ObsEva Announces Upcoming Presentations Related to its Endometriosis and Uterine Fibroid Development Programs with its Novel Oral GnRH Receptor Antagonist OBE2109 (KLH-2109)

Geneva, Switzerland and Boston, MA - 23 April 2018 - ObsEva SA (Nasdaq: OBSV), a Swiss biopharmaceutical company focused on the development and commercialization of novel therapeutics for serious conditions that compromise a woman's reproductive health and pregnancy, today announced it will make presentations at the 4th Congress of the Society of Endometriosis and Uterine Disorders (SEUD) taking place April 26 - 28, 2018 in Florence (Italy). These presentations will include clinical data on the PK/PD profile of OBE2109 as well as a drug-drug interaction study:

• Pharmacokinetic Interactions of Midazolam with OBE2109, A Novel Oral GnRH Receptor Antagonist (posters session, beginning at 19:00 on Thursday, April 26th).
  OBE2109 at doses up to 200mg neither induced nor inhibited drug-metabolizing enzyme CYP3A4, and therefore is not expected to impact efficacy or safety of co-administered add-back hormone replacement therapy (ABT).
  
  
• GnRH Receptor Antagonist KLH-2109 (OBE2109) dose-dependent E2 suppression in Japanese and Caucasian women  (Free Communication session 3, beginning at 15:30 on Friday, April 27th).
  KLH-2109 (OBE2109) at doses up to 400mg/d is safe, with favorable pharmacokinetic characteristics and controlled suppression of LH and estradiol.
  
  
• Pharmacodynamics of GnRH Receptor Antagonist OBE2109 Alone or Together With Add-Back Therapy (Free Communication session 13, beginning at 18:30 on Friday, April 27th).
  Results provide support for the selection of the ABT dosage in ongoing phase 3 clinical trials.

"We are pleased to inform the medical community on the development of our orally available and potent GnRH receptor antagonist OBE2109 (KLH-2109). Low pharmacokinetic and pharmacodynamic variability may allow estradiol to be managed to effectively treat symptoms of endometriosis and uterine fibroids while minimizing hypoestrogenic side effects. We believe these results support our treatment strategy to offer flexible dosing alternatives to achieve either partial or full estrogen suppression in individual patients thus providing potential therapies both with and without hormonal add-back therapy." said Jean-Pierre Gotteland, CSO and Head of R&D at ObsEva.

About Uterine Fibroids

Uterine fibroids are common non-cancerous tumors that grow within the muscular wall of the uterus. They can vary in size and number and when symptomatic, are most often accompanied by heavy menstrual bleeding, anemia, abdominal pressure and pain, bloating, increased urinary frequency and reproductive dysfunction. Uterine fibroids are associated with an increased risk of pregnancy complications such as infertility, miscarriage, placental abruption and early onset of labor. According to a study published in the American Journal of Obstetrics & Gynecology in 2003, uterine fibroids affect an estimated 20 to 40 percent of women over the age of 30 in the United States based on clinical cases and women who undergo treatment.

For the millions of women with symptomatic uterine fibroids seeking treatment options, selection is driven by symptom severity, the woman's age, and her desire to have children now or in the future. While medical, surgical and minimally invasive treatments are available, the standard of care for symptomatic uterine fibroids is a hysterectomy or, in women who wish to preserve their fertility, surgical removal of the fibroid(s).

About Endometriosis

Endometriosis is a disease in which the endometrium (tissue lining the inside of the uterus) grows outside of the uterus, where it induces a chronic inflammatory reaction in the abdomen that may result in scar tissue. It is primarily found on the pelvic peritoneum, on the ovaries, in the rectovaginal septum, on the bladder and in the bowels. The most common symptom of endometriosis is pelvic pain, which often correlates to the menstrual cycle. Patients may also experience painful ovulation, pain during or after sexual intercourse, heavy bleeding, chronic pelvic pain, fatigue and infertility. For many, endometriosis pain can be so severe and debilitating that it impacts do day-to-day activities and has a negative effect on general physical, mental and social well-being.

Endometriosis treatments aim first to alleviate pain, then to remove or decrease the size and number of endometrial lesions, and possibly improve fertility. Oral contraceptives, progestins and NSAIDs are generally first-line treatments for women experiencing pain. Following the failure of first-line therapies, current treatment options are limited to intra-muscular or subcutaneous GnRH agonist injections, GnRH agonists nasal spray pumps or surgery (including hysterectomy) for the most symptomatic cases.

The World Endometriosis Research Foundation's EndoCost study estimated the aggregate annual cost of endometriosis to be approximately $80 billion in the United States and approximately $60 billion in Germany, the UK, France and Italy in 2012 based on current exchange rates.

About OBE2109

OBE2109 is a novel, orally administered GnRH receptor antagonist with a potentially best-in-class profile in late-stage clinical development for the treatment of pain associated with endometriosis and heavy menstrual bleeding associated with uterine fibroids. OBE2109 acts by binding to and blocking the GnRH receptor in the pituitary gland, ultimately reducing estrogen production by the ovaries. Through previously reported results from this class of drugs and sophisticated pharmacological modelling, it has been established that maintaining estradiol within a specific target range provides the optimal balance between reducing symptoms while mitigating bone density loss associated with excessive estradiol suppression. ObsEva licensed OBE2109 from Kissei in late 2015 and retains worldwide commercial rights, excluding Asia, for OBE2109.

OBE2109 is currently in Phase 2b clinical trial for the treatment of pain associated with endometriosis (EM) and in Phase 3 clinical trials for the treatment of heavy menstrual bleeding (HMB) associated with uterine fibroids (UF) in pre-menopausal women.

About Kissei

Kissei is a Japanese pharmaceutical company with approximately 70 years of history, specialized in the field of urology, kidney - dialysis and Unmet Medical Needs. Silodosin is a Kissei product for the treatment of the signs and symptoms of benign prostatic hyperplasia which is sold worldwide through its licensees. KLH-2109/OBE2109 is a new chemical entity discovered by Kissei R&D.

About ObsEva

ObsEva is a clinical-stage biopharmaceutical company focused on the clinical development and commercialization of novel therapeutics for serious conditions that compromise a woman's reproductive health and pregnancy. Through strategic in-licensing and disciplined drug development, ObsEva has established a late-stage clinical pipeline with development programs focused on treating endometriosis, uterine fibroids, preterm labor and improving IVF outcomes. ObsEva is listed on The Nasdaq Global Select Market and is trading under the ticker symbol "OBSV". For more information, please visit www.ObsEva.com.

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Media Contact:
Liz Bryan
Spectrum Science
lbryan@spectrumscience.com
+1 202-955-6222 x2526

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

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

Attachment

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