ObsEva SA to start trading today on the SIX Swiss

• Trading of ObsEva's shares on SIX Swiss Exchange starts under the ticker symbol 'OBSN'

• Reference price at CHF 15.00 per share  
• ObsEva with unique pipeline of novel and potential best-in class therapeutics to address serious conditions with a high unmet medical need affecting millions of women  
• Company will ring the opening bell at SIX Swiss Exchange today at market opening

Geneva, Switzerland and Boston, MA - July 13, 2018 - ObsEva SA (NASDAQ: OBSV / SIX: OBSN), a Swiss clinical-stage biopharmaceutical company focused on the development and commercialization of novel therapeutics for serious conditions that compromise a woman's reproductive health and pregnancy, announced that its shares will be listed and start trading today under the "International Reporting Standard" on SIX Swiss Exchange. The issued share capital comprises 45'381'252 registered shares with a nominal value of 1/13 of CHF 1 each. The reference price is CHF 15.00 per share, corresponding to a market capitalization of CHF 680 million. ObsEva will not issue any new shares in connection with the listing in Switzerland.

Ernest Loumaye, CEO and Co-Founder of ObsEva said : "We are proud to initiate the listing at the SIX today as it marks an important milestone for our company. The SIX Swiss Exchange is Europe's leading exchange for life sciences companies and Swiss institutional and private investors have developed a strong understanding of the healthcare sector. Our late-stage clinical pipeline offers numerous opportunities and is progressing well. Recent results demonstrate the efficacy of our therapies and confirm the potential therapeutic benefits."

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Members of ObsEva's leadership team will open the market and ring the IPO bell today at market opening.

This press release and further information can be found at www.obseva.com .

Copies of the listing prospectus can be obtained, free of charge in Switzerland for 12 months following the first day of trading, at the following address: ObsEva SA, 12 Chemin des Aulx, 1228 Plan-les-Ouates, Switzerland (+41 22 552 38 40 / IR@obseva.com ).

About ObsEva ObsEva is a clinical-stage biopharmaceutical company focused on the clinical development and commercialization of novel therapeutics for serious conditions that compromise a woman'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 IVF outcomes. ObsEva is listed on The NASDAQ Global Select Market and is trading under the ticker symbol "OBSV". For more information, please visit www.ObsEva.com .

For further information, please contact:

Media Contact Switzerland and Europe: Christophe Lamps Dynamics Group cla@dynamicsgroup.ch +41 22 308 6220 Office +41 79 476 26 87 Mobile

Media Contact U.S.: Jeanene Timberlake RooneyPartners LLC jtimberlake@rooneyco.com +1 646 770 8858

CEO Office Contact: Shauna Dillon Shauna.dillon@obseva.ch +41 22 552 1550

Investor Contact: Mario Corso Senior Director, Investor Relations mario.corso@obseva.com +1 857 972 9347 Office +1 781 366 5726 Mobile

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 expectations regarding our potential listing on the SIX Swiss Exchange, the effects on ObsEva's profile and protections that may be afforded to ObsEva's shareholders. 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 in the listing process, inherent uncertainties in the development and commercialization of therapies and clinical trials 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, 2017, and other filings ObsEva makes with the SEC. These documents are available on the Investors page of ObsEva's website at http://www.obseva.com . 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.

Disclaimer This is not an offer of securities for sale in the United States. Securities may not be offered or sold in the United States unless they are registered or exempt from registration. Any public offering of securities in the United States, if any, will be made by means of a prospectus that may be obtained from the Company and that will contain detailed information about the Company and management as well as financial statements.

This material does not constitute or contain any offer to sell or invitation to subscribe or make commitments for or in respect of any security in any jurisdiction. There may be restrictions on the distribution of this material in certain jurisdictions, including Canada, Australia, Japan and the member states of the European Economic Area and the United Kingdom of Great Britain and Northern Ireland. Persons into whose possession this material may come are required to inform themselves of and observe any such restrictions.

Attachment

• Press Release.pdf