Bihua Chen - 06 Aug 2026 Form 4 Insider Report for BlossomHill Therapeutics, Inc. (BLSM)

Reporting relationship: Director, 10%+ Owner
Issuer ticker: BLSM
Reported as of: 06 Aug 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 10 Aug 2026, 18:32:08 UTC
Prior SEC filing: 06 Jul 2026
Source filing: View source filing
Reporting owner signature: /s/ Bihua Chen

Key filing fact

Bihua Chen filed Form 4 for BlossomHill Therapeutics, Inc. (BLSM) on 10 Aug 2026.

Key facts

This page summarizes Bihua Chen's Form 4 filing for BlossomHill Therapeutics, Inc. (BLSM).
6 reported transactions and 18 derivative rows are listed below.
Accepted by SEC: 10 Aug 2026, 18:32.

Change

Previous filing in this sequence was filed on 06 Jul 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (6)

CIK 0001599214 Primary reporting owner

Chen Bihua

Relationship: Director, 10%+ Owner
Address: C/O CORMORANT ASSET MANAGEMENT LP, 200 CLARENDON STREET, 50TH FLOOR, BOSTON
Signature: /s/ Bihua Chen
Signature date: 10 Aug 2026

CIK 0001583977

Cormorant Asset Management, LP

Relationship: 10%+ Owner
Address: 200 CLARENDON STREET 50TH FLOOR, BOSTON
Signature: CORMORANT ASSET MANAGEMENT, LP By: /s/ Bihua Chen, Managing Member
Signature date: 10 Aug 2026

CIK 0001618442

Cormorant Global Healthcare Master Fund, LP

Relationship: 10%+ Owner
Address: 200 CLARENDON STREET 50TH FLOOR, BOSTON
Signature: CORMORANT GLOBAL HEALTHCARE MASTER FUND, LP By: Cormorant Global Healthcare GP, LLC, its General Partner By: /s/ Bihua Chen, Managing Member
Signature date: 10 Aug 2026

CIK 0001817320

Cormorant Private Healthcare Fund III LP

Relationship: 10%+ Owner
Address: 200 CLARENDON STREET 50TH FLOOR, BOSTON
Signature: CORMORANT PRIVATE HEALTHCARE FUND III, LP By: Cormorant Private Healthcare GP III, LLC, its General Partner By: /s/ Bihua Chen, Managing Member
Signature date: 10 Aug 2026

CIK 0001969296

Cormorant Private Healthcare Fund V LP

Relationship: 10%+ Owner
Address: 200 CLARENDON STREET 50TH FLOOR, BOSTON
Signature: CORMORANT PRIVATE HEALTHCARE FUND V, LP By: Cormorant Private Healthcare GP V, LLC, its General Partner By: /s/ Bihua Chen, Managing Member
Signature date: 10 Aug 2026

CIK 0002098185

Cormorant Private Healthcare Fund VI, LP

Relationship: 10%+ Owner
Address: 200 CLARENDON STREET 50TH FLOOR, BOSTON
Signature: CORMORANT PRIVATE HEALTHCARE FUND VI, LP By: Cormorant Private Healthcare GP VI, LLC, its General Partner By: /s/ Bihua Chen, Managing Member
Signature date: 10 Aug 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,599,993
Change %
Price
Shares after: 1,599,993
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F1, F2, F3, F4

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,599,993
Change %
Price
Shares after: 1,599,993
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F1, F2, F3, F4

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,599,993
Change %
Price
Shares after: 1,599,993
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F1, F2, F3, F4

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,599,993
Change %
Price
Shares after: 1,599,993
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F1, F2, F3, F4

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,599,993
Change %
Price
Shares after: 1,599,993
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F1, F2, F3, F4

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,599,993
Change %
Price
Shares after: 1,599,993
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F1, F2, F3, F4

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,701,541
Change %: +106%
Price
Shares after: 3,301,534
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F2, F3, F4, F5, F6

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,701,541
Change %: +106%
Price
Shares after: 3,301,534
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F2, F3, F4, F5, F6

