Exhibit A AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13DJoint Filing Agreement • February 4th, 2019 • Polaris Venture Partners V, L.P. • Pharmaceutical preparations
The undersigned, being duly authorized thereunto, hereby execute this agreement as an exhibit to this Schedule 13D Amendment No. 3 to evidence the agreement of the below-named parties, in accordance with the rules promulgated pursuant to the Securities Exchange Act of 1934, to file this Amendment No. 3 jointly on behalf of each such party.
