A multi-center retrospective cohort study of patients with mCRPC who received lutetium Lu177 vipivotide tetraxetan.
Authors: Desai Kunal , Schaffer Kerry Roe , Beckermann Katy , Smith Gary , Ancell Kristin Kathleen , Catenacci Meghan , Appelbaum Daniel , Patnaik Akash , Trujillo Jonathan , Stadler Walter Michael , Rini Brian I. , Szmulewitz Russell Zelig 
Published: January 2024

89

Background: Lu177-vipivotide tetraxetan (Pluvicto) (Lu177-Plu) is the first FDA approved theragnostic for mCRPC. Since FDA approval in March 2022, there have been no published multicenter evaluations of real-world experiences with Lu177-Plu in the United States (US). We therefore present data from 2 academic centers on patient (pt) characteristics, treatment patterns and outcomes for mCRPC pts receiving SOC Lu177-Plu. Methods: Retrospective data was aggregated from University of Chicago & Vanderbilt University on pt demographics, disease course and treatment for mCRPC pts who received SOC Lu177-Plu between 6/1/2022 and 9/1/2023. Research was conducted under IRBs VU211334 and IRB23-0718. 146 pts were identified who completed Lu177-Plu treatment by data cutoff 9/1/2023; their data is reported here. Results: Median age at cycle 1 (C1) was 72 years (range 49-93). Self-reported race was Black (23%), White (65%), Other/Unknown (UNK) (12%). Mean distance from home to treatment center was 79 mi. (range 1-1,317); 37% travelled > 50 mi. At diagnosis, Gleason score was >8 in 57%; 55% had locoregional disease, 44% had metastases, 1% were UNK. Median lines of prior systemic therapy were 4 (range 1-6), 95% received prior taxane(s) and 100% received prior androgen receptor signaling inhibitor (ARSI); 67% received 2 prior ARSI classes. PSMA-PET scan reported disease in bone in 93% of pts, lymph node 63%, liver 14%, lung 6%, other 25% (mostly prostate & soft tissue). While undergoing 177Lu-Plu, 10% received concurrent ARSI (n=9 abiraterone, n=6 enzalutamide). Median cycles received was 3.5. 27 pts (18%) discontinued after C1, 46 (32%) after C2/3, 24 (16%) after C4/5 and 49 (34%) completed 6 cycles. 38% had a PSA > 50% decline on treatment. 71 pts (49%) got scans between C1 and C6. Reasons cited for discontinuation prior to 6 cycles (n=97) included: progressive disease (including radiographic and/or PSA progression) (31%), progressive disease and toxicity (13%), toxicity (30%), clinical decline (including ECOG PS, transition to hospice or death) (23%), other (3%). 36 pts (25%) required supportive care with blood products (n=35 RBC, n=2 platelets). At data cutoff, 73 of 146 pts were alive (confirmed (n=66), unconfirmed (n=7)). Of deceased patients, median survival from C1 to death was 4.8 months (range 0.4-11.7). Conclusions: To our knowledge, this is the largest multicenter retrospective analysis of a racially diverse cohort of mCRPC pts receiving SOC Lu177-Plu following FDA approval in the US. PSA decline, median number of cycles received, fraction not requiring blood products in this cohort were all lower than in the VISION trial, likely due to baseline pt characteristics and potentially more liberal pt selection. Our data highlights numerous areas of need: expanded geographic access, optimized pt selection, standardization of scan type and interval on therapy and further data on concurrent therapy.