Exhibit 99.1 Focused on unmet needs in women’s reproductive health March 2021Exhibit 99.1 Focused on unmet needs in women’s reproductive health March 2021

Disclaimer Matters discussed in this presentation may constitute forward-looking statements. We expressly disclaim any obligation to update or revise the information herein, The forward-looking statements contained in this presentation reflect our views as of including the forward-looking statements, except as required by law. Please also the date of this presentation about future events and are subject to risks, note that this presentation does not constitute an offer to sell or a solicitation of an uncertainties, assumptions, and changes in circumstances that may cause our actual offer to buy any securities. results, performance, or achievements to differ significantly from those expressed or This presentation concerns products that are under clinical investigation and which implied in any forward-looking statement. Although we believe that the expectations have not yet been approved for marketing by the US Food and Drug Administration. reflected in the forward-looking statements are reasonable, we cannot guarantee It is currently limited by federal law to investigational use, and no representation is future events, results, performance, or achievements. Some of the key factors that made as to its safety or effectiveness for the purposes for which it is being could cause actual results to differ from our expectations include our plans to develop investigated. The trademarks included herein are the property of the owners thereof and potentially commercialize our product candidates; our planned clinical trials and and are used for reference purposes only. Such use should not be construed as an preclinical studies for our product candidates; the timing of and our ability to obtain endorsement of such products. and maintain regulatory approvals for our product candidates; the extent of clinical trials potentially required for our product candidates; the clinical utility and market This presentation also contains estimates and other statistical data made by acceptance of our product candidates; our plans and development of any new independent parties and by us relating to market size and growth and other data indications for our product candidates; our commercialization, marketing and about our industry. This data involves a number of assumptions and limitations, and manufacturing capabilities and strategy; our intellectual property position; and our you are cautioned not to give undue weight to such estimates. In addition, ability to identify and in-license additional product candidates. For further information projections, assumptions and estimates of our future performance and the future regarding these risks, uncertainties and other factors that could cause our actual performance of the markets in which we operate are necessarily subject to a high results to differ from our expectations, you should read the risk factors set forth in our degree of uncertainty and risk. Annual Report on Form 20-F for the year ended December 31, 2020 filed with the SEC on March 5, 2021, and our other filings we make with the Securities and Exchange Commission from time to time. 2Disclaimer Matters discussed in this presentation may constitute forward-looking statements. We expressly disclaim any obligation to update or revise the information herein, The forward-looking statements contained in this presentation reflect our views as of including the forward-looking statements, except as required by law. Please also the date of this presentation about future events and are subject to risks, note that this presentation does not constitute an offer to sell or a solicitation of an uncertainties, assumptions, and changes in circumstances that may cause our actual offer to buy any securities. results, performance, or achievements to differ significantly from those expressed or This presentation concerns products that are under clinical investigation and which implied in any forward-looking statement. Although we believe that the expectations have not yet been approved for marketing by the US Food and Drug Administration. reflected in the forward-looking statements are reasonable, we cannot guarantee It is currently limited by federal law to investigational use, and no representation is future events, results, performance, or achievements. Some of the key factors that made as to its safety or effectiveness for the purposes for which it is being could cause actual results to differ from our expectations include our plans to develop investigated. The trademarks included herein are the property of the owners thereof and potentially commercialize our product candidates; our planned clinical trials and and are used for reference purposes only. Such use should not be construed as an preclinical studies for our product candidates; the timing of and our ability to obtain endorsement of such products. and maintain regulatory approvals for our product candidates; the extent of clinical trials potentially required for our product candidates; the clinical utility and market This presentation also contains estimates and other statistical data made by acceptance of our product candidates; our plans and development of any new independent parties and by us relating to market size and growth and other data indications for our product candidates; our commercialization, marketing and about our industry. This data involves a number of assumptions and limitations, and manufacturing capabilities and strategy; our intellectual property position; and our you are cautioned not to give undue weight to such estimates. In addition, ability to identify and in-license additional product candidates. For further information projections, assumptions and estimates of our future performance and the future regarding these risks, uncertainties and other factors that could cause our actual performance of the markets in which we operate are necessarily subject to a high results to differ from our expectations, you should read the risk factors set forth in our degree of uncertainty and risk. Annual Report on Form 20-F for the year ended December 31, 2020 filed with the SEC on March 5, 2021, and our other filings we make with the Securities and Exchange Commission from time to time. 2

About ObsEva ObsEva (NASDAQ: OBSV and SIX: OBSN) is a clinical-stage biopharmaceutical company developing and commercializing novel therapies to improve women’s reproductive health. 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 and preterm labor. • Founded in 2012 • Locations: Geneva, Switzerland and Boston, MA • Employees: 46 total EU and US • Listings: NASDAQ (OBSV) and SIX (OBSN) • Collaborations with Kissei, Yuyuan Bioscience, Merck Serono 3About ObsEva ObsEva (NASDAQ: OBSV and SIX: OBSN) is a clinical-stage biopharmaceutical company developing and commercializing novel therapies to improve women’s reproductive health. 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 and preterm labor. • Founded in 2012 • Locations: Geneva, Switzerland and Boston, MA • Employees: 46 total EU and US • Listings: NASDAQ (OBSV) and SIX (OBSN) • Collaborations with Kissei, Yuyuan Bioscience, Merck Serono 3

Seasoned leadership team Elizabeth Garner MD, Fabien de Ladonchamps Jean-Pierre Wim Souverijns, PhD Brian O’Callaghan David Renas MPH Chief Gotteland, PhD Chief Commercial Chief Executive Officer Chief Financial Officer Chief Medical Officer Administrative Officer Chief Scientific Officer Officer 4Seasoned leadership team Elizabeth Garner MD, Fabien de Ladonchamps Jean-Pierre Wim Souverijns, PhD Brian O’Callaghan David Renas MPH Chief Gotteland, PhD Chief Commercial Chief Executive Officer Chief Financial Officer Chief Medical Officer Administrative Officer Chief Scientific Officer Officer 4

Board of Directors Barbara Duncan Frank Verwiel, MD Ernest Loumaye, Annette Clancy, BSc James I. Healy, MD, Rafaèle Tordjman, Jacky Vonderscher, Audit Committee Ed Mathers Chairperson MD, PhD (Hons) PhD MD, PhD PhD Chair 5Board of Directors Barbara Duncan Frank Verwiel, MD Ernest Loumaye, Annette Clancy, BSc James I. Healy, MD, Rafaèle Tordjman, Jacky Vonderscher, Audit Committee Ed Mathers Chairperson MD, PhD (Hons) PhD MD, PhD PhD Chair 5

Investor highlights Pursuing promising large indications for serious conditions that compromise women's reproductive 1 health and beyond, with the potential to extend into other indications including prostate cancer Ebopiprant, the only known product in development for preterm labor, has positive Phase 2a data 2 that support a Phase 2b dose ranging study Yselty® has potential best in class efficacy, a favorable tolerability profile, and unique flexible dosing 3 options Business model built on strong global partnerships and collaborations 4 Seasoned leadership team with a track record for success 5 6Investor highlights Pursuing promising large indications for serious conditions that compromise women's reproductive 1 health and beyond, with the potential to extend into other indications including prostate cancer Ebopiprant, the only known product in development for preterm labor, has positive Phase 2a data 2 that support a Phase 2b dose ranging study Yselty® has potential best in class efficacy, a favorable tolerability profile, and unique flexible dosing 3 options Business model built on strong global partnerships and collaborations 4 Seasoned leadership team with a track record for success 5 6

Product overview YSELTY® EBOPIPRANT NOLASIBAN (LINZAGOLIX) (OBE022) Potential to improve live birth Potential to relieve symptoms Potential to delay preterm rate following IVF & embryo of heavy menstrual bleeding birth to improve newborn transfer due to uterine fibroids and health and reduce medical pain associated with costs endometriosis 7Product overview YSELTY® EBOPIPRANT NOLASIBAN (LINZAGOLIX) (OBE022) Potential to improve live birth Potential to relieve symptoms Potential to delay preterm rate following IVF & embryo of heavy menstrual bleeding birth to improve newborn transfer due to uterine fibroids and health and reduce medical pain associated with costs endometriosis 7

