Uterine Fibroids

Research & Development Day

December 7, 2018 NASDAQ:OBSV | SIX:OBSN DISCLAIMER

Matters discussed in this presentation may constitute forward-looking statements. The forward-looking statements contained in this presentation reflect our views as of the date of this presentation about future events and are subject to risks, uncertainties, assumptions, and changes in circumstances that may cause our actual results, performance, or achievements to differ significantly from those expressed or implied in any forward-looking statement. Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee future events, results, performance, or achievements. Some of the key factors that could cause actual results to differ from our expectations include our plans to develop and potentially commercialize our product candidates; our planned clinical trials and preclinical studies for our product candidates; the timing of and our ability to obtain and maintain regulatory approvals for our product candidates; the extent of clinical trials potentially required for our product candidates; the clinical utility and market acceptance of our product candidates; our commercialization, marketing and manufacturing capabilities and strategy; our intellectual property position; and our ability to identify and in-license additional product candidates. For further information regarding these risks, uncertainties and other factors that could cause our actual results to differ from our expectations, you should read our Annual Report on Form 20-F for the year ended December 31, 2017, as filed with the Securities and Exchange Commission on March 9, 2018 and our other filings it makes with the Securities and Exchange Commission from time to time. We expressly disclaim any obligation to update or revise the information herein, including the forward-looking statements, except as required by law. Please also note that this presentation does not constitute an offer to sell or a solicitation of an offer to buy any securities. This presentation concerns products that are under clinical investigation and which have not yet been approved for marketing by the U.S. Food and Drug Administration. It is currently limited by federal law to investigational use, and no representation is made as to its safety or effectiveness for the purposes for which it is being investigated. The trademarks included herein are the property of the owners thereof and are used for reference purposes only. Such use should not be construed as an endorsement of such products. This presentation also contains estimates and other statistical data made by independent parties and by us relating to market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.

2 WHY OBSEVA

• Women rightly aspire to high education and The World Is top professional achievements • First pregnancy moving beyond 30 years old Changing … • More infertility, more endometriosis, more fibroids, more complicated pregnancies ‘Contributing to empower women to take control of their lives by bringing innovative therapeutic solutions’ Women Want to • Women want to measure and know their health status Be in Control of • Women want to drive their own health Their Health decisions • Unique expertise in women health drug development • Rich innovative clinical late stage pipeline Pharma Is • Marginal investment in developing new Abandoning therapies • Strive to create a commercial Women’s Health • Disinvestment by major players leader in women health

3 HOW THIS TRANSLATES – STRATEGIC FOCUS

Our Focus: ➔ (Women ages 15 - 49)

Uterine Fibroids

Endometriosis

Infertility - ART

Preterm Labor

Preeclampsia

4 HOW THIS TRANSLATES – ROBUST PIPELINE COMMERCIAL PRODUCT CANDIDATE PRECLINICAL PHASE 1 PHASE 2 PHASE 3 NEXT MILESTONES RIGHTS

IVF – IMPLANT 2 EU * Primary endpoint data NOLASIBAN Exclusive Oral oxytocin IVF – IMPLANT 4 EU Phase 3 IMPLANT 4 ** & EU MAA filing Q4 2019 Worldwide receptor antagonist ** US IMPLANT 3 Phase 3 IVF – IMPLANT 3 US Initiation 2019 – FDA interaction ongoing

FDA EoP2 Meeting Q4 2018 Endometriosis – EDELWEISS LINZAGOLIX *** Initiate 2x Phase 3 Q1 2019 (US/EU) Exclusive (OBE2109) Worldwide Oral GnRH US/EU Phase 3 (ex-Asia) receptor antagonist PRIMROSE 1 & 2 Enrolling Uterine Fibroids – PRIMROSE 1 & 2 6 month Primary Endpoint Data H2 2019

OBE022 EU Phase 2a PROLONG Exclusive Oral PGF2α Preterm Labor – PROLONG Interim Efficacy Q1 2019 Worldwide receptor antagonist

* Week 10 ongoing pregnancy primary endpoint met – Live Birth Rate secondary endpoint met ** Second Phase 3 study (EU/Canada/Russia) initiated *** Primary and secondary endpoints met 5 UNIQUE POSITIONING DRIVING MULTIPLE COMMERCIAL OPPORTUNITIES

• Increasing ‘Take Home Baby Rate’ in IVF by 35% Deliver more babies at • Potentially significant savings for healthcare system NOLASIBAN lower cost • Potential for global blockbuster commercial opportunity with lean infrastructure

Uniquely effective • Endometriosis – pain controlled in 3 out of 4 patients with 75mg without ABT LINZAGOLIX without hormone • Fibroids – targeting bleeding control without ABT replacement therapy • Potential for global blockbuster as first line therapy

• Promising early data for novel MoA to stop preterm labor Potential to save • Potential reduction of short/long term morbidity and OBE022 newborn lives mortality related to preterm birth • Aiming at reducing cost of neonatal intensive care

6 SEASONED LEADERSHIP TEAM

Ernest Loumaye, Tim Adams Jean-Pierre Gotteland, PhD Wim Souverijns MD, PhD, OB/GYN Chief Financial Officer Chief Scientific Officer Chief Commercial Officer CEO and Co-founder

7 TRANSITIONING FROM LATE STAGE CLINICAL DEVELOPMENT TO COMMERCIAL

Commercializing Nolasiban represents a critical inflection point for ObsEva …

FOCUSED TARGETED FLEXIBLE

Exclusive focus on Small number of ART Owning our pipeline women’s health allows centers will require allows us to be strategic for specialty approach limited investment only about partnering where needed

