Myovant showcases positive relugolix data; will Pfizer swoop?

At the highest dose, the drug cut menstrual bleeding, increased hemoglobin levels and reduced fibroid volume.

Swiss biotech Myovant Sciences is celebrating after its lead hormonal therapy relugolix aced a mid-stage trial in uterine fibroids, adding to positive studies in prostate cancer.

The oral, once-daily, gonadotropin-releasing hormone receptor antagonist showed its mettle in a phase 2 trial in women with heavy menstrual bleeding caused by uterine fibroids carried out by Takeda, which originated the drug and licensed it to Myovant last year, keeping an equity stake in the biotech.

Myovant says relugolix (TAK-385) met its main objective or significantly reducing menstrual blood loss compared to placebo in the 12-week study, with three out of four patients on the highest dose (40mg) reporting no menstrual blood loss at all between weeks six and 12.

By the end of the study women on the drug reported fewer painful episodes and there was an increase in hemoglobin levels and a reduction in uterine and fibroid volume of around 50%, according to the data, which were reported at the American Congress of Obstetricians and Gynecologists over the weekend.

Myovant CEO Lynn Seely, MD, (pictured) said the results "provide a strong basis for our ongoing phase 3 studies, LIBERTY 1 & 2, which are evaluating relugolix co-administered with low-dose hormonal add-back therapy in women with uterine fibroids and heavy menstrual bleeding." Those studies are due to report top-line results in early 2019, a few months ahead of a phase 3 trial in advanced prostate cancer.

With positive data now building for relugolix, there is speculation that Pfizer—which was a lead investor in Myovant's $218 million initial public offering last year with a $30 million investment in the biotech—may follow through on an option to license or buy the candidate or indeed the company.

Part of Pfizer's reported interest in relugolix stems from its potential in prostate cancer, as the drug could complement the big pharma company's fast-growing Xtandi (enzalutamide) product, a key driver for its $14 billion takeover of Medivation last year.

And with sales failing to meet expectations so far this year, the big pharma group is under pressure from investors to carry out plenty of M&A and bulk up its pipeline, which according to Bernstein analysts is "on the thinner side."

Takeda has retained commercial rights for relugolix in Asian countries, including Japan, where the drugmaker is actively conducting two phase 3 registration studies for the treatment of uterine fibroids.