X0306 4 2019-05-19 0 0001269021 PORTOLA PHARMACEUTICALS INC PTLA 0001574591 Dier Mardi C/O PORTOLA PHARMACEUTICALS, INC. 270 EAST GRAND AVENUE SOUTH SAN FRANCISCO CA 94080 0 1 0 0 EVP, CFO & CBO Common Stock 2019-05-19 4 A 0 5859 0.00 A 72592 D Common Stock 2019-05-20 4 F 0 3022 28.69 D 69570 D Performance Stock Unit 2019-05-19 4 M 0 5859 0.00 D 2027-01-30 Common Stock 5859 0 D Each Performance Stock Unit ("PSU") granted January 30, 2017 represented a contingent right to receive one (1) share of the Issuer's Common Stock. 5,859 became vested on the upon the first anniversary of the Compensation Committee's certification of regulatory approval of Andexanet alfa in the United States in 2018. Represents the number of shares required to be sold by the reporting person to cover tax withholding obligations in connection with the vesting of Performance Stock Units. This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the reporting person. The sale is intended to comply with the requirements of Rule 10b5-1(c)(1)(i)(B) under the Exchange Act and be interpreted to meet the requirements of Rule 10b5-1(c). /s/ Mike Ouimette, as attorney-in-fact 2019-05-21