8 UNIQUE POSITIONING DRIVING MULTIPLE COMMERCIAL OPPORTUNITIES

NOLASIBAN Deliver more babies at lower cost

LINZAGOLIXNolasiban Uniquely effective without hormone replacement therapy

OBE022 Potential to save newborn lives

9 TODAY’S AGENDA

• ObsEva OVERVIEW ✔

• NOLASIBAN Deliver more babies at lower cost

• LINZAGOLIX Uniquely effective without hormone replacement therapy

• OBE022 Potential to save newborn lives

• FINANCIAL SNAPSHOT Advancing & building the pipeline commercial operations

10 NOLASIBAN (OBE001) Improving In Vitro Fertilization Outcomes GUEST SPEAKER

NOLASIBAN Deliver more babies at lower cost

Uniquely effective LINZAGOLIX without hormone replacement therapy

Newborn life saving OBE022 Annette Lee, MD potential Medical Director of Reproductive Endocrinology & Infertility, Abington Reproductive Medicine in Abington, Pennsylvania

12 INFERTILITY – A GLOBAL PUBLIC HEALTH ISSUE, BUT IVF IS COSTLY AND NOT EFFICIENT ENOUGH

• Infertility – a health & societal issue ✓ 9% of women 20-44 affected globally

✓ Ageing population problematic China: ~22.7 million Europe: ~7.2 million women aged 20-44 • Too few healthy babies women aged 20-44 Japan: ~1.6 million women aged 20-44 ✓ Despite good quality embryos & using best practice (9% of 18 million) transfer techniques, IVF success rate not optimal

• IVF comes with a significant cost

✓ Couples often self fund Japan: ~1.6 million ✓ Payers see an unacceptably U.S.: ~4.8 million women aged 20-44 women aged 20-44 high multiple pregnancy rate ✓ Society pays a higher cost per healthy baby

* WHO infertility website, April 2018. http://www.who.int/reproductivehealth/topics/infertility/perspective/en/

13 INFERTILITY – POPULATION AND CYCLE FIGURES

Total

Women (20-44 year) with 7.2M 22.7M 4.8M 1.6M 36.3M Infertility *

ART Cycles/Year > 800K > 800K > 200K > 400K >2.2M

* 9% of 20-44 years of age (ESHRE 2018 ART Fact Sheet), 20-40 years of age (World Databank 2017) ** A TFR below 2.4 indicates a declining population 14 IVF – THE PROCESS

Therapeutic Options

• Follicle Stimulating Hormone (r-hFSH) • Birth Control Pills • GnRH agonist • GnRH antagonist • Human chorionic gonadotropin (hCG) • Antibiotics/steroids • Progesterone

15 POSSIBLE NEGATIVE IMPACT OF HORMONAL STIMULATION & EMBRYO TRANSFER

• Supraphysiologic hormone levels create a suboptimal uterine environment (contractions and reduced endometrium vascularization)

• Difficult embryo transfer can induce additional contractions

• Adverse impact on the chance of implantation/pregnancy

16 MULTIPLE EMBRYO TRANSFERS ARE STILL TOO OFTEN USED TO IMPROVE PREGNANCY RATES CDC NATIONAL ART REPORT 2015: DAY 5 FRESH TRANSFERS FROM NON -DONORS

No. embryos transferred LBR and % infants with SET or DET Three 5.8% 1.1% Four or more % Infants from No. ET LBR multiple births One 38.6% SET 50% 2.2%

54.6% DET 58% 45.9% Two DET 16% relative increase in LBR BUT ~2000% relative increase in % infants 55% of embryo transfers were from multiple births double embryo transfer

17 CONCLUSIONS

• Improving IVF success rate is a global need, U.S. cycles negatively impacted by limited reimbursement

• Patients need lower failure rate – emotional and financial costs

• Healthcare system needs less DET and less multiple births

• Ideal treatment addresses uterus environment at the time of transfer and improves pregnancy/LBR rates with SET

18 GUEST SPEAKER

NOLASIBAN Deliver more babies at lower cost

Uniquely effective LINZAGOLIX without hormone replacement therapy

Newborn life saving OBE022 Christophe Blockeel, PhD potential Medical Director, Centre for Reproductive Medicine, University Hospitals Brussels, Belgium

19 PATIENT PERSPECTIVE AND NEEDS

• Financial costs aside, patients want to avoid cycle failure • Emotional costs of failure are high ✓ Stress ✓ Anxiety and depression ✓ Embarrassment ✓ Feeling of failure to create life • Pressures on patients mount over time ✓ Success declines with age ✓ Previous failures • Primary patient needs ✓ Increased odds of success ✓ No increased risk of congenital malformation or developmental delay, health issues ✓ Increasing awareness of multiple pregnancy risks & complications

20 OVERVIEW OF IVF IN EUROPE

• Most recent ESHRE data (2014) indicates nearly 800,000 annual cycles performed ✓ 39 European countries, nearly 1,300 clinics reporting ✓ Clinical pregnancy rate 35.8% ✓ 35% SET / 55% DET ✓ 52% D3 / 48% D5 ✓ 82% singleton births ✓ Term delivery >37 weeks in 77% of singletons, 42% of twins, 13% of triplets

21 OVERVIEW OF IVF IN EUROPE

• Significant country differences in IVF utilization & ET practices ✓ Demographic & cultural drivers ✓ Embryo transfer practices: ➢ Fresh vs. frozen ➢ D3 vs D5 ➢ SET vs DET ➢ PGD or not • E.g., Belgium provides public funding contingent upon limiting transfer to a single embryo due to costs of multiple pregnancies

22 CONCLUSIONS

• Europe as a region has the largest number of annual IVF cycles at ~800K

• Demographics & lifestyle driving the increasing number of cycles

• Cycles reimbursed, but number varies by country

• SET should be more encouraged

• Patients’ need for better outcomes is global

23 Nolasiban: Background & Rationale WINDOW OF IMPLANTATION (WOI) AND RECEPTIVE ENDOMETRIUM

The implantation window is defined as that period when the uterus is receptive for implantation of the free-lying blastocyst.

