A poster presented by POINT Biopharma at the European Society for Medical Oncology Congress 2022 reviewed preliminary results from the SPLASH trial, which evaluated the use of 177Lu-PNT2002 as a therapy for patients with metastatic castration-resistant prostate cancer (mCRPC) who are prostate-specific membrane antigen (PSMA)-positive and have progressed after receiving prior treatment with androgen receptor axis-targeted therapy (ARAT).
The trial analyzed 33 patients using PSMA PET/CT to determine eligibility. Of those patients, 27 were eligible for treatment. The patients had tumors with high PSMA uptake on PSMA PET/CT per blinded independent central review (BICR), were progressing on an ARAT, were chemotherapy naïve for CRPC, and had sufficient bone marrow and end organ reserve. The patients were given 177Lu-PNT2002 for a median of 4 cycles at a median of 6.9 (6.2-7.5) GBq per cycle every 8 weeks. Key end points measured in the study included radiographic progression-free survival (rPFS) per BICR, prostate-specific antigen (PSA) response, dosimetry and safety, and overall survival.
Based on a median rPFS follow-up of 7.5 months at data cut-off, 21 (78%) of the patients remained event-free by the end of the trial, with an rPFS rate of 75.4% at 9 months. A total of 5 (15.2%) patients failed because of PSMA avidity criteria, and 6 (22%) patients who received treatment had received a prior taxane for hormone-sensitive disease.
One non-treatment-related death occurred, and 11 (42%) patients had a PSA50 response. Treatment-emergent adverse events grade 3 or higher included dry mouth, nausea, fatigue, hematuria, and anemia.
Overall, utilizing 177Lu-PNT2002 in patients with PSMA-positive mCRPC showed a favorable rPFS and was well-tolerated by the test group. The preliminary trial results confirm that 177Lu-PNT2002 can be advanced to the randomized portion of the SPLASH registrational trial.
Hansen AR. Efficacy and safety of 177Lu-PNT2002 prostate-specific membrane antigen (PSMA) therapy in metastatic castration resistant prostate cancer (mCRPC): initial results from SPLASH. E-poster 1400P. Presented at the European Society for Medical Oncology Congress 2022; September 9-13, 2022; Paris, France.