Relugolix Beneficial for Prostate Cancer Patients Undergoing Radiotherapy

FRIDAY, March 29, 2024 (HealthDay News) — For patients with localized and advanced prostate cancer receiving radiotherapy, relugolix achieves sustained castration, according to a study published online March 7 in JAMA Oncology.

Daniel E. Spratt, M.D., from the University Hospitals Seidman Cancer Center and Case Western Reserve University in Cleveland, and colleagues examined the efficacy and safety of the oral gonadotropin-releasing hormone antagonist relugolix with radiotherapy for treating prostate cancer in a multicenter, post-hoc analysis of patients with localized and advanced prostate cancer receiving radiotherapy in two randomized clinical trials. Data were included for 260 patients, 164 of whom received relugolix: 103 received radiotherapy and short-term ADT (patients received relugolix or degarelix for 24 weeks) and 157 received radiotherapy and longer-term ADT (patients received relugolix or leuprolide acetate injections during 48 weeks).

The researchers found that relugolix achieved castration rates (<50 ng/dL) of 95 and 97 percent among patients receiving short- and longer-term ADT, respectively. At 12 weeks after short-term relugolix, 52 percent achieved testosterone levels to baseline or more than 280 ng/dL. Among a subset of participants assessed for testosterone recovery, mean testosterone levels were 310.5 and 53.0 ng/dL with relugolix and leuprolide acetate, respectively, at 90 days after longer-term ADT. There was no significant difference noted in castration resistance-free survival between the relugolix and leuprolide acetate cohorts. For short- or longer-term relugolix, adverse events of grade 3 or greater were uncommon.

“Relugolix appeared safe and effective at inducing rapid and sustained testosterone suppression across patients treated with short-term and longer-term ADT in combination with radiotherapy,” the authors write.

The C27003 study was sponsored by Millenium Pharmaceuticals, and the HERO study was sponsored by Sumitomo Pharma Switzerland. The manuscript was funded by Pfizer in collaboration with Sumitomo Pharma Switzerland.

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