RISK FACTORS 4 Risks covered Insurer Amount Excess per claim Study GS-LHON-CLIN-03B in France HDI Gerling métropolitaine and DOM-TOM : • Per victim €1,000 K €1,500 per victim capped at €16,000 per protocol • Per research protocol €6,000 K • Claims made during an insurance €10,000 K year by one and the same sponsor for several research protocol Study GS-LHON-CLIN-03B in Italy, ALLIANZ U.K. and USA • ITALY – Per victim €1,500 K – Per research protocol €5,000 K • UNITED KINGDOM – Per research protocol £5,000 K • UNITED STATES – Per research protocol $5,000 K Study GS-LHON-CLIN-03B ALLIANZ in Germany • Per victim €500 K – i f up to 1,000 patients participate €5,000 K in this trial – i f more than 1,000 patients and up €10,000 K to 3,000 participate in this trial – i f more than 3,000 patients €15,000 K participate in this trial GS-LHON-CLIN-01 HDI Gerling In mainland France and overseas departments and territories: • Per victim €1,000 K €1,500 per victim capped at €16,000 per protocol • Per Research protocol €6,000 K • Claims made during an insurance €10,000 K year by one and the same sponsor for several research protocol Although we maintain insurance coverage for our clinical trials in each time we commence a clinical trial and if we successful ly the amount of €1 million per victim, €6 million per protocol and commercialize any product candidate. Insurance coverage is €10 million in the aggregate over a one-year period, this insurance increasingly expensive. We may not be able to maintain insurance may not be adequate to cover all liabilities that we may incur. We coverage at a reasonable cost or in an amount adequate to satisfy anticipate that we will need to increase our insurance coverage any liability that may arise. GENSIGHT BIOLOGICS – 2017 Registration Document– 57