Third Rock Ventures V, L.P. - Oct 24, 2024 Form 3 Insider Report for Septerna, Inc. (SEPN)

Role: 10%+ Owner
Signature: /s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P., general partner of Third Rock Ventures V, L.P.
Stock symbol: SEPN
Transactions as of: Oct 24, 2024
Transactions value $: $0
Form type: 3
Date filed: 10/24/2024, 09:30 PM
Previous filing: Jun 10, 2024
Next filing: Oct 28, 2024

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
holding	SEPN	Common Stock						1.05M	Oct 24, 2024	Direct	F1, F4

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	SEPN	Series A Preferred Stock							Oct 24, 2024	Common Stock	4.79M		Direct	F1, F2, F4
holding	SEPN	Series B Preferred Stock							Oct 24, 2024	Common Stock	2.87M		See Footnotes	F2, F3, F4

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

Explanation of Responses:

Id	Content
F1	The shares are held directly by Third Rock Ventures V, L.P. ("TRV V"). The general partner of TRV V is Third Rock Ventures GP V, L.P. ("TRV GP V"). The general partner of TRV GP V is TRV GP V, LLC ("TRV GP V LLC"). Each of TRV GP V and TRV GP V LLC, disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it is the beneficial owner of such shares.
F2	Each share of Series A Preferred Stock and Series B Preferred Stock (collectively, the "Preferred Stock") is convertible into Common Stock on a one-for-8.6103 basis at the option of the holder, and will convert automatically upon closing of the Issuer's initial public offering into the number of shares shown in column 3 without payment of consideration. The Preferred Stock has no expiration date.
F3	The shares are held directly by Third Rock Ventures VI, L.P. ("TRV VI"). The general partner of TRV VI is Third Rock Ventures GP VI, L.P. ("TRV GP VI"). The general partner of TRV GP VI is TRV GP VI, LLC ("TRV GP VI LLC"). Each of TRV GP VI and TRV GP VI LLC, disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it is the beneficial owner of such shares.
F4	Each of Reporting Persons disclaims the existence of a Section 13(d) "group" as between the TRV V related parties and the TRV VI related parties and this report shall not be deemed an admission that any of such parties is or may be part of such a group with any of the other parties.