Novel Oral Hormone Therapy Shows Promising Results for Prostate Cancer Treatment with Radiation Therapy

For the first time, Dr. Daniel Spratt from University Hospitals and colleagues demonstrated there was no difference between leuprolide, an LHRH agonist, and relugolix, a novel GnRH antagonist, in time to castration resistant-prostate cancer, a near uniformly lethal form of the disease.

CLEVELAND - A high impact study led by Daniel Spratt, MD, Vincent K. Smith Chair in Radiation Oncology at University Hospitals Seidman Cancer Center demonstrates the safety and efficacy of a novel oral hormone therapy, relugolix, in conjunction with radiation therapy for treating men with localized and advanced prostate cancer. This work is published in JAMA Oncology.

This research, encompassing an individual patient level analysis from two multinational randomized clinical trials, showcases relugolix's ability to rapidly achieve and maintain low testosterone levels, a necessary condition for some men’s prostate cancer treatment, in both short-term (24 weeks) and longer-term (48 weeks) therapy periods. A total of 260 men participated in these studies and received the hormone therapy with radiotherapy, showing significant castration rates with relugolix of 95% and 97% for short-term and longer-term therapy, respectively.

“Remarkably, Relugolix demonstrated a faster return to baseline testosterone levels compared to traditional therapies, a crucial aspect for patients' quality of life post-treatment. This rapid recovery could significantly reduce the adverse impacts associated with long-term testosterone suppression, such as cardiovascular risks and bone density reduction”, said Dr. Spratt.

For the first time, Dr. Spratt and colleagues demonstrated that there was no difference between leuprolide, an LHRH agonist, and relugolix in time to castration resistant-prostate cancer, a near uniformly lethal form of the disease.

Furthermore, the safety profile of relugolix was commendably consistent, with only a minor percentage of participants experiencing severe adverse effects. This positions relugolix as a potentially safer alternative to existing therapies, particularly for patients with pre-existing cardiovascular conditions.

The study's findings further support the safety and efficacy of relugolix when combined with radiation therapy, and given the often finite durations of hormone therapy used with radiation therapy, relugolix is a very attractive treatment option for these men. Dr. Spratt's research not only underscores the importance of advancing combinatorial therapeutic approaches to managing prostate cancer, but also highlights the potential of oral therapies in oncology.

Dr. Spratt is also the national PI of the open OPTYX prospective study that is evaluating the real-world practice patterns and outcomes of Relugolix in men with prostate cancer, and has accrued over 600 of the anticipated 1000 men.