CUSIP No. 02083G100 13G Exhibit 99.1

AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree that only one statement containing the information required by Schedule 13G need be filed with respect to the ownership by each of the undersigned of Common Stock of Alpine Immune Sciences, Inc.

Dated: August 6, 2020
OMEGA FUND VI, L.P.
BY:	Omega Fund VI GP, L.P.
ITS:	GENERAL PARTNER
BY:	Omega Fund VI GP Manager, Ltd.
ITS:	GENERAL PARTNER
By:	/s/ Anne-Mari Paster
	Director
OMEGA FUND VI GP, L.P.
BY:	Omega Fund VI GP Manager, Ltd.
ITS:	GENERAL PARTNER
By:	/s/ Anne-Mari Paster
	Director
OMEGA FUND VI GP MANAGER, LTD.
By:	/s/ Anne-Mari Paster
	Director
/s/ * Anne-Mari Paster, as Attorney-in-Fact
Claudio Nessi
/s/ * Anne-Mari Paster, as Attorney-in-Fact
Otello Stampacchia
/s/ Anne-Mari Paster*
Anne-Mari Paster