X0206 3 2015-06-24 0 0001454789 CATABASIS PHARMACEUTICALS INC CATB 0001407426 Advanced Technology Ventures VIII LP C/O ADVANCED TECHNOLOGY VENTURES 500 BOYLSTON STREET SUITE 1380 BOSTON MA 02116 0 0 1 0 0001621174 ATV Associates VIII, L.L.C. C/O ADVANCED TECHNOLOGY VENTURES 500 BOYLSTON STREET SUITE 1380 BOSTON MA 02116 0 0 1 0 Series A Preferred Stock Common Stock 674446 D Series B Preferred Stock Common Stock 304309 D The Series A Preferred Stock is convertible into Common Stock on a 1-for-12.85 basis into the number of shares shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date. The Series B Preferred Stock is convertible into Common Stock on a 1-for-12.85 basis into the number of shares shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering without payment of further consideration. The shares have no expiration date. These shares are held directly by Advanced Technology Ventures VIII, L.P. ("ATV VIII"). ATV Associates VIII, LLC ("ATV A VIII") is the General Partner of ATV VIII and exercises voting and dispositive authority over the shares held by ATV VIII. Voting and dispositive decisions of ATV A VIII are made collectively by Michael A. Carusi, Jean George, Steven N. Baloff, Robert C. Hower and William C. Wiberg (collectively, the "ATV VIII Managing Directors"). ATV A VIII and the ATV VIII Managing Directors disclaim beneficial ownership of the shares held by ATV VIII except to the extent of their pecuniary interest therein. Exhibit Index: 24.1 Power of Attorney By:/s/ Jean George, Managing Director of ATV Associates VIII, L.L.C., general partner of Advanced Technology Ventures VIII, L.P. 2015-06-24 By:/s/ Jean George, Managing Director of ATV Associates VIII, L.L.C. 2015-06-24