Pre-receptive, receptive and post-receptive endometrium The majority of embryos suitable for transfer do not implant

Potential factors responsible for impairing receptivity and leading to implantation failure

• Premature high level of progesterone

• High rate of uterine contractions

• Low endometrial blood flow

• Inappropriate cellular responses (decidualization, leukocyte Infiltration, chemotaxis, …)

Evans, J., et al, (2016) Nat Rev Endocrinol 12, 654-66 25 NOLASIBAN, AN OXYTOCIN RECEPTOR ANTAGONIST, INHIBITS UTERINE CONTRACTIONS

In Pregnant Monkeys In Pregnant Women Myometrium

26 AN OXYTOCIN RECEPTOR ANTAGONIST (OTRA) INCREASES ENDOMETRIUM BLOOD FLOW IN IVF PATIENTS

3D Criteria Control OTRA Echogenic 100% 8% endometrium Triple line 0% 92% endometrium Endometrial thickness > 7 85% 100% mm Endometrial volume > 2.31 39% 85% mm • 26 women undergoing IVF/ D2 ET Abnormal sub- 23% 23% ✓13 OTRA (admin. 2 days post-ET) endometrial halo Endometrial 46% 85% ✓13 control flow* • 3D Doppler assessed 3 days post-ET Complex vessel 15% 46% • * RI < 0.53 architecture

27 NOLASIBAN – HOW IT WORKS INCREASING CLINICAL PREGNANCY AND LIVE BIRTH RATE

Nolasiban

Functional Oxytocin receptors are expressed in human non- pregnant uterus on: • Myometrium smooth muscle cells • Uterus arteries smooth muscle cells • Endometrium glandular epithelial cells

28 Nolasiban: Clinical Development Program COMPLETED CLINICAL TRIALS IN IVF PATIENTS

Dose and Design Objectives N Location Status Regimen

Phase 2 (IMPLANT 1): Double-blind, 100 mg Efficacy dose-finding, placebo-controlled study of a 300 mg Safety 247 Europe Complete single oral administration of nolasiban in 900 mg PK women undergoing D3 SET or DET placebo

Phase 3 (IMPLANT 2): Double-blind, Main study (W10), randomized, placebo-controlled study to Efficacy live birth & neonatal 900 mg assess the safety and efficacy of a single Safety 778 Europe follow-up complete placebo oral administration of nolasiban in fresh D3 Infant follow-up or D5 SET ongoing

• 1,025 IVF patients included in both trials • 570 women have received nolasiban

30 IMPLANT 2 PHASE 3 CLINICAL TRIAL

Main study Follow-up

Primary 2 weeks 900 mg nolasiban Analysis n=194 Ongoing D3 ET Not pregnant 9 weeks pregnancy Placebo 10 weeks n=194 28 days 6 months Screening - IVF 900 mg nolasiban Neonatal Infant Pregnant W6 W10 n=194 FU FU • Age 18–36 y D5 ET • Fresh D3 or D5 Placebo n=196 SET • Max 1 failed Birth previous IVF • P4 ≤ 4.7 nmol on Randomized day hCG • Vaginal P4 for luteal support 778 Patients enrolled – Trial conducted in 41 fertility centers in 9 European countries FPI Mar 2017 – Recruitment completed Aug 2017 – Positive top Line Results Feb 2018

31 IMPLANT 2 – PRIMARY EFFICACY ENDPOINT POOLED DAY 3 & DAY 5 SET – 25% INCREASE VS PLACEBO

Pooled D3 and D5 Nolasiban Placebo p 900 mg N 390 388 Ongoing pregnancy 28.5% 35.6% 0.031 rate at 10 weeks

Live birth rate 27.7% 34.8% * 0.025

• * 25% increase compared to placebo

• Absolute 7.1% increase compared to placebo with > 5% considered clinically meaningful

32 IMPLANT 2 – SECONDARY EFFICACY ENDPOINT SUBGROUP EFFICACY ANALYSES – D5 SET 35% INCREASE

D3 D5

Nolasiban p- Nolasiban p- Placebo Placebo 900 mg value 900 mg value N 194 194 196 194 Ongoing pregnancy 22.2% 25.3% 0.477 34.7% 45.9% 0.034 rate at 10 weeks

Live birth rate 22.7% 24.7% 0.552 33.2% 44.8% * 0.025

• * Live Birth Rate increased by 35% after SET at day 5

33 IMPLANT 2 – OBSTETRIC OUTCOMES

Placebo Nolasiban (n=108) (n=131) Delivery – no. (%) • Singleton 107 (99.1) 126 (96.2) • Twins 1 (0.9) 5 (3.8) Type of delivery – no. (%) • Spontaneous 47 (43.5) 58 (44.3) • Induced 5 (4.6) 10 (7.6) • Caesarian 56 (51.9) 63 (48.1) Gestational age at delivery – no. (%) • Term (≥ 37 weeks) 97 (89.8) 112 (85.5) • Preterm (32 to 366/7 weeks) 11 (10.2) 15 (11.5) • Very preterm (≤ 316/7 weeks) 1 (0.9) 4 (3.1)

34 IMPLANT 2 – NEONATAL OUTCOMES UP TO 28 DAYS AFTER BIRTH

Placebo Nolasiban (n=109) (n=136)

Breast-feeding – no. (%) 91 (83.5) 111 (81.6)

Admission to intensive care – no. (%) 9 (8.3) 9 (6.6)

Neonatal morbidity – no. (%) 29 (26.6) 26 (19.1)

• Jaundice 20 (18.3) 18 (13.2)

• Respiratory Distress Syndrome 10 (9.2) 8 (5.9)

• Difficulty in feeding 2 (1.8) 11 (8.1)

• Difficulty in thermoregulation 0 (0) 6 (4.4)

