RISK FACTORS 4 trial for GS010 wil l result in success in our ongoing Phase I I I • perceived risks and benefits of gene therapy-based approaches clinical trials. In addition, we cannot assure you that we will be able to treat diseases; to achieve the same or similar success in our preclinical studies • availability of competing therapies and clinical trials; and clinical trials of our other product candidates. • severity of the disease under investigation; There is a high failure rate for drugs, biological products and • availability of genetic testing for potential patients; devices proceeding through clinical trials. Companies in the • proximity and availability of clinical trial sites for prospective pharmaceutical, medical devices and biotechnology industries subjects; frequently suffer significant setbacks in late-stage clinical trials, • ability to obtain and maintain subject consent; even after earlier clinical trials have shown promising results. Data obtained from preclinical and clinical activities are subject • efforts to facilitate timely enrollment in clinical studies; and to varying interpretations, which may delay, limit or prevent • patient referral practices of physicians. regulatory approval. Only a small percentage of medical products We may not be able to initiate or continue clinical trials if we cannot under development result in the submission of a new product enroll a sufficient number of eligible patients to participate in the application to the FDA, the EMA or other regulatory agencies, clinical trials required by the FDA or the EMA or other regulatory and even fewer are approved for commercialization. Any such authorities. In addition to risks related to patient enrollment, our delays or rejections could material ly and adversely affect our ability to successfully initiate and complete a clinical trial in any business, financial condition, results of operations and prospects. other country is subject to numerous risks unique to conducting We may find it difficult to conduct our clinical trials, in particular business in other countries, including: with respect to patient enrollment, which could delay or prevent • inability to find contract research organizations, or CROs, us from proceeding with clinical trials of our product candidates. qualified local consultants, physicians and partners, or difficulty Identifying and qualifying patients to participate in clinical trials in establishing or managing relationships with such persons; of our product candidates is critical to our success. The timing of • difficulty in making patients and patients’ communities aware of our clinical trials depends on how quickly we can recruit patients the existence of the clinical trials; and complete required follow-up periods. If patients are unwilling • different standards for the conduct of clinical trials; to participate in our gene therapy studies because of negative • absence in some countries of regulatory authorities with publicity from adverse events related to the biotechnology or sufficient expertise for review of gene therapy protocols; and gene therapy fields, competitive clinical trials for similar patient • the potential burden of complying with a variety of laws, medical populations, clinical trials in products employing our vectors or standards and regulatory requirements, including the regulation our platform or for other reasons, the timeline for recruiting of pharmaceutical and biotechnology products and treatment. patients, conducting studies and obtaining regulatory approval of our product candidates may be delayed. These delays could result If we have difficulty enrolling a sufficient number of patients to in increased costs, delays in advancing our product candidates, conduct our clinical trials as planned, we may need to delay, limit delays in testing the effectiveness of our product candidates or or terminate ongoing or planned clinical trials, any of which would termination of the clinical trials altogether. have an adverse effect on our business, financial condition, results of operations and prospects. We may not be able to identify, recruit and enrol l a sufficient number of patients, or those with required or desired We may encounter substantial delays in our clinical trials, and characteristics, to complete our clinical trials in a timely manner. we cannot guarantee that any clinical trials will be conducted as In particular, our current product candidates are being developed planned or completed on schedule, if at all. to treat rare conditions with limited patient pools. The eligibility Before obtaining marketing approval from regulatory authorities criteria of our clinical trials will further limit the pool of available for the sale of our product candidates, we must conduct extensive trial participants. clinical trials to demonstrate the safety and efficacy of the product Patient enrollment is affected by factors including: candidates. Clinical testing is expensive and time-consuming and • size of the patient population and process for identifying the results are uncertain. We cannot guarantee that any clinical subjects; trial will be conducted as planned or completed on schedule, if at all. Failure of a clinical trial can occur at any stage of testing. Events • design of the trial protocol; that may prevent successful or timely completion of clinical • eligibility and exclusion criteria; development include: • perceived risks and benefits of the product candidate under • delays in raising, or inability to raise, sufficient capital to fund study; the planned or ongoing clinical trials; GENSIGHT BIOLOGICS – 2017 Registration Document– 23