Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues:
Total revenues	$ 25	$ 18
Operating expenses:
Research and development (Net of recoveries of $33 and $30 from a related party)	81	61
General and administrative	30	24
Total operating expenses	111	85
Loss from operations	(86)	(67)
Non-operating income (expense):
Interest and other income, net	9
Effective interest on liability for sale of future royalties	(1)
Total non-operating income, net	8
Loss before income taxes	(78)	(67)
Income tax expense	(2)	(1)
Net loss	$ (80)	$ (68)
Net loss per share, basic	$ (1.09)	$ (0.96)
Net loss per share, diluted	$ (1.09)	$ (0.96)
Shares used to compute net income loss per share, basic	73.0	71.2
Shares used to compute net income loss per share, diluted	73.0	71.2
License and Development Services Revenue
Revenues:
Total revenues	$ 17	$ 8
Other Collaboration Revenue
Revenues:
Total revenues	$ 8	$ 10