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,701,541
Change %: +106%
Price
Shares after: 3,301,534
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F2, F3, F4, F5, F6

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,701,541
Change %: +106%
Price
Shares after: 3,301,534
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F2, F3, F4, F5, F6

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,701,541
Change %: +106%
Price
Shares after: 3,301,534
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F2, F3, F4, F5, F6

BLSM transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +1,701,541
Change %: +106%
Price
Shares after: 3,301,534
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F2, F3, F4, F5, F6

BLSM transaction

Common Stock

Purchase

Transaction value
Shares: +312,500
Change %: +9.5%
Price: $16.00^*
Shares after: 3,614,034
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F3, F4, F7, F8

BLSM transaction

Common Stock

Purchase

Transaction value
Shares: +312,500
Change %: +9.5%
Price: $16.00^*
Shares after: 3,614,034
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F3, F4, F7, F8

BLSM transaction

Common Stock

Purchase

Transaction value
Shares: +312,500
Change %: +9.5%
Price: $16.00^*
Shares after: 3,614,034
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F3, F4, F7, F8

BLSM transaction

Common Stock

Purchase

Transaction value
Shares: +312,500
Change %: +9.5%
Price: $16.00^*
Shares after: 3,614,034
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F3, F4, F7, F8

BLSM transaction

Common Stock

Purchase

Transaction value
Shares: +312,500
Change %: +9.5%
Price: $16.00^*
Shares after: 3,614,034
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F3, F4, F7, F8

BLSM transaction

Common Stock

Purchase

Transaction value
Shares: +312,500
Change %: +9.5%
Price: $16.00^*
Shares after: 3,614,034
Date: 10 Aug 2026
Ownership: See footnotes
Footnotes: F3, F4, F7, F8

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

BLSM transaction Derivative

Director Stock Option (Right to Buy)

Award

Transaction value
Shares: +23,904
Change %
Price: $0.000000^*
Shares after: 23,904
Date: 06 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 23,904
Exercise price: $16.00
Footnotes: F9

BLSM transaction Derivative

Director Stock Option (Right to Buy)

Award

Transaction value
Shares: +23,904
Change %
Price: $0.000000^*
Shares after: 23,904
Date: 06 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 23,904
Exercise price: $16.00
Footnotes: F9

BLSM transaction Derivative

Director Stock Option (Right to Buy)

Award

Transaction value
Shares: +23,904
Change %
Price: $0.000000^*
Shares after: 23,904
Date: 06 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 23,904
Exercise price: $16.00
Footnotes: F9

BLSM transaction Derivative

Director Stock Option (Right to Buy)

Award

Transaction value
Shares: +23,904
Change %
Price: $0.000000^*
Shares after: 23,904
Date: 06 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 23,904
Exercise price: $16.00
Footnotes: F9

BLSM transaction Derivative

Director Stock Option (Right to Buy)

Award

Transaction value
Shares: +23,904
Change %
Price: $0.000000^*
Shares after: 23,904
Date: 06 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 23,904
Exercise price: $16.00
Footnotes: F9

BLSM transaction Derivative

Director Stock Option (Right to Buy)

Award

Transaction value
Shares: +23,904
Change %
Price: $0.000000^*
Shares after: 23,904
Date: 06 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 23,904
Exercise price: $16.00
Footnotes: F9

BLSM transaction Derivative

Series A Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,599,993
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,599,993
Exercise price
Footnotes: F1, F2, F3, F4

BLSM transaction Derivative

Series A Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,599,993
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,599,993
Exercise price
Footnotes: F1, F2, F3, F4

BLSM transaction Derivative

Series A Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,599,993
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,599,993
Exercise price
Footnotes: F1, F2, F3, F4

BLSM transaction Derivative

Series A Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,599,993
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,599,993
Exercise price
Footnotes: F1, F2, F3, F4

BLSM transaction Derivative

Series A Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,599,993
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,599,993
Exercise price
Footnotes: F1, F2, F3, F4

BLSM transaction Derivative

Series A Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,599,993
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,599,993
Exercise price
Footnotes: F1, F2, F3, F4