Multiple development programs drive value Phase 1 Phase 2 Phase 3 Next Milestones Uterine Fibroids – Ph3 PRIMROSE 2 (EU & US) NDA submission (Q3:21) MAA for uterine fibroids expected approval YSELTY® Uterine Fibroids – Ph3 PRIMROSE 1 (US) (Q4:21) (LINZAGOLIX) Oral GnRH receptor antagonist EDELWEISS 3: Primary endpoint readout Endometriosis – Ph3 EDELWEISS 3 (EU & US) expected (Q4:21) EBOPIPRANT Initiation of Phase 2b dose ranging study Preterm Labor – Ph2b (EU & Asia) Oral PGF 2α (Q4:21) receptor antagonist NOLASIBAN In development, partnership with Yuyuan IVF – Ph1/2 (China) Oral oxytocin BioScience Technology (PRC) receptor antagonist 8Multiple development programs drive value Phase 1 Phase 2 Phase 3 Next Milestones Uterine Fibroids – Ph3 PRIMROSE 2 (EU & US) NDA submission (Q3:21) MAA for uterine fibroids expected approval YSELTY® Uterine Fibroids – Ph3 PRIMROSE 1 (US) (Q4:21) (LINZAGOLIX) Oral GnRH receptor antagonist EDELWEISS 3: Primary endpoint readout Endometriosis – Ph3 EDELWEISS 3 (EU & US) expected (Q4:21) EBOPIPRANT Initiation of Phase 2b dose ranging study Preterm Labor – Ph2b (EU & Asia) Oral PGF 2α (Q4:21) receptor antagonist NOLASIBAN In development, partnership with Yuyuan IVF – Ph1/2 (China) Oral oxytocin BioScience Technology (PRC) receptor antagonist 8

EBOPIPRANT Potential To Delay Preterm Birth To Improve Newborn Health And Reduce Medical CostsEBOPIPRANT Potential To Delay Preterm Birth To Improve Newborn Health And Reduce Medical Costs

Preterm birth is delivery before 37 weeks of pregnancy Life altering & costly /yr $26B >1 1million US economic burden In 10 babies are born preterm related preterm deaths in 2015 1 WW Preterm birth, a costly burden per baby LEADING cause of death in children US infant medical costs $16.9B+ under age 5 average cost per US survivor Babies surviving early birth $195K+ infant born 24-26 weeks face greater likelihood of lifelong disabilities average US cost for a preterm $50K infant WHO ‘Born Too Soon: The Global Action Report on Preterm Birth’ (2012); Kissin et al. NEJM, 2014 Behrman et al., National Academies Press, 2007 10 1 WHO: 15 million babies born preterm each year worldwide, and number is rising.Preterm birth is delivery before 37 weeks of pregnancy Life altering & costly /yr $26B >1 1million US economic burden In 10 babies are born preterm related preterm deaths in 2015 1 WW Preterm birth, a costly burden per baby LEADING cause of death in children US infant medical costs $16.9B+ under age 5 average cost per US survivor Babies surviving early birth $195K+ infant born 24-26 weeks face greater likelihood of lifelong disabilities average US cost for a preterm $50K infant WHO ‘Born Too Soon: The Global Action Report on Preterm Birth’ (2012); Kissin et al. NEJM, 2014 Behrman et al., National Academies Press, 2007 10 1 WHO: 15 million babies born preterm each year worldwide, and number is rising.

Ebopiprant is designed to treat preterm labor (PTL) Treating Preterm Labor Preventing Preterm Labor No FDA–approved PTL treatment available in US Makena approved for prevention of PTL in women with history of Current treatment in US includes off-label use of non- preterm birth selective prostaglandin (COX) inhibitors, Indomethacin, calcium Drug(s) channel blocker, beta-mimetics; all are associated with safety Not approved for treatment of PTL issues that limit use Potential withdrawal from US Atosiban (oxytocin receptor antagonist) approved in market after failed confirmatory EU/some Asian countries trial Use in setting of active preterm labor and threatened Use starts between 16 and 20 Use premature delivery weeks of pregnancy 11Ebopiprant is designed to treat preterm labor (PTL) Treating Preterm Labor Preventing Preterm Labor No FDA–approved PTL treatment available in US Makena approved for prevention of PTL in women with history of Current treatment in US includes off-label use of non- preterm birth selective prostaglandin (COX) inhibitors, Indomethacin, calcium Drug(s) channel blocker, beta-mimetics; all are associated with safety Not approved for treatment of PTL issues that limit use Potential withdrawal from US Atosiban (oxytocin receptor antagonist) approved in market after failed confirmatory EU/some Asian countries trial Use in setting of active preterm labor and threatened Use starts between 16 and 20 Use premature delivery weeks of pregnancy 11

Ebopiprant: an advancement in treatment of preterm labor Orally active, selective prostaglandin F (PGF ) receptor antagonist 2α 2α Potential to treat preterm labor ebopiprant with improved safety over non- Selectively blocks selective COX *inhibitors the PGF2 2α (NSAIDS) receptor *COX: cyclooxygenase 12Ebopiprant: an advancement in treatment of preterm labor Orally active, selective prostaglandin F (PGF ) receptor antagonist 2α 2α Potential to treat preterm labor ebopiprant with improved safety over non- Selectively blocks selective COX *inhibitors the PGF2 2α (NSAIDS) receptor *COX: cyclooxygenase 12

Ebopiprant is designed to delay delivery by at least 48 hours Short-term prolongation of pregnancy (at least 48 hours) provides a critical window for impact on neonatal outcomes: • Allows full effect of corticosteroids on neonatal lung maturity ‒ Prematurity associated with respiratory complications due to insufficient lung maturation ‒ Corticosteroids used to speed up maturation process ‒ Maximum effect occurs ~48+ hours after administration • Allows patient transfer to centers with NICU* 13 *NICU=neonatal intensive care unitEbopiprant is designed to delay delivery by at least 48 hours Short-term prolongation of pregnancy (at least 48 hours) provides a critical window for impact on neonatal outcomes: • Allows full effect of corticosteroids on neonatal lung maturity ‒ Prematurity associated with respiratory complications due to insufficient lung maturation ‒ Corticosteroids used to speed up maturation process ‒ Maximum effect occurs ~48+ hours after administration • Allows patient transfer to centers with NICU* 13 *NICU=neonatal intensive care unit

Ebopiprant Phase 2a PROLONG study Dosing period and FU visit Maternal and neonatal FU Infant follow-up - Visits at site - - Site visits or medical records - - Non-interventional, no site visits - End of Screening Follow-up treatment and day 1 visit visit # # # Delivery D14 Delivery Term Term D7 Term D1 D2 D3 +28 D +6 M +12 M +24 M ≤24h ebopiprant or # placebo Expected Term Atosiban Study design: Endpoints: Hospitalization • Double-blind, randomized • Incidence of delivery within 48 hours and 7 days of treatment • Atosiban + Ebopiprant vs • Time to delivery and delivery prior to 37 weeks of gestation • Atosiban + Placebo • Maternal, fetal, neonatal safety 14Ebopiprant Phase 2a PROLONG study Dosing period and FU visit Maternal and neonatal FU Infant follow-up - Visits at site - - Site visits or medical records - - Non-interventional, no site visits - End of Screening Follow-up treatment and day 1 visit visit # # # Delivery D14 Delivery Term Term D7 Term D1 D2 D3 +28 D +6 M +12 M +24 M ≤24h ebopiprant or # placebo Expected Term Atosiban Study design: Endpoints: Hospitalization • Double-blind, randomized • Incidence of delivery within 48 hours and 7 days of treatment • Atosiban + Ebopiprant vs • Time to delivery and delivery prior to 37 weeks of gestation • Atosiban + Placebo • Maternal, fetal, neonatal safety 14

Ebopiprant Phase 2a PROLONG study Demographics and baseline characteristics Atosiban + Placebo Atosiban + Ebopiprant n=55 n=58 29.6 (5.1) 29.7 (5.7) Mean age – years (SD) Race 39 (70.9%) 42 (72.4%) White – n (%) 16 (29.1%) 14 (24.1%) Asian – n (%) 29 (3.0) 30.2 (2.6) Mean (SD) gestational age – weeks 23 (41.8%) 25 (43.1%) 24 to 30 weeks – n (%) 32 (58.2%) 33 (56.9%) 30 to 34 weeks – n (%) 41 (74.5%) 42 (72.4%) Singleton – n (%) 14 (25.5%) 16 (27.6%) Twin – n (%) 15Ebopiprant Phase 2a PROLONG study Demographics and baseline characteristics Atosiban + Placebo Atosiban + Ebopiprant n=55 n=58 29.6 (5.1) 29.7 (5.7) Mean age – years (SD) Race 39 (70.9%) 42 (72.4%) White – n (%) 16 (29.1%) 14 (24.1%) Asian – n (%) 29 (3.0) 30.2 (2.6) Mean (SD) gestational age – weeks 23 (41.8%) 25 (43.1%) 24 to 30 weeks – n (%) 32 (58.2%) 33 (56.9%) 30 to 34 weeks – n (%) 41 (74.5%) 42 (72.4%) Singleton – n (%) 14 (25.5%) 16 (27.6%) Twin – n (%) 15

