ADDITIONAL INFORMATION 21 Date Nature of Operation Number Nominal Issue Share premium Issue price Number Capital Share of shares value of price per (in €) (in €) of shares increase capital issued the share share representing (in €) (in €) (in €) (in €) the share capital June 30, 2015 Share capital increase 4,624,871 0.025 6.950 32,027,233.06 32,142,854.84 13,609,120 115,621.78 340,228.00 (issuance of Series B preferred shares) July 7, 2015 Series B-related — — — (1,305,561.25) — 13,609,120 — 340,228.00 costs July 8, 2015 Subscription — — — 30,250.00 30,250.00 13,609,120 — 340,228.00 of warrants (BSA2015-07) July 31, 2015 Share capital 2 0.025 0.025 — 0.05 13,609,122 0.05 340,228.05 increase (issuance of ordinary share through exercise of BCE2013-02) July 13, 2016 Share capital increase 5,000,000 0.025 8.000 39,875,000.00 40,000,000.00 18,609,122 125,000.00 465,228.05 (Euronext IPO) July 13, 2016 Euronext IPO- — — (3,571,365.00) — 18,609,122 — 465,228.05 related costs August 10, Share capital 655,859 0.025 8.000 5,230,475.53 5,246,872.00 19,264,981 16,396.48 481,624.53 2016 increase (Euronext IPO – Overallotment option) August 10, Euronext IPO — — — (236,109.24) — 19,264,981 — 481,624.53 2016 overallotment option-related costs September 3, Share capital 112,000 0.025 0.025 — 2,800.00 19,376,981 2,800.00 484,424.53 2016 increase (issuance of ordinary share through exercise of BCE2013-02) October 6, Share capital 31,720 0.025 0.025 — 793.00 19,408,701 793.00 485,217.53 2016 increase (issuance of ordinary share through exercise of BCE2013-02) October 6, Share capital 1,000 0.025 3.275 3,250.00 3,275.00 19,409,701 25.00 485,242.53 2016 increase (issuance of ordinary share through exercise of BCE2015-07) October 31, Subscription — 0.025 — 133,250.00 133,250.00 19,409,701 — 485,242.53 2016 of warrants (BSA2016-07) January 11, Share capital 117,320 0.025 0.025 — 2,933.00 19,527,021 2,933.00 488,175.53 2017 increase (issuance of ordinary share through exercise of BCE2013-02) January 11, Share capital 13,432 0.025 3.275 43,654.00 43,989.80 19,540,453 335.80 488,511.33 2017 increase (issuance of ordinary share through exercise of BCE2015-07) 224– GENSIGHT BIOLOGICS – 2017 Registration Document