Exhibit 12.1

STATEMENT REGARDING COMPUTATION OF RATIOS

(in thousands)

	Year Ended December 31,
	2012		2013			2014			2015			2016
Earnings:
Pretax income (loss)		5,025		(46,090	)		(60,542	)		(88,929	)		(141,090	)
Add fixed charges		2,807		2,568			2,295			1,984			1,633
Total Earnings		7,832		(43,522	)		(58,247	)		(86,945	)		(139,457	)
Fixed charges:
Interest expensed, including amortization of debt discount and deferred financing costs		0		0			0			0			0
Estimated interest component of rent expense		2,807		2,568			2,295			1,984			1,633
Total fixed charges		2,807		2,568			2,295			1,984			1,633
Ratio of earnings to fixed charges		2.8		N/A			N/A			N/A			N/A
Deficiency of earnings available to cover fixed charges		—		(46,090	)		(60,542	)		(88,929	)		(141,090	)