Relugolix now available in Canada for advanced prostate cancer

Relugolix (Orgovyx), an oral androgen deprivation therapy treatment, is now available for prescription in Canada for the treatment of patients with advanced prostate cancer, announced Sumitomo Pharma, the developer of the therapy, in a news release.¹

Relugolix received Health Canada approval in October 2023 and FDA approval in December 2020 based on findings from the phase 3 HERO trial.

"Lowering the body's testosterone level is a first-line treatment approach for men with advanced prostate cancer. Now, physicians in Canada have a once-daily oral GnRH antagonist treatment option in their armamentarium that helps men with advanced prostate cancer by lowering testosterone levels without leading to testosterone flares,” said Fred Saad, MD, FRCS, in the news release.¹ Saad is a professor and chairman of the department of surgery and the director of genitourinary oncology at the University of Montreal.

Relugolix is an oral gonadotropin-releasing hormone (GnRH) receptor antagonist indicated for adult patients with advanced prostate cancer. The therapy received Health Canada approval in October 2023² and FDA approval in December 2020³ based on findings from the phase 3 HERO trial (NCT03085095).

Overall, the trial demonstrated the superiority of relugolix to leuprolide in achieving rapid and sustained suppression of testosterone levels in men with prostate cancer, in addition to demonstrating a lower risk of major adverse cardiovascular events.⁴

Specifically, treatment with relugolix led to lower testosterone levels (< 50 ng/dL) by day 29 through week 48 in 96.7% of patients, compared with 88.8% among those who received leuprolide acetate injections. This difference demonstrated noninferiority and superiority of relugolix in regard to the trial’s primary end point (P < .001).

Additionally, relugolix demonstrated superiority over leuprolide on all other key secondary end points (P < .001). In the study, 56% of patients who received relugolix showed castrate levels of testosterone on day 4, compared with 0% of patients who received leuprolide. Further, in a subgroup of 184 men who were followed for testosterone recovery, the mean testosterone levels at 90 days following treatment discontinuation were 288.4 ng/dL among patients who received relugolix, vs 58.6 ng/dL among patients who received leuprolide.

Regarding safety, 2.9% of patients in the relugolix arm experienced a major adverse cardiovascular event, compared with 6.2% in the leuprolide arm, translating to a 54% reduced risk of major adverse cardiovascular events with relugolix (hazard ratio, 0.46; 95% CI, 0.24 to 0.88). The most common adverse events (reported in at least 10% of men) among patients in the relugolix arm were hot flush, musculoskeletal pain, fatigue, constipation, and diarrhea.

The phase 3 trial enrolled adult patients with advanced prostate cancer who were randomly assigned 2:1 to receive 120 mg orally once daily relugolix (n = 622) or leuprolide acetate injections every 3 months (n = 308) for 48 weeks. The primary end point for the study was sustained testosterone suppression to castrate level (<50 ng/dL) through 48 weeks. Secondary end points for the trial included noninferiority in regard to the primary end point and castrate levels of testosterone on day 4. A subgroup of patients (n = 184) were also included in an assessment of testosterone recovery.

Lisa Mullett, SVP, General Manager of Sumitomo Pharma Canada, Inc, concluded in the news release on the availability of relugolix in Canada,¹ "An estimated 24,700 Canadian men were diagnosed with prostate cancer last year, making the disease the most common cancer experienced by men in the country. With the availability of [relugolix] as of today, we are pleased to offer Canadian physicians an oral GnRH antagonist treatment option with proven safety and tolerability for their patients with advanced prostate cancer."

References

1. Sumitomo Pharma announces availability of ORGOVYX (relugolix) in Canada, the first and only oral androgen deprivation therapy treatment for men with advanced prostate cancer. News release. Sumitomo Pharma Canada, Inc. March 12, 2024. Accessed March 13, 2024. https://news.us.sumitomo-pharma.com/2024-03-12-Sumitomo-Pharma-Announces-Availability-of-ORGOVYX-R-relugolix-in-Canada,-the-First-and-Only-Oral-Androgen-Deprivation-Therapy-Treatment-for-Men-with-Advanced-Prostate-Cancer

2. Sumitomo Pharma announces authorization in Canada of ORGOVYX (relugolix) for the treatment of men with advanced prostate cancer. News release. Sumitomo Pharma Canada, Inc. October 23, 2023. Accessed March 13, 2024. https://news.us.sumitomo-pharma.com/2023-10-23-Sumitomo-Pharma-Announces-Authorization-in-Canada-of-ORGOVYX-R-relugolix-for-the-Treatment-of-Men-with-Advanced-Prostate-Cancer

3. FDA approves first oral hormone therapy for treating advanced prostate cancer. News release. US Food & Drug Administration. December 18, 2020. Accessed March 13, 2024. https://www.fda.gov/news-events/press-announcements/fda-approves-first-oral-hormone-therapy-treating-advanced-prostate-cancer

4. 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