Merrimack Pharmaceuticals (MACK) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 03, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Trading Symbol	MACK
Entity Registrant Name	MERRIMACK PHARMACEUTICALS INC
Entity Central Index Key	0001274792
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		13,410,243
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock, $0.01 par value
Security Exchange Name	NASDAQ
Entity File Number	001-35409
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3210530
Entity Address, Address Line One	One Broadway
Entity Address, Address Line Two	14th Floor
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02142
City Area Code	617
Local Phone Number	441-1000
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 13,890	$ 14,038
Prepaid expenses and other current assets	2,360	2,506
Total current assets	16,250	16,544
Other assets	191	232
Total assets	16,441	16,776
Current liabilities:
Accounts payable, accrued expenses and other	684	770
Total current liabilities	684	770
Total liabilities	684	770
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value: 10,000 shares authorized at March 31, 2021 and December 31, 2020; no shares issued or outstanding at March 31, 2021 or December 31, 2020
Common stock, $0.01 par value: 30,000 shares authorized at March 31, 2021 and December 31, 2020; 13,410 and 13,380 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	1,334	1,334
Additional paid-in capital	558,756	558,309
Accumulated deficit	(544,333)	(543,637)
Total stockholders’ equity	15,757	16,006
Total liabilities and stockholders’ equity	$ 16,441	$ 16,776

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	13,410,000	13,380,000
Common stock, shares outstanding	13,410,000	13,380,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive (Loss) Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating expenses:
General and administrative expenses	$ 746	$ 1,935
Gain on sale of assets	(50)	(2,139)
Total operating (income) expenses	696	(204)
(Loss) income from operations	(696)	204
Other income and expenses:
Interest income		45
Total other income and expenses		45
Net (loss) income and comprehensive (loss) income	$ (696)	$ 249
Net (loss) income per common share - basic and diluted	$ (0.05)	$ 0.02
Weighted-average common shares used to compute basic and diluted net loss per common share	13,397	13,380

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2019	$ 17,312	$ 1,334	$ 556,587	$ (540,609)
Balance (in shares) at Dec. 31, 2019		13,380
Stock-based compensation	484		484
Net income (loss)	249			249
Balance at Mar. 31, 2020	18,045	$ 1,334	557,071	(540,360)
Balance (in shares) at Mar. 31, 2020		13,380
Balance at Dec. 31, 2020	16,006	$ 1,334	558,309	(543,637)
Balance (in shares) at Dec. 31, 2020		13,380
Exercise of stock options	239		239
Exercise of stock options (in shares)		30
Stock-based compensation	208		208
Net income (loss)	(696)			(696)
Balance at Mar. 31, 2021	$ 15,757	$ 1,334	$ 558,756	$ (544,333)
Balance (in shares) at Mar. 31, 2021		13,410

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income (loss)	$ (696)	$ 249
Changes in operating assets and liabilities:
Prepaid expenses and other assets	187	186
Accounts payable, accrued expenses and other	(86)	215
Net cash used in operating activities	(437)	(1,005)
Gain on sale of in process research and development	(50)	(2,139)
Stock-based compensation expense	208	484
Cash flows from investing activities
Proceeds from sale of in process research and development	50	2,450
Net cash provided by investing activities	50	2,450
Cash flows from financing activities
Proceeds from exercise of stock options	239
Net cash provided by financing activities	239
Net (decrease) increase in cash and cash equivalents	(148)	1,445
Cash and cash equivalents, beginning of period	14,038	16,580
Cash and cash equivalents, end of period	$ 13,890	$ 18,025

