X0306 4 2015-05-29 0 0001459266 ZS Pharma, Inc. ZSPH 0001399763 Alta Partners VIII, L.P. ONE EMBARCADERO CENTER, SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001399894 Alta Partners Management VIII, LLC ONE EMBARCADERO CENTER, SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001198321 CHAMPSI FARAH ONE EMBARCADERO CENTER, SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001198325 JANNEY DANIEL ONE EMBARCADERO CENTER, SUITE 3700 SAN FRANCISCO CA 94111 0 0 1 0 0001198330 NOHRA GUY P ONE EMBARCADERO CENTER, SUITE 3700 SAN FRANCISCO CA 94111 1 0 1 0 Common Stock 2015-05-29 4 S 0 124865 58.63 D 3105225 D Common Stock 2015-05-29 4 S 0 14696 59.69 D 3090529 D Common Stock 2015-06-01 4 S 0 72520 58.00 D 3018009 D Common Stock 2015-06-02 4 S 0 84342 56.77 D 2933667 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $58.50 - $59.50, inclusive. The reporting persons undertake to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (1) to this Form 4. These shares were sold by Alta Partners VIII, L.P. ("APVIII"), the holder of record of the securities. Alta Partners Management VIII, LLC ("APMVIII") is the general partner of APVIII. Guy Nohra, Daniel Janney and Farah Champsi are managing directors of APMVIII and exercise shared voting and investment power with respect to the shares owned by APVIII. Each of the reporting persons disclaims beneficial ownership of such securities, except to the extent of his, her or its proportionate pecuniary interest therein. Mr. Nohra is also a director of the issuer. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $59.51 - $59.94, inclusive. The reporting persons undertake to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (3) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $57.60 - $58.50, inclusive. The reporting persons undertake to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (4) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $56.50 - $57.05, inclusive. The reporting persons undertake to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (5) to this Form 4. /s/Laurence Randall 2015-06-02 Laurence Randall 2015-06-02 Farah Champsi 2015-06-02 Daniel Janney 2015-06-02 Guy Nohra 2015-06-02