair Value of Financial Instruments - Summary of the changes in the fair value of the embedded derivative liabilities (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Embedded Derivative [Line Items]
Balance, December 31, 2020	$ 3,100
Fair Value Measurement of Embedded Derivative using Significant Unobservable Inputs (Level 3)
Embedded Derivative [Line Items]
Additions during the period	3,100
Change in fair value during the period	(1,200)
Balance, December 31, 2020	$ 1,900

Inventory - Schedule Of Invento

Inventory - Schedule Of Inventory Current (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 6,786
Work in process	3,857
Finished goods	312
Total inventory	$ 10,955

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 1,026	$ 654
Less accumulated depreciation	(492)	(320)
Property and equipment, net	534	334
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	553	431
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	358	108
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 115	$ 115

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Abstract]
Depreciation	$ 172	$ 55	$ 88

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued payroll and employee benefits	$ 4,900	$ 1,872
Accrued selling, general, administrative and other expenses	3,830	1,485
Accrued research and development expenses	3,128	4,219
Total accrued expenses	$ 11,858	$ 7,576

Deferred Royalty Obligation - A

Deferred Royalty Obligation - Additional Information (Detail) - USD ($)	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2020	Jul. 31, 2020	Apr. 30, 2020	Dec. 31, 2020
Deferred Royalty Obligation [Line Items]
Fair value of embedded derivative						$ 3,100,000
Carrying value of the deferred royalty obligation						63,548,000
Significant Unobservable Inputs (Level 3) [Member]
Deferred Royalty Obligation [Line Items]
Fair value of embedded derivative						1,900,000
Fair value of the deferred royalty obligation						$ 82,100,000
Healthcare Royalty Partners IV, L.P. ("HCR") [Member]
Deferred Royalty Obligation [Line Items]
Proceeds from first investment amount					$ 25,000,000
Royalty payments applicable tiered percentage					195.00%
Variable rate of total return					95.00%
Minimum Cash Covenant					$ 20,000,000
Healthcare Royalty Partners IV, L.P. ("HCR") [Member] | Forecast [Member]
Deferred Royalty Obligation [Line Items]
Royalty guarantees commitments percentage	100.00%	60.00%
Food and Drug Administration [Member]
Deferred Royalty Obligation [Line Items]
Proceeds from second investment amount				$ 25,000,000
Food and Drug Administration [Member] | Healthcare Royalty Partners IV, L.P. ("HCR") [Member] | Deferred Royalty Obligation [Member]
Deferred Royalty Obligation [Line Items]
Effective interest rate deferred royalty obligation						17.00%
Debt issuance costs incurred						$ 600,000
Food and Drug Administration [Member] | Healthcare Royalty Partners IV, L.P. ("HCR") [Member] | Significant Unobservable Inputs (Level 3) [Member] | Deferred Royalty Obligation [Member]
Deferred Royalty Obligation [Line Items]
Fair value of embedded derivative						1,900,000
Commercial Drug Supply And First Commercial Sale [Member]
Deferred Royalty Obligation [Line Items]
Proceeds from third investment amount			$ 15,000,000
Commercial Milestone [Member]
Deferred Royalty Obligation [Line Items]
Proceeds from fourth investment amount						$ 10,000,000

Earnings per Share of Common _2

Earnings per Share of Common Stock - Additional Information (Detail) - $ / shares	Dec. 31, 2020	Jul. 31, 2020
Pre Funded Warrant [Member]
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.0001	$ 0.0001

