Greater PSA Decline Predicts Better 177Lu-PSMA-617 Outcomes in mCRPC

Greater PSA decline from baseline in men with metastatic castration-resistant prostate cancer (mCRPC) treated with the radioligand therapy ¹⁷⁷lutetium-PSMA-617 (¹⁷⁷Lu-PSMA-617) predicts better outcomes, investigators reported at the European Society for Medical Oncology’s 2022 Congress (ESMO 2022) in Paris, France.

The finding is from a post hoc analysis of the phase 3 VISION trial, which previously demonstrated that men with PSMA-positive mCRPC treated with ¹⁷⁷Lu-PSMA-617 had prolonged radiographic progression-free survival (rPFS) and overall survival (OS).

For the post hoc analysis, Andrew J. Armstrong, MD, of Duke Cancer Institute Center for Prostate and Urologic Cancers at Duke University in Durham, North Carolina, and colleagues classified patients into 4 subgroups by magnitude of confirmed best PSA decline from baseline: no decline; 50% or less; more than 50% and up to 90%; and more than 90%.

Compared with patients who had no PSA decline, those with declines of 50% or less, greater than 50% and up to 90%, and more than 90% from baseline had a significant 60%, 80%, and 96% reduced risk for radiographic disease progression, respectively, and 42%, 58%, and 90% lower risk for death, respectively.

The median rPFS and OS were 3.0 and 8.4 months, respectively, for the patients who did not have a PSA decline. By comparison, the patients who had a PSA decline of 50% or less, more than 50% and up to 90%, and more than 90% had a median rPFS of 6.0, 8.8, and 19.7 months, respectively. Patients who had a PSA decline of 50% or less and more than 50% and up to 90% had a median OS of 12.0 and 15.0 months, respectively. The median OS was not estimable for those with a PSA decline greater than 90%.

In addition, study findings show that PSA declines delayed worsening of health-related quality of life, according to the investigators.

“These findings suggest that PSA decline is of prognostic importance for clinical outcomes during radioligand therapy with ¹⁷⁷Lu-PSMA-617 in patients with PSMA-positive mCRPC,” Dr Armstrong’s team reported.

Disclosure: This research was supported by Advanced Accelerator Applications, a Novartis Company. Please see the original reference for a full list of disclosures.

Reference

Armstrong AJ, Sartor O, Saad F, et al. Association between prostate-specific antigen decline and clinical outcomes in patients with metastatic castration-resistant prostate cancer in the VISION trial. Presented at: ESMO 2022, September 9-13, Paris, France. Abstract 1372P.