• Bronchopulmonary dysplasia 0 (0) 3 (2.2)

35 IMPLANT 1 & 2 – PREGNANCY OUTCOMES AND SAFETY IN IVF PATIENTS CUMULATIVE DATA FROM 2 PLACEBO -CONTROLLED RANDOMIZED TRIALS Placebo Nolasiban (n=455) (n=570) Positive pregnancy test (Day 14 post-OPU) 188 (41.3%) 274 (48.1%)

Pregnancy loss (≤ week 10) 53 (28.2%*) 61 (22.3%*)

Ectopic pregnancy 5 (2.7%*) 3 (1.1%*)

Ongoing pregnancy at week 10 post-ET 130 (28.6%) 213 (37.4%)

Pregnancy loss (week 10 to 24) 3 (2.3%**) 6 (2.8%**)

Fetus/neonate with Serious Adverse Event 9 (6.9%**) 15 (7.0%**)

Congenital malformations 7 (5.4%**) 11 (5.2%**)

* % of positive pregnancy test at 14 days post-OPU ** % of ongoing pregnancy at week 10

36 NOLASIBAN SIGNIFICANTLY INCREASES ONGOING PREGNANCY RATE AND LIVE BIRTH RATE

• Pooled D3/D5 ET ✓Ongoing pregnancy rate : 25% increase (p=0.031) ✓Live birth rate: 26% increase (p=0.025)

• D5 ET ✓Ongoing pregnancy rate : 32% increase (p=0.034) ✓Live birth rate : 35% increase (p=0.025)

• Excellent safety profile, not different from placebo

37 REGULATORY STRATEGY – MARKETING AUTHORIZATION APPLICATION ANTICIPATED LATE 2019* IN EU

• EU – Agreement for MAA dossier submission :

✓ One Phase 3 (IMPLANT 4) in addition to IMPLANT 2 ✓ D5 SET – 900mg versus placebo ✓ Submission acceptable with week 10 data ➢ Live Birth Rate and 6 months infant follow-up to be provided later when available

• U.S. – Ongoing interactions with FDA to agree on development plan ✓ FDA feedback expected Q2 2019 ✓ IMPLANT 3 U.S. trial ready to be initiated pending FDA feedback

* Pending IMPLANT 4 positive data

38 Nolasiban: Commercial Opportunity NOLASIBAN ENABLES US TO DELIVER MORE BABIES AT LOWER COST

• Nolasiban can deliver 1/3 more babies

• Potential to lower cost of obtaining a baby

• Potential to further lower healthcare costs by reducing the need for multiple embryo transfer

40 INFERTILITY – TOTAL FERTILITY RATE & MARKET SIZE

Major Markets

Women (20-44 year) with 7.2M 22.7M 4.8M 1.6M 36.3M Infertility *

ART Cycles/Year >800k >800k >200k >400k >2.2M

Total Fertility Rate (TFR) 1.6 1.5 1.8 1.4 < 2.1 **

Fertility Drugs Sales (2017) $0.7B $0.3B $1.2B $0.1B $2.3B (16% CAGR) (10% CAGR)

* 9% of 20-44 years of age (ESHRE 2018 ART Fact Sheet), 20-40 years of age (World Databank 2017) ** A TFR below 2.1 indicates a declining population 41 ART TRENDING TO ACCELERATE – EUROPE

ART in Europe

Period 1997 – 2011 Period 2010 – 2014 • In first 15 years of ART registry in Europe (1997 ~ 800K – 2011) almost 6 million (#) cycles and >1 million ~ 600K 7.7% ~ 550K CAGR births reported Cycles v v 3.43% • Latest numbers for 2014 CAGR almost 800’000 ART ~ 200K

cycles Number of ART Number of

1997 2011 2010 2014

Source: ESHRE ART Fact sheet 18 Feb 2018; Ferraretti et al, 2017

42 VALUE OF NOLASIBAN DRIVEN BY REDUCING HEALTHCARE COSTS

• Reduction of cost per baby delivered ✓ 33% increase in live births for the same IVF investment

• Reduction of costs associated with prenatal delivery of twins ✓ Multiple pregnancies reduced from 20-40% to 3% ✓ Cost for twins born preterm, can amount to $50,000 to $100,000

• Reduction of long term costs associated with multiple pregnancies ✓ Long term healthcare costs for twins can amount to over $50K annually 1

Significant opportunity to add value to IVF

1 Behrman et al. Committee on Understanding Premature Birth and Assuring Healthy Outcomes. National Academies Press, 2012 43 MARKET OPPORTUNITY SEEMS TO BE UNDERESTIMATED ~ $1.5B Revenue Potential ($B) • Penetration driven by evolution to D5 SET ~ $1B

• China market significant opportunity ~ $0.5B • Price should reflect the value

Penetration 20% 50% 33% 50% Average Price $1,400 $1,400 $2,000 $2,000

44 A LEAN OPERATION TO COMMERCIALIZE NOLASIBAN EFFECTIVELY

• Highly concentrated • Sophisticated B2B market

ART Centers (#) 105 134 354 231 82 ~ 500

Less than 100 FTEs to drive a blockbuster business

45 UNIQUE POSITIONING DRIVING MULTIPLE COMMERCIAL OPPORTUNITIES

Milestones

Uniquely effective • 2019 : LINZAGOLIX without hormone ✓ Finalize US trial design and begin US IVF replacement therapy development program ✓ Prepare commercial operations in EU & US • Q4 2019 Newborn life saving OBE022 ✓ Primary endpoint pregnancy results from potential EU IMPLANT 4 in IVF ✓ Planned EU MAA submission for IVF

46 Questions

D e c e m b e r 2018 NASDAQ:OBSV | SIX:OBSN LINZAGOLIX (OBE2109) Potential Best in Class Oral GnRH antagonist Indications: Endometriosis and Uterine Fibroids GUEST SPEAKER

