Exhibit 1
JOINT FILING AGREEMENT
In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them as a statement on Schedule 13G (including amendments thereto) with respect to the common shares of Hemab Therapeutics Holdings, Inc. and further agree that this agreement be included as an exhibit to such filing. Each party to this agreement expressly authorizes each other party to file on its behalf any and all amendments to such statement. Each party to this agreement agrees that this joint filing agreement may be signed in counterparts.
In evidence whereof, the undersigned have caused this agreement to be executed on their behalf on August 5, 2026.
| Sofinnova Crossover II SLP | Sofinnova Partners SAS, a French corporation | |||
| By: | /s/ Antonie Papiernik | By: | /s/ Antonie Papiernik | |
| Name: | Antonie Papiernik | Name: | Antonie Papiernik | |
| Title: | Managing Partner | Title: | Managing Partner | |
| By: | /s/ Antonie Papiernik | By: | /s/ Cédric Moreau | |
| Name: | Antonie Papiernik | Name: | Cédric Moreau |
| By: | /s/ Kinam Hong | By: | /s/ Joseph Anderson | |
| Name: | Kinam Hong | Name: | Joseph Anderson |
| By: | /s/ David Evans | |||
| Name: | David Evans |