Nature of the Business

Nature of the Business	3 Months Ended
	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business Merrimack Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company based in Cambridge, Massachusetts that is entitled to receive up to $450.0 million in contingent milestone payments related to its sale of ONIVYDE ® The $450.0 million in contingent milestone payments resulting from the Ipsen sale consist of: • $225.0 million upon approval by the U.S. Food and Drug Administration (“FDA”) of ONIVYDE ® for the first-line treatment of metastatic adenocarcinoma of the pancreas, subject to certain conditions; • $150.0 million upon approval by the FDA of ONIVYDE ® for the treatment of small-cell lung cancer after failure of first-line chemotherapy; and • $75.0 million upon approval by the FDA of ONIVYDE ® for an additional indication unrelated to those described above. On May 30, 2019, the Company announced the completion of its review of strategic alternatives, following which the Company’s board of directors (the “Board”) implemented a series of measures designed to extend the Company’s cash runway and preserve its ability to capture the potential milestone payments resulting from the Ipsen Sale. In connection with that announcement, the Company discontinued the discovery efforts on its remaining preclinical programs: MM-401, an agonistic antibody targeting a novel immuno-oncology target, TNFR2; and MM-201, a highly stabilized agonist-Fc fusion protein targeting death receptors 4 and 5. The Company is seeking potential acquirers for its remaining preclinical and clinical assets. The Company’s termination of its executive management team and all other employees was substantially completed by June 28, 2019 and fully completed by July 12, 2019. As of July 12, 2019, the Company does not have any employees. The Company has engaged external consultants to run the day-to-day operations of the Company. The Company has also entered into consulting agreements with certain former members of its executive management team who are supporting the Company’s relationship with current partners, assisting with the potential sale of remaining preclinical and clinical assets, and assisting with certain legal and regulatory matters and the continued wind-down of operations. On July 12, 2019, the Company completed the sale to Elevation Oncology, Inc. (formerly known as 14ner Oncology, Inc.) (“Elevation”) of its anti-HER3 antibody programs, MM-121 (seribantumab) and MM-111 (the “Elevation sale”). In connection with the Elevation sale, the Company received an upfront cash payment of $3.5 million. The Company is also eligible to receive up to $54.5 million in additional potential development, regulatory approval and commercial-based milestone payments, consisting of: • $3.0 million for achievement of the primary endpoint in the first registrational clinical study of either MM-121 or MM-111; • Up to $16.5 million in total payments for the achievement of various regulatory approval and reimbursement-based milestones in the United States, Europe and Japan; and • Up to $35.0 million in total payments for achieving various cumulative worldwide net sales targets between $100.0 million and $300.0 million for MM-121 and MM-111. On March 27, 2020, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Celator Pharmaceuticals, Inc. (the “Buyer”), pursuant to which the Buyer agreed to purchase certain assets (the “Transferred Assets”) relating to certain of the Company’s preclinical nanoliposome programs (the “Transaction”). The Company and the Buyer completed the Transaction simultaneously with the execution of the Asset Purchase Agreement. Under the terms of the Asset Purchase Agreement, the Buyer paid to the Company a cash payment of $2.3 million and reimbursed the Company for $0.2 million related to certain specified expenses. The Company incurred $0.4 million expenses related to the Transaction as of March 31, 2020. The Company is subject to risks and uncertainties common to companies in the biopharmaceutical industry, including, among other things, development by competitors of new technological innovations, protection of proprietary technology and compliance with government regulations, approval by the FDA and other foreign health agencies to approve any pharmaceutical under development, obtaining insurance reimbursement for any drug if and when approved by regulators, and its ability to secure additional capital to fund operations. None of the Company’s product candidates are approved for any indication by the FDA or any other regulatory agency. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies, among others. In addition, the Company is dependent upon the services of its external consultants for the operation of the Company. The Company’s business strategy depends substantially upon its ability to receive future milestone payments from Ipsen and Elevation. Any failure to achieve such milestones or a perception that the milestones may not be achieved will materially and adversely affect the Company and the value of its common stock. The recent COVID-19 outbreak has created significant volatility and economic disruption and the impact on the Company’s future consolidated results of operations is uncertain In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern will allow the Company to continue its operations into 2027, when the Company estimates the longest-term potential Ipsen milestone may be achieved. The continued viability of the Company beyond that point is dependent on its ability to realize milestone payments from its licensed product candidates, raise additional capital to finance its operations or to reduce operating expenses. There can be no assurance that the Company will be successful in receiving future milestone payments or able to obtain sufficient capital to cover its costs on acceptable terms, if at all. The Company expects that it would seek to finance any future cash needs through a combination of divestitures of its product candidates or other assets, equity offerings and debt financings. There can be no assurance as to the timing, terms or consummation of any divestiture or financing, and the terms of any such financing may adversely affect the holdings or the rights of the Company’s stockholders or require the Company to relinquish rights to certain of its revenue streams or product candidates.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements reflect the operations of Merrimack Pharmaceuticals, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated. The condensed consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The accounting policies followed in the preparation of the interim condensed consolidated financial statements are consistent in all material respects with those presented in Note 1 to the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020. Unaudited Interim Financial Information The condensed consolidated balance sheet as of December 31, 2020 was derived from audited financial statements, but does not include all disclosures required by GAAP. The condensed consolidated balance sheet as of March 31, 2021, the condensed consolidated statements of operations and comprehensive (loss) income for the three months ended March 31, 2021 and 2020, the condensed consolidated statements of stockholders’ equity for the three months ended March 31, 2021 and 2020 and the condensed consolidated statements of cash flows for the three months ended March 31, 2021 and 2020 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2021, the results of its operations for the three months ended March 31, 2021 and 2020, its statements of stockholders’ equity for the three months ended March 31, 2021 and 2020 and its statements of cash flows for the three months ended March 31, 2021 and 2020. The financial data and other information disclosed in the notes related to the three months ended March 31, 2021 and 2020 are unaudited. The results for the three months ended March 31, 2021 and 2020 are not necessarily indicative of results to be expected for the year ending December 31, 20 2 1 , any other interim periods, or any future year or period. The unaudited interim financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 10, 2021. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates, assumptions and judgments reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	3. Fair Value of Financial Instruments The following tables show assets measured at fair value on a recurring basis as of March 31, 2021 and December 31, 2020: March 31, 2021 (in thousands) Level 1 Level 2 Level 3 Cash equivalents: Money market funds $ 13,443 $ — $ — Totals $ 13,443 $ — $ — December 31, 2020 (in thousands) Level 1 Level 2 Level 3 Cash equivalents: Money market funds $ 13,943 $ — $ — Totals $ 13,943 $ — $ — There were no

