Lu177-PSMA therapy for men with advanced prostate cancer: Initial 18 months experience at a single Australian tertiary institution.

INTRODUCTION: Lutetium-177-PSMA (LuPSMA) is a targeted systemic radioligand treatment for metastatic castration-resistant prostate cancer (mCRPC). LuPSMA is considered as an experimental treatment not yet used in routine practice. Here, we report our experience following the introduction of LuPSMA therapy at our institution.

METHODS: Referred mCRPC patients were assessed for treatment suitability including Gallium-68-PSMA PET/CT and blood tests. Suitable patients underwent up to four cycles of LuPSMA treatment. Response to treatment was assessed by changes in serum prostate-specific antigen (PSA) levels. Toxicity was assessed by recording of adverse events.

RESULTS: In an 18 month period, 50 patients underwent 132 cycles of LuPSMA therapy. Patients underwent a median of three cycles each (range: 1-4) and the mean administered amount of activity per cycle was 5.9 GBq (range: 3.5-8.2 GBq). PSA decline could be calculated for 49 patients, with a best PSA decline of ≥ 50% observed in 22 patients (44.9%). Adverse events were reported across 45 of 132 LuPSMA cycles. Most adverse events were grade I (42/45) and the remaining three events were grade II.

CONCLUSION: Initial experience at our site supports the use of LuPSMA as an emerging safe and effective treatment for mCRPC. Since introducing LuPSMA therapy at our institution, 44.9% of patients have experienced a decline in PSA level ≥ 50% with low or minimal toxicity. This is an important finding as these patients had previously exhausted all available treatment options. Overall, we have found patients and their primary care doctors have eagerly accepted LuPSMA as another line of defence against mCRPC.