If your doctor gave you a choice to take hormone therapy (ADT) using the traditional injection every month, three months, or every six months or to take a daily pill, which would you opt to do? Prepare yourself; you might be facing this question sometime in the later part of 2020!
Recently released data from the phase III HERO study of relugolix showed it met its primary efficacy endpoint as well as all 6 secondary endpoints in men with advanced prostate. The released data comes from Myovant, the drug’s developer.
These strong results support a new drug application (NDA) submission to the FDA and regulatory submissions in both Europe and Japan.
“If approved, relugolix would become the first-of-its-kind oral option for men with advanced prostate cancer,” steering committee member Neal Shore, MD, Carolina Urologic Research Center, said in a press release issued by the company.
The HERO study was a randomized, open-label, parallel-group, multinational clinical study that evaluated the safety and efficacy of relugolix, an oral ADT drug in men with androgen-sensitive advanced prostate cancer who required at least 1 year of continuous androgen deprivation therapy.
The study was randomized in a 2:1 ratio of men to receive either a single loading dose of 360 mg relugolix followed by 120 mg relugolix once daily or leuprolide acetate (Lupron) 3-month depot injection.
The primary endpoint was to achieve and maintain testosterone suppression to castrate levels (< 50 ng/dL) through 48 weeks.
Overall, 96.7% of men receiving relugolix achieved sustained testosterone suppression to castrate levels (95% CI, 94.9%-97.9%).
Moreover, relugolix demonstrated superiority to leuprolide acetate in regards to its rapid suppression of testosterone at day 4 and day 15, profound suppression of testosterone at day 15, rapid suppression of prostate-specific antigen (PSA) at day 15.
Also, relugolix demonstrated it was at least equal to leuprolide acetate (Lupron) on sustained testosterone suppression through 48 weeks.
Lastly, pharmacodynamic results showed no testosterone flare after starting relugolix and the mean testosterone levels returned to normal levels within 90 days after treatment discontinuation. This would mean that a man starting ADT would not first need to kick off their ADT session with the additional drug, Casodex (bicalutamide).
Like all other ADT treatments, relugolix has its share of side effects. The most frequently reported adverse events reported in at least 10% of men in the relugolix group were hot flashes, fatigue, constipation, diarrhea, and arthralgia.
Relugolix’s mode of action is to serve as a gonadotropin-releasing hormone (GnRH) receptor antagonist (like Lupron, etc.) that reduces the making of testicular testosterone and ovarian estradiol production.