Overall delivery rate within 48 hours reduced by >40% Percentage of women delivering within 48 hours 30% Placebo + atosiban ebopiprant + atosiban 26.8% 22.6% 21.8% 20% 20.8% 12.9% 12.5% 12.5% 12.5% 12.0% 10% 7.1% n=55 n=56 n=24 n=25 n=31 n=31 n=41 n=40 n=14 n=16 0% Overall GA 24 to GA 30 to Singletons Twins 30 weeks 34 weeks OR (90% CI) 0.52 (0.22, 1.23) 1.05 (0.20, 5.43) 0.77 (0.21, 2.89) 0.39 (0.15, 1.04) 2.05 (0.23, 18.1) 16 Percentage of subjectsOverall delivery rate within 48 hours reduced by >40% Percentage of women delivering within 48 hours 30% Placebo + atosiban ebopiprant + atosiban 26.8% 22.6% 21.8% 20% 20.8% 12.9% 12.5% 12.5% 12.5% 12.0% 10% 7.1% n=55 n=56 n=24 n=25 n=31 n=31 n=41 n=40 n=14 n=16 0% Overall GA 24 to GA 30 to Singletons Twins 30 weeks 34 weeks OR (90% CI) 0.52 (0.22, 1.23) 1.05 (0.20, 5.43) 0.77 (0.21, 2.89) 0.39 (0.15, 1.04) 2.05 (0.23, 18.1) 16 Percentage of subjects

Singleton delivery rate within 48 hours reduced by >50% Percentage of women delivering within 48 hours 40% Placebo + atosiban ebopiprant + atosiban 30% 30.0% 26.8% 23.8% 20% 15.8% 12.5% 10% 9.5% n=41 n=40 n=21 n=21 n=20 n=19 0% Overall GA 24 to GA 30 to 30 weeks 34 weeks OR (90% CI) 0.39 (0.15, 1.04) 0.34 (0.08, 1.49) 0.44 (0.12, 1.62) 17 Percentage of subjectsSingleton delivery rate within 48 hours reduced by >50% Percentage of women delivering within 48 hours 40% Placebo + atosiban ebopiprant + atosiban 30% 30.0% 26.8% 23.8% 20% 15.8% 12.5% 10% 9.5% n=41 n=40 n=21 n=21 n=20 n=19 0% Overall GA 24 to GA 30 to 30 weeks 34 weeks OR (90% CI) 0.39 (0.15, 1.04) 0.34 (0.08, 1.49) 0.44 (0.12, 1.62) 17 Percentage of subjects

Reduced Singleton 24- to 30-week delivery rate within 7 days Percentage of women delivering within 7 days 50% Placebo + atosiban ebopiprant + atosiban 40% 42.1% 40.0% 30% 31.7% 27.5% 23.8% 20% 14.3% 10% n=41 n=40 n=21 n=21 n=20 n=19 0% Overall GA 24 to GA 30 to 30 weeks 34 weeks OR (90% CI) 0.81 (0.36, 1.83) 0.53 (0.14, 2.01) 1.09 (0.37, 3.18) 18 Percentage of subjectsReduced Singleton 24- to 30-week delivery rate within 7 days Percentage of women delivering within 7 days 50% Placebo + atosiban ebopiprant + atosiban 40% 42.1% 40.0% 30% 31.7% 27.5% 23.8% 20% 14.3% 10% n=41 n=40 n=21 n=21 n=20 n=19 0% Overall GA 24 to GA 30 to 30 weeks 34 weeks OR (90% CI) 0.81 (0.36, 1.83) 0.53 (0.14, 2.01) 1.09 (0.37, 3.18) 18 Percentage of subjects

Ebopiprant Maternal and neonatal safety Atosiban + Placebo Atosiban + Ebopiprant Maternal & Fetal AEs until 7 days post treatment – n (%) n=55 n=58 23 (41.8%) 24 (41.4%) At least one TEAE 0 0 SAEs 4 (7.3%) 4 (6.9%) Most common (constipation) Neonatal AEs and prematurity related Events – n (%) n=69 n=72 41 (59.4%) 44 (61.1%) At least one TEAE or prematurity related event 9 (13.0%) 10 (13.9%) SAEs 28 (40.6%) 22 (30.6%) Most common (neonatal jaundice) Neonatal outcomes – n (%) singletons n=41 n=40 Duration of hospitalization in days – mean (SD) 18.0 (25.8) 13.7 (16.5) 19Ebopiprant Maternal and neonatal safety Atosiban + Placebo Atosiban + Ebopiprant Maternal & Fetal AEs until 7 days post treatment – n (%) n=55 n=58 23 (41.8%) 24 (41.4%) At least one TEAE 0 0 SAEs 4 (7.3%) 4 (6.9%) Most common (constipation) Neonatal AEs and prematurity related Events – n (%) n=69 n=72 41 (59.4%) 44 (61.1%) At least one TEAE or prematurity related event 9 (13.0%) 10 (13.9%) SAEs 28 (40.6%) 22 (30.6%) Most common (neonatal jaundice) Neonatal outcomes – n (%) singletons n=41 n=40 Duration of hospitalization in days – mean (SD) 18.0 (25.8) 13.7 (16.5) 19

Ebopiprant Phase 2b dose ranging study Anticipated initiation Q4:21* Study Design: Endpoints: • Global (EU and Asia) • Optimal dose • Dose escalating • Incidence of delivery within 48 hours • Double-blind, randomized and 7 days of treatment • Atosiban + Ebopiprant • Time to delivery and delivery prior to • Atosiban + Placebo 37 weeks of gestation • Maternal, fetal, neonatal safety Key Eligibility Criteria: • Single gestation • 24-34 weeks • Confirmed preterm labor • No contraindication to tocolysis 20 *Discussions with FDA on requirements for US clinical development to occur in parallel Ebopiprant Phase 2b dose ranging study Anticipated initiation Q4:21* Study Design: Endpoints: • Global (EU and Asia) • Optimal dose • Dose escalating • Incidence of delivery within 48 hours • Double-blind, randomized and 7 days of treatment • Atosiban + Ebopiprant • Time to delivery and delivery prior to • Atosiban + Placebo 37 weeks of gestation • Maternal, fetal, neonatal safety Key Eligibility Criteria: • Single gestation • 24-34 weeks • Confirmed preterm labor • No contraindication to tocolysis 20 *Discussions with FDA on requirements for US clinical development to occur in parallel

Ebopiprant development in the US • FDA approved the beta-mimetic ritodrine (Yutopar) in 1980 Ø Withdrawn from the market in 1995 due to cardiovascular complications Ø No subsequent US approvals for PTL treatment • Discussions with FDA regarding clinical development program will be required • Currently engaging with US KOLs/advocacy groups • Potential approaches include: ‒ Combination with non-registered standard of care ‒ Comparison with non-registered standard of care ‒ Open label single-arm study vs historical data • Single Phase 3 study may be acceptable 21Ebopiprant development in the US • FDA approved the beta-mimetic ritodrine (Yutopar) in 1980 Ø Withdrawn from the market in 1995 due to cardiovascular complications Ø No subsequent US approvals for PTL treatment • Discussions with FDA regarding clinical development program will be required • Currently engaging with US KOLs/advocacy groups • Potential approaches include: ‒ Combination with non-registered standard of care ‒ Comparison with non-registered standard of care ‒ Open label single-arm study vs historical data • Single Phase 3 study may be acceptable 21

Ebopiprant, a potential breakthrough for preterm labor Supports Over 50% Favorable advancing reduction of maternal, ebopiprant singleton delivery fetal and into Phase 2b within 48 hrs neonatal safety ü ü ü Phase 2b study will include higher Enabling administration of Maternal, fetal and doses to more fully define critical drugs for neonatal neonatal safety ebopiprant potential and the longer- protection comparable to placebo term benefits for babies Ebopiprant has demonstrated proof of concept in delaying preterm birth 22Ebopiprant, a potential breakthrough for preterm labor Supports Over 50% Favorable advancing reduction of maternal, ebopiprant singleton delivery fetal and into Phase 2b within 48 hrs neonatal safety ü ü ü Phase 2b study will include higher Enabling administration of Maternal, fetal and doses to more fully define critical drugs for neonatal neonatal safety ebopiprant potential and the longer- protection comparable to placebo term benefits for babies Ebopiprant has demonstrated proof of concept in delaying preterm birth 22

D ES IGNED TO TREAT MORE WOMEN SUFFERING FROM UTERINE FIBROIDS Yselty®, our proposed trade name for linzagolix, is conditionally acceptable for the FDA. Linzagolix has not been approved by FDA for any indication for use. Linzagolix is an investigational drug.D ES IGNED TO TREAT MORE WOMEN SUFFERING FROM UTERINE FIBROIDS Yselty®, our proposed trade name for linzagolix, is conditionally acceptable for the FDA. Linzagolix has not been approved by FDA for any indication for use. Linzagolix is an investigational drug.

