 Primary endpoint successfully met in Phase 3 PRIMROSE 1 trial of linzagolix for the treatment of heavy menstrual bleeding due to uterine fibroids Phase 3 data from PRIMROSE 2 trial demonstrated sustained efficacy and continued safety over 52 weeks of treatment with linzagolix,including bone mineral density changes Phase 3 trial results support the advancement of linzagolix 100 mg without add-back therapy and 200 mg with add-back therapy doses to regulatory submissions planned for Q4:20H1:21 in EuropeU.S. Actively discussing commercial partnership to maximize linzagolix best-in-class potential OBE022 Phase 2 PROLONG trial results on track for Q4:20 YuYuan Bioscience Technology submitted pre-IND meeting request for nolasiban development in China GENEVA, Switzerland and BOSTON, MA August 6, 2020 ObsEva SA NASDAQ: OBSV SIX: OBSN, a late clinical-stage biopharmaceutical company developing and commercializing novel therapies to improve womens reproductive health, today reported financial results for the quarter ended June 30, 2020 and provided a business update.The excellent phase 3 results from PRIMROSE 1 and PRIMROSE 2 last month were critical achievements as we now embark upon regulatory filings and commercial preparation, said Ernest Loumaye, MD, PhD, OBGYN, CEO and Co-Founder of ObsEva. We strongly believe that our strategy to develop both a low dose of linzagolix without hormonal add back therapy and a high dose with hormonal add back therapy is the optimal way to treat more women suffering from heavy menstrual bleeding due to uterine fibroids. Pipeline Update Linzagolix for the treatment of uterine fibroids and endometriosis Positive Phase 3 results for PRIMROSE 1 and PRIMROSE 2 trials of linzagolix for the treatment of HMB due to uterine fibroids: PRIMROSE 1 is being conducted in approximately 500 women experiencing heavy menstrual bleeding HMB due to uterine fibroids. As announced July 6, 2020, the 24-week responder rate was 75.5 for women receiving 200mg linzagolix and add back therapy ABT and 56.4 for women receiving 100 mg linzagolix without ABT, vs. 35.0 for placebo p0.001 and p0.003 respectively. In addition, 52-week data from PRIMROSE 2 demonstrate that continued treatment with linzagolix provides sustained efficacy and is well tolerated. Responder rates of 91.6 and 53.2 were observed in women receiving 200 mg with ABT and 100 mg without ABT, respectively, both of which are similar to the responder rates observed at week 24 of the study. The pooled week 24 data from these two Phase 3 studies support a potentially best-in-class profile, with a responder rate of 84.7 in women receiving linzagolix 200 mg with ABT, and 56.6 in women receiving linzagolix 100 mg without ABT. New patient enrollment in Phase 3 trials EDELWEISS 2 U.S. and EDELWEISS 3 U.S. and Europe resuming: Following the decision to temporarily stop enrolling new patients due to the COVID-19 pandemic announced in March 2020, the EDELWEISS 2 and 3 trials resumed enrollment of new patients in the latter part of the second quarter. Each of these trials is designed to assess two once daily oral doses of linzagolix in women with endometriosis-associated pain, including 75mg without ABT and 200mg with ABT. Linzagolix commercial partnership: ObsEva is engaged in active discussions with several parties for a commercial partnership to maximize the best-in-class potential of linzagolix. OBE022 to delay childbirth in pregnant women with preterm labor at 24-34 weeks of gestation Enrollment completed in Phase 2 PROLONG part B: Part B is the multicenter, randomized, double-blind, placebo-controlled portion of the PROLONG trial that enrolled up to 120 women with preterm labor at a gestational age between 24 and 34 weeks. Enrollment in Part B was completed in March 2020, and infant delivery and follow-up is ongoing. Nolasiban for improving pregnancy and live birth in women undergoing embryo transfer ET following in-vitro fertilization IVF Nolasiban partnership with YuYuan BioScience Technology YuYuan for development and commercialization in China: On July 1, 2020, ObsEva and YuYuan announced a pre-IND meeting request to the Chinese National Medical Products Administration NMPA to enable a Phase 1 and Phase 2 proof of concept study in China. Anticipated MilestonesObsEva expects to achieve the following clinical and regulatory milestones in 2020-21: Fourth Quarter 2020 Linzagolix: Pending feedback from national authorities, submit a Marketing Authorization Application MAA in