MPM BioVentures 2014, L.P. sold TRDA

Footnotes

The shares were sold as follows: 9,819 by MPM BioVentures 2014, L.P. ("BV 2014"), 655 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 338 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"), 10,077 by MPM BioVentures 2018, L.P. ("BV 2018"), 535 by MPM BioVentures 2018 (B), L.P. ("BV 2018(B)") and 199 by MPM Asset Management Investors BV2018 LLC ("AM BV2018"). MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV2014 LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). BV2014 LLC is the manager of AM BV2014. MPM BioVentures 2018 GP LLC and MPM BioVentures 2018 LLC ("BV2018 LLC") are the direct and indirect general partners of BV 2018 and BV 2018(B). BV 2018 LLC is the manager of AM BV2018. Messrs. Evnin, Foley and Gadicke are managing directors of BV 2014 LLC and BV 2018 LLC.; Price represents the weighted average sale price of the shares sold. The sale price ranged from $7.0852 to $7.58 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.; The shares are held as follows: 1,979,549 by BV 2014, 132,032 by BV 2014(B), 68,137 by AM BV2014, 2,031,644 by BV 2018, 107,980 by BV 2018(B) and 40,097 by AM BV2018.; Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its respective pecuniary interest therein.