Interdisciplinary model-informed drug development for extending duration of elagolix treatment in patients with uterine fibroids.

Aim: Elagolix, a gonadotropin-releasing hormone receptor antagonist, was recently approved for heavy menstrual bleeding associated with uterine fibroids (UF, Oriahnn) at a dose of 300 mg twice daily (BID) in combination with add-back therapy (oestradiol 1 mg/norethindrone acetate 0.5 mg [E2/NETA] once daily) for 24 months use. The limited duration of treatment is related to elagolix dose- and duration-dependent decrease in oestrogen that is mechanistically linked to changes in bone mineral density (BMD). The work herein supported the extended treatment duration of 24 months.
Methods: An integrated exposure-response and epidemiological modelling framework of elagolix effects on femoral neck BMD (FN-BMD), informed by real-world data and phase 3 clinical trials data, was developed to predict the time course and magnitude of changes in BMD and its relation to risk of bone fracture in women with UF.
Results: Model results indicated that women treated with elagolix 300 mg BID + E2/NETA in the long term (ie, >24 months) may experience less than 1% loss in FN-BMD per year, relative to placebo. The exposure-response model simulations and clinical risk factors were used to estimate 10-year risk of fractures using the clinically validated Fracture Risk Assessment Tool (FRAX). The impact of elagolix 300 mg BID + E2/NETA treatment on the 10-year risk of hip or major osteoporotic fractures estimated from the FRAX model was minimal compared to that of placebo.
Conclusion: The elagolix integrated exposure-BMD analysis and translation to fracture risk provided an interdisciplinary model-informed drug development framework for clinical benefit-risk evaluation and enabled approval of longer treatment duration to benefit the patient.
(© 2022 AbbVie Inc and Analysis Group, Inc. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)