Samira Shaikhly - 02 Mar 2026 Form 4 Insider Report for Septerna, Inc. (SEPN)

Role
Chief People Officer
Signature
/s/ Mark A. Wilson, Attorney-in-Fact
Issuer symbol
SEPN
Transactions as of
02 Mar 2026
Net transactions value
-$1,979,838
Form type
4
Filing time
04 Mar 2026, 19:00:54 UTC
Previous filing
10 Feb 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Shaikhly Samira Chief People Officer C/O SEPTERNA, INC., 250 EAST GRAND AVENUE, SOUTH SAN FRANCISCO /s/ Mark A. Wilson, Attorney-in-Fact 04 Mar 2026 0002040363

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction SEPN Common Stock Options Exercise +53,714 +6774% $1.55* 54,507 02 Mar 2026 Direct F1
transaction SEPN Common Stock Options Exercise +11,638 +21% $2.76* 66,145 02 Mar 2026 Direct
transaction SEPN Common Stock Options Exercise +5,101 +7.7% $2.76* 71,246 02 Mar 2026 Direct
transaction SEPN Common Stock Sale $112,496 -4,090 -5.7% $27.51 67,156 02 Mar 2026 Direct F2, F3
transaction SEPN Common Stock Sale $1,867,342 -66,363 -99% $28.14 793 02 Mar 2026 Direct F2, 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
transaction SEPN Stock Option (Right to Buy) Options Exercise -53,714 -77% $0.000000* 15,969 02 Mar 2026 Common Stock 53,714 $1.55 Direct F5
transaction SEPN Stock Option (Right to Buy) Options Exercise -11,638 -77% $0.000000* 3,460 02 Mar 2026 Common Stock 11,638 $2.76 Direct F5
transaction SEPN Stock Option (Right to Buy) Options Exercise -5,101 -50% $0.000000* 5,101 02 Mar 2026 Common Stock 5,101 $2.76 Direct F6
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
F1 Includes 793 shares acquired under the Septerna, Inc. 2024 Employee Stock Purchase Plan on October 31, 2025 in a transaction that was exempt under Rule 16b-3(c).
F2 This transaction was effected pursuant to a Rule 10b5-1 sales plan adopted by the Reporting Person on October 31, 2025.
F3 The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $26.90 to $27.89. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range.
F4 The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $27.90 to $28.70. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range.
F5 25% of the shares underlying this option vested on February 1, 2024, with the remainder vesting in thirty-six substantially equal monthly installments thereafter, subject to the Reporting Person's continuous service the Issuer on each such vesting date.
F6 1/48th of the shares subject to such option vest and become exercisable in substantially equal monthly installments on each monthly anniversary of March 1, 2024, subject to the Reporting Person's continuous service to the Issuer on each such date.