Deliver more babies at NOLASIBAN lower cost

Uniquely effective LINZAGOLIX without hormone replacement therapy

Potential for saving OBE022 Hugh Taylor, MD newborn lives Professor and Chair, Department of Obstetrics Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut

49 ENDOMETRIOSIS AND UTERINE FIBROIDS REDUCING ESTROGEN ALLEVIATES SYMPTOMS

Endometriosis Uterine Fibroids

Symptoms: pelvic pain and infertility Symptoms: heavy menstrual bleeding, pelvic pressure/pain, and dysmenorrhea

50 ENDOMETRIOSIS & UTERINE FIBROIDS CURRENT STANDARD OF CARE CALLS FOR NEW, IMPROVED THERAPIES

LARGE U.S. PATIENT POPULATION EXISTING TREATMENTS

Endometriosis • 2.5 million women diagnosed and Oral Contraceptives/NSAID’s/Opioids treated annually • Limited symptom reduction • Seeking to unlock another 2.5 million undiagnosed due to non-specific LUPRON® Injections (GnRH agonist) symptoms and invasive laparoscopy • Not ideal for younger, chronic population • Associated with initial symptom flares • Full estrogen suppression • ABT* mandatory > 6 months Uterine Fibroids • 4 million women diagnosed and Surgical Interventions treated annually • Avoid hysterectomy to preserve fertility & integrity • Approximately 200,000 surgeries • High rate of reconcurrence after conservative surgery (Hysterectomy) annually

* Low dose Add Back Therapy (ABT) = estradiol/norethindrone acetate - tablet 1.0 mg/ 0.5 mg

51 GnRH RECEPTOR AGONISTS VS ANTAGONISTS MECHANISM OF ACTION

GnRH agonist GnRH antagonist (blocker)

• Initial overstimulation • GnRH antagonist have GnRH of GnRH receptors Hypothalamus GnRH Hypothalamus an immediate onset leads to an increase in of action, preventing LH and estradiol gonadotrophin production release through GnRH Anterior pituitary Anterior pituitary receptor blockade, GnRH agonist gland gland leading to rapid • Chronic administration antagonist suppression of LH and FSH, LH eventually leads to FSH, LH estradiol suppression of LH, resulting in suppression of • Competitively prevent estradiol Estradiol endogenous GnRH Ovary Estradiol Ovary from binding and activating its pituitary receptor

• Induce neither downregulation nor Uterus Uterus desensitization of the receptors

Reduction of serum E2 suppresses the growth and symptoms of estrogen-dependent tissues like endometriosis, endometrium and fibroids 52 BENEFITS OF GnRH RECEPTOR ANTAGONISTS VS AGONISTS Allows for partial or full estrogen • Competitively suppression Immediate preventing endogenous action GnRH from binding and No initial flare Rapid Reversibility activating its pituitary & worsening receptor of symptoms Partial • Contrasting with GnRH estrogen agonists, inducing suppression does not neither downregulation, require ABT nor desensitization of Oral dosing Consistent the receptors enhances PK/PD allows patient for QD & no compliance food effect

More suitable 53 for chronic therapy

53 “ABT OR NO ABT, THAT IS THE QUESTION”

• Trend toward patients preferring avoidance of hormone therapy

• Gynecologist survey in US shows high preference of no ABT as first line therapy

• ABT associated with HRT safety boxed warning

54 “ABT OR NO ABT, THAT IS THE QUESTION” REAL WORLD USE OF ADD BACK THERAPY

ONLY when severe E2 suppression (< 20pg/mL) Activella ABT (1.0 mg/0.5 mg) FDA Approved label

55 ENDOMETRIOSIS IMPACT AND UNMET NEED

• Reported prevalence of endometriosis is 2%-10% in the general population BURDEN • ~50% in the infertile population, > than 60% in patients with chronic pelvic pain (CCP)

• Simoens et al. (2007) estimated total U.S. endometriosis cost of $22B • Average total direct costs from $1,109 per patient per year in Canada (Levy et al., COST 2011) to $12,118 per patient per year in the U.S. (Mirkin et al., 2007) • Procedure cost from $4,852 for a diagnostic laparoscopy to $12,894 for an abdominal hysterectomy

• Post medical/surgical treatment, recurrence is estimated to be 21.5% at 2 years and UNMET 40%- 50% at 5 years NEED • Aromatase inhibitors are reserved for managing severe, intractable endometriosis pain in combination with oral contraceptive pills, progestins, and GnRH agonists

* Source: IQVIA’s MIDAS Data Tool , 2018. 56 UTERINE FIBROIDS BURDEN AND UNMET NEED

• Uterine fibroids are a major public health issue and the most frequent indication for hysterectomy in premenopausal women BURDEN • Patients who do not undergo surgery often require medical management, hospitalization and additional outpatient physician visits, which further increase the annual costs

• Total costs of UF in the U.S. estimated at $5.9 to $34.4B annually • Estimated annual direct costs (surgery, hospital, outpatient, medication) $4.1 to $9.4B COST • Estimated lost work costs range from $1.55 to $17.2B annually • Obstetric complications associated with UF estimated at $238M to $7.76B annually

• Of the 550,000 hysterectomies performed annually in the U.S., one-third are due to UNMET fibroids NEED • Approximately 30,000 myomectomies are performed annually in the US for UF • GnRH agonists are largely used as a bridge to surgery, recurrence rates are high

* Source: IQVIA’s MIDAS Data Tool , 2018. 57 CONCLUSIONS

• Tremendous unmet need in EM/UF with current treatments

• Oral GnRH antagonist MoA major advance over agonists

• Endometriosis patients need more than OCs, NSAIDs and surgery

• Uterine fibroid patients need more than hysterectomy and Lupron

• Ideal treatment alleviates symptoms without use of ABT, offers choice to physicians and patients

