Among patients with metastatic, castration-resistant prostate cancer, treatment with the experimental 177Lu-PSMA-617 radiopharmaceutical, along with other standard treatments, improved survival by four months over treatment with standard therapies alone, researchers reported in the New England Journal of Medicine. The therapy targets the PMSA protein and may one day be an option when other treatments have failed.
The researchers evaluated 177Lu-PSMA-617 in 831 patients with metastatic castration-resistant prostate cancer who had prior therapy with at least one androgen-receptor-pathway inhibitor and one or two taxane-based regimens. All of the participants had PSMA-positive tumors, as determined by PSMA positron-emission tomography imaging.
Overall, they found that adding 177Lu-PSMA-617 to standard care improved overall survival to a median of 15.3 months, compared to 11.3 months for standard care alone. Progression-free survival also improved to a median of 8.7 months for the radiopharmaceutical versus 3.4 months for standard care. The most common side effects were bone marrow suppression, nausea, and dry mouth. About 13% of patients required blood transfusions for bone marrow–related effects.
Additional clinical trials are planned and underway to confirm and expand on the findings, including using the agent in combination with other treatments such as targeted therapies like PARP inhibitors and immunotherapy.
The U.S. Food and Drug Administration granted 177Lu-PSMA-617 breakthrough designation, and if approved, “it should become a standard of care for these patients, because there are so few existing treatments that prolong their lives,” the authors said.