Uterine fibroids A significant unmet need translating into a multibillion market /yr $34B 9million 70%+ total US costs from direct women in the US of women have costs, lost workdays and affected by fibroids fibroids by age 50 complications Quality 600,000 >4 million hysterectomies are women in the US of Life performed annually are treated annually in the US for fibroids premenopausal women may experience heavy menstrual bleeding, anemia, bloating, infertility, 300,000 pain and swelling are because of uterine fibroids Cardozo et al., Am J Obstet Gynecol 2012; Stewart et al. NEJM, 2015; Flynn et al., Am J Obstet Gynecol 2006; Truven Health, 24 Fibroid Foundation website; Epidemiology of women’s health, Jones & Bartlett Learning, Ruby T. Senie, 2014Uterine fibroids A significant unmet need translating into a multibillion market /yr $34B 9million 70%+ total US costs from direct women in the US of women have costs, lost workdays and affected by fibroids fibroids by age 50 complications Quality 600,000 >4 million hysterectomies are women in the US of Life performed annually are treated annually in the US for fibroids premenopausal women may experience heavy menstrual bleeding, anemia, bloating, infertility, 300,000 pain and swelling are because of uterine fibroids Cardozo et al., Am J Obstet Gynecol 2012; Stewart et al. NEJM, 2015; Flynn et al., Am J Obstet Gynecol 2006; Truven Health, 24 Fibroid Foundation website; Epidemiology of women’s health, Jones & Bartlett Learning, Ruby T. Senie, 2014

GnRH antagonist mechanism of action Hypothalamus GnRH Anterior pituitary gland 1. Yselty® binds 3. Rapid suppression competitively to of LH and FSH pituitary gland GnRH receptors FSH, LH Yselty® (linzagolix) 2. Prevents receptor activation by Estradiol endogenous GnRH Ovary 4. Gonadotropin suppression leads Uterus to dose-dependent decrease in serum estradiol concentration 25GnRH antagonist mechanism of action Hypothalamus GnRH Anterior pituitary gland 1. Yselty® binds 3. Rapid suppression competitively to of LH and FSH pituitary gland GnRH receptors FSH, LH Yselty® (linzagolix) 2. Prevents receptor activation by Estradiol endogenous GnRH Ovary 4. Gonadotropin suppression leads Uterus to dose-dependent decrease in serum estradiol concentration 25

Promise of GnRH antagonists Dose dependent reduction of estradiol (E2) Women with symptoms of uterine fibroids No estradiol suppression Target estradiol Full estradiol suppression Disease Symptoms Outcomes Symptoms/Safety Concerns ‒ Heavy menstrual bleeding/anemia‒ Reduction in bleeding‒ BMD loss ‒ Abdominal/pelvic pain and pressure‒ Minimal to no impact on BMD‒ Hot flushes *ABT not required *ABT required for long term use (>6 months) *ABT: 1mg estradiol/0.5 mg norethisterone acetate 26Promise of GnRH antagonists Dose dependent reduction of estradiol (E2) Women with symptoms of uterine fibroids No estradiol suppression Target estradiol Full estradiol suppression Disease Symptoms Outcomes Symptoms/Safety Concerns ‒ Heavy menstrual bleeding/anemia‒ Reduction in bleeding‒ BMD loss ‒ Abdominal/pelvic pain and pressure‒ Minimal to no impact on BMD‒ Hot flushes *ABT not required *ABT required for long term use (>6 months) *ABT: 1mg estradiol/0.5 mg norethisterone acetate 26

A potential new gold standard treatment for uterine fibroids Differentiated PK/PD profile 1 2 3 No CYP3A4 Bioavailability Half-life induction/food > 80% 14-15 hours effect Reliable absorption Optimal balance for “No hassle” Predictable exposure/effect with dosing and effectiveness administration profile each dose • Convenient once-daily dosing • Can be taken with or without that fits into women’s busy food lives • No relevant interactions with • Blood levels that last long hormonal add-back therapy, enough to allow flexibility in oral iron, calcium or other dosing time common medications 27A potential new gold standard treatment for uterine fibroids Differentiated PK/PD profile 1 2 3 No CYP3A4 Bioavailability Half-life induction/food > 80% 14-15 hours effect Reliable absorption Optimal balance for “No hassle” Predictable exposure/effect with dosing and effectiveness administration profile each dose • Convenient once-daily dosing • Can be taken with or without that fits into women’s busy food lives • No relevant interactions with • Blood levels that last long hormonal add-back therapy, enough to allow flexibility in oral iron, calcium or other dosing time common medications 27

Uterine fibroids are ruining lives… No two women are the same, but millions share a common problem: suffering the daily consequences of uterine fibroids Yselty® 200 mg once daily Yselty® 100 mg once Yselty® 200 mg once with concomitant ABT daily without ABT daily without ABT For long-term use for women For long-term use for women with For short-term use (up to 6 months) for whom ABT is appropriate a contraindication to or who prefer when rapid reduction in fibroid and to avoid ABT uterine volume is desired …Yselty®, designed to treat more women 28 The hypothetical patients represented on this slide are for illustrative purposes only as no strength of linzagolix has been approved nor is there FDA-approved Prescribing Information to guide clinical decisionsUterine fibroids are ruining lives… No two women are the same, but millions share a common problem: suffering the daily consequences of uterine fibroids Yselty® 200 mg once daily Yselty® 100 mg once Yselty® 200 mg once with concomitant ABT daily without ABT daily without ABT For long-term use for women For long-term use for women with For short-term use (up to 6 months) for whom ABT is appropriate a contraindication to or who prefer when rapid reduction in fibroid and to avoid ABT uterine volume is desired …Yselty®, designed to treat more women 28 The hypothetical patients represented on this slide are for illustrative purposes only as no strength of linzagolix has been approved nor is there FDA-approved Prescribing Information to guide clinical decisions

Up to 50% of US women suffering from uterine fibroids may have a contraindication to hormonal ABT* Black women are overrepresented Proportion of US population 60% 50% Non-Hispanic Black 40% Non-Hispanic White 30% 20% 10% 0% Obesity (BMI ≥ 30) Hypertension Genetic risk factors Severe obesity Smokers aged ≥18 Dyslipidemia in women uncontrolled** for Venous (BMI ≥40) in aged ≥20 thromboembolism women aged ≥20 *US FDA elagolix PI, section 4. Contraindications and section 5.1. Warnings and precautions – thromboembolic disorders and vascular events ** Proportion of individuals with hypertension - Overall population Male vs Female: 47% vs 43% **Hales et al., Prevalence of obesity and severe obesity among adults: United States, 2017–2018. NCHS Data Brief, no 360 Current Cigarette Smoking Among Adults in the United States. Centers for Disease Control and Prevention 29 https://www.cdc.gov/tobacco/data_statistics/fact_sheets/adult_data/cig_smoking/index.htm#nation ; https://www.cdc.gov/ 2018 Proportion of US population (%)Up to 50% of US women suffering from uterine fibroids may have a contraindication to hormonal ABT* Black women are overrepresented Proportion of US population 60% 50% Non-Hispanic Black 40% Non-Hispanic White 30% 20% 10% 0% Obesity (BMI ≥ 30) Hypertension Genetic risk factors Severe obesity Smokers aged ≥18 Dyslipidemia in women uncontrolled** for Venous (BMI ≥40) in aged ≥20 thromboembolism women aged ≥20 *US FDA elagolix PI, section 4. Contraindications and section 5.1. Warnings and precautions – thromboembolic disorders and vascular events ** Proportion of individuals with hypertension - Overall population Male vs Female: 47% vs 43% **Hales et al., Prevalence of obesity and severe obesity among adults: United States, 2017–2018. NCHS Data Brief, no 360 Current Cigarette Smoking Among Adults in the United States. Centers for Disease Control and Prevention 29 https://www.cdc.gov/tobacco/data_statistics/fact_sheets/adult_data/cig_smoking/index.htm#nation ; https://www.cdc.gov/ 2018 Proportion of US population (%)

