Relugolix mutes endometriosis pain

Oral relugolix provides pain relief in women with endometriosis in a dose–response manner, according to the results of a phase II study.

In total, 483 patients (average age, 35 years) with endometriosis-related pain were randomized to receive relugolix at 10 mg (n=103), 20 mg (n=100), or 40 mg (n=103), or placebo (n=97) as a daily oral dose, or leuprorelin 3.75 mg (n=80) as a monthly subcutaneous injection. Treatment lasted 12 weeks.

The mean visual analogue (VAS) scores at baseline across treatment groups ranged from 14.6 to 15.6 mm for pelvic pain, from 27.1 to 30.4 mm for dysmenorrhea, and from 8.8 to 12.5 mm for dyspareunia.

The primary endpoint of change from baseline in mean VAS score for pelvic pain during 28 days prior to treatment conclusion was greater with relugolix than with placebo (–6.2, –8.1, and –10.4 mm in the 10-mg, 20-mg, and 40-mg groups, respectively, vs –3.8 mm; p<0.05 for all). The efficacy of the highest relugolix dose was comparable to that of leuprorelin (−10.6 mm).

Similar results were observed for dysmenorrhea pain, which improved with relugolix vs placebo in a dose–response manner. The therapeutic effect with the highest dose was also similar to that with leuprorelin.

Treatment-emergent adverse events (TEAEs) occurred in 71.1 percent of patients in the placebo group; 79.6 percent, 89.0 percent, and 94.2 percent in the relugolix 10-mg, 20-mg, and 40-mg groups, respectively; and 91.3 percent in the leuprorelin group. The most common TEAEs with relugolix were hot flush, metrorrhagia, menorrhagia, and irregular menstruation. There was a dose-dependent decrease seen in bone mineral density.

The findings suggest that relugolix is a promising new therapeutic option for patients with endometriosis-associated pain, researchers said. The 40-mg dose is currently being evaluated in phase III studies.