Main Session
Sep
29
PQA 06 - Genitourinary Cancer, Gynecological Cancer, and Health Care Access and Engagement
3276 - Real-World Outcomes of [177 Lu]Lu-PSMA-617 (177 Lu-PSMA-617) Treatment Extension in Patients with Metastatic Castration-Resistant Prostate Cancer (mCRPC): A PRostatE Cancer dISease observatION (PRECISION) Database Analysis
Presenter(s)
Xiao Wei, MD, MAS - Dana-Farber Cancer Institute, Boston, MA
E. I. Heath1, O. Sartor2, X. X. Wei3, D. J. George4, J. Nguyen5, J. Patel5, A. Sawhney5, B. Kang5, C. Byrne6, K. Runeckles6, and N. Shore7; 1Mayo Clinic, Rochester, MN, 2Medical Oncology Department, East Jefferson/LCMC Health, New Orleans, LA, 3Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 4Department of Medicine, Duke Cancer Institute, Duke University School of Medicine, Durham, NC, 5Novartis Pharmaceuticals Corporation, East Hanover, NJ, 6Asclepius Analytics, New York, NY, 7START Carolinas/Carolina Urologic Research Center, Myrtle Beach, SC
Purpose/Objective(s):
The recommended dosage of 177Lu-PSMA-617 is 7.4 GBq every 6 weeks for up to 6 cycles. However, certain patients may benefit from additional cycles. This study was performed to understand the characteristics, treatment patterns, and outcomes among patients receiving 177Lu-PSMA-617 treatment extension in real-world US settings. Materials/Methods: This was a retrospective, observational study using the PRECISION data platform. Included patients were adults with mCRPC who received >6 cycles of 177Lu-PSMA-617 during 03/23/2022–06/27/2025 and who had no evidence of disease progression or another mCRPC treatment before extension (cycle 7 administration). The dates of 177Lu-PSMA-617 initiation and treatment extension were used as anchors for outcome assessment. Characteristics, treatment patterns, and prostate-specific antigen (PSA) response rates were evaluated descriptively, with Kaplan–Meier curves used for progression-free survival (PFS).Results:
Among 1,908 patients treated with 177Lu-PSMA-617, 127 (6.7%) received treatment extension (median age, 74 years). The median number of cycles was 8 (interquartile range [IQR], 7–9) and the median time from cycle 6 to 7 was 6 weeks (IQR, 4–6 weeks). Among patients with available PSA values at both 177Lu-PSMA-617 initiation and during the initial 6 cycles (n=97, 76%), 69 (71%), 46 (47%), and 31 (32%) had PSA declines of =50%, =80%, and =90%, respectively. Following extension, 71% of patients maintained PSA control (had no rise >20%) to cycle 8 and 63% maintained PSA control to the end of treatment. The median PFS was 25 months from 177Lu-PSMA-617 initiation and 20 months from the start of treatment extension. See Table for adverse events (AEs).Conclusion:
These results demonstrate that some patients are receiving 177Lu-PSMA-617 treatment extension in clinical practice. Treatment extension was associated with clinical benefit in most patients deemed appropriate for it, and the observed AEs were consistent with the known safety profile of 177Lu-PSMA-617. Additional research to identify which patients may benefit from treatment extension is needed. aNumber of patients with evaluable labs differed by AE and time window; thus, denominators vary and columns may not sum. bAE was present in the 12 months prior. cAE occurred any time on treatment among patients with confirmed absence at baseline. dAE occurred during treatment regardless of baseline status. AE, adverse event.| Among all patients with lab data (n=100)a | |||
| AEs, n (%) | Prior to 177Lu-PSMA-617 initiationb | New-onset during 177Lu-PSMA-617c | Overall casesd |
| Any lab-based AE | 85 (85) | 17 (17) | 86 (86) |
| Any hematologic AE | 85 (85) | 3 (3) | 86 (86) |
| Anemia | 79 (79) | 3 (3) | 83 (83) |
| Leukopenia | 82 (82) | 0 | 83 (83) |
| Lymphopenia | 81 (81) | 0 | 84 (84) |
| Neutropenia | 82 (82) | 0 | 84 (84) |
| Thrombocytopenia | 85 (85) | 0 | 86 (86) |