Phase 3 registration studies PRIMROSE 1 (US) and PRIMROSE 2 (EU/US) P1/P2 2 full menstrual cycles 24 weeks 28 weeks 24 weeks Placebo (P1 only) n = 103/102 Placebo 200 mg + ABT n = 94/97 100 mg 100 mg 24-Week n = 107/101 Screening 100 mg + ABT 100 mg + ABT Post Treatment Follow-up n = 105/103 200 mg 200 mg + ABT n = 102/98 200 mg + ABT 200 mg + ABT Double-Blind Treatment Double-Blind Treatment Primary efficacy endpoint Key secondary endpoints, Safety Primary efficacy endpoint: proportion of women with menstrual blood loss ≤ 80 mL Patients in the studies received no (by alkaline hematin method) and ≥ 50% reduction from baseline Vitamin D or calcium supplementation ABT = Add Back Therapy (1mg estradiol + 0.5 mg norethindrone acetate) 30Phase 3 registration studies PRIMROSE 1 (US) and PRIMROSE 2 (EU/US) P1/P2 2 full menstrual cycles 24 weeks 28 weeks 24 weeks Placebo (P1 only) n = 103/102 Placebo 200 mg + ABT n = 94/97 100 mg 100 mg 24-Week n = 107/101 Screening 100 mg + ABT 100 mg + ABT Post Treatment Follow-up n = 105/103 200 mg 200 mg + ABT n = 102/98 200 mg + ABT 200 mg + ABT Double-Blind Treatment Double-Blind Treatment Primary efficacy endpoint Key secondary endpoints, Safety Primary efficacy endpoint: proportion of women with menstrual blood loss ≤ 80 mL Patients in the studies received no (by alkaline hematin method) and ≥ 50% reduction from baseline Vitamin D or calcium supplementation ABT = Add Back Therapy (1mg estradiol + 0.5 mg norethindrone acetate) 30

PRIMROSE 1 and 2 achieved primary endpoint for both doses Responder* analysis at week 24 PRIMROSE 1 PRIMROSE 2 PRIMROSE 1 and 2 Week 24 Week 24 Week 24 pooled P<0.001 100% P<0.001 93.9% P<0.001 80% 84.5% P=0.003 P<0.001 75.5% P<0.001 60% 56.7% 56.4% 56.5% 40% 35.0% 32.2% 29.4% 20% n=103 n=94 n=102 n=102 n=97 n=98 n=205 n=191 n=200 0% Placebo Linzagolix Linzagolix Placebo Linzagolix Linzagolix Placebo Linzagolix Linzagolix 100 mg 200 mg + ABT 100 mg 200 mg + ABT 100 mg 200 mg + ABT *Proportion of women with menstrual blood loss ≤ 80 mL (by alkaline hematin method) and ≥ 50% reduction from baseline 31 Error bars are 95% CI Proportion of womenPRIMROSE 1 and 2 achieved primary endpoint for both doses Responder* analysis at week 24 PRIMROSE 1 PRIMROSE 2 PRIMROSE 1 and 2 Week 24 Week 24 Week 24 pooled P<0.001 100% P<0.001 93.9% P<0.001 80% 84.5% P=0.003 P<0.001 75.5% P<0.001 60% 56.7% 56.4% 56.5% 40% 35.0% 32.2% 29.4% 20% n=103 n=94 n=102 n=102 n=97 n=98 n=205 n=191 n=200 0% Placebo Linzagolix Linzagolix Placebo Linzagolix Linzagolix Placebo Linzagolix Linzagolix 100 mg 200 mg + ABT 100 mg 200 mg + ABT 100 mg 200 mg + ABT *Proportion of women with menstrual blood loss ≤ 80 mL (by alkaline hematin method) and ≥ 50% reduction from baseline 31 Error bars are 95% CI Proportion of women

PRIMROSE 1 and 2 achieved sustained reduction in MBL Responder* analysis at week 52 PRIMROSE 1 PRIMROSE 2 PRIMROSE 1 and 2 Week 52 Week 52 Week 52 pooled 100% 91.6% 89.3% 86.4% 80% 60% 60.7% 56.4% 53.2% 40% 38.7% 20% n=31 n=61 n=66 n=79 n=83 n=140 n=149 0% Placebo Linzagolix Linzagolix Linzagolix Linzagolix Linzagolix Linzagolix 100 mg 200 mg + ABT 100 mg 200 mg + ABT 100 mg 200 mg + ABT *Proportion of women with menstrual blood loss ≤ 80 mL (by alkaline hematin method) and ≥ 50% reduction from baseline 32 Proportion of womenPRIMROSE 1 and 2 achieved sustained reduction in MBL Responder* analysis at week 52 PRIMROSE 1 PRIMROSE 2 PRIMROSE 1 and 2 Week 52 Week 52 Week 52 pooled 100% 91.6% 89.3% 86.4% 80% 60% 60.7% 56.4% 53.2% 40% 38.7% 20% n=31 n=61 n=66 n=79 n=83 n=140 n=149 0% Placebo Linzagolix Linzagolix Linzagolix Linzagolix Linzagolix Linzagolix 100 mg 200 mg + ABT 100 mg 200 mg + ABT 100 mg 200 mg + ABT *Proportion of women with menstrual blood loss ≤ 80 mL (by alkaline hematin method) and ≥ 50% reduction from baseline 32 Proportion of women

Significant pain reduction maintained at weeks 52 and 64 PRIMROSE 1 PRIMROSE 2 P1 Wk 24 P1 Wk 52 Week 24 Week 52 Week 64 0 n=63 n=62 n=65 n=21 n=47 n=44 n=83 n=76 n=80 n=55 n=73 n=49 n=54 -0.6 -0.7 -1 -1.2 -1.9 -2.1 -2 -2.2 -2.6 -2.8 -2.8 -3 -3.3 -3.7 -3.9 Placebo -4 LGX 100 mg LGX 200 mg + ABT Error bars are 95% CI -5 Pain assessed on Numerical Rating Scale: 0-10 33 Mean change from baseline in pain scoreSignificant pain reduction maintained at weeks 52 and 64 PRIMROSE 1 PRIMROSE 2 P1 Wk 24 P1 Wk 52 Week 24 Week 52 Week 64 0 n=63 n=62 n=65 n=21 n=47 n=44 n=83 n=76 n=80 n=55 n=73 n=49 n=54 -0.6 -0.7 -1 -1.2 -1.9 -2.1 -2 -2.2 -2.6 -2.8 -2.8 -3 -3.3 -3.7 -3.9 Placebo -4 LGX 100 mg LGX 200 mg + ABT Error bars are 95% CI -5 Pain assessed on Numerical Rating Scale: 0-10 33 Mean change from baseline in pain score

LGX 200 mg without ABT significantly reduces uterine volume Substantial reduction compared to placebo & LGX 200 mg with ABT at Week 24 PRIMROSE 2 PRIMROSE 1 100 100 Placebo LGX 200 mg + ABT LGX 200 mg/200 mg + ABT 0 0 -100 -100 Error bars are 95% CI -200 -200 Baseline 12 24 36 52 Baseline 12 24 36 52 Weeks Weeks 34 Mean CFB 3 uterine volume cmLGX 200 mg without ABT significantly reduces uterine volume Substantial reduction compared to placebo & LGX 200 mg with ABT at Week 24 PRIMROSE 2 PRIMROSE 1 100 100 Placebo LGX 200 mg + ABT LGX 200 mg/200 mg + ABT 0 0 -100 -100 Error bars are 95% CI -200 -200 Baseline 12 24 36 52 Baseline 12 24 36 52 Weeks Weeks 34 Mean CFB 3 uterine volume cm

