Exhibit A AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13DAgreement Regarding the Joint Filing of Schedule 13d • February 16th, 2016 • Polaris Venture Partners V, L.P. • Biological products, (no disgnostic substances)
The undersigned, being duly authorized thereunto, hereby execute this agreement as an exhibit to this Schedule 13D 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 Schedule jointly on behalf of each such party.
