Recent studies have revealed that immunotherapy can successfully treat prostate cancer in men chosen based on the specific genetic traits of their tumors. A study carried out at Radboud University Medical Center showed that for certain men with a distinct genetic variation of prostate cancer, the speed at which the disease progressed was delayed by an impressive 33 months. These results were published in the Annals of Oncology.
Although immunotherapy has not been broadly effective for all men diagnosed with prostate cancer, a detailed review of current research indicates it can work remarkably well for specific groups of patients. Oncologist Niven Mehra from Radboudumc commented, ‘Our findings revealed that men who had a good response to immunotherapy possessed unique DNA mutations within their tumors. These genetic changes lead to protein alterations that trigger the immune response, thus enhancing immunotherapy’s effectiveness.’
Following these insights, Mehra and his team initiated a study to evaluate the effectiveness of immunotherapy among men whose prostate cancer was identified by particular genetic subtypes. The research focused on four DNA variations – MMRd, hTMB, BRCAm, and CDK12i – which are present in roughly fifteen percent of prostate cancer cases. A total of 69 men participated in the study, receiving a combination of two immunotherapy drugs, ipilimumab and nivolumab.
Slowing Down the Disease
The investigation revealed that this combined immunotherapy approach delayed the advancement of prostate cancer in select patients by four months. The most significant results were seen in individuals with the MMRd mutation, where the cancer progression was hindered by an astounding 33 months. In some situations, the disease was stabilized or even diminished to the point where it couldn’t be detected in blood tests or imaging scans. At the time of publishing, twenty patients still had their cancer effectively under control.
This study did not compare the efficacy of dual immunotherapy against standard treatment options, such as hormone therapy or chemotherapy. However, it is known that single-agent immunotherapy for MMRd patients usually manages the disease for about eight months, whereas the dual therapy tested here showed an extension to 33 months.
Like any treatment approach, immunotherapy can lead to various side effects. Nearly half of the participants in this trial reported experiencing adverse effects, such as diarrhea, and about twenty percent had to stop treatment due to these complications.
Importance of Early Screening
Immunotherapy is particularly beneficial for prostate cancer with MMRd, which is found in four to five percent of cases. ‘Although it’s a small population, for these individuals, immunotherapy can markedly slow down the progression of prostate cancer,’ remarked clinician-scientist Sandra van Wilpe. ‘The ability to maintain control of the cancer for 33 months is an extraordinary outcome.’
To better identify men with genetic mutations, Mehra encourages early genomic screening for diagnosis, a protocol already implemented at Radboudumc. He stated, ‘Based on our findings, it might be advantageous for men with MMRd to begin immunotherapy even before initiating hormone therapy or chemotherapy. Therefore, examining the tumor’s DNA early in the disease lifecycle is crucial. There is potential for us to cure these men with MMRd metastatic prostate cancer, though more research is needed.’