24-week efficacy data support Yselty® (linzagolix) as potential best-in-class GnRH antagonist Caution advised when comparing across clinical trials. Below data are not head-to-head comparison, and no head-to-head trials have been completed, nor are underway Elagolix Relugolix Yselty® (Linzagolix) Pooled Pooled Pooled ELARIS 1 ELARIS 2 LIBERTY 1 LIBERTY 2 PRIMROSE 1 PRIMROSE 2 Analysis Analysis Analysis 200mg + ABT 300 mg + ABT 40mg + ABT Dose Regimen Once daily Twice daily Once daily 41.6 43.1 42.6 42.5 41.3 42.1 Mean Age (y) 197 212 238 229 229 247 Baseline MBL (mL per cycle) + ++ Responder* Rate (RR) (%) 75.5 93.9 84.7 68.5 76.5 72.2 73.4 71.2 72.3 Amenorrhea üüüüüü Pain üü NR NR üü ** ** Fibroid Volume ûü NR NRûû Uterine Volume ** ** ûü NR NRüü Menstrual Blood Loss üüüüüü Anemia üüüüüü Quality of Life üüüüüü 35 Source: Company information Note: NR = Not reported. ** *Primary endpoint: Proportion of women with menstrual blood loss ≤ 80 mL (by alkaline hematin method) and ≥ 50% reduction from baseline P-value not reported + Simon et al, Obstet Gynecol 135, 1313-1326 2020 ++ Venturella R et al, ESHRE 2020 abstract.24-week efficacy data support Yselty® (linzagolix) as potential best-in-class GnRH antagonist Caution advised when comparing across clinical trials. Below data are not head-to-head comparison, and no head-to-head trials have been completed, nor are underway Elagolix Relugolix Yselty® (Linzagolix) Pooled Pooled Pooled ELARIS 1 ELARIS 2 LIBERTY 1 LIBERTY 2 PRIMROSE 1 PRIMROSE 2 Analysis Analysis Analysis 200mg + ABT 300 mg + ABT 40mg + ABT Dose Regimen Once daily Twice daily Once daily 41.6 43.1 42.6 42.5 41.3 42.1 Mean Age (y) 197 212 238 229 229 247 Baseline MBL (mL per cycle) + ++ Responder* Rate (RR) (%) 75.5 93.9 84.7 68.5 76.5 72.2 73.4 71.2 72.3 Amenorrhea üüüüüü Pain üü NR NR üü ** ** Fibroid Volume ûü NR NRûû Uterine Volume ** ** ûü NR NRüü Menstrual Blood Loss üüüüüü Anemia üüüüüü Quality of Life üüüüüü 35 Source: Company information Note: NR = Not reported. ** *Primary endpoint: Proportion of women with menstrual blood loss ≤ 80 mL (by alkaline hematin method) and ≥ 50% reduction from baseline P-value not reported + Simon et al, Obstet Gynecol 135, 1313-1326 2020 ++ Venturella R et al, ESHRE 2020 abstract.

Minimal BMD change with both doses, plateauing after week 24 Expected age-related BMD decline observed in placebo arm at Week 52 PRIMROSE 1 PRIMROSE 2 2% 2% Week 24 Week 52 Week 24 Week 52 n=78 n=52 0% 0% 0.4% 0.5% -0.8% -1.3% -1.4% -2.0% -2.0% -2.1% -2.3% -2.4% n=56 -2% -2% n=72 n=71 n=38 n=60 -3.6% n=55 n=50 -4% -4% n=20 -6% n=40 -6% -8% Placebo -8% Linzagolix 100 mg Error bars are 95% CI Linzagolix 200 mg + ABT -10% -10% Recovery at 6 months post-treatment (in subjects with a decrease at Week 52): Median % BMD increase: LGX 100 mg about 0.8%, LGX 200 mg + ABT about 1.2% 36 Mean % change from baseline lumbar spine BMDMinimal BMD change with both doses, plateauing after week 24 Expected age-related BMD decline observed in placebo arm at Week 52 PRIMROSE 1 PRIMROSE 2 2% 2% Week 24 Week 52 Week 24 Week 52 n=78 n=52 0% 0% 0.4% 0.5% -0.8% -1.3% -1.4% -2.0% -2.0% -2.1% -2.3% -2.4% n=56 -2% -2% n=72 n=71 n=38 n=60 -3.6% n=55 n=50 -4% -4% n=20 -6% n=40 -6% -8% Placebo -8% Linzagolix 100 mg Error bars are 95% CI Linzagolix 200 mg + ABT -10% -10% Recovery at 6 months post-treatment (in subjects with a decrease at Week 52): Median % BMD increase: LGX 100 mg about 0.8%, LGX 200 mg + ABT about 1.2% 36 Mean % change from baseline lumbar spine BMD

Bone mineral density – no change in z-scores Expected age-related BMD decline observed in placebo arm at Week 52 P1 Placebo P1 LGX 100 mg P1 LGX 200 mg + ABT 6 6 6 4 4 4 2 2 2 0 0 0 -2 -2 -2 -4 -4 -4 P2 Placebo P2 LGX 100 mg P2 LGX 200 mg + ABT 6 6 6 4 4 4 Z-score compares BMD to the average values of a person of 2 2 2 the same age and gender. 0 0 0 A score < -2 is a sign of less -2 -2 -2 bone mass than expected -4 -4 -4 37 Baseline Week 24 Week 52 Baseline Baseline Week 24 Week 52 Week 24 Baseline Baseline Week 24 Week 24 Week 52 Week 52 Week 76 Baseline Week 24 Week 52 Week 76 z-score z-score z-score z-score z-score z-scoreBone mineral density – no change in z-scores Expected age-related BMD decline observed in placebo arm at Week 52 P1 Placebo P1 LGX 100 mg P1 LGX 200 mg + ABT 6 6 6 4 4 4 2 2 2 0 0 0 -2 -2 -2 -4 -4 -4 P2 Placebo P2 LGX 100 mg P2 LGX 200 mg + ABT 6 6 6 4 4 4 Z-score compares BMD to the average values of a person of 2 2 2 the same age and gender. 0 0 0 A score < -2 is a sign of less -2 -2 -2 bone mass than expected -4 -4 -4 37 Baseline Week 24 Week 52 Baseline Baseline Week 24 Week 52 Week 24 Baseline Baseline Week 24 Week 24 Week 52 Week 52 Week 76 Baseline Week 24 Week 52 Week 76 z-score z-score z-score z-score z-score z-score

Favorable tolerability profile Summary of adverse events—week 24 to 52 PRIMROSE 1 PRIMROSE 2 Yselty® Yselty® Number (%) of women Yselty® Yselty® Placebo 100 mg 200 mg + ABT 100 mg 200 mg + ABT n=31 n=62 n=70 n=79 n=84 12 (38.7) 25 (40.3) 25 (35.7) 22 (27.8) 21 (25.0) Subject with at least one TEAE 1 (3.2) 2 (3.2) 1 (1.4) 7 (8.9) 1 (1.2) TEAE leading to discontinuation 0 0 0 0 0 SAE related to linzagolix Occurrence after week 24 of most frequently reported AEs (> 5%) up to week 24 0 1 (1.6) 0 2 (2.5) 3 (3.6) Hot flush 1 (3.2) 3 (4.8) 0 1 (1.3) 1 (1.2) Headache 1 (3.2) 0 0 2 (2.5) 1 (1.2) Anemia 38Favorable tolerability profile Summary of adverse events—week 24 to 52 PRIMROSE 1 PRIMROSE 2 Yselty® Yselty® Number (%) of women Yselty® Yselty® Placebo 100 mg 200 mg + ABT 100 mg 200 mg + ABT n=31 n=62 n=70 n=79 n=84 12 (38.7) 25 (40.3) 25 (35.7) 22 (27.8) 21 (25.0) Subject with at least one TEAE 1 (3.2) 2 (3.2) 1 (1.4) 7 (8.9) 1 (1.2) TEAE leading to discontinuation 0 0 0 0 0 SAE related to linzagolix Occurrence after week 24 of most frequently reported AEs (> 5%) up to week 24 0 1 (1.6) 0 2 (2.5) 3 (3.6) Hot flush 1 (3.2) 3 (4.8) 0 1 (1.3) 1 (1.2) Headache 1 (3.2) 0 0 2 (2.5) 1 (1.2) Anemia 38