58 ENDOMETRIOSIS CLINICAL DEVELOPMENT

59 EDELWEISS TRIAL OVERVIEW

Primary endpoint: VRS pain score Key secondary responder rate endpoint: BMD** June 2018 September 2018 12 weeks

Placebo 12 weeks

8–14 weeks 50 mg daily 50 mg daily 24 weeks

LEAD-IN 75 mg daily 75 mg daily FOLLOW-UP

100 mg daily 100 mg daily

200 mg daily 200 mg daily Optional extension 75 mg daily* * Titrated dose 50–100 mg 6 m + 6m f-up

* Titration after 12 weeks based on E2 serum level at weeks 4 and 8

Enrollment 328 patients • 50 sites in US (n=177) • 14 sites in EU (n= 151) **BMD: Bone Mineral Density

60 DEMOGRAPHICS AND BASELINE CHARACTERISTICS

Linzagolix Linzagolix Linzagolix Linzagolix Linzagolix Elagolix* Placebo 50 mg 75 mg FD 75 mg TD 100 mg 200 mg 150 mg QD (N=55) (N=49) (N=58) (N=56) (N=52) (N=57) (N=249)

Median age – years 32.0 31.0 33.0 31.5 33.0 31.0 32 (range) (22 - 45) (22 – 43) (18 – 45) (21 – 45) (22 – 44) (19 – 45) (19–48)

BMI (kg/m²) – mean (SD) 27 (7.6) 26 (7.7) 26 (5.9) 27 (7.1) 26 (5.9) 25 (5.4) 28 (6) Race n (%) White 51 ( 92.7) 47 ( 95.9) 53 ( 91.4) 48 ( 85.7) 49 ( 94.2) 54 ( 94.7) 221 (88.8) Black 4 ( 7.3) 2 ( 4.1) 6 ( 10.3) 8 ( 14.3) 4 ( 7.7) 4 ( 7.0) 19 (7.6) Other 0 1 ( 2.0) 0 0 1 ( 1.9) 1 ( 1.8) 9 (3.6) Pain Scores Dysmenorrhea (VRS) 2.1 (0.44) 2.1 (0.39) 2.1 (0.43) 2.1 (0.45) 2.1 (0.40) 2.1 (0.42) 2.2±0.5 Non-menstrual pelvic pain (VRS) 1.7 (0.50) 1.5 (0.56) 1.6 (0.53) 1.5 (0.56) 1.7 (0.50) 1.6 (0.58) 1.6±0.5 Dyspareunia (VRS) 1.7 (0.80) 1.4 (0.82) 1.7 (0.86) 1.4 (0.85) 1.7 (0.89) 1.6 (0.84) 1.5±0.8 Overall pelvic pain (NRS) 5.9 (1.84) 5.2 (1.97) 5.5 (1.79) 5.5 (1.77) 5.7 (1.75) 5.3 (1.70) 5.7±1.7 *Elaris EM-I NEJM, 2017

61 EDELWEISS – WEEK 12 & 24 SUMMARY PRIMARY AND SECONDARY ENDPOINTS (FAS)

p-value * <0.05 * * <0.01 * * * < 0.001

62 EDELWEISS – ADDITIONAL OUTCOMES 75MG TO 200MG SIGNIFICANTLY AND CONSISTENTLY IMPROVED ASSOCIATED SYMPTOMS

Confirmed Efficacy on Patient Well Being assessed by the following:

• Endometriosis Health Profile-30 score

• Patient Global Impression of p-value versus placebo = 0.311 0.010 0.026 0.003 Change scale (PGIC) • Patient Global Impression of Severity (PGIS) • Activity impairment score • Modified Biberoglu & Behrman score

63 EDELWEISS – CHANGE IN BONE MINERAL DENSITY (BMD) MEAN % CHANGE FROM BASELINE TO MONTH 6

Lumbar Spine Total Hip Femoral Neck 1

0.5

-0.5

-1 Pbo 50 mg -1.5 -1.6% lower bound CI for 75mg 75 mg FD -2 100 mg -2.2% Cutoff requiring ABT -2.5 200 mg -3 -3.6% lower bound CI for 200mg

64 NEXT STEP – EOP2 MEETING WITH FDA (DEC2018) EDELWEISS II & III (PHASE 3)

• To confirm safety, tolerability and efficacy of linzagolix in women with endometriosis- associated pain ✓ 2 active treatments – 75 mg & 200 mg + ABT ✓ 24 weeks placebo control ✓ Primary analysis at 24 weeks ✓ Optional 6 months extended treatment with no placebo control

• 1 study 100% US and 1 study US/EU

• To support US NDA and EU MAA

65 65 UTERINE FIBROIDS CLINICAL DEVELOPMENT

66 LINZAGOLIX REDUCED MENSTRUAL BLEEDING & UTERINE VOLUME IN UTERINE FIBROIDS (NO ADD BACK)

KLH1202 TRIAL: % OF DAYS WITH KLH1202 TRIAL: TIME TO NO KLH1202 TRIAL: CHANGE IN BLEEDING DURING 12-WEEK BLEEDING FOR UTERINE UTERINE TREATMENT PERIOD FIBROIDS PATIENTS VOLUME OVER TIME

100 100 Mean±SEM OBE2109 50 mg OBE2109 100 mg 90 OBE2109 200 mg Placebo 80 50 70

28.98 50 0 24.18 40 ** * ** 30 *** *** ** Meier Meier (%)estimate **

- 20 * *** 13.63 volume uterine in Percentage -50 *** ***

10 Δ

Kaplan Percentage of Days with (%) with Bleeding Days of Percentage 7.99 0 p < 0.05 * p < 0.01 ** 0 28 56 84 112 p < 0.001 *** vs Placebo -100 Placebo OBE2109 50 mg OBE2109 100 mg OBE2109 200 mg Days Pretreatment Week 1 Week 4 Week 8 Week 12 Post-treatment KLH-2109 50 mg KLH-2109 100 mg (Week 4) p < 0.01 * KLH-2109 200 mg Placebo Time (Weeks) Two sample t-test (vs Placebo) Censor