Warrants - Summary of common st

Warrants - Summary of common stock warrants activity (Detail)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Disclosure Of Warrants Activity [Line Items]
Class of Warrant or Right, Outstanding	3,567,015
Warrants Issued	5,000,000
Warrants Exercised	(410,642)
Class of Warrant or Right, Outstanding	8,156,373
October 2012 Warrants
Disclosure Of Warrants Activity [Line Items]
Exercise Price | $ / shares	$ 0.0910
Expiration Date	Oct. 22, 2022
Class of Warrant or Right, Outstanding	829,686
Warrants Exercised	(205,321)
Class of Warrant or Right, Outstanding	624,365
March 2013 Warrants
Disclosure Of Warrants Activity [Line Items]
Exercise Price | $ / shares	$ 0.0910
Expiration Date	Mar. 28, 2022
Class of Warrant or Right, Outstanding	829,686
Warrants Exercised	(205,321)
Class of Warrant or Right, Outstanding	624,365
December 2014 Warrants
Disclosure Of Warrants Activity [Line Items]
Exercise Price | $ / shares	$ 9.1320
Expiration Date	Dec. 16, 2024
Class of Warrant or Right, Outstanding	923,527
Class of Warrant or Right, Outstanding	923,527
February 2015 Warrants
Disclosure Of Warrants Activity [Line Items]
Exercise Price | $ / shares	$ 9.1320
Expiration Date	Dec. 16, 2024
Class of Warrant or Right, Outstanding	984,116
Class of Warrant or Right, Outstanding	984,116
July 2020 Pre-Funded Warrants
Disclosure Of Warrants Activity [Line Items]
Exercise Price | $ / shares	$ 0.0001
Warrants Issued	5,000,000
Class of Warrant or Right, Outstanding	5,000,000

Warrants - Additional Informati

Warrants - Additional Information (Detail) - Pre Funded Warrant [Member] - $ / shares	Dec. 31, 2020	Jul. 31, 2020
Class of Warrant or Right [Line Items]
Warrants exercise price per share	$ 0.0001	$ 0.0001
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		5,000,000

Stock Incentive Plan - Addition

Stock Incentive Plan - Additional Information (Detail)	Jan. 01, 2016	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2015Directorshares	Jan. 01, 2021shares	Jan. 01, 2020shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized for issuance		9,775,418
Shares of common stock available for grant		1,033,460
Number of stock option outstanding		8,378,060	6,489,692
Weighted average grant date fair value of stock options per share | $ / shares		$ 3.32	$ 4.79	$ 1.06
Aggregate intrinsic value of stock options exercised | $		$ 700,000	$ 1,000,000	$ 200,000
Unrecognized compensation cost related to stock options, expected to be recognized | $		$ 12,200,000
Expected recognition, weighted-average period		3 years
Share Based Compensation Arrangement Inventory Capitalized Compensation Cost | $		$ 54,000
Number of directors who exercised options to purchase common stock | Director					2
Stock options exercised		207,416
Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercised					122,644
2008 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized for issuance		3,547,741
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized for issuance		3,566,296					1,683,136
Percentage of shares issued and outstanding under plan	4.00%
2015 Plan [Member] | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized for issuance						2,312,623
Employee Stock Option [Member] | Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock, shares issued					116,258
Employee Stock Option [Member] | 2008 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options expiration period		10 years
Stock options vesting period		4 years

Stock Incentive Plan - Schedule

Stock Incentive Plan - Schedule of Fair Value Calculation of Option Granted (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected volatility	85.00%	97.00%	77.00%
Expected term (years)	6 years 2 months 12 days	6 years	6 years 2 months 12 days
Risk-free interest rate	0.93%	1.93%	2.72%
Expected dividend yield	0.00%	0.00%	0.00%

Stock Incentive Plan - Summary

Stock Incentive Plan - Summary of Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning balance	6,489,692
Number of stock options granted	2,307,500
Number of stock options, Exercised	(207,416)
Number of stock options, Forfeited / Expired	(211,716)
Ending balance	8,378,060	6,489,692
Number of stock options, Exercisable	4,774,332
Number of stock options, Vested and expected to vest	8,378,060
Weighted-average exercise price options outstanding, Beginning balance	$ 5.01
Weighted-average exercise price options, Granted	4.63
Weighted-average exercise price options, Exercised	1.35
Weighted-average exercise price options, Forfeited / Expired	5.47
Weighted-average exercise price options outstanding, Ending balance	4.98	$ 5.01
Weighted-average exercise price options, Exercisable	4.98
Weighted-average exercise price options, Vested and expected to vest	$ 4.98
Weighted- average remaining contractual term outstanding options	7 years 2 months 12 days	7 years 3 months 18 days
Weighted- average remaining contractual term options, Exercisable	6 years
Weighted- average remaining contractual term options, Vested and expected to vest	7 years 2 months 12 days
Aggregate Intrinsic Value options outstanding	$ 5,611,109	$ 8,166,882
Aggregate Intrinsic Value options, exercisable	4,634,332
Aggregate Intrinsic Value options, vested and expected to vest	$ 5,611,109