Designed to treat more women Excellent clinical data driving differentiated profile Favorable Unique set Potentially tolerability of treatment best-in-class profile options ü ü ü • Unique PD/PK Profile • No safety signal of concern • Unique low dose option without ABT • Efficacy sustained up to 52 weeks for • BMD remains within normal ranges • Significant uterine volume reduction all dose regimens during and after treatment for 200 mg without ABT ABT-containing regimens may be contraindicated in up to 50% of US women with uterine fibroids based on the elagolix US label* and analysis of CDC data** *US FDA elagolix PI, section 4. Contraindications and section 5.1. Warnings and precautions – thromboembolic disorders and vascular events 39 ** Current Cigarette Smoking Among Adults in the United States. Centers for Disease Control and Prevention https://www.cdc.gov/tobacco/data_statistics/fact_sheets/adult_data/cig_smoking/index.htm#nation ; https://www.cdc.gov/2018Designed to treat more women Excellent clinical data driving differentiated profile Favorable Unique set Potentially tolerability of treatment best-in-class profile options ü ü ü • Unique PD/PK Profile • No safety signal of concern • Unique low dose option without ABT • Efficacy sustained up to 52 weeks for • BMD remains within normal ranges • Significant uterine volume reduction all dose regimens during and after treatment for 200 mg without ABT ABT-containing regimens may be contraindicated in up to 50% of US women with uterine fibroids based on the elagolix US label* and analysis of CDC data** *US FDA elagolix PI, section 4. Contraindications and section 5.1. Warnings and precautions – thromboembolic disorders and vascular events 39 ** Current Cigarette Smoking Among Adults in the United States. Centers for Disease Control and Prevention https://www.cdc.gov/tobacco/data_statistics/fact_sheets/adult_data/cig_smoking/index.htm#nation ; https://www.cdc.gov/2018

Endometriosis An emotionally and physically painful condition /yr $22B 176million 60%+ total US costs women worldwide of women feel suffer from symptoms by endometriosis age 16 Endometriosis Quality 5million affects up to women in the US of Life in the general are treated annually 10%+ population for endometriosis premenopausal women may experience pelvic pain, in the fertile pain during intercourse and 50%+ population defecation, infertility and emotional distress in patients with 60%+ chronic pelvic pain Cardozo et al., Am J Obstet Gynecol 2012; 2017; Stewart et al. NEJM, 2015; Flynn et al., Am J Obstet Gynecol 2006; 40 Truven Health, Fibroid Foundation websiteEndometriosis An emotionally and physically painful condition /yr $22B 176million 60%+ total US costs women worldwide of women feel suffer from symptoms by endometriosis age 16 Endometriosis Quality 5million affects up to women in the US of Life in the general are treated annually 10%+ population for endometriosis premenopausal women may experience pelvic pain, in the fertile pain during intercourse and 50%+ population defecation, infertility and emotional distress in patients with 60%+ chronic pelvic pain Cardozo et al., Am J Obstet Gynecol 2012; 2017; Stewart et al. NEJM, 2015; Flynn et al., Am J Obstet Gynecol 2006; 40 Truven Health, Fibroid Foundation website

Phase 2b EDELWEISS in endometriosis 8-14 weeks 24 weeks 24 weeks Placebo 50 mg daily 50 mg daily Lead-in 75 mg daily 50 mg daily Follow-up 100 mg daily 100 mg daily Optional 200 mg daily 200 mg daily extension: 6M + 6M follow-up 75 mg daily* Titrated dose 50-100 mg Enrollment 328 patients, ~65/arm Primary efficacy endpoint: VRS PAIN SCORE RESPONDER RATE 50 sites in US (n=177) Secondary endpoint: BMD** 14 sites in EU (n= 151) Patients were provided with Vitamin D and calcium * Titration after 12 weeks based on E2 serum level at weeks 4 and 8 41 **BMD = bone mineral densityPhase 2b EDELWEISS in endometriosis 8-14 weeks 24 weeks 24 weeks Placebo 50 mg daily 50 mg daily Lead-in 75 mg daily 50 mg daily Follow-up 100 mg daily 100 mg daily Optional 200 mg daily 200 mg daily extension: 6M + 6M follow-up 75 mg daily* Titrated dose 50-100 mg Enrollment 328 patients, ~65/arm Primary efficacy endpoint: VRS PAIN SCORE RESPONDER RATE 50 sites in US (n=177) Secondary endpoint: BMD** 14 sites in EU (n= 151) Patients were provided with Vitamin D and calcium * Titration after 12 weeks based on E2 serum level at weeks 4 and 8 41 **BMD = bone mineral density

Phase 2b EDELWEISS in endometriosis Dysmenorrhea (%) Overall Pelvic Pain (%) Responder (0-3 VRS) Responder (0-3 VRS) Plc 75mg 200mg Plc 75mg 200mg 84.1 78.9 77.3 68.2 58.3 70.8 *** *** 61.5 28.5 56.3 0 ** * 34.5 Week 12 Week 24 Non-menstrual Pelvic Pain (%) Responder (0-3 VRS) Week 12 Week 24 Plc 75mg 200mg 72.9 72.7 58.5 Potential point of differentiation as 75mg partial suppression 47.7 37.1 * dose is nearly as effective as 200mg full suppression dose Week 12 Week 24 *p value <0.05 **p value <0.01 ***p value <0.001 for linzagolix doses compared to placebo 42Phase 2b EDELWEISS in endometriosis Dysmenorrhea (%) Overall Pelvic Pain (%) Responder (0-3 VRS) Responder (0-3 VRS) Plc 75mg 200mg Plc 75mg 200mg 84.1 78.9 77.3 68.2 58.3 70.8 *** *** 61.5 28.5 56.3 0 ** * 34.5 Week 12 Week 24 Non-menstrual Pelvic Pain (%) Responder (0-3 VRS) Week 12 Week 24 Plc 75mg 200mg 72.9 72.7 58.5 Potential point of differentiation as 75mg partial suppression 47.7 37.1 * dose is nearly as effective as 200mg full suppression dose Week 12 Week 24 *p value <0.05 **p value <0.01 ***p value <0.001 for linzagolix doses compared to placebo 42

Phase 2b EDELWEISS in endometriosis Sustained improvement in overall endometriosis symptoms (PGIC) 100% Week 12 Week 24 Week 52 80% 76.2% 70.0% p=0.003 64.3% 60% 61.7% p=0.010 56.5% 49.0% 40% 25.6% 20% n=43 n=98 n=46 n=47 n=40 n=28 n=21 0% Placebo 75 mg 200 mg 75 mg 200 mg 75 mg 200/ 100 mg 43 Much or very much improved (%)Phase 2b EDELWEISS in endometriosis Sustained improvement in overall endometriosis symptoms (PGIC) 100% Week 12 Week 24 Week 52 80% 76.2% 70.0% p=0.003 64.3% 60% 61.7% p=0.010 56.5% 49.0% 40% 25.6% 20% n=43 n=98 n=46 n=47 n=40 n=28 n=21 0% Placebo 75 mg 200 mg 75 mg 200 mg 75 mg 200/ 100 mg 43 Much or very much improved (%)

Phase 2b EDELWEISS in endometriosis 75 mg effective without significantly affecting BMD Mean % change in BMD from baseline to 24 weeks (12 weeks for placebo) Lumbar Spine Total hip Femoral neck 2 75mg 200mg 1 Placebo 50mg 0 75mg FD -1 100mg 200mg -2 -3 -4 Error bars are 95% CIs 44Phase 2b EDELWEISS in endometriosis 75 mg effective without significantly affecting BMD Mean % change in BMD from baseline to 24 weeks (12 weeks for placebo) Lumbar Spine Total hip Femoral neck 2 75mg 200mg 1 Placebo 50mg 0 75mg FD -1 100mg 200mg -2 -3 -4 Error bars are 95% CIs 44

Phase 3 endometriosis trial EDELWEISS 3 11±5 weeks 24 weeks treatment 24 weeks extension 24 weeks 75 mg daily Placebo 200 mg daily + ABT Post Treatment Follow-up Lead-in 75 mg daily 75 mg daily 200 mg daily + ABT 200 mg daily + ABT Co-Primary efficacy endpoint: DYS/NMPP Responder Analysis Patients are provided with Vitamin D and calcium ABT: Add Back Therapy (estradiol + norethindrone acetate) 45Phase 3 endometriosis trial EDELWEISS 3 11±5 weeks 24 weeks treatment 24 weeks extension 24 weeks 75 mg daily Placebo 200 mg daily + ABT Post Treatment Follow-up Lead-in 75 mg daily 75 mg daily 200 mg daily + ABT 200 mg daily + ABT Co-Primary efficacy endpoint: DYS/NMPP Responder Analysis Patients are provided with Vitamin D and calcium ABT: Add Back Therapy (estradiol + norethindrone acetate) 45

