Prostate cancer patients with distant metastasis have poor prognosis and develop resistance to all standard drugs at various time intervals. Therapeutic options which can alleviate symptoms and prolong survival are required for these patients. [177Lu]prostate-specific membrane antigen ([177Lu]PSMA) is a novel drug based on a theranostic concept. Here, we have presented the safety and efficacy profile of one cycle of [177Lu]PSMA in metastatic castration-resistant prostate cancer (mCRPC) patients who have exhausted all standard therapeutic options.
Twenty two patients treated with at least first line anti-androgens and docetaxel were treated with one cycle of [177Lu]PSMA therapy on a compassionate basis. Haemoglobin, total leukocyte counts, platelets and serum creatinine for toxicity profile while prostate specific antigen (PSA), Eastern Cooperative Oncology Group (ECOG) performance status, visual analogue scale (VAS) and analgesic quantification scale (AQS) for therapeutic efficacy were recorded pre and 8 weeks post therapy. Wilcoxon signed-rank and ANOVA tests were used for statistical analysis.
Partial response (PR), stable disease (SD) and progressive disease (PD) for PSA were seen in 5 (22.7%), 13 (59.1%) and 4 (18.2%) patients, respectively, treated with mean 6.88GBq dose of [177Lu]PSMA. 8/22 (36.4%) patients showed ≥ 30% drop in PSA. Grade 3 haemoglobin toxicity was seen in 5/22 (22.7%) patients. No patient developed grade 4 haemoglobin toxicity. No patients had grade 3 or 4 leukocytopenia or thrombocytopenia. Wilcoxon signed-rank test showed statistically significant (p < 0.05) difference in pre- and post-treatment ECOG, VAS, AQS scores while it was not significant for PSA (P > 0.05). ANOVA test showed a statistically significant difference in mean doses of [177Lu]PSMA used in the three PSA response groups while the difference was non-significant for other variables.
We conclude that [177Lu]PSMA therapy delivers adequate pain palliation in all end-stage mCRPC patients and it has a potential to become an effective therapeutic option in properly selected patients.
Manoj Gupta.
Has not received any funding.
All authors have declared no conflicts of interest.