FDA grants priority review to relugolix for advanced prostate cancer
The FDA granted priority review to relugolix for treatment of men with advanced prostate cancer.
Relugolix (Myovant Sciences) is a once-daily oral gonadotropin-releasing hormone receptor antagonist that reduces production of testicular testosterone — which stimulates prostate cancer growth — and ovarian estradiol, which stimulates growth of endometriosis and uterine fibroids.
“We are delighted that the FDA has accepted for priority review our new drug application for relugolix, bringing us one step closer to providing a one-pill, once-a-day potential new treatment option to men with advanced prostate cancer,” Lynn Seely, MD, CEO of Myovant Sciences, said in a company-issued press release.
The FDA is expected to make a decision on approval for this indication by Dec. 20.
The phase 3 HERO trial compared the efficacy and safety of relugolix vs. leuprolide acetate among 934 men with androgen-sensitive advanced prostate cancer. The researchers randomly assigned 622 men to a single 360 mg loading dose of relugolix, followed by relugolix dosed at 120 mg once daily. The other 308 men received leuprolide acetate via 3-month depot injection.
Achieving and maintaining serum testosterone suppression to castrate levels less than 50 ng/dL through 48 weeks served as the study’s primary endpoint. Castration rates at day 4, rates of profound castration — defined as less than 20 ng/dL — at days 4 and 15, PSA response rate at day 15 and follicle-stimulating hormone (FSH) levels at week 25 served as secondary endpoints.
Researchers also evaluated testosterone recovery in a subset of 184 patients.
As Healio previously reported, results presented during the ASCO20 Virtual Scientific Program showed 96.7% (95% CI, 94.9-97.9) of men assigned relugolix achieved and maintained castration through 48 weeks compared with 88.8% of men on leuprolide acetate, demonstrating noninferiority with difference of 7.9% (95% CI, 4.1-11.8).
Testosterone suppression to less than 50 ng/dL at day 4 occurred among 56% of men in the relugolix group compared with no men in the leuprolide acetate group (P < .0001). At day 15, testosterone suppression to less than 50 ng/dL occurred among 98.71% of men in the relugolix group and 12.05% of men in the leuprolide group, with 78.38% of men on relugolix and 0.98% of men on leuprolide acetate achieving profound castration.
A higher percentage of men in the relugolix group achieved confirmed PSA response at day 15 followed by confirmation at day 29 (79.4% vs. 19.8%; P < .0001). Mean FSH levels at day 1 of week 25 were 1.72 for the relugolix group and 5.95 for the leuprolide group.
Median testosterone levels among men in the testosterone recovery subset were 270.76 ng/dL in the relugolix group and 12.26 ng/dL in the leuprolide group 90 days after therapy discontinuation.
Incidence of major adverse cardiovascular events was lower in the relugolix group compared with the leuprolide group (2.9% vs. 6.2%).