Stock Incentive Plan - Schedu_2

Stock Incentive Plan - Schedule of Stock-based Compensation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expenses	$ 5,020	$ 3,270	$ 2,730
General and Administrative [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expenses	4,082	2,243	1,412
Research and Development [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expenses	$ 938	$ 1,027	$ 1,318

License Agreement - Additional

License Agreement - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended
	Mar. 31, 2018	Mar. 31, 2016	Dec. 31, 2016
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Abstract]
Aggregate amount of obligation			$ 5.1
Contractual obligation, final payment made	$ 1.7	$ 1.7

Income Taxes - Summary of loss

Income Taxes - Summary of loss before provision (benefit) for income taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Domestic	$ (75,102)	$ (36,407)	$ (31,477)
Foreign	407	371	185
Loss before income taxes	$ (74,695)	$ (36,036)	$ (31,292)

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Income Tax Provision (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current Income Tax Expense Benefit Continuing Operations [Abstract]
U.S.	$ 61	$ 18	$ 12
Foreign	27	288	(59)
Total current provision for income taxes	88	306	(47)
Deferred tax provision (benefit) - foreign	(4)	(22)	16
Total deferred provision (benefit) for income taxes	(4)	(22)	16
Total provision (benefit) for income taxes	$ 84	$ 284	$ (31)

Income Taxes - Summary of Diffe

Income Taxes - Summary of Differences Between Effective Tax Rates and U.S. Federal Statutory Tax (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract]
U.S. federal tax provision at statutory rate	21.00%	21.00%	21.00%
State and local tax, net of federal benefit	6.20%	5.60%	5.30%
Foreign rate differences	0.00%	0.10%	0.20%
Non-deductible foreign stock compensation	(0.10%)	(0.30%)	(0.40%)
Effect of other permanent differences	(0.10%)	(0.50%)	(0.30%)
Uncertain tax positions	0.10%	(0.40%)	0.20%
Change in valuation allowance	(2.40%)	(26.10%)	(26.00%)
Section 382 limitation of net operating loss	(24.90%)	0.00%	0.00%
Other adjustments	0.00%	(0.20%)	0.10%
Effective tax rate	(0.10%)	(0.80%)	0.10%

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Federal and state net operating loss carryforwards	$ 55,220	$ 54,269
Intangible and other related assets	439	379
Accrued expenses	29	710
Stock compensation	3,505	2,180
Lease liability	244	325
Other	168	18
Total deferred tax assets	59,605	57,881
Deferred tax liabilities:
Right of use asset	(209)	(291)
Total deferred tax liabilities	(209)	(291)
Valuation allowance	(59,358)	(57,560)
Net deferred tax assets	$ 38	$ 30

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Increase in valuation allowance	$ 1,800,000	$ 9,400,000
Net operating loss carryforwards	132,800,000
Federal NOLs Unutilized	$ 96,700,000
Effective income from non- research and development activities	(0.10%)	(0.80%)	0.10%
Undistributed earnings of subsidiary	$ 2,000,000
Unrecognized deferred tax liability	200,000
Alternative Minimum Tax [Member]
Income Taxes [Line Items]
Income Taxes Receivable		$ 500,000
Prior To May Two Thousand Eight Year [Member]
Income Taxes [Line Items]
U.S.Federal net operating loss carryforwards subject to annual limitation	1,100,000
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	234,400,000
United States [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 288,600,000
Non-US [Member]
Income Taxes [Line Items]
Net operating loss carryforwards		$ 0
Israel [Member]
Income Taxes [Line Items]
Effective income tax rate on income from research and development activities	16.00%
Effective income from non- research and development activities	23.00%