67 PRIMROSE 1 & 2 PHASE 3 CLINICAL TRIALS FOR THE TREATMENT OF

UTERINE FIBROIDS Primary endpoint: Responder-HMB Reduction 8–14 weeks 24 weeks H2:19 28 weeks 16-OBE2109-008 24 weeks Placebo + placebo add-back 100% US sites n = 100 Placebo + placebo add-back 200mg + add-back

n = 100 100mg + placebo add-back 100mg + placebo add-back 24w follow-up n = 100 Screening 100 mg + add-back 100 mg + add-back

n = 100 200 mg + placebo add-back 200 mg + add-back

n = 100 200 mg + add-back 200 mg + add-back

16-OBE2109-009 70% Europe 30% US sites n = 100 Placebo + placebo add-back 200mg + add-back n = 100 100mg + placebo add-back 100mg + placebo add-back 24w follow-up n = 100 Screening 100 mg + add-back 100 mg + add-back

n = 100 200 mg + placebo add-back 200 mg + add-back

n = 100 200 mg + add-back 200 mg + add-back • IND granted in April 2017 • Currently recruiting • Aiming at supporting the registration of two regimens of administration 68 OVERALL SAFETY DATA

69 LINZAGOLIX – END OF NOVEMBER CUTOFF >1,600 SUBJECTS EXPOSED – NO SAFETY SIGNALS

No liver toxicity observed • 6 subjects with transaminase (AST/ALT) > 3ULN in EDELWEISS or PRIMROSE 1/2 ✓ 2 subjects only AST elevation with CK increase (indicates muscular origin) ✓ 2 subjects with decrease of TA under continued treatment ✓ 2 subjects with concomitant disease (NASH and Hepatitis C) • No TA increase with associated increase of bilirubin • No dose-dependent increase of TA in EDELWEISS

No suicidal ideation observed • No suicide/suicidal ideation in EDELWEISS or PRIMROSE • No difference vs placebo in occurrence of associated TEAEs (EDELWEISS): ✓ Review of Psychiatric Disorder SOC (PT of mood swings, irritability, anxiety, depression)

70 70 COMMERCIALIZATION

71 ENDOMETRIOSIS ASSOCIATED PAIN LITERALLY “INVADES PATIENTS’ LIVES” …

Cannot function Avoid intercourse Work/school missed Negative impact on Bedridden couple/relationship Unable to perform household chores Mood swings Need analgesics to be able Feel anxiety and stress to cope with daily activities

Unable to look after children Depression, tearfulness Social events missed Sleepless nights Fatigue

72 ORAL GnRH ANTAGONISTS COULD IMPROVE THE LIVES OF ~14 MILLION AMERICAN WOMEN WITH ENDOMETRIOSIS OR UTERINE FIBROIDS

Market US Women with Endometriosis or Uterine Expansion Fibroids Are Underdiagnosed and Underserved Market Opportunity Today’s Expansion Market 13.9 Opportunity Today’s • Millions of American women are in Market need of long-term treatment options 9.0 to manage QoL- reducing symptoms 7.5 associated with endometriosis or 5.0 uterine fibroids, from puberty until 4.0 US Women (M) Women US 2.5 menopause

• 50% or less of women seeking Endometriosis Uterine Fibroids treatment for their symptoms are diagnosed and treated Prevalence Seeking Diagnosed Treatment & Treated

*ICER assumes $3.5 billion annual budget impact for treating the eligible endometriosis population with elagolix

73 HOW TO WIN LINZAGOLIX, FIRST LINE G nRH ANTAGONIST

• Strong efficacy data ✓ Low dose allows for reducing pain in ¾ of patients

PRIORITY FOR PATIENTS CLINICIANS Strong Efficacy Data – Endometriosis ✓ Effective at reducing overall pelvic pain ✓ ✓ ✓ Effective at reducing dysmenorrhea ✓✓✓ ✓✓✓ ✓ Effective at reducing non-menstrual pelvic pain ✓ ✓✓ ✓ Effective at reducing dyspareunia ✓✓ ✓✓ ✓ Effective at reducing dyschezia ✓✓ ✓

* DE/FR/US market research October 2018, AplusA

74 HOW TO WIN LINZAGOLIX, FIRST LINE G nRH ANTAGONIST

• Strong efficacy data ✓ Low dose allows for reducing pain in ¾ of patients • NO need for ABT in majority of patients ✓ Only a minority of patients require a higher dose with ABT ✓ ABT sparing avoids exposing women to rare, but potentially severe consequences

* DE/FR/US market research October 2018, AplusA

75 “ABT OR NO ABT, THAT IS THE QUESTION” DIFFERENTIATING BY NO ABT

• Trend toward patients preferring avoidance of hormone therapy

• Gynecologist survey in US shows high preference of no ABT as first line therapy

• ABT associated with HRT safety boxed warning

76 HOW TO WIN LINZAGOLIX, FIRST LINE G nRH ANTAGONIST

✓ Overall no safety signals of concern observed (n > 1,600) ✓ No evidence of liver damage ✓ No evidence of suicide or suicidal ideation

77 HOW TO WIN LINZAGOLIX, FIRST LINE G nRH ANTAGONIST

• Strong efficacy data

Start on 75 mg without ABT & dose • NO need for ABT in majority of patients escalate if needed with ABT

