CONTEXT

Degarelix is associated with high rates of injection site reaction. The US Food and Drug Administration approved relugolix, an oral gonadotropin-releasing hormone (GnRH) antagonist, for the treatment of advanced prostate cancer patients.

OBJECTIVE

This systematic review and network meta-analysis aimed to compare the efficacy and safety of relugolix versus degarelix.

EVIDENCE ACQUISITION

A systematic search was performed using major web databases for studies published before January 30, 2021, according to the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) extension statement for a network meta-analysis. Studies that compared the efficacy (12-mo castration rate with testosterone ≤50 ng/dl) and safety (adverse events [AEs]) of relugolix or degarelix and of the control group (GnRH agonists) were included. We used the Bayesian approach in the network meta-analysis.

EVIDENCE SYNTHESIS

Four studies (n = 2059) met our eligibility criteria. The main efficacy analysis was conducted for two different treatments (relugolix and all doses of degarelix vs GnRH agonists); relugolix (risk ratio [RR] 1.09, 95% credible interval [CrI]: 0.95-1.23) and degarelix (RR 0.98, 95% CrI: 0.91-1.06) were not associated with different 12-mo castration rates. In the subgroup analysis, degarelix 480 mg was significantly associated with a lower castration rate (RR 0.46, 95% CrI: 0.07-0.92). In all efficacy ranking analyses, relugolix achieved the best rank. The safety analyses showed that relugolix (RR 0.99, 95% CrI: 0.6-1.6 and RR 0.72, 95% CrI: 0.4-1.3, respectively) and degarelix (RR 1.1, 95% CrI: 0.75-1.35 and RR 1.05, 95% CrI: 0.42-2.6, respectively) were not associated with either all AE or serious AE rates. In the ranking analyses, degarelix achieved the worst rank of all AEs and the best rank of serious AEs. Relugolix (RR 0.44, 95% CrI: 0.16-1.2) and degarelix (RR 0.74, 95% CrI: 0.37-1.52) were not associated with different cardiovascular event (CVE) rates; both were associated with lower CVE rates than GnRH agonists in the ranking analyses.

CONCLUSIONS

We found that the efficacy and safety of relugolix are comparable with those of degarelix, albeit with no injection site reaction. Such data should be interpreted with caution until large-scale direct comparison studies with a longer follow-up are available.

PATIENT SUMMARY

We found that relugolix, an oral gonadotropin-releasing hormone (GnRH) antagonist, has comparable efficacy and safety with degarelix, a parenteral GnRH antagonist, for the treatment of advanced prostate cancer patients.