Form 4 for BLSM BlossomHill Therapeutics, Inc.

Accepted 2026-08-12 16:46:16 ET · period of report 2026-08-10 · accession 0000947871-26-000785 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X	Filed	Traded	Ticker	Insider	Title	Type	Price	Qty	Owned	ΔOwn	Value
DMI	2026-08-12 16:46	2026-08-10	BLSM	GORDON CARL L	Dir	C - Cnv Deriv	—	+2.09M	2.09M	New	—
DI	2026-08-12 16:46	2026-08-10	BLSM	GORDON CARL L	Dir	P - Purchase	$16.00	+625.0K	2.71M	+30%	+$10.00M
DMI	2026-08-12 16:46	2026-08-10	BLSM	GORDON CARL L	Dir	C - Cnv Deriv	$0.00	-2.09M	0	-100%	$0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#	Table	Security	Date	Code	A/D	Shares	Price	Owned after	Own	Exercise / expiry	Underlying	Footnotes
1	Common	Common Stock	2026-08-10	C	A	1,039,996	—	1,039,996	I See footnotes	—	—	(F1) Each 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. (F3) These 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 the Reporting Person, W. Carter Neild, and Geoffrey C. Hsu, each of whom disclaims beneficial ownership of the shares held by OPI VIII. (F4) Each of the Reporting Person, OrbiMed Advisors, and GP VIII 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. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, or GP VIII is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.
2	Common	Common Stock	2026-08-10	C	A	1,049,283	—	2,089,279	I See footnotes	—	—	(F1) Each 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. (F3) These 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 the Reporting Person, W. Carter Neild, and Geoffrey C. Hsu, each of whom disclaims beneficial ownership of the shares held by OPI VIII. (F4) Each of the Reporting Person, OrbiMed Advisors, and GP VIII 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. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, or GP VIII is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.
3	Common	Common Stock	2026-08-10	P	A	625,000	$16.00	2,714,279	I See footnotes	—	—	(F2) Reflects shares of the Issuer's Common Stock purchased in the Issuer's initial public offering. (F3) These 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 the Reporting Person, W. Carter Neild, and Geoffrey C. Hsu, each of whom disclaims beneficial ownership of the shares held by OPI VIII. (F4) Each of the Reporting Person, OrbiMed Advisors, and GP VIII 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. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, or GP VIII is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.
4	Derivative	Series A Preferred Stock	2026-08-10	C	D	1,039,996	$0.00	0	I See footnotes	— · — to —	1,039,996 Common Stock	(F1) Each 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. (F1) Each 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. (F1) Each 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. (F3) These 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 the Reporting Person, W. Carter Neild, and Geoffrey C. Hsu, each of whom disclaims beneficial ownership of the shares held by OPI VIII. (F4) Each of the Reporting Person, OrbiMed Advisors, and GP VIII 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. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, or GP VIII is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.
5	Derivative	Series B Preferred Stock	2026-08-10	C	D	1,049,283	$0.00	0	I See footnotes	— · — to —	1,049,283 Common Stock	(F1) Each 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. (F1) Each 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. (F1) Each 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. (F3) These 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 the Reporting Person, W. Carter Neild, and Geoffrey C. Hsu, each of whom disclaims beneficial ownership of the shares held by OPI VIII. (F4) Each of the Reporting Person, OrbiMed Advisors, and GP VIII 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. This report shall not be deemed an admission that any of the Reporting Person, OrbiMed Advisors, or GP VIII is a beneficial owner of such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.