Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2021

Commitments and Contingencies Disclosure [Abstract]

Schedule of future minimum lease payments under non-cancelable operating leases

Future minimum lease payments under non-cancelable operating leases as of December 31, 2021, are as follows (in millions):

Year Ending December 31,
2022	$	3.1
2023	2.7
2024	2.4
2025	1.7
2026	1.8
Thereafter	7.2
Total	$	18.9

Schedule of financial obligation under various agreements

The following table outlines our financial obligations under certain of these agreements:

Counterparty	Relevant Product	Our Financial Obligation
Supernus Pharmaceuticals, Inc.	Orenitram	Single-digit royalty on net product sales of Orenitram, through the second quarter of 2026
Lilly	Adcirca	Ten percent royalty on net sales, plus milestone payments of $325,000 for each $1,000,000 in net product sales
The Scripps Research Institute	Unituxin	One percent royalty on net product sales of Unituxin
DEKA Research & Development Corp.	Remunity Pump	Product fees and single-digit royalty on net product sales of the Remunity Pump and on net sales of Remodulin for use with the system; reimbursement of DEKA’s development and manufacturing costs
MannKind Corporation	Tyvaso DPI	Low double-digit royalty on net product sales of Tyvaso DPI and up to $50.0 million in developmental milestone payments (all of which have already been paid)
Arena	Ralinepag	Low double-digit, tiered royalty on net product sales of ralinepag (any route of administration); a one-time payment of $250.0 million upon FDA approval of an inhaled formulation of ralinepag to treat PAH; and a one-time payment of $150.0 million upon approval in certain non-U.S. jurisdictions of an oral version of ralinepag to treat any indication