13D Filing: Baker Bros. Advisors Owns 18% of Bellicum Pharmaceuticals, Inc (BLCM)

Page 6 of 9 SEC Filing

Amendment No. 1 to Schedule 13D

This Amendment No. 1 to Schedule 13D amends and supplements
the previously filed Schedule 13D filed by Baker Bros. Advisors LP (the “Adviser”), Baker Bros. Advisors (GP), LLC
(the “Adviser GP”), Julian C. Baker and Felix J. Baker. Except as supplemented herein, such statements, as heretofore
amended and supplemented, remain in full force and effect. All capitalized terms contained herein but not
otherwise defined shall have the meanings ascribed to such terms in the previously filed Schedule 13D.

The Adviser GP is the sole general partner of the Adviser. Pursuant
to the amended and restated management agreements, among the Adviser, Baker Brothers Life Sciences, L.P. (“Life Sciences”),
14159, L.P. (“14159”), and 667, L.P. (“667”, and together with Life Sciences and 14159, the “Funds”),
and their respective general partners, the Adviser has complete and unlimited discretion and authority with respect to the Funds’
investments and voting power over investments.

Item 5. Interest in Securities of
the Issuer.

(a) and (b) Items 7 through 11 and 13 of each
of the cover pages of this Amendment No. 1 are incorporated herein by reference. Set forth below is the aggregate number and percentage
of shares of Common Stock directly held, as of the date hereof, by each of the following based upon 26,998,423 shares of Common
Stock outstanding as of January 12, 2016, as reported in the Issuer’s Form S-3 filed with the SEC on January 15, 2016. Such
percentage figures were calculated in accordance with Rule 13d-3 under the Securities Exchange Act of 1934, as amended.