Prostate cancer The second most prevalent form of cancer in men and a 1 leading cause of death due to cancer 3.8% 1.3M 2X Mortality Rate Of all cancer deaths New cases of prostate In African-American men compared in men in 2018 due cancer reported to Caucasians; incidence rate of 2 3 to prostate cancer globally in 2018 158.3 new cases diagnosed per 4 100K African-American men ~130K $600M $2.1B Number of patients in the Total US sales for GnRH Total global prostate cancer US treated with Lupron agonists market for GnRH agonists in 5 2020 Lupron was the biggest product in the US with Or over half of the total global 6 nearly $350M in revenue GnRH agonist market 1-4. World J Oncol. 2019. 10; 63 46 46 5 . IMS MIDAS data, monthly audit Dec 2020 6 . Evaluate Pharma, aggregation of brokers forecast, 2020Prostate cancer The second most prevalent form of cancer in men and a 1 leading cause of death due to cancer 3.8% 1.3M 2X Mortality Rate Of all cancer deaths New cases of prostate In African-American men compared in men in 2018 due cancer reported to Caucasians; incidence rate of 2 3 to prostate cancer globally in 2018 158.3 new cases diagnosed per 4 100K African-American men ~130K $600M $2.1B Number of patients in the Total US sales for GnRH Total global prostate cancer US treated with Lupron agonists market for GnRH agonists in 5 2020 Lupron was the biggest product in the US with Or over half of the total global 6 nearly $350M in revenue GnRH agonist market 1-4. World J Oncol. 2019. 10; 63 46 46 5 . IMS MIDAS data, monthly audit Dec 2020 6 . Evaluate Pharma, aggregation of brokers forecast, 2020

Advanced prostate cancer opportunity Current Standard of Care Aims to reduce testosterone (T) to castration levels Injectable GnRH agonists (leuprolide) most commonly used but associated with initial T level Limitations spike that can worsen symptoms and delay recovery upon drug discontinuation Evidence from pooled analyses suggest lower cardiovascular risk with GnRH antagonists versus Benefit of GnRH antagonists 1 GnRH agonists Once-daily oral drugs that can safely and effectively suppress T levels would represent a Paradigm Change paradigm change in chronic treatment of the disease Myovant’s relugolix (Orgovyx™) demonstrated superiority in Phase 3 versus Lupron and Superiority of relugolix launched in January 2021 1 47 Albertsen et al., Eur Urol. 2014. 65; 565Advanced prostate cancer opportunity Current Standard of Care Aims to reduce testosterone (T) to castration levels Injectable GnRH agonists (leuprolide) most commonly used but associated with initial T level Limitations spike that can worsen symptoms and delay recovery upon drug discontinuation Evidence from pooled analyses suggest lower cardiovascular risk with GnRH antagonists versus Benefit of GnRH antagonists 1 GnRH agonists Once-daily oral drugs that can safely and effectively suppress T levels would represent a Paradigm Change paradigm change in chronic treatment of the disease Myovant’s relugolix (Orgovyx™) demonstrated superiority in Phase 3 versus Lupron and Superiority of relugolix launched in January 2021 1 47 Albertsen et al., Eur Urol. 2014. 65; 565

* GnRH analogues in prostate cancer †† Profile Efficacy Safety ‡ Injection MACE Site Castration Sustained T PSA Overall/ Reaction Hot Flush Delivery Flare Castration on on Day 15 Level to 48 Prior History Response at † GnRH analog Route Effect Day 4 (%) (%) Weeks (%) Day 15 (%) (%) (%) (%) GnRH Agonist Injection Leuprolide Yes 0 12 89 20 6.2/17.8 14 51.6 (Every 1-3 months) Injection § Degarelix No 96 99 97 - - 40 26.0 (Monthly) 56 99 n/a Relugolix Oral No 97 79 2.9/3.6 54.3 *Phase 3 relugolix (HERO) results for leuprolide and Relugolix (Shore et al., NEJM. 2020; 382: 2187 -96 ; Degarelix package insert (PI) †Flare effect = initial spike in T levels upon treatment initiation due to initial activation of GnRH receptor ††Responder = Testosterone levels <50 ng/dL (i.e., castration) ‡MACE=major cardiovascular event after 48 weeks of treatment; KM analysis showed 54% lower risk in relugolix group vs leuprolide group 48 §Degarelix PI: Day 3 and Day 14; sustained levels to Day 364 for 240/80mg dose; *rate of hot flush for leuprolide in Degarelix studies was 21%* GnRH analogues in prostate cancer †† Profile Efficacy Safety ‡ Injection MACE Site Castration Sustained T PSA Overall/ Reaction Hot Flush Delivery Flare Castration on on Day 15 Level to 48 Prior History Response at † GnRH analog Route Effect Day 4 (%) (%) Weeks (%) Day 15 (%) (%) (%) (%) GnRH Agonist Injection Leuprolide Yes 0 12 89 20 6.2/17.8 14 51.6 (Every 1-3 months) Injection § Degarelix No 96 99 97 - - 40 26.0 (Monthly) 56 99 n/a Relugolix Oral No 97 79 2.9/3.6 54.3 *Phase 3 relugolix (HERO) results for leuprolide and Relugolix (Shore et al., NEJM. 2020; 382: 2187 -96 ; Degarelix package insert (PI) †Flare effect = initial spike in T levels upon treatment initiation due to initial activation of GnRH receptor ††Responder = Testosterone levels <50 ng/dL (i.e., castration) ‡MACE=major cardiovascular event after 48 weeks of treatment; KM analysis showed 54% lower risk in relugolix group vs leuprolide group 48 §Degarelix PI: Day 3 and Day 14; sustained levels to Day 364 for 240/80mg dose; *rate of hot flush for leuprolide in Degarelix studies was 21%

ObsEva’s linzagolix could potentially challenge the current standard of care as the best-in-class oral GnRH antagonist for advanced prostate cancer Potentially best-in-class GnRH antagonist in uterine fibroids & endometriosis ObsEva exploring development of linzagolix in combination with estrogen for the treatment of advanced prostate cancer Potential improvement on GnRH antagonist-only regimen by further decreasing cardiovascular & bone loss risk, and mitigating hot flushes: Phase 3 results showed similar 1 hot flush rates (>50%) for relugolix and leuprolide ObsEva has exclusive global rights (excluding Asia) to linzagolix for all indications 1 Shore et al., NEJM. 2020; 382:2187-96 49ObsEva’s linzagolix could potentially challenge the current standard of care as the best-in-class oral GnRH antagonist for advanced prostate cancer Potentially best-in-class GnRH antagonist in uterine fibroids & endometriosis ObsEva exploring development of linzagolix in combination with estrogen for the treatment of advanced prostate cancer Potential improvement on GnRH antagonist-only regimen by further decreasing cardiovascular & bone loss risk, and mitigating hot flushes: Phase 3 results showed similar 1 hot flush rates (>50%) for relugolix and leuprolide ObsEva has exclusive global rights (excluding Asia) to linzagolix for all indications 1 Shore et al., NEJM. 2020; 382:2187-96 49

Investor highlights Pursuing promising large indications for serious conditions that compromise women's reproductive 1 health and beyond, with the potential to extend into other indications including prostate cancer Ebopiprant, the only known product in development for preterm labor, has positive Phase 2a data 2 that support a Phase 2b dose ranging study Yselty® has potential best in class efficacy, a favorable tolerability profile, and unique flexible dosing 3 options Business model built on strong global partnerships and collaborations 4 Seasoned leadership team with a track record for success 5 50Investor highlights Pursuing promising large indications for serious conditions that compromise women's reproductive 1 health and beyond, with the potential to extend into other indications including prostate cancer Ebopiprant, the only known product in development for preterm labor, has positive Phase 2a data 2 that support a Phase 2b dose ranging study Yselty® has potential best in class efficacy, a favorable tolerability profile, and unique flexible dosing 3 options Business model built on strong global partnerships and collaborations 4 Seasoned leadership team with a track record for success 5 50

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