Exhibit 12.1

PORTOLA PHARMACEUTICALS, INC.

STATEMENT RE COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

(in thousands)

Our earnings were insufficient to cover fixed charges for the nine months ended September 30, 2015, and the years ended December 31, 2014, 2013 and 2010. The following table sets forth our deficiency of earnings to cover fixed charges for the nine months ended September 30, 2015, and the years ended December 31, 2014, 2013 and 2010.

	Nine Months Ended September 30,			Year Ended December 31,
	2015			2014			2013			2012		2011		2010
Fixed charges:
Interest expense	$	0		$	0		$	0		$	0	$	21	$	380
Estimated interest portion of rental expense		287			433			421			409		404		370
Total fixed charges	$	287		$	433		$	421		$	409	$	425	$	750
Earnings:
(Loss) income before income taxes	$	(160,399	)	$	(137,125	)	$	(83,352	)	$	11,366	$	19,984	$	(17,475	)
Fixed charges per above		287			433			421			409		425		750
Earnings	$	(160,112	)	$	(136,692	)	$	(82,931	)	$	11,775	$	20,409	$	(16,725	)
Ratio of earnings to fixed charges		N/A			N/A			N/A			29:1		48:1		N/A
Deficiency of earnings available to cover fixed charges	$	(160,399	)	$	(137,125	)	$	(83,352	)	$	N/A	$	N/A	$	(17,475	)