FDA clears ENDO-205 Investigational New Drug application for endometriosis

An Investigational New Drug (IND) application for ENDO-205 (EndoCyclic Therapeutics), a first-in-class, non-hormonal targeted peptide therapeutic for endometriosis, has been cleared by the FDA, according to a press release from EndoCyclic Therapeutics on March 23, 2026. The company is planning to initiate a phase 1 clinical study among healthy women in the pre-menopausal age who are of reproductive age.¹

According to the application acceptance announcement, ENDO-205 is the first therapy “in development designed to eliminate endometriosis lesions and address associated symptoms, including pain and systemic complications,” the company wrote.

"FDA IND clearance validates the strong scientific foundation behind ENDO-205,” said Tanya Petrossian, founder and CEO of EndoCyclic Therapeutics, in a statement. “We are thrilled to advance ENDO-205 into the clinic as we pioneer the future of endometriosis care and move closer to bringing patients a much-needed treatment for endometriosis. This milestone marks an important step forward for the more than 190 million girls and women worldwide affected by endometriosis, which still remains one of the most overlooked diseases in medicine."

RELATED: Anna Klepchukova, MD, Erica Stockwell, DO, discuss digital symptom checkers for endometriosis

The chronic, progressive disease that can present with symptoms or be present in patients who are asymptomatic impacts approximately 10% of girls and women in their reproductive years. The World Health Organization (WHO), among many other medical societies, acknowledges that access to early diagnosis and effective treatment is limited, especially in low- and middle-income countries. WHO stated the average time to diagnosis is between 4 and 12 years.^1,2

Recent data backs that up, as findings published in the Journal of Women’s Health stated women in France with endometriosis or adenomyosis experienced an average diagnostic delay of a decade or more.³

“A reduction of more than 4 years and diagnostic delay for endometriosis would be extremely significant clinically, economically, and psychologically,” said Erica Stockwell, DO, MBA, FACOG, in a recent Q&A interview with Contemporary OB/GYN. The discussion focused on how digital symptom checkers could help mitigate the diagnostic and financial burdens associated with endometriosis.⁴

“Endometriosis is one of the conditions with the longest diagnostic delays in medicine, and shortening that delay directly affects disease severity, fertility, and quality of life,” Stockwell added.

EndoCyclic stated its other lead program, FemLUNA, is in development as a potential non-invasive alternative to laparoscopy. FemLUNA is an “investigational imaging agent in development for accurate detection of endometriosis, including superficial lesions,” according to the company.¹

Reference:

1. Endo Cyclic Therapeutics announces FDA clearance of Investigational New Drug (IND) application for ENDO-205, a first-in-class non-hormonal precision peptide therapeutic for endometriosis. Press release. EndoCyclic Therapeutics. March 23, 2026. Accessed March 23, 2026. https://prnmedia.prnewswire.com/news-releases/endocyclic-therapeutics-announces-fda-clearance-of-investigational-new-drug-ind-application-for-endo-205-a-first-in-class-non-hormonal-precision-peptide-therapeutic-for-endometriosis
2. Endometriosis. World Health Organization. Updated October 15, 2025. Accessed March 23, 2026. https://www.who.int/news-room/fact-sheets/detail/endometriosis
3. Fitch J. Women with endometriosis or adenomyosis face 10- to 11-year diagnostic delays, study finds. Contemporary OB/GYN. Published February 16, 2026. Accessed March 23, 2026. https://www.contemporaryobgyn.net/view/women-with-endometriosis-or-adenomyosis-face-10--to-11-year-diagnostic-delays-study-finds
4. Fitch J. Anna Klepchukova, MD, Erica Stockwell, DO, discuss digital symptom checkers for endometriosis. Contemporary OB/GYN. Published March 20, 2026. Accessed March 23, 2026. https://www.contemporaryobgyn.net/view/anna-klepchukova-md-erica-stockwell-do-discuss-digital-symptom-checkers-for-endometriosis