Author: By Lynda Williams, Senior medwireNews Reporter
medwireNews: In-depth analysis of the HERO study adds to evidence that relugolix is significantly better at achieving profound and sustained testosterone suppression in men with advanced prostate cancer than leuprolide acetate.
Bertrand Tombal, from Université Catholique de Louvain in Brussels, Belgium, presented an update from the study at the 37th Annual European Association of Urology Congress in Amsterdam, the Netherlands.
The phase III trial previously showed that men given a daily dose of the oral, nonpeptide gonadotropin-releasing hormone (GnRH) receptor antagonist were more likely than those given the luteinising hormone-releasing hormone (LHRH) agonist every 3 months to achieve the secondary endpoint of profound castration (<20 ng/dL) on day 15 of treatment (78.4 vs 1.0%).
Now, the exploratory analyses for the modified intention-to-treat study population showed that the 622 relugolix-treated patients were more likely than their 308 leuprolide-treated counterparts to achieve profound castration at all the other measured timepoints over the first month of treatment, namely day 4 (6.9 vs 0.0%), day 8 (27.1 vs 0.0%), day 22 (91.1 vs 10.5%) and day 29 (95.3 vs 56.9%).
Although almost all men in both the relugolix and leuprolide treatment arms achieved profound castration by approximately day 150 (98.4 vs 98.1%), the median duration to reach this target was 15.0 days for those given relugolix compared with 29.0 days for those given leuprolide.
Moreover, the Kaplan–Meier survival curve for the modified intention-to-treat population demonstrated higher rates of sustained profound castration with relugolix than leuprolide throughout days 29 to 337 of the study. At week 48, there was a 13 percentage point difference in the rates of profound castration between the two treatment arms, at 81.6% and 68.6%, respectively, the investigator reported.
Safety analysis of the relugolix and leuprolide treatment arms showed “generally consistent” rates of both any-grade (92.9 vs 93.5%) and grade 3 and more severe adverse events (18.0 vs 20.5%), the researcher said. The most common events of any grade were hot flush (54.3 vs 51.6%), fatigue (21.5 vs 24.4%), diarrhoea (12.2 vs 6.8%), constipation (12.2 vs 9.7%), arthralgia (12.1 vs 9.1%) and hypertension (7.9 vs 11.7%).
Noting that profound castration is associated with improved overall and cancer-specific survival for patients with advanced prostate cancer, Bertrand Tombal concluded that relugolix offered a “more rapid and higher sustained profound testosterone suppression compared with leuprolide in the phase 3 HERO study at all measured timepoints.”
- Tombal B, Shore ND, George DJ, et al. Sustained castration to < 20 ng/dl for relugolix vs. leuprolide in men with advanced prostate cancer: Results from the phase 3 HERO study. 37th Annual EAU Congress; Amsterdam, the Netherlands: 1–4 July 2022
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