X0206 3 2017-07-24 1 0001626199 ALPINE IMMUNE SCIENCES, INC. ALPN 0001055951 ORBIMED ADVISORS LLC 601 LEXINGTON AVENUE, 54TH FLOOR NEW YORK NY 10022-4629 1 0 0 0 0001682115 OrbiMed Capital GP VI LLC 601 LEXINGTON AVENUE, 54TH FLOOR NEW YORK NY 10022 1 0 0 0 0001055949 ISALY SAMUEL D 601 LEXINGTON AVENUE, 54TH FLOOR NEW YORK NY 0022 1 0 0 0 Peter Thompson ("Thompson") serves on the Issuer's Board as a representative of OrbiMed Private Investments VI, LP ("OPI VI"). OrbiMed Capital GP VI LLC ("GP VI") is the sole general partner of OPI VI, and OrbiMed Advisors LLC ("Advisors"), a registered adviser under the Investment Advisers Act of 1940, as amended, is the sole managing member of GP VI. Samuel D. Isaly ("Isaly"), a natural person, is the managing member of, and holder of a controlling interest in, Advisors. By virtue of such relationships, GP VI, Advisors and Isaly may be deemed to have voting and investment power with respect to the Issuer's securities held by OPI VI and as a result may be deemed to have beneficial ownership over such securities. Thompson is an employee of Advisors. /s/ Samuel D. Isaly 2017-07-26