BLSM transaction Derivative

Series B Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,701,541
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,701,541
Exercise price
Footnotes: F2, F3, F4, F5

BLSM transaction Derivative

Series B Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,701,541
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,701,541
Exercise price
Footnotes: F2, F3, F4, F5

BLSM transaction Derivative

Series B Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,701,541
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,701,541
Exercise price
Footnotes: F2, F3, F4, F5

BLSM transaction Derivative

Series B Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,701,541
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,701,541
Exercise price
Footnotes: F2, F3, F4, F5

BLSM transaction Derivative

Series B Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,701,541
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,701,541
Exercise price
Footnotes: F2, F3, F4, F5

BLSM transaction Derivative

Series B Preferred Stock

Conversion of derivative security

Transaction value
Shares: -1,701,541
Change %: -100%
Price
Shares after: 0
Date: 10 Aug 2026
Ownership: See footnotes
Underlying class: Common Stock
Underlying amount: 1,701,541
Exercise price
Footnotes: F2, F3, F4, F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 9 footnotes

Footnote F1

Represents (i) 1,228,315 shares issued upon conversion of shares of Series A Preferred Stock beneficially owned by Fund III (defined below), and (ii) 371,678 shares issued upon conversion of shares of Series A Preferred Stock beneficially owned by Master Fund (defined below).

Footnote F2

Each share of Series A Preferred Stock and Series B Preferred Stock (together, the "Preferred Stock") automatically converted into 1 share of Common Stock upon the closing of the Issuer's initial public offering without payment of further consideration. The Preferred Stock had no expiration date.

Footnote F3

Cormorant Asset Management, LP ("Cormorant") serves as the investment manager of Cormorant Global Healthcare Master Fund, LP (the "Master Fund"), Cormorant Private Healthcare Fund III, LP ("Fund III"), Cormorant Private Healthcare Fund V, LP ("Fund V") and Cormorant Private Healthcare Fund VI, LP ("Fund VI"). Cormorant Global Healthcare GP, LLC ("GP LLC"), Cormorant Private Healthcare GP III, LLC ("GP III"), Cormorant Private Healthcare GP V, LLC ("GP V") and Cormorant Private Healthcare GP VI, LLC ("GP VI") serve as General Partner of the Master Fund, Fund III, Fund V and Fund VI, respectively.

Footnote F4

Bihua Chen serves as manager of Cormorant, GP LLC, GP III, GP V and GP VI. Each of the Reporting Persons disclaims beneficial ownership of the shares reported herein except to the extent of its or her pecuniary interest therein, and the filing of this Form 4 shall not be construed as an admission that any of the Reporting Persons is the beneficial owner of any such shares for purposes of Section 16(a) of the Securities Exchange Act of 1934 or for any other purpose.

Footnote F5

Represents (i) 274,912 shares issued upon conversion of shares of Series B Preferred Stock beneficially owned by Master Fund, (ii) 1,052,460 shares issued upon conversion of shares of Series B Preferred Stock beneficially owned by Fund V and (iii) 374,169 shares issued upon conversion of shares of Series B Preferred Stock beneficially owned by Fund VI.

Footnote F6

Represents an aggregate of (i) 646,590 shares beneficially owned by Master Fund, (ii) 1,228,315 shares beneficially owned by Fund III, (iii) 1,052,460 shares beneficially owned by Fund V, and (vi) 374,169 beneficially owned by Fund VI.

Footnote F7

The shares purchased are beneficially owned by Master Fund.

Footnote F8

Represents an aggregate of (i) 959,090 shares beneficially owned by Master Fund, (ii) 1,228,315 shares beneficially owned by Fund III, (iii) 1,052,460 shares beneficially owned by Fund V, and (vi) 374,169 beneficially owned by Fund VI.

Footnote F9

1/36th of the shares subject to the option shall vest in equal monthly installments over a three year period following August 6, 2026.

SEC remarks

Master Fund, Fund III, Fund V and Fund VI may be deemed directors by deputization by virtue of their representation on the board of directors of the Issuer.