ObsEva SA Presented Nolasiban Poster at the ASRM 2020 Virtual Scientific Congress October 17-21

Geneva, Switzerland and Boston, MA – October 20, 2020 – ObsEva SA (NASDAQ: OBSV), a clinical-stage biopharmaceutical company developing and commercializing novel therapies to improve women’s reproductive health, today announced the presentation of a poster at the ASRM 2020 Virtual Scientific Congress and Expo.

Poster number # P-482: The Effect of the Oral Oxytocin Antagonist, Nolasiban, On Pregnancy Rates in Women Undergoing Embryo Transfer Following IVF

Dr. Georg Griesinger, Professor at Luebeck University, Germany, and chair of the Department of Gynecological Endocrinology and Reproductive Medicine, University Hospital of Schleswig-Holstein, is lead author of a poster presenting results from a meta-analysis of the clinical trials and a mechanism of action study of nolasiban, an oxytocin receptor antagonist being developed for its potential to increase pregnancy rates following in vitro fertilization (IVF). Results support the further evaluation of higher doses and/or alternate regimens of nolasiban. ObsEva is partnering with YuYuan BioScience Technology, a Chinese company, for the development of nolasiban.

The related abstract is scheduled to be published online in the Fertility and Sterility Abstract Supplement in October 2020.

About ObsEva

ObsEva is a biopharmaceutical company developing and commercializing novel therapies to improve women’s 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 embryo transfer (ET) outcomes following IVF. 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 .

About Nolasiban

Nolasiban (previously known as OBE001), is an oral oxytocin receptor antagonist which was licensed from Merck KGaA, Darmstadt, Germany, in 2013. ObsEva retains worldwide, exclusive, commercial rights (ex China).

About Assisted Reproductive Technology

Infertility affects about 10% of reproductive-aged couples, with more than two million assisted reproductive technology (ART) treatments (including IVF and intracytoplasmic sperm injection (ICSI)) performed worldwide each year. In China, more than 950,000 ART cycles (IVF, ICSI, fetal ET) were performed in 2017 (National Health Commission of the PRC, presented at the 23rd International Federation of Fertility Societies conference in Shanghai, 2019).

While the success of ART depends on multiple factors including ovarian response, fertilization, embryo quality and ET procedure, a successful pregnancy ultimately hinges on the receptivity of the uterus to accept embryo implantation. Uterine contractions at the time of ET, as well as suboptimal thickness of the uterine wall and insufficient blood flow to the uterus, may impair the implantation of the embryo.

About YuYuan Bioscience Technology

YuYuan Bioscience Technology is a leading biopharmaceutical company based in China focused on discovering, developing and commercializing innovative medicines for unmet medical needs in the assisted reproductive area. The company continues to introduce a competitive portfolio of therapeutic programs aimed at helping to bring more solutions to this field. YuYuan Bioscience has a top class leadership team with deep experience at assisted reproductive therapeutics and within biotech organizations. The team has a strong track record of success – successfully having taken drug candidates into clinical trials in China, secured regulatory approvals and achieved great market success. YuYuan Bioscience has always adhered to the development concept of “doing moral business, craving long-lasting career”, providing comprehensive, accurate and professional services for China's assisted reproductive medical field.

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 ObsEva’s current beliefs and expectations. These forward-looking statements include statements regarding the potential of nolasiban to improve pregnancy rates following IVF. 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 and related regulatory reviews and approvals, 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, the impact of the novel coronavirus outbreak, and other risks and uncertainties that are described in the Risk Factors section of ObsEva’s Annual Report on Form 20-F for the year ended December 31, 2019, the Risk Factors disclosed in ObsEva’s Report on Form 6-K filed with the Securities and Exchange Commission (SEC) on August 6, 2020 and other filings ObsEva makes with the SEC. These documents are available on the Investors page of ObsEva’s 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

Shauna.dillon@.ch

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