Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

The following table contains quarterly financial information for 2015 and 2014. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair statement of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period.

	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
	(in thousands, except per share data)
2015
Product revenues, net	$	—		$	—		$	—		$	4,328
License and collaboration revenues		14,842			36,558			16,440			17,090
Cost of product revenues		—			—			—			46
Research and development expenses		35,679			42,806			37,763			44,740
Selling, general and administrative expenses		9,189			12,315			16,956			19,335
Net loss		(34,432	)		(22,901	)		(42,386	)		(48,068	)
Net loss attributable to Merrimack Pharmaceuticals, Inc.		(34,759	)		(22,778	)		(42,594	)		(47,826	)
Net loss per share available to common stockholders—basic and diluted	$	(0.32	)	$	(0.21	)	$	(0.38	)	$	(0.41	)

	First Quarter			Second Quarter			Third Quarter			Fourth Quarter
	(in thousands, except per share data)
2014
License and collaboration revenues	$	13,034		$	27,815		$	28,002		$	33,905
Research and development expenses		30,324			33,795			43,632			30,744
Selling, general and administrative expenses		6,224			7,921			8,095			8,277
Net loss		(27,754	)		(18,290	)		(28,038	)		(9,477	)
Net loss attributable to Merrimack Pharmaceuticals, Inc.		(27,585	)		(18,109	)		(27,901	)		(9,696	)
Net loss per share available to common stockholders—basic and diluted	$	(0.27	)	$	(0.17	)	$	(0.27	)	$	(0.09	)