FDA Approval Sought for Relugolix in Advanced Prostate Cancer

A New Drug Application (NDA) has been submitted to the FDA for once-daily, oral relugolix (RRVT-601, Relumina) at a dose of 120 mg as treatment of male patients with advanced prostate cancer, Myovant Sciences, developer of the agent, announced in a press release.

“The submission of our NDA for prostate cancer is a major step towards providing a one pill, once a day potential new treatment option for men with advanced prostate cancer,” said Lynn Seely, MD, chief executive officer of Myovant Sciences, in a statement. “Based on the robust efficacy and safety data from the phase III HERO study, we believe relugolix, if approved, could provide men an important oral alternative to leuprolide injections, the current standard of care.”

Submission of the NDA is based on compelling results from the phase III HERO study (NCT03085095) of relugolix versus leuprolide acetate in men with advanced prostate cancer. In the study, 96.7% of men had sustained testosterone suppression to castrate levels (<50 ng/dL) through 48 weeks, meeting the study’s primary end point. Treatment with relugolix also demonstrated superiority to leuprolide acetate in terms of 6 of the secondary end points: sustained testosterone suppression to castrate levels, rapid suppression of testosterone, profound suppression of testosterone, rapid suppression of prostate-specific antigen, and suppression of follicle-stimulating hormone.

Between the 2 arms, the overall incidence of adverse events (AEs) was comparable with 92.9% of patients experiencing an AE in the relugolix group and 93.5% in the leuprolide acetate. In the relugolix arm versus the leuprolide acetate arm, 2.9% and 6.2% of men experienced major cardiovascular AEs, respectively. The major cardiovascular AEs included non-fatal myocardial infarction, non-fatal stroke, and all-cause mortality.

The ongoing randomized, open-label, parallel-group study is evaluating the efficacy and safety of relugolix in 1100 participants with androgen-sensitive advanced prostate cancer requiring at least 1 year of continuous androgen deprivation therapy (ADT). Patients in the study are randomized 2:1 to a single-loading dose of oral relugolix at 360 mg followed by 120 mg once daily or leuprolide acetate 22.5 mg 3-month depot subcutaneous or intramuscular injection. Monthly patient visits are conducted for investigators to assess serum testosterone and PSA. Over the course of the study, investigators will also monitor AEs, physical examinations, vital signs, 12-lead electrocardiograms, and clinical laboratory tests to assess the safety of relugolix.

To be eligible to enroll in the HERO study, patients were require to have a histologically or cytologically confirmed diagnosis of adenocarcinoma of the prostate and were good candidates for 1 year on continuous ADT, according to investigator opinion. Patients were required to have an ECOG performance status of 0 or 1 at the time of initial screening and at baseline; at their screening visits, patients were also required to have a serum testosterone level of ≥150 ng/dL and a serum PSA concentration of >2.0 ng/mL (2.0 μg/L).

The study excluded patients who required chemotherapy or surgery, based on investigator opinion, and patients with brain metastases, history of surgical castration or having been treated with received gonadotropin-releasing hormone analog or another form of ADT, or those who have had prior systemic cytotoxic treatment for prostate cancer.

“We made the decision to prioritize this NDA submission and potentially accelerate the availability of an oral treatment option for men with advanced prostate cancer,” said Juan Camilo Arjona, MD, chief medical officer of Myovant Sciences, in a statement. “This is of particular importance in the current environment and for the foreseeable future due to COVID-19 and the need for men with advanced prostate cancer to go to a clinic to receive injections in person.”

^References:

^{Myovant Sciences submits New Drug Application (nda) to the FDA for once-daily, oral relugolix for the treatment of men with advanced prostate cancer [news release]. Basel, Switzerland: Myovant Sciences; April 21, 2020. https://bit.ly/2VI4XAq. Accessed April 21, 2020.}