Income Taxes - Summary of Tax Y

Income Taxes - Summary of Tax Years that Remain Subject to Examination (Detail)	12 Months Ended
	Dec. 31, 2020
2003 and Forward [Member] | United States [Member]
Income Tax Examination [Line Items]
Income tax examination	2003 and forward
2016 and Forward [Member] | Israel [Member]
Income Tax Examination [Line Items]
Income tax examination	2016 and forward

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Beginning and Ending Amount of Uncertain Tax Position (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Uncertain tax position at the beginning of year	$ 568	$ 391	$ 471
Additions for uncertain tax positions of prior year	43	177
Reductions for settlements with taxing authorities	(72)
Reductions for lapses of the applicable statutes of limitations			(80)
Uncertain tax position at the end of the year	$ 539	$ 568	$ 391

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2018
Loss Contingencies [Line Items]
Estimated settlement liability		$ 18.8
Litigation insurance settlements receivable		$ 18.3
Active Pharmaceutical Ingredient [Member]
Loss Contingencies [Line Items]
Outstanding purchase commitment amount	$ 20.3
Purchase commitment for 2021	$ 17.8

Leases - Summary of Operations

Leases - Summary of Operations in Leased Facilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases Operating [Abstract]
Operating lease expense	$ 675	$ 366
Operating cash flows from operating leases	662	219
Operating leases	122	1,690
Operating lease right-of-use assets	985	1,371
Other current liabilities	$ 633	$ 465
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherCurrentLiabilitiesMember	us-gaap:OtherCurrentLiabilitiesMember
Long-term liabilities	$ 480	$ 1,036
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	chma:LongTermLiabilitiesMember	chma:LongTermLiabilitiesMember
Total operating lease liabilities	$ 1,113	$ 1,501
Operating Lease, Liability, Statement of Financial Position [Extensible List]	chma:OperatingLeaseLiabilitiesMember	chma:OperatingLeaseLiabilitiesMember
Weighted average remaining lease term - operating leases	21 months	31 months
Weighted average discount rate - operating leases	10.90%	10.80%

Leases - Additional Information

Leases - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Leases Operating [Abstract]
Operating Leases, Rent Expense	$ 0.2

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Rental Commitments for Operating Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases Operating [Abstract]
2021	$ 726
2022	497
2023	7
Total future minimum lease payments	1,230
Less: imputed interest	(117)
Total	$ 1,113	$ 1,501

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Accrued liabilities	$ 11,858,000	$ 7,576,000
Head of Clinical [Member]
Related Party Transaction [Line Items]
Costs incurred for services	100,000	300,000	$ 300,000
Accrued liabilities	$ 35,000	$ 100,000

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Chiasma (Israel) Ltd [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Employee benefit plans expense	$ 0.4	$ 0.2	$ 0.2

Interest and Other Income, Ne_2

Interest and Other Income, Net - Summary of Interest and Other Income, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest And Other Income [Abstract]
(Loss) / gain on foreign currency transactions, net	$ (42)	$ (75)	$ 37
Interest income	668	1,554	1,007
Change in fair value of derivative liabilities	1,200
Other income		64
Total	$ 1,826	$ 1,543	$ 1,044

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) - Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Data [Abstract]
Loss from operations	$ (17,173)	$ (17,432)	$ (20,337)	$ (15,707)	$ (12,266)	$ (8,226)	$ (8,166)	$ (8,921)	$ (70,649)	$ (37,579)	$ (32,336)
Net loss	$ (19,808)	$ (18,457)	$ (21,128)	$ (15,386)	$ (12,047)	$ (7,683)	$ (7,840)	$ (8,750)	$ (74,779)	$ (36,320)	$ (31,261)
Earnings per share
Basic	$ (0.32)	$ (0.30)	$ (0.50)	$ (0.36)	$ (0.29)	$ (0.20)	$ (0.25)	$ (0.36)	$ (1.43)	$ (1.06)	$ (1.28)
Diluted	$ (0.32)	$ (0.30)	$ (0.50)	$ (0.36)	$ (0.29)	$ (0.20)	$ (0.25)	$ (0.36)	$ (1.43)	$ (1.06)	$ (1.28)