Exhibit 99.A
AGREEMENT
Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13D need be filed with respect to the ownership by each of the undersigned of Common Stock of Alpine Immune Systems, Inc.
| Date: September 21, 2021 | FRAZIER LIFE SCIENCES VIII, L.P. | |||||
| By FHM Life Sciences VIII, L.P., its general partner | ||||||
| By FHM Life Sciences VIII, L.L.C., its general partner | ||||||
| By: | /s/ Steve R. Bailey | |||||
| Steve R. Bailey, Chief Financial Officer | ||||||
| Date: September 21, 2021 | FHM LIFE SCIENCES VIII, L.P. | |||||
| By FHM Life Sciences VIII, L.L.C., its general partner | ||||||
| By: | /s/ Steve R. Bailey | |||||
| Steve R. Bailey, Chief Financial Officer | ||||||
| Date: September 21, 2021 | FHM LIFE SCIENCES VIII, L.L.C. | |||||
| By: | /s/ Steve R. Bailey | |||||
| Steve R. Bailey, Chief Financial Officer | ||||||
| Date: September 21, 2021 | FRAZIER LIFE SCIENCES PUBLIC FUND L.P. | |||||
| By: FHMLSP, L.P., its General Partner | ||||||
| By: FHMLSP, L.L.C., its General Partner | ||||||
| By: | /s/ Steve R. Bailey | |||||
| Steve R. Bailey, Chief Financial Officer | ||||||
| Date: September 21, 2021 | FHMLSP, L.P. | |||||
| By: FHMLSP, L.L.C., its General Partner | ||||||
| By: | /s/ Steve R. Bailey | |||||
| Steve R. Bailey, Chief Financial Officer | ||||||
| Date: September 21, 2021 | FHMLSP, L.L.C. | |||||
| By: | /s/ Steve R. Bailey | |||||
| Steve R. Bailey, Chief Financial Officer | ||||||
| Date: September 21, 2021 | By: | * | ||||
| James N. Topper |
| Date: September 21, 2021 | By: | * | ||||
| Patrick J. Heron |
| Date: September 21, 2021 | By: | ** | ||||
| Albert Cha |
| Date: September 21, 2021 | By: | ** | ||||
| James Brush |
| Date: September 21, 2021 | By: | /s/ Steve R. Bailey | ||||
| Steve R. Bailey, as Attorney-in-Fact |
| * | This Agreement was executed by Steve R. Bailey on behalf of the individuals listed above pursuant to a Power of Attorney, a copy of which was filed with the SEC on July 31, 2017. |
| ** | This Agreement was executed by Steve R. Bailey on behalf of the individuals listed above pursuant to a Power of Attorney, a copy of which was filed with the SEC on August 16, 2021. |
