SEC Form 4 · accession 0000947871-26-000784

BlossomHill Therapeutics, Inc. · BLSM

Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗

Reporting owners

ORBIMED ADVISORS LLC

Director

OrbiMed Capital GP VIII LLC

Director

Period of report

Aug 10, 2026

Accepted (ET)

Aug 12, 2026 · 4:43 pm EDT

Rule 10b5-1 plan

box not checked

Issuer CIK

0001839970

Table I — non-derivative securities

Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock^F1,F3,F4	Aug 10, 2026	C	1,039,996	—	A	1,039,996	I	See footnotes
Common Stock^F1,F3,F4	Aug 10, 2026	C	1,049,283	—	A	2,089,279	I	See footnotes
Common Stock^F2,F3,F4	Aug 10, 2026	P	625,000	$16.00	A	2,714,279	I	See footnotes

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
Series A Preferred Stock^F3,F4,F1	—	Aug 10, 2026	C	1,039,996	D	—	—	Common Stock	1,039,996	0	I
Series B Preferred Stock^F3,F4,F1	—	Aug 10, 2026	C	1,049,283	D	—	—	Common Stock	1,049,283	0	I

Explanation of responses

F1Each share of Series A Preferred Stock and Series B Preferred Stock (together, the "Preferred Stock") automatically converted into 1 share of the Issuer's Common Stock upon the closing of the Issuer's initial public offering on August 10, 2026 without payment of consideration. The Preferred Stock has no expiration date.
F2Reflects shares of the Issuer's Common Stock purchased in the Issuer's initial public offering.
F3These securities are held directly by OrbiMed Private Investments VIII, LP ("OPI VIII"). OrbiMed Capital GP VIII LLC ("GP VIII") is the general partner of OPI VIII. OrbiMed Advisors LLC ("OrbiMed Advisors") is the managing member of GP VIII. By virtue of such relationships, GP VIII and OrbiMed Advisors may be deemed to have voting power and investment power over the securities held by OPI VIII and as a result, may be deemed to have beneficial ownership over such securities. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, W. Carter Neild, and Geoffrey C. Hsu, each of whom disclaims beneficial ownership of the shares held by OPI VIII.
F4This report on Form 4 is jointly filed by OrbiMed Advisors and GP VIII. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. The Reporting Persons have designated Carl L. Gordon, a member of OrbiMed Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any of such entity or person is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.