SAN DIEGO, July 29 /PRNewswire-FirstCall/ -- Neurocrine Biosciences, Inc. (Nasdaq: NBIX) today announced new six month safety and efficacy results from its fourth Phase II clinical trial using its proprietary, orally-active non-peptide Gonadotropin-Releasing Hormone (GnRH) receptor antagonist, elagolix, in patients with endometriosis. Consistent with previously reported six month (Petal Study) and three month (Lilac Petal Study) results, a favorable safety profile and clinically meaningful efficacy have again been confirmed through month six of the Lilac Petal Study. This newly available data also provides clinical confirmation of Neurocrine's extensive pharmacologic modeling related to the elagolix dose-response continuum. The outcome of primary interest at month six was the impact of the elagolix 250 mg dose on bone mineral density (BMD) as measured by dual energy X-ray absorptiometry (DXA) scanning.
Over the six month treatment period, elagolix 150 mg once daily had minimal impact on BMD (-0.80% mean change from baseline, femur; -0.66% mean change from baseline, spine). The 250 mg once daily dose, as expected, had slightly greater percentage change from baseline at month six (-1.0% femur, -1.6% spine). The 150 mg once daily BMD profile in this Lilac Petal Study is consistent with that previously demonstrated in the six-month Petal Study.
"We selected the 150 mg and 250 mg once daily doses for this study based upon predictions generated from extensive modeling of dose, estradiol and bone mineral density relationships. Prior to this study we anticipated that the 250 mg dose would provide exposure such that we would start to see an increased impact on bone mineral density in a small portion of study subjects. The Lilac Petal data confirm that our modeling of the dose-response curve was accurate," said Chris O'Brien, Chief Medical Officer of Neurocrine Biosciences, "Most importantly, we find that the 250 mg once-daily dose, chosen to inform us about the upper limit of dosing, met the pre-defined threshold for bone impact."
From an efficacy standpoint, the exploratory daily pain scales for Dysmenorrhea and Non-Menstrual Pelvic Pain demonstrated that women had minimal endometriosis pain symptoms at month six (mean scores of approximately 0.5 for both doses and both of the 0-3 scales). The overall assessment of benefit using the Patient Global Impression of Change (PGIC) revealed that 80% of elagolix 150 mg subjects and 79% of elagolix 250 mg subjects were "Much Improved" or "Very Much Improved" after six months of treatment. Subjects treated with elagolix also reported considerable improvement on the Endometriosis Health Profile (EHP-5), a validated endometriosis-specific scale which reveals the impact of treatment on a variety of health outcome domains.
