Exhibit 99.1
13G
| CUSIP No. 36870A108 |
AGREEMENT
Pursuant to Rule13d-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 Gemphire Therapeutics Inc.
| Dated: | February 7, 2017 | |
| EXCEL VENTURE FUND II, L.P. | ||
| BY: | EXCEL VENTURES II GP, LLC | |
| ITS: | GENERAL PARTNER | |
| By: | /s/ Steven R. Gullans | |
| Manager | ||
| EXCEL VENTURES II GP, LLC | ||
/s/ Steven R. Gullans | ||
| Manager | ||
/s/ Frederick R. Blume | ||
| Frederick R. Blume | ||
/s/ Steven R. Gullans | ||
| Steven R. Gullans | ||
/s/ Juan Enriquez | ||
| Juan Enriquez | ||
/s/ Caleb Winder | ||
| Caleb Winder | ||
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