Rock Springs Capital Management LP - Oct 6, 2021 Form 3 Insider Report for Theseus Pharmaceuticals, Inc. (THRX)

Role: 10%+ Owner
Signature: By: /s/ Mark Bussard, Authorized Signatory, Rock Springs Capital Management LP
Stock symbol: THRX
Transactions as of: Oct 6, 2021
Transactions value $: $0
Form type: 3
Date filed: 10/6/2021, 07:01 PM
Previous filing: Jun 22, 2021
Next filing: Oct 14, 2021

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	THRX	Series B Convertible Preferred Stock							Oct 6, 2021	Common Stock	349K		See Footnote	F1, F2
holding	THRX	Series B Convertible Preferred Stock							Oct 6, 2021	Common Stock	87.3K		See Footnote	F1, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The reported security is convertible into the issuer's Common Stock on a one-for-one basis at any time at the holder's election and shall automatically convert into Common Stock immediately prior to the closing of the issuer's initial public offering without payment of further consideration. The shares have no expiration date.
F2	The securities reported herein are held of record by Rock Springs Capital Master Fund LP ("Master Fund"). Rock Springs Capital LLC ("RSC") is the general partner of Rock Springs Capital Management LP ("RSCM") which is the investment manager to Master Fund. RSC and RSCM may therefore be deemed to have or share beneficial ownership of the shares held directly by Master Fund.
F3	The securities reported herein are held of record by Four Pines Master Fund LP ("Four Pines"). RSC is the general partner of RSCM which is the investment manager to Four Pines. RSC and RSCM may therefore be deemed to have or share beneficial ownership of the shares held directly by Four Pines.