Accounts Payable, Accrued Expen

Accounts Payable, Accrued Expenses and Other	3 Months Ended
	Mar. 31, 2021
Payables And Accruals [Abstract]
Accounts Payable, Accrued Expenses and Other	4. Accounts Payable, Accrued Expenses and Other Accounts payable, accrued expenses and other as of March 31, 2021 and December 31, 2020 consisted of the following: (in thousands) March 31, 2021 December 31, 2020 Accounts payable $ 108 $ 123 Accrued goods and services 123 194 Accrued clinical trial costs 112 112 Others 341 341 Total accounts payable, accrued expenses and other $ 684 $ 770

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	5. Stock-Based Compensation The Company’s 2011 Stock Incentive Plan (the “2011 Plan”) is administered by the Company’s Board of Directors and permits the Company to grant incentive and non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards. There were no options granted during the three months ended March 31, 2021. At March 31, 2021, there were 1.4 million shares remaining available for grant under the 2011 Plan. The Company recognized stock-based compensation expense of $0.2 million and $0.5 million in general and administrative expense during the three months ended March 31, 2021 and 2020, respectively.

Net (Loss) Income Per Common Sh

Net (Loss) Income Per Common Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Net Income (Loss) Per Common Share	6. Net (Loss) Income Per Common Share Basic net (loss) income per share is calculated by dividing the net (loss) income attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of common shares outstanding during the period. Diluted net (loss) income per share is computed by dividing the net (loss) income attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of dilutive common shares outstanding during the period. Dilutive shares outstanding is calculated by adding to the weighted shares outstanding any potential (unissued) shares of common stock from outstanding stock options based on the treasury stock method. Outstanding stock options were not included in the diluted net (loss) income per share calculation because the options were out of the money or to do so would have been antidilutive (i.e., the total proceeds upon exercise would have exceeded the market value of the underlying common shares). In a period when a net loss is reported, all common stock equivalents are excluded from the calculation because they would have an anti-dilutive effect, meaning the loss per share would be reduced. Therefore, in periods where a loss is reported, there is no difference in basic and dilutive loss per share. Stock options are excluded from the calculation of diluted (loss) income per share because the net (loss) income for the three months ended March 31, 2021 and 2020 causes such securities to be anti-dilutive. Outstanding options excluded from the calculation of diluted (loss) income per share for the three months ended March 31, 2021 and 2020 are shown in the chart below: Three Months Ended March 31, (in thousands) 2021 2020 Outstanding options to purchase common stock 1,832 1,877

