AGREEMENT

EXHIBIT 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 Phathom Pharmaceuticals, Inc.

Date: November 4, 2019				XXXXXXX LIFE SCIENCES IX, L.P.
				By FHMLS IX, L.P., its general partner
				By FHMLS IX, L.L.C., its general partner
				By:		/s/ Xxxxx X. Xxxxxx
						Xxxxx X. Xxxxxx, Chief Financial Officer
Date: November 4, 2019				FHMLS IX, L.P.
				By FHMLS IX, L.L.C., its general partner
				By:		/s/ Xxxxx X. Xxxxxx
						Xxxxx X. Xxxxxx, Chief Financial Officer
Date: November 4, 2019				FHMLS IX, L.L.C.
				By:		/s/ Xxxxx X. Xxxxxx
						Xxxxx X. Xxxxxx, Chief Financial Officer
Date: November 4, 2019				By:		*
						Xxxxx Xxxxxx
Date: November 4, 2019				By:		*
						Xxxxxxx Xxxxx
Date: November 4, 2019				*By:		/s/ Xxxxx X. Xxxxxx
						Xxxxx X. Xxxxxx, as Attorney-in-Fact

This Agreement was executed by Xxxxx X. Xxxxxx 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.