• Excellent safety profile

78 UNIQUE POSITIONING DRIVING MULTIPLE COMMERCIAL OPPORTUNITIES

Deliver more babies at NOLASIBAN lower cost • Endometriosis – pain controlled in 3 out of 4 patients with 75mg without ABT • Fibroids – targeting bleeding control without ABT • Potential for global blockbuster as first line therapy Uniquely effective LINZAGOLIX without hormone Milestones replacement therapy • Q1 2019 ✓ Phase 3 US & EU endometriosis start • H2 2019 Newborn life saving OBE022 ✓ 6 Month US & EU Phase 3 PRIMROSE 1 potential and 2 results in uterine fibroids

79 Questions OBE022 Treating Preterm Labor PRETERM LABOR LACKING EFFECTIVE SOLUTIONS FOR A DEADLY CONDITION

• Leading cause of death among children < 5 years of age ✓ More than 1 in 10 babies, are born too soon (before week 37) & number rising ✓ ~1 million deaths in 2015 • Tremendous avoidable medical & societal cost ✓ Average cost for a preterm infant is $40-50K (U.S.) ✓ Average cost per survivor infant born at 24-26 weeks amounts to $195K (U.S.) ✓ Babies surviving early birth face greater likelihood of lifelong disabilities resulting in > $26B avoidable costs • Very few & limited solutions today ✓ Only treatment with limited efficacy and restricted safety issues ✓ No drug approved in the US – Off-label used of Nifedipine, NSAID (indomethacin) ✓ Ex-US, atosiban (Tractocile) approved as bolus + infusion up to 48 hours

82 PROSTAGLANDIN SYNTHESIS INHIBITORS (NSAIDS) FOR TREATMENT OF PRETERM BIRTH

• Prostaglandin inhibitors are effective to delay birth* • But are associated with serious fetal side effects due to non-selective PG inhibition including:

✓Renal function impairment ✓Constriction of ductus arteriosus ✓Necrotizing enterocolitis ✓Intraventricular hemorrhage • Therefore, NSAIDs are only recommended in early gestational ages for 48 hours

* Tocolytic Therapy. Haas et al, Obstet Gynecol 2009; 113:585–94.

83 OBE022 POTENTIAL FIRST-IN-CLASS, ORAL AND SELECTIVE PGF2Α RECEPTOR ANTAGONIST FOR PRETERM LABOR (PTL)

OBE022 AT-A-GLANCE

Phospholipids ‘Inflammation’ Phospholipids Prostaglandins • Prostaglandin F2α (FP) receptor Arachidonic Acid Arachidonic Acid Indomethacin Cytokines PGHS-1/2 = COX1/2 PGHS-1/2 = COX1/2 antagonist Chemokines PGH2 PGH2 OBE022

• Licensed from Merck Serono PGE2 PGF2α PGE2 PGF2α

EP1 EP2 EP1 EP2 FP FP • Strong IP into the late 2030’s EP3 EP4 EP3 EP4 UTERUS: UTERUS: CONTRACT RELAX CONTRACT CONTRACT RELAX CONTRACT

kidney, brain, vascular smooth muscle RUPTURE

CONTRACT

DILATE

84 OBE022 INHIBITS CONTRACTIONS OF THE HUMAN MYOMETRIUM AND DELAYS PRETERM LABOR IN PRECLINICAL MODELS OT-induced contractions in Human Myometrium LPS-induced preterm parturition in mice

N=6 $$ p<0.01 vs vehicle, * p<0.05 vs combination * p<0.05, ** p<0.01, *** p<0.001 vs DMSO vehicle control # p<0.05, ## p<0.01, ### p<0.001 vs Atosiban 6nM

85 OBE022 NON-CLINICAL SAFETY DEMONSTRATED NO ADVERSE FETAL SIDE EFFECTS SEEN WITH INDOMETHACIN Rat foetus Newborn Rabbit No induction of vasoconstriction Not induction of vasoconstriction No platelet of ductus arteriosus of kidney vessels aggregation inhibition

86 OBE022 PROLONG PH2A STUDY (PARTS A AND B)

Preliminary safety Final Part A Main study end End of Infant FU & PK analysis Main analysis

Part A Dosing for 7d Maternal + neonatal FU 24-month Infant FU Up to 8 patients Open-label: Atosiban + OBE022

Final Part B Main analysis

Part B Dosing for 7d Maternal + neonatal FU 24-month Infant FU up to 60 patients + up to 60 patients

• Double-blind: Atosiban + OBE022 vs Atosiban + PLACEBO • Part A concluded in Q3 18 • Part B initiated in Q4 18

87 UNIQUE POSITIONING DRIVING MULTIPLE COMMERCIAL OPPORTUNITIES

Deliver more babies at NOLASIBAN lower cost Milestones

• Q1 2019 ✓ Interim efficacy from Phase 2a Uniquely effective PROLONG in PTL LINZAGOLIX without hormone • H2 2019 replacement therapy ✓ Complete first 60 patients

MEETING TAKE-AWAYS FOR 2019

• Up to six ongoing Phase 3 studies Deliver more babies at NOLASIBAN lower cost • NOLASIBAN – Preparing for commercialization (first in Europe)

• LINZAGOLIX – Developing for best in Uniquely effective class profile LINZAGOLIX without hormone replacement therapy • OBE022 – Nearing go-no-go inflection • Major 2019 catalysts ahead ✓ PRIMROSE 1 & 2 pivotal data Potential to save ✓ IMPLANT 4 readout and MAA filing OBE022 newborn lives ✓ PROLONG readout

90 COMPREHENSIVE FINANCIAL STRATEGY

September 30, 2018 Cash $156 million

Projected December 31, 2018 Cash $137-139 million

Projected 2018 Cash Use $63-65 million

Projected 2019 Cash Use $90-100 million

Cash Runway Mid-2020 vs. 1H:20 prior

Royalty financing Venture debt Capital Creative and Strategic collaborations Plans Opportunistic Public equity …

91 Questions