Europe through a centralized procedure for the uterine fibroid indication. OBE022: Report final safety and efficacy results from the PROLONG trial encompassing maternal and neonatal follow-up. Nolasiban: Investigational new drug IND submission in China by YuYuan Bioscience Technology to initiate clinical development. First Half 2021 Linzagolix: Complete safety follow-up, and submit a New Drug Application NDA to the U.S. Food and Drug Administration for the uterine fibroid indication. Second Quarter 2020 Financial ResultsNet loss for the quarter ending June 30, 2020 was 18.2 million, or 0.38 per share, compared with a net loss of 34.8 million, or 0.80 per share, for the quarter ending June 30, 2019. Research and development expenses were 15.4 million and general and administrative expenses were 2.2 million for the quarter, compared with 28.4 million and 6.2 million, respectively, for the prior year quarter. The net loss for the quarter included non-cash expenses of 1.4 million for stock-based compensation, compared with 3.1 million a year ago. As of June 30, 2020, ObsEva had cash and cash equivalents of 45.0 million, compared with 69.4 million as of December 31, 2019.The half-year report 2020 will be available in the financial reports section of the Companys website.To access the financial reports section of the Companys website, please click here. To access the half-year report 2020 directly, please click here. About ObsEvaObsEva is a clinical-stage biopharmaceutical company focused on the clinical development and commercialization of novel therapeutics for serious conditions that compromise a womens reproductive health and pregnancy. Through strategic in-licensing and disciplined drug development, ObsEva has established a late-stage clinical pipeline with development programs focused on treating endometriosis, uterine fibroids, preterm labor, and improving IVF outcomes. ObsEva is listed on the Nasdaq Global Select Market and is trading under the ticker symbol OBSV and on the SIX Swiss Exchange where it is trading under the ticker symbol OBSN. For more information, please visit Cautionary Note Regarding Forward-Looking Statements Any statements contained in this press release that do not describe historical facts may constitute forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as believe, expect, may, plan, potential, will, and similar expressions, and are based on ObsEvas current beliefs and expectations. These forward-looking statements include expectations regarding the clinical development of ObsEvas product candidates, the potential therapeutic benefits of such product candidates, the timing of enrollment in and data from clinical trials, including the impact of the COVID-19 pandemic on such trials, ObsEvas plan to submit its MAA in Europe and NDA in the United States, YuYuans submission of an investigational new drug application in China, the results of interactions with regulatory authorities and ObsEvas ability to enter into a future commercial partnership for linzagolix. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements. Risks and uncertainties that may cause actual results to differ materially include uncertainties inherent in the conduct of clinical trials and clinical development, including the risk that the results of earlier clinical trials may not be predictive of the results of later stage clinical trials, related interactions with regulators, ObsEvas reliance on third parties over which it may not always have full control, the effects of the COVID-19 pandemic, any benefits from the joint collaboration with YuYuan or any future commercial partnership for linzagolix may not be fully realized or may take longer to realize than expected and other risks and uncertainties that are described in the Risk Factors section of ObsEvas Annual Report on Form 20-F for the year ended December 31, 2019, and other filings ObsEva makes with the SEC. These documents are available on the Investors page of ObsEvas website at Any forward-looking statements speak only as of the date of this press release and are based on information available to ObsEva as of the date of this release, and ObsEva assumes no obligation to, and does not intend to, update any forward-looking statements, whether as a result of new information, future events or otherwise. For further information, please contact: CEO Office Contact: Shauna Dillon 41 22 552 1550Investor Contact: Mario Corso Vice President, Investor Relations mario.corsoobseva. 