Shareholders’ Equity (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Stock Option Activity and Related Data

	Equity Awards		Weighted- average Exercise Price per Share		Weighted- average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding at December 31, 2018	6,466,214		$	23.26
Granted(1)	2,126,023		$	6.33
Exercised	(5,211	)	$	6.00
Cancelled/forfeited	(2,970,186	)	$	18.29
Outstanding at December 31, 2019	5,616,840		$	19.50	4.33 years	$	—
Exercisable at December 31, 2019	3,645,726		$	22.76	4.48 years	$	—

Stock Options, Valuation Assumptions

	Year Ended December 31,
	2019		2018
Volatility	97	%	114	%
Expected life (years)	6.05		6.07
Risk-free interest rate	2.5	%	2.8	%
Dividend yield	—		—

Summary of Share-based Compensation Expense

	Year Ended December 31,
	2019		2018
Research and development	$	14,861	$	21,113
Selling, general and administrative	8,872		14,038
Total share-based compensation expense	$	23,733	$	35,151