Study Characterizes Real-World Use of Relugolix in Combination With Other Prostate Cancer Therapies

Relugolix was frequently used in combination with other medications for prostate cancer (PC) in patients both new to androgen-deprivation therapy (ADT) and continuing ADT in a real-world study. The results were presented during a poster session at the 2023 American Society of Clinical Oncology (ASCO) Genitourinary Cancer Symposium in San Francisco, CA.¹

Relugolix is an oral gonadotropin-releasing hormone (GnRH) receptor antagonist that was FDA approved for the treatment of advanced PC in 2020 based on data from the phase 3 HERO trial (NCT03085095).² The randomized, open-label study included men who required at least 1 year of ADT, either after recurrence following PC treatment or for newly diagnosed castration-sensitive advanced PC.

A subgroup analysis of the HERO trial found that relugolix in combination with enzalutamide or docetaxel was similarly effective to other study subgroups, the authors noted, but some guidelines do not recommend using relugolix concurrently with other therapies due to limited data.

The new study evaluated real-world use patterns of relugolix and leuprolide, another GnRH agonist, in combination with other PC medications at 89 urology practices across the United States. The observational retrospective analysis examined electronic medical record (EMR) data for 51,735 patients treated with ADT in 2021. Patients who received either relugolix or leuprolide during the study period were eligible for the analysis, which focused on ADT prescription occurrence and ADT in combination with other medications for PC.

A total of 3096 (6%) patients received at least 1 prescription for relugolix, and 45,599 (88.1%) received leuprolide. The proportion of patients given combination PC regimens was higher among those treated with relugolix vs those treated with leuprolide (22.5% and 19.5%, respectively; P < 0.0001).

Among patients who were being treated with ADT for the first time in the study, those receiving relugolix were more likely to be on a combination of PC medications compared with leuprolide users (15.8% vs 10.9%, respectively). In both the relugolix and leuprolide groups, the most common medications used concurrently were novel anti-androgen therapies.

The therapies most frequently combined with relugolix were enzalutamide, apalutamide, abiraterone, and darolutamide (9%, 6.9%, 5.9%, and 1.1%, respectively). In the leuprolide cohort, the same PC medications were seen at similar proportions.

Overall, the study suggests that in the real world, relugolix is frequently combined with other PC medications among patients both new to and continuing ADT. In the relugolix cohort, the proportion of patients undergoing combination therapy was also higher than the proportion of patients receiving combination therapy with leuprolide.

“These results provide insight into the real-world use of relugolix in combination with other PC medications,” the authors concluded. “Further analyses are needed to make informed treatment decisions.”

References

1. McKay RR, Gandhi R, Yang E, Pruett J, Nwokeji E, Fallick M. Real-world combination therapy patterns in patients receiving leuprolide or relugolix for androgen deprivation therapy in 2021 (The REAL-ADT COMBO Study): Analysis from a US EMR database. Abstract presented at: 2023 ASCO GU Cancers Symposium; February 16-18, 2023; San Francisco, CA. Accessed February 17, 2023. https://meetings.asco.org/abstracts-presentations/216934

2. FDA approves relugolix for advanced prostate cancer. News release. FDA. December 18, 2020. Accessed February 17, 2023. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-relugolix-advanced-prostate-cancer