Prostate Ca: Immunotherapy consensus statement published
According to the statement: “With respect to an overall role for immunotherapy in the treatment of mCRPC, the general consensus was that there are major characteristics of mCRPC that favor an immunotherapy approach. Therefore, the goals should be to define optimal patient and tumor characteristics, identify best immunotherapy approaches, and identify the optimal sequence of immunotherapy with other available treatments that will benefit patients.
“Given the importance of immunologic activation and the asymptomatic status of the patient, 100% of the panel recommended that when sipuleucel-T is used, it be used first if all other criteria are met.”
About 10% of U.S. patients with metastatic castration-resistant prostate cancer receive sipuleucel-T, according to Dr. Gulley.
“It is important that patients and providers understand that unlike enzalutamide [XTANDI] or abiraterone [ZYTIGA], the PSA may not decrease in treated patients, despite improvements in overall survival,” he said. “It is also important to note that [sipuleucel-T] has very little in terms of toxicity, and patients like the fact that their body’s immune system is helping fight the cancer.”
According to Dr. Gulley, the statement points out that a number of prostate cancer specialists elect, at least in some patients, to use sipuleucel-T with other treatments, such as enzalutamide. “Another key take home was that this group recommended using immunotherapy early on in the course of treatment of patients (front-line for mCRPC).”
The panel of experts suggests there is great opportunity for improvements in immunotherapy for prostate cancer. Immune checkpoint inhibitors, such as nivolumab (Opdivo), pembrolizumab (KEYTRUDA), or atezolizumab (Tecentriq), which recently were approved for other solid tumors, have significant activity but only in T-cell-inflamed tumors. And while prostate cancer is typically not a T-cell-inflamed tumor, therapeutic vaccines, such as sipuleucel-T, may be able to induce T-cell responses within the tumor. The responses could be further augmented with immune checkpoint inhibitors, according to Dr. Gulley.
“Other therapeutic vaccines in late-stage development, such as Prostvac, should have overall survival data soon,” he said. “Finally, these vaccines, because they are so well tolerated, could be used early on in the disease process. Indeed, a study of Prostvac versus placebo in patients eligible for active surveillance is ongoing, and another study recently opened combining Prostvac with immune checkpoint inhibitors in patients prior to prostatectomy.”
Dr. Gulley declared no competing interests. Several of the consensus statement’s co-authors have a financial relationship with Dendreon and/or other pharmaceutical companies.
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