Exhibit A AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13G

Exhibit A

AGREEMENT REGARDING THE JOINT FILING OF

SCHEDULE 13G

The undersigned, being duly authorized thereunto, hereby execute this agreement as an exhibit to this Schedule 13G 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.

Date: February 12, 2020

POLARIS VENTURE PARTNERS III, L.P.
By:		Polaris Venture Management Co. III, L.L.C.
By:		*
		Authorized Signatory
POLARIS VENTURE PARTNERS ENTREPRENEURS’ FUND III, L.P.
By:		Polaris Venture Management Co. III, L.L.C.
By:		*
		Authorized Signatory
POLARIS VENTURE PARTNERS FOUNDERS’ FUND III, L.P.
By:		Polaris Venture Management Co. III, L.L.C.
By:		*
		Authorized Signatory
POLARIS VENTURE MANAGEMENT CO. III, L.L.C.
By:		*
		Authorized Signatory
XXXXXXXX X. XXXXX
By:		*
		Xxxxxxxx X. Xxxxx
XXXXXXXX X. XXXXXXX
By:		*
		Xxxxxxxx X. XxXxxxx

*By:		/s/ Xxxxxx Xxxxxxxx
Name:		Xxxxxx Xxxxxxxx
		Attorney-in-Fact

[This Schedule 13G was executed pursuant to a Power of Attorney. Note that copies of the applicable Powers of Attorney are already on file with the appropriate agencies.]