Clinical outcome of Lu-177 PSMA in metastatic castration-resistant prostate cancer: An initial experience from a tertiary care cancer hospital

Abstract

Aim: We analyzed the clinical outcome of Lutetium-177 Prostate-specific membrane antigen (Lu-177 PSMA) in metastatic castration-resistant prostate cancer (mCRPC) patients. Material and Methods: Twenty-five mCRPC patients were treated with Lu-177 PSMA on a compassionate basis. Pre and 8-10 weeks post-treatment PSA, Eastern cooperative oncology group (ECOG) performance status, Visual analog scale (VAS), and Analgesic quantification scale (AQS) were recorded. Based on PSA response (partial response PR, stable disease SD, progressive disease PD), patients were categorized into responder (PR+SD) and non-responder (PD). Wilcoxon signed-rank, and Kruskal–Wallis test, Kaplan Meier with Log-rank test were computed. Results: Twenty-five mCRPC patients were treated with a median of 7.4 GBq Lu-177 PSMA. Overall, PR, SD, and PD were 24%, 60%, and 16%, respectively. Sixteen patients who received ≥7.4 GBq Lu-177 PSMA dose, PR, and SD were seen in 31.2% and 68.8%, respectively. We had 84% responders and 16% non-responders. Statistically significant difference (P = < 0.05) was seen in pre and post ECOG, VAS, and AQS parameters while it was in-significant for PSA (P = 0.170). Lu-177 PSMA dose was the only significant pre-therapy variable (P = 0.024) on Kruskal–Wallis test. Overall median PFS was 24 weeks, while two years PFS in PR, SD, and PD response group was 50%, 37.3%, and 0%, respectively. A significant difference was seen in the PFS of responder and non-responder groups. Conclusions: We concluded that Lu-177 PSMA was a suitable palliative option in heavily pre-treated mCRPC patients with notable PSA response. However, proper randomized studies are warranted.