Restructuring Activities

Restructuring Activities	3 Months Ended
	Mar. 31, 2021
Restructuring And Related Activities [Abstract]
Restructuring Activities	7. Restructuring Activities On November 7, 2018, the Company announced that it was implementing a reduction in headcount as part of a corporate restructuring. All the restructuring expenses were paid off as of December 31, 2020. No additional restructuring expenses was recognized during the three months ended March 31, 2020. The Company paid approximately less than $0.1 million of these restructuring expenses during the three months ended March 31, 2020. No additional The following table summarizes the charges related to the restructuring activities as of March 31, 2020: (in thousands) Accrued Restructuring Expenses at December 31, 2019 Expenses Less: Payments Accrued Restructuring Expenses at March 31, 2020 Severance, benefits and related costs due to workforce reduction $ 66 $ — $ (20 ) $ 46 Totals $ 66 $ — $ (20 ) $ 46

Recent Accounting Pronouncement

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2021
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	8. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed above, the Company does not believe that the adoption of recently issued standards has or may have a material impact on the Company’s condensed consolidated financial statements or disclosures.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements reflect the operations of Merrimack Pharmaceuticals, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated. The condensed consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The accounting policies followed in the preparation of the interim condensed consolidated financial statements are consistent in all material respects with those presented in Note 1 to the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The condensed consolidated balance sheet as of December 31, 2020 was derived from audited financial statements, but does not include all disclosures required by GAAP. The condensed consolidated balance sheet as of March 31, 2021, the condensed consolidated statements of operations and comprehensive (loss) income for the three months ended March 31, 2021 and 2020, the condensed consolidated statements of stockholders’ equity for the three months ended March 31, 2021 and 2020 and the condensed consolidated statements of cash flows for the three months ended March 31, 2021 and 2020 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2021, the results of its operations for the three months ended March 31, 2021 and 2020, its statements of stockholders’ equity for the three months ended March 31, 2021 and 2020 and its statements of cash flows for the three months ended March 31, 2021 and 2020. The financial data and other information disclosed in the notes related to the three months ended March 31, 2021 and 2020 are unaudited. The results for the three months ended March 31, 2021 and 2020 are not necessarily indicative of results to be expected for the year ending December 31, 20 2 1 , any other interim periods, or any future year or period. The unaudited interim financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 10, 2021.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates, assumptions and judgments reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.
Recent Accounting Pronouncements	From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed above, the Company does not believe that the adoption of recently issued standards has or may have a material impact on the Company’s condensed consolidated financial statements or disclosures.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Summary of Assets Measured at Fair Value on a Recurring Basis	The following tables show assets measured at fair value on a recurring basis as of March 31, 2021 and December 31, 2020: March 31, 2021 (in thousands) Level 1 Level 2 Level 3 Cash equivalents: Money market funds $ 13,443 $ — $ — Totals $ 13,443 $ — $ — December 31, 2020 (in thousands) Level 1 Level 2 Level 3 Cash equivalents: Money market funds $ 13,943 $ — $ — Totals $ 13,943 $ — $ —

Accounts Payable, Accrued Exp_2

Accounts Payable, Accrued Expenses and Other (Tables)	3 Months Ended
	Mar. 31, 2021
Payables And Accruals [Abstract]
Schedule of Accounts Payable, Accrued Expenses and Other	Accounts payable, accrued expenses and other as of March 31, 2021 and December 31, 2020 consisted of the following: (in thousands) March 31, 2021 December 31, 2020 Accounts payable $ 108 $ 123 Accrued goods and services 123 194 Accrued clinical trial costs 112 112 Others 341 341 Total accounts payable, accrued expenses and other $ 684 $ 770

Net (Loss) Income Per Common _2

Net (Loss) Income Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of Outstanding Options Excluded from Computation of Diluted Income (Loss) Per Share	Outstanding options excluded from the calculation of diluted (loss) income per share for the three months ended March 31, 2021 and 2020 are shown in the chart below: Three Months Ended March 31, (in thousands) 2021 2020 Outstanding options to purchase common stock 1,832 1,877

Restructuring Activities (Table

Restructuring Activities (Tables)	3 Months Ended
	Mar. 31, 2021
Restructuring And Related Activities [Abstract]
Summary of Charges Related to Restructuring Activities	The following table summarizes the charges related to the restructuring activities as of March 31, 2020: (in thousands) Accrued Restructuring Expenses at December 31, 2019 Expenses Less: Payments Accrued Restructuring Expenses at March 31, 2020 Severance, benefits and related costs due to workforce reduction $ 66 $ — $ (20 ) $ 46 Totals $ 66 $ — $ (20 ) $ 46

