A New Drug Application (NDA) for linzagolix for the treatment of uterine fibroids has been submitted to the Food and Drug Administration.

Linzagolix is a novel, oral gonadotropin-releasing hormone (GnRH) receptor antagonist. The NDA submission is supported by data from the 52-week, double-blind, placebo-controlled phase 3 PRIMROSE 1 (ClinicalTrials.gov Identifier: NCT03070899) and PRIMROSE 2 (ClinicalTrials.gov Identifier: NCT03070951) studies, which evaluated the efficacy and safety of linzagolix in 1061 women with heavy menstrual bleeding associated with uterine fibroids.

Patients were randomly assigned to receive linzagolix 100mg or 200mg once daily or placebo, with or without hormonal add-back therapy (estradiol 1mg and norethindrone acetate 0.5mg daily). The primary endpoint was the percentage of responders based on menstrual blood loss.

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Pooled data from both studies showed that at week 52, linzagolix met the primary endpoint, demonstrating responder rates of 89.3% and 56.4% among women receiving linzagolix 200mg with ABT and linzagolix 100mg without ABT, respectively. Linzagolix also met key secondary endpoints including pain reduction, anemia and quality of life.

The NDA submission also included data from the 76-week post-treatment follow-up study. Results showed that off-treatment pain scores remained lower than baseline across all linzagolix treatment arms in PRIMROSE 1; these findings were consistent with those observed in PRIMROSE 2. Improvements in hemoglobin levels and quality of life were also maintained with linzagolix. Patients treated with linzagolix 100mg and 200mg with ABT also showed evidence of bone mineral density recovery.

“The NDA submission is a major milestone in making linzagolix available in the US, and an important step toward addressing the diverse medical needs that exist for women with uterine fibroids,” said Brian O’Callaghan, CEO of ObsEva. “Our positive phase 3 PRIMROSE results underscore linzagolix’s clinical utility and well-known differentiated profile.” 


ObsEva announces submission of New Drug Application to US FDA for linzagolix for the treatment of uterine fibroids. News release. ObsEva SA. Accessed September 15, 2021. https://www.globenewswire.com/news-release/2021/09/15/2297146/0/en/ObsEva-Announces-Submission-of-New-Drug-Application-to-U-S-FDA-for-Linzagolix-for-the-Treatment-of-Uterine-Fibroids.html

This article originally appeared on MPR