As of March 31, 2017, the Commercial Business met all the conditions to be classified as held-for-sale and represents a discontinued operation since the disposal of the Commercial Business is a strategic shift that will have a major effect on the Company’s operations and financial results. The Company will not have further significant involvement in the operations of the discontinued Commercial Business. The operating results of the Commercial Business are reported as discontinued operations, net of tax in the consolidated statements of operations and comprehensive loss for all periods presented.

The consolidated financial statements for the years ended December 31, 2018 and 2017 reflect the operations of the Commercial Business as a discontinued operation. Discontinued operations for the years ended December 31, 2018 and 2017 includes the following:

(in thousands)	Years Ended December 31,
	2018			2017
Revenues:
Product revenues, net	$	—		$	16,135
License and collaboration revenues		—			7,797
Other revenues		—			1,973
Total revenues		—			25,905
Costs and expenses:
Cost of revenues		—			3,890
Research and development expenses		171			3,002
Selling, general and administrative expenses		—			10,907
Restructuring expenses		—			9,535
Total costs and expenses		171			27,334
Other income and expenses:
Interest expense		—			(6,743	)
Gain on sale of Commercial Business		28,000			601,670
Income from discontinued operations	$	27,829		$	593,498
Income tax expense		(7,568	)		(46,626	)
Total income from discontinued operations	$	20,261		$	546,872

In connection with the sale of the Commercial Business, the Company retained the right to receive net milestone payments that may become payable related to the development and commercialization of ONIVYDE for up to $33.0 million.

During the year ended December 31, 2018, the Company received $28.0 million of the potential $33.0 million in milestone payments related to the development and commercialization of ONIVYDE. The Company included the $28.0 million in discontinued operations because the amounts directly relate to the Commercial Business, which was classified as a discontinued operation. The disposal of the Commercial Business represented a strategic shift that had a major effect on the Company’s operations and financial results. The Company also recorded $0.2 million of research and development expense in discontinued operations in the year ended December 31, 2018, as this expense is directly associated with the $28.0 million in milestones.