¹⁷⁷Lu-PSMA-617 in the Treatment of Castration-Resistant Prostate Cancer: Experience in Uruguay

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Introduction: Prostate cancer is the most frequent solid neoplasm in the world, ranking first in incidence and mortality in Uruguayan men. Despite recent therapeutic advances, metastatic-Castration-Resistant-Prostate-Cancer (mCRPC) remains invariably fatal. Long before ¹⁷⁷Lutetium-PSMA radio-directed therapy was approved by the FDA (03/2022), Uruguay already had this technology available for this group of patients. To assess the therapeutic response and safety profile of ¹⁷⁷Lu-PSMA-617 in the treatment of mCRPC-patients.

Methods: Prospective, analytical and experimental study of mCRPC patients who underwent doses of ¹⁷⁷Lu-PSMA-617 (7.4GBq every 6 weeks) at CUDIM in the period October 2017/June 2022.

We included 24 PET/CT-PSMA-positive patients who received at least one new androgen-axis drug and 1 or 2 taxane regimens. ⁶⁸Ga-PSMA-11 PET/CT was performed periodically assessing PSMA expression in metastatic lesions and response. Primary end-point was the therapeutic response in terms of imaging tumor volume. Biochemical response, clinical response (visual analog pain scale, VS) and adverse events (Clavien–Dindo Scale) were assessed as secondary end-points.

Results: In total, 80% of patients completed at least 3 cycles of ¹⁷⁷Lu-PSMA-617. Five patients completed 4 cycles and 1 completed 5 cycles due to high response rate. In addition, 44% presented a positive response regarding decreased tumor volume, measured in all cases by PET/CT. A total of 63% showed a positive biochemical response (PSA decrease). 75% of patients with metastatic debut did not respond to therapy and 100% of patients with Gleason score of 8 or more progressed after the third cycle. There were no cases of hepatotoxicity or nephrotoxicity. 55% reported sustained pain relief after treatment.

Conclusion: ¹⁷⁷Lu-PSMA-617 therapy is a promising option in the treatment of patients with mCRPC, whose survival and quality of life have not been able to improve despite the innumerable treatments available. Carrying out a longer follow-up to confirm encouraging data on prolongation of overall survival and imaging relapse-free survival is mandatory.

Publication History

Article published online:
25 May 2023