ASCO 2021: PSMA-Targeted Radioligand Therapy Improves Survival in Metastatic Prostate Cancer

Michael Morris, MD

Michael Morris, MD

New data from researchers at Memorial Sloan Kettering Cancer Center (MSK) featured in the 2021 ASCO Annual Meeting press program highlights a promising new treatment option for individuals previously treated for metastatic castration-resistant prostate cancer (mCRPC). The phase III international VISION trial found that treatment with a novel form of prostate-specific membrane antigen (PSMA)-targeted radioligand therapy, in combination with standard-of-care treatment, led to an increase in radiographic progression-free survival (rPFS) and overall survival (OS). Trial findings will be presented in the virtual meeting’s plenary session on June 6 by MSK’s Michael Morris, MD, Prostate Cancer Section Head, Genitourinary Oncology.  

“This work represents a transformation in care for individuals with metastatic castration-resistant prostate cancer,” explained Dr. Morris. “By utilizing a theranostic approach, we can identify where the cancer is in the body through a PSMA PET scan and use this tumor-directed radioligand therapy to zero in on prostate cancer cells and destroy them.”

“PSMA-directed radioligand therapy represents a novel application of molecular diagnostics and therapeutics to prostate cancer, an approach that prolongs life where few other agents have activity,” added Lisa Bodei, MD, PhD, Director of Targeted Radionuclide Therapy, Molecular Imaging and Therapy Service.

The phase III VISION trial included 831 patients previously treated with androgen receptor pathway inhibitors and up to two taxane chemotherapy regimens. Patients had PSMA-positive disease, as demonstrated by PSMA PET imaging. (PSMA is a cancer-cell surface protein that is highly expressed in approximately 80 percent of patients with prostate cancer, making it an attractive potential therapeutic target.) The highly targeted therapy uses a novel form of liquid radiation, Lutetium-labeled PSMA-617 (177Lu-PSMA-617), to selectively seek out and attach to PSMA on the cancer cell surface before delivering radiation that destroys the cancer cell. 

Dr. Morris and colleagues found that the addition of 177Lu-PSMA-617 to the standard of care significantly improved rPFS compared with standard of care alone, with a median rPFS of 8.7 months versus 3.4 months, respectively. OS was also significantly improved in the 177Lu-PSMA-617 arm, with a median of 15.3 months versus 11.3 months. While more high-grade treatment-emergent adverse events were seen with 177Lu-PSMA-617 than with the standard of care (52.7 percent versus 38 percent), there were no unexpected or concerning safety signals.