Nature of the Business - Additi

Nature of the Business - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended
	Mar. 27, 2020	Jul. 12, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Apr. 03, 2017
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit			$ 544,333,000		$ 543,637,000
Net loss from continuing operations			700,000
Cash used in operating activities			437,000	$ 1,005,000
Cash, cash equivalents and marketable securities			$ 13,900,000
Celator Pharmaceuticals Inc [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash payment received	$ 2,300,000
Reimbursement of expenses	200,000
Transaction expenses	$ 400,000
Ipsen [Member] | Asset Sale Agreement [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Contingent milestone payments receivable						$ 450,000,000
Ipsen [Member] | First Line Treatment of Metastatic Adenocarcinoma of Pancreas [Member]
Summary Of Significant Accounting Policies [Line Items]
Contingent milestone payments receivable						225,000,000
Ipsen [Member] | After Failure of First Line Chemotherapy [Member]
Summary Of Significant Accounting Policies [Line Items]
Contingent milestone payments receivable						150,000,000
Ipsen [Member] | Additional Indication [Member]
Summary Of Significant Accounting Policies [Line Items]
Contingent milestone payments receivable						$ 75,000,000
14ner Sale [Member]
Summary Of Significant Accounting Policies [Line Items]
Upfront cash payment received		$ 3,500,000
14ner Sale [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional payments receivable on achievement of certain milestone events		54,500,000
14ner Sale [Member] | Achievement of the Primary Endpoint in the First Registrational Clinical Study of Either MM-121 or MM-111 [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional payments receivable on achievement of certain milestone events		3,000,000
14ner Sale [Member] | Achievement of Various Regulatory Approval and Reimbursement-Based Milestones in the United States, Europe and Japan [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional payments receivable on achievement of certain milestone events		16,500,000
14ner Sale [Member] | Achievement Various Cumulative Worldwide Net Sales Targets Between $100.0 million and $300.0 million for MM-121 and MM-111 [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional payments receivable on achievement of certain milestone events		35,000,000
Cumulative worldwide net sales target		$ 300,000,000

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Summary of Assets Measured at Fair Value on a Recurring Basis (Detail) - Recurring Basis [Member] - Level 1 [Member] - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 13,443	$ 13,943
Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 13,443	$ 13,943

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Additional Information (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Recurring Basis [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities measured at fair value	$ 0	$ 0

Accounts Payable, Accrued Exp_3

Accounts Payable, Accrued Expenses and Other - Schedule of Accounts Payable, Accrued Expenses and Other (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accounts payable	$ 108	$ 123
Accrued goods and services	123	194
Accrued clinical trial costs	112	112
Others	341	341
Total accounts payable, accrued expenses and other	$ 684	$ 770

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share Based Compensation Expense	$ 200,000	$ 500,000
Stock Incentive Plan 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for grant (in shares)	1,400,000
Number of Options, Granted	0

Net (Loss) Income Per Common _3

Net (Loss) Income Per Common Share - Schedule of Outstanding Options Excluded from Computation of Diluted Income (Loss) Per Share (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Outstanding Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding options to purchase common stock	1,832	1,877

Restructuring Activities - Addi

Restructuring Activities - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring expenses	$ 0	$ 0
Payments for restructuring		20,000
Maximum [Member]
Restructuring Cost And Reserve [Line Items]
Payments for restructuring		$ 100,000
November 2018 Corporate Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring activity, announcement date		Nov. 7, 2018

Restructuring Activities - Summ

Restructuring Activities - Summary of Charges Related to Restructuring Activities (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost And Reserve [Line Items]
Accrued Restructuring Expenses		$ 66,000
Expenses	$ 0	0
Less: Payments		(20,000)
Accrued Restructuring Expenses		46,000
Severance, Benefits and Related Costs Due to Workforce Reduction [Member]
Restructuring Cost And Reserve [Line Items]
Accrued Restructuring Expenses		66,000
Less: Payments		(20,000)
Accrued Restructuring Expenses		$ 46,000