161MO - Efficacy and safety of relugolix in Asian men with advanced prostate cancer (APC): A subgroup analysis from the randomized, phase III HERO study versus leuprolide

Background

Although prostate cancer occurrence is relatively low in Asia, incidence and mortality have been rapidly increasing across the continent (Zhu et al. Nat Rev Urol 2021;18:282-301). In the global phase 3 HERO study, relugolix, the once-daily oral gonadotropin-releasing hormone receptor antagonist, demonstrated superior continuous suppression of testosterone to castrate levels through week 48 compared to leuprolide (relugolix:96.7% vs leuprolide:88.8%; difference:7.9% (95% confidence interval [CI], 4.1 to 11.8); Shore et al. NEJM 2020;382:2187) in men with APC. To further characterize the results from this trial in Asian men, a subgroup analysis of HERO was undertaken.

Methods

HERO was a phase 3 randomized, open-label, study that evaluated relugolix (120 mg once daily after a single oral loading dose of 360 mg) vs leuprolide (22.5 mg [or 11.25 mg in Japan and China+Taiwan], 3-month injections) in 1130 men with APC (final HERO analysis population). The subgroups analyzed included all Asian men enrolled in HERO and the subgroups of men from the individual Asian countries (China+Taiwan, Japan, and Korea). Assessments included sustained testosterone suppression to castrate levels (<50 ng/dL) from day 29 through 48 weeks and safety.

Results

A total of 297 Asian men were randomized and treated in the HERO study (China+Taiwan:92; Japan:121; Korea:84). Of the Asian men who received relugolix (N=194), 97.2% (95% CI, 93.3% to 98.8%) maintained castration through 48 weeks, vs 89.1% (95% CI, 81.2% to 93.8%) of men receiving leuprolide (N=103; difference: 8.1% [95% CI, 1.5% to 14.6%]), with generally similar rates in individual countries (China+Taiwan:98% vs 93.0%; Japan:97.5% vs 92.7%; Korea:95.4% vs 81.4%). In Asian men, the incidences of any adverse events were 89.7% vs 86.4% and grade ≥3 adverse events were 18.0% vs 16.5% in the relugolix and leuprolide groups, respectively. Hot flash was the most common adverse event in both groups (35.6% vs 21.4%).

Conclusions

In this HERO study subgroup analysis, relugolix was effective and generally well tolerated in Asian men, consistent with the relugolix results in the overall population.

Clinical trial identification

NCT03085095.

Editorial acknowledgement

Editorial support provided by JD Cox with Mayville Medical Communications was funded by Myovant Sciences GmbH.

Legal entity responsible for the study

Myovant Sciences GmbH.

Funding

Myovant Sciences GmbH.

Disclosure

B. Brown, S. Lu: Financial Interests, Personal, Full or part-time Employment: Myovant. Q.Q. Xu: Financial Interests, Personal, Full or part-time Employment: Takeda. All other authors have declared no conflicts of interest.