(290) Impact of Neoadjuvant Relugolix on Patient-Reported Sexual Function and Bother

Abstract

Abstract Introduction Relugolix is an oral GnRH receptor antagonist used in combination with radiation therapy in the treatment of unfavorable prostate cancer. It has been shown to achieve rapid and profound testosterone suppression (total testosterone <20 ng/dL) without the need for bothersome injections. Such low testosterone levels may impact sexual functioning and perceptions. Objective Given the potential benefits of Relugolix over other androgen deprivation therapies (ADTs), this prospective study sought to assess neoadjuvant Relugolix-induced sexual dysfunction prior to the initiation of stereotactic body radiation therapy (SBRT). Methods Prospective, patient-reported data was collected from a male cohort diagnosed with localized prostate cancer and subsequently treated with neoadjuvant Relugolix and SBRT. Relugolix was initiated at least 2 months prior to SBRT. Sexual function and bother were assessed via the sexual domain of the validated Expanded Prostate Index Composite (EPIC-26) survey which includes five function questions (erections and orgasm) and one overall bother question. Individual scores ranged from 0-100 with higher scores reflecting improved function/less bother. EPIC-26 was collected for each patient at pre-Relugolix baseline and one hour prior to SBRT initiation. Individual items were evaluated for statistical significance (paired t-test, p < 0.05) and clinical significance by minimally important difference (MID, +/- 0.5 SD from baseline score). Results Between July 2021 and January 2023, 49 patients with localized prostate cancer were treated with neoadjuvant Relugolix (4-6 months) and SBRT (36.25-40 Gy in 5 fractions) at Georgetown University Hospital per institutional protocol IRB 12-1775. The median age was 73 years. 27% of patients were black and 26.1% were obese (BMI ≥30 kg/m2). Patients initiated Relugolix at a median of 3.6 months prior to SBRT. 82% of patients had intermediate risk disease. All individual EPIC sexual function scores declined in a similar manner following neoadjuvant Relugolix therapy. These declines were both statistically and clinically significant. There was no statistically or clinically significant change in the EPIC sexual overall bother score. Conclusions In concordance with known side effects of ADT, neoadjuvant Relugolix was associated with a significant decline in self-reported sexual function. However, patients indicated only a minimal and non-significant increase in bother. Relugolix was well-tolerated as patients on Relugolix did not subjectively find their sexual dysfunction troublesome. Future investigations should compare outcomes while on Relugolix directly to GnRH agonist-induced sexual dysfunction. Disclosure No.