Material Agreement, Private Placement (Form 8-K)

Securities Purchase Agreement

On April 12, 2026, ImageneBio, Inc., a Delaware corporation (the "Company"), entered into a Securities Purchase Agreement (the "Purchase Agreement") with certain institutional and accredited investors (the "Investors"), pursuant to which the Company agreed to sell and issue pre-fundedwarrants to purchase shares of the Company's voting common stock, par value $0.001 ("Common Stock" and the shares subject to the pre-fundedwarrants, the "Warrant Shares"), in a private placement transaction (the "Private Placement").

The closing of the Private Placement is anticipated to occur on or about April 14, 2026 (the "Closing"), subject to customary closing conditions. At the Closing, the Company has agreed to issue and sell pre-fundedwarrants to purchase up to 5,770,335 Warrant Shares at a purchase price of $5.199 per Warrant Share to the Investors for gross proceeds to the Company of approximately $30 million pursuant to the Purchase Agreement.

The pre-fundedwarrant will have an exercise price of $0.001 per Warrant Share, subject to customary adjustments, and will be exercisable at any time after original issuance and will not expire until exercised in full. The pre-fundedwarrant will also be exercisable on a net exercise "cashless" basis. The pre-fundedwarrant may not be exercised if the aggregate number of shares of Common Stock beneficially owned by the holder thereof immediately following such exercise would exceed a specified beneficial ownership limitation, not to exceed 19.99%.

The Purchase Agreement contains customary representations, warranties and covenants that were made solely for the benefit of the parties to the Purchase Agreement. Such representations, warranties and covenants (i) are intended as a way of allocating risk between the parties to the Purchase Agreement and not as statements of fact, and (ii) may apply standards of materiality in a way that is different from what may be viewed as material by stockholders of, or other investors in, the Company. Accordingly, the Purchase Agreement is included with this filing only to provide investors with information regarding the terms of the transaction and not to provide investors with any other factual information regarding the Company. Investors should not rely on the representations, warranties and covenants or any descriptions thereof as characterizations of the actual state of facts or condition of the Company or any of its subsidiaries or affiliates. Moreover, information concerning the subject matter of the representations and warranties may change after the date of the Purchase Agreement, which subsequent information may or may not be fully reflected in public disclosures.

Registration Rights Agreement

In connection with the Private Placement, the Company has agreed to enter into a Registration Rights Agreement (the "Registration Rights Agreement") with the Investors at the Closing, pursuant to which the Company will agree to prepare and file, within three business days following August 1, 2026, subject to certain allowable delays, a registration statement with the U.S. Securities and Exchange Commission (the "SEC") to register for resale the Warrant Shares issuable upon the exercise of the pre-fundedwarrants that were issued and sold under the Purchase Agreement, and generally to cause the applicable registration statement to promptly become effective. Certain cash penalties will apply to the Company in the event of registration failures, as described in the Registration Rights Agreement.

The foregoing summaries of the Purchase Agreement, the pre-fundedwarrant and the Registration Rights Agreement do not purport to be complete and are qualified in their entirety by reference to the complete text of the Purchase Agreement, the form of pre-fundedwarrant and the Registration Rights Agreement, which are filed with this report as Exhibits 10.1, 4.1 and 4.2, respectively.

The disclosure regarding the securities to be sold and issued under the Purchase Agreement set forth under Item 1.01 of this report is incorporated by reference under this Item 3.02. The Company expects to use the net proceeds from the Closing of the Private Placement, together with the Company's existing cash and cash equivalents, to support late-phase development readiness in atopic dermatitis, expand development of IMG-007into additional indications, including alopecia areata.

The securities described above under Item 1.01 have not been registered under the Securities Act of 1933, as amended ("Securities Act"), or any state securities laws. The Company is relying on the exemption from the registration requirements of the Securities Act by virtue of Section 4(a)(2) thereof. The Investors provided representations appropriate for a private placement of securities. Restrictive legends will be affixed to the securities issued in the Private Placement.

Neither this Current Report on Form 8-Knor any exhibit attached hereto is an offer to sell or the solicitation of an offer to buy shares of Common Stock or other securities of the Company.