Relugolix officially launches in US prostate cancer market

The prostate cancer drug relugolix (Orgovyx) is now available in the United States through authorized specialty distributors, according to Myovant Sciences, the developer of the GnRH receptor antagonist.¹

Relugolix was approved in December 2020 for the treatment of patients with advanced prostate cancer. The approval was based on data from the phase 3 HERO study, which showed that 96.7% of patients randomized to relugolix maintained castration through 48 weeks, compared with 88.8% of patients receiving leuprolide (P <.001).²

The benefit with relugolix was sustained across all major secondary end points (P <.001). Relugolix was also associated with a 54% lower risk of major adverse cardiovascular events compared with leuprolide (HR, 0.46).

“Myovant has been focused on ensuring access to Orgovyx for men with advanced prostate cancer as quickly as possible following approval, and we are delighted to announce that it is now available,” David Marek, chief executive officer of Myovant, stated in a press release. “As part of our commitment to redefine care for women and for men, this is a critical step as we work to bring about a new standard of care for men with advanced prostate cancer.”

The open-label international phase 3 HERO trial included 930 patients treated at 155 clinical sites. The median patient age was 71 years (range, 47-97), with 28.6% of patients being aged ≥75 years. Overall, 31.7% of patients had metastatic disease, 15.5% of patients had a Gleason score of 5-6, 38.6% of patients had a Gleason score of 7, and 43.1% of patients had a Gleason score of 8-10. Half (50.2%) of patients had evidence of biochemical or clinical relapse after local primary intervention with curative intent.

The median PSA level at baseline was 10.8 ng/ml and the average testosterone level at baseline was 427.5 ± 156.2 ng/ml. The ECOG performance status was 0 in 88.1% of patients, 11.9% of patients, had prior androgen-deprivation therapy, and 30.3% had prior radiotherapy.

Patients were randomized in a 2:1 ratio to relugolix at 120 mg orally once daily or leuprolide injections every 3 months. Treatment was administered for 48 weeks, with a primary end point of sustained testosterone suppression to castrate levels (<50 ng/dL) through 48 weeks.

On day 4 of treatment, 56% of the relugolix cohort had castrate levels of testosterone versus 0% of the leuprolide group. On day 15, the rates were 98.7% versus 12%, respectively. Also on day 15, 79.4% of the relugolix arm had a confirmed PSA response, compared with 19.8% of patients on the leuprolide arm (P <.001).

Among a subgroup of men followed for testosterone recovery (n = 184), the mean testosterone levels 90 days following discontinuation of treatment were 288.4 ng/dL versus 58.6 ng/dL, respectively.

The incidence of adverse events (AEs) was similar across the study arms. In the relugolix group, all-grade AEs occurred in 92.9% of patients compared with 93.5% in the leuprolide arm. Grade 3/4 AEs occurred in 18% versus 20.5% of the 2 arms, respectively. There were 7 AE-related deaths in the relugolix cohort compared with 9 in the leuprolide arm.

Major adverse cardiovascular events occurred in 2.9% of the relugolix arm compared with 6.2% of the leuprolide cohort. The study defined major adverse cardiovascular events as nonfatal stroke or myocardial infarction, or death due to any cause.

References

1.Myovant Sciences Announces U.S. Availability of ORGOVYX™ for the Treatment of Advanced Prostate Cancer. Posted January 5, 2021. https://bit.ly/3rQnWbc. Accessed January 5, 2021.

2. Shore ND, Saad F, Cookson MS, et al. Oral relugolix for androgen-deprivation therapy in advanced prostate cancer. N Engl J Med. 2020;382(23):2187-2196. doi: 10.1056/NEJMoa2004325