The Food and Drug Administration ( FDA ) has approved the first oral gonadotropin-releasing hormone ( GnRH ) receptor antagonist, Orgovyx ( Relugolix ) for adult patients with advanced prostate cancer.
Efficacy was evaluated in HERO, a randomized, open label trial in men requiring at least one year of androgen deprivation therapy with either prostate cancer recurrence following radiation or surgery or newly diagnosed castration-sensitive advanced prostate cancer.
Patients ( n=934 ) were randomized ( 2:1 ) to receive Relugolix 360 mg oral loading dose on the first day, followed by daily oral doses of 120 mg, or Leuprolide acetate 22.5 mg injection subcutaneously every 3 months for 48 weeks.
The main efficacy outcome measure was medical castration rate defined as achieving and maintaining serum testosterone suppression to castrate levels ( less than 50 ng/dL ) by day 29 through 48 weeks of treatment.
The medical castration rate was 96.7% ( 95% CI: 94.9%, 97.9% ) in the Relugolix arm.
The most common adverse reactions ( greater than or equal to 10% ) in patients receiving Relugolix in HERO were hot flush, musculoskeletal pain, fatigue, diarrhea, and constipation.
The most common laboratory abnormalities ( gretaer than or equal to 15% ) were increased glucose, triglycerides, alanine aminotransferase, and aspartate aminotransferase.
Decreased hemoglobin was also observed.
The recommended Relugolix dose is a loading dose of 360 mg on the first day followed by a daily oral dose of 120 mg at approximately the same time with or without food. ( Xagena )
Source: FDA, 2020