A novel combination therapy recently trialled in Australia shows promise for long-term treatment of endometriosis-associated pain, investigators say.

An international group of researchers, including reproductive health specialist Professor Neil Johnson from the Robinson Research Unit at the University of Adelaide, conducted two replicate phase III double-blinded trials to evaluate the once-daily oral treatment.

The pill combines a gonadotropin-releasing hormone (GnRH) antagonist, relugolix (40mg), with oestradiol (1mg) and norethisterone acetate (0.5mg).

It is already approved by the US Food and Drug Administration as Myfembree (Myovant Sciences, Pfizer) for treatment of uterine fibroids but researchers believe it may also address “the unmet clinical need” for a long-term endometriosis therapy that avoids opioids and repeated surgeries.