Endometriosis is an estrogen-dependent condition that affects approximately 10% of women of reproductive age, and may lead to chronic pelvic pain, infertility, or both. It is estimated that endometriosis is present in 24–50% of women with infertility, and in over 20% of those with chronic pelvic pain. Information gathered by the American Congress of Obstetricians and Gynecologists indicates that in approximately 60% of adult endometriosis patients, symptoms start before the age of 20 years.

Key Takeaways

• Datamonitor Healthcare estimates that in 2019, there were 191.0 million prevalent cases of endometriosis in women aged 15–49 years worldwide, and forecasts that number to increase to 201.8 million prevalent cases by 2028.
• Endometriosis affects an estimated one in 10 women in the reproductive age group of 15–49 years. The approved drugs in the endometriosis space target the gonadotropin-releasing hormone (GnRH) receptor, progesterone receptor, follicle-stimulating hormone (FSH), gonadotropin-releasing hormone (GnRH), and androgen receptors. The majority of marketed drugs are administered via the subcutaneous route, while the remainder are oral and intramuscular formulations.
• The majority of industry-sponsored drugs in active clinical development for endometriosis are in Phase II, with only one drug in the NDA/BLA phase.
• Therapies in development for endometriosis focus on targets such as the gonadotropin-releasing hormone (GnRH) receptor, progesterone receptor, luteinizing hormone receptor (LHR), androgen receptors, and follicle-stimulating hormone (FSH). The majority of pipeline drugs are administered via the oral route, with only one product being tested as a topical formulation.
• High-impact upcoming events for drugs in the endometriosis space comprise topline Phase III trial results for Trelstar and Yselty. The overall likelihood of approval of a Phase I gynecology asset is 12.3%, and the average probability a drug advances from Phase III is 70%. Drugs, on average, take 11.6 years from Phase I to approval, compared to 12.8 years in the overall obstetrics/gynecology space.
• The distribution of clinical trials across Phase I–IV indicates that the majority of trials for endometriosis have been in the early and mid-phases of development, with 73% of trials in Phase I–II, and only 27% in Phase III–IV.
• The US has a substantial lead in the number of endometriosis clinical trials globally. Germany leads the major European markets, while Japan has the top spot in Asia.
• Clinical trial activity in the endometriosis space is dominated by completed trials. Bayer has the highest number of completed clinical trials for endometriosis, with 46 trials.
• Bayer leads industry sponsors with the highest overall number of clinical trials for endometriosis, followed by AbbVie and Takeda.