Results from a trial looking into the effectiveness of combining two drugs (olaparib and abiraterone) for patients with a prostate cancer have recently been published in the Lancet Oncology.
Prostate cancer is the fifth leading cause of cancer-associated deaths in men worldwide. Prostate cancer needs the male sex hormone testosterone to grow. Standard treatments for this cancer commonly include hormone therapy or surgical castration to reduce the level of testosterone in your body, but after some time, treatment can stop working and prostate cancer might start to grow again. This is called castration resistant prostate cancer.
Castration resistant prostate cancer is usually treated with hormone therapy, such as enzalutamide and abiraterone, or chemotherapy, such as docetaxel or cabazitaxel. Sadly, treatment response is often short-lived because the cancer grows resistant to standard treatment. Our researchers are looking for new ways to help men in this situation.
This study was initially a Phase 1b study to test if the drug combination of olaparib and abiraterone could be delivered safely. Once this was established it progressed into a phase two trial, an early stage of testing the effectiveness of new treatments in patients.
142 patients took part in the study and were randomly assigned to receive either olaparib and abiraterone, or a placebo and abiraterone. Although those who received olaparib faced more side effects than those on the placebo trial, this group of patients derived a significant clinical benefit compared to patients receiving placebo.
Dr Rob Jones leads our early phase trials research and was the only UK oncologist named on the paper. Dr Jones said, “Velindre Cancer Centre was the UK’s top recruiter to the Olaparib study. We treated 21 patients here in Wales. One of our patients has been on the drug combination for almost five years. This patient would likely have progressed within three to four months on standard treatment.”
The trial results suggest that the combination of olaparib and abiraterone might provide a greater benefit to patients with castration-resistant prostate cancer that has spread to other parts of the body. The trial will now progress to phase three, where a larger group of patients will be recruited to trial the drug and we can more accurately assess its benefits.