Impact of lutetium Lu 177 vipivotide tetraxetan on prostate cancer outcomes by race.

Abstract

155 Background: Lutetium Lu-177 vipivotide tetraxetan (Pluvicto) is a PSMA-targeted radioligand therapy approved for men with metastatic castration-resistant prostate cancer (mCRPC) who progressed after novel hormonal and taxane based therapy. The VISION trial showed improved overall and radiographic progression-free survival versus standard care with good tolerability. However, real-world data remain limited, particularly among underrepresented groups. Only 34 Black men were included in VISION, and the TheraP trial occurred in Australia. This study evaluates real-world outcomes and safety of patients treated with lutetium Lu 177 vipivotide tetraxetan at Ochsner Medical Center (OMC), focusing on racial differences. Methods: We conducted a retrospective, IRB-approved cohort study of patients with mCRPC treated with lutetium Lu 177 vipivotide tetraxetan at OMC after October 10, 2023, with up to one year of follow-up. Demographic and treatment data were collected from institutional databases. Descriptive statistics summarized patient characteristics. Group comparisons were performed using chi-square or Fisher’s exact tests, and relative risk estimates were calculated to assess associations. Results: Among 62 patients, 27 (43.6%) were Black or African American and 35 (56.5%) were White (Table). A ≥50% decline in prostate-specific antigen (PSA50) following Pluvicto treatment was observed in 47.8% of Black or African American patients (n=11) and 35.5% of White patients (n=11) (p=0.36). Among patients with homologous recombination repair (HRR) mutations, 33.3% achieved a PSA50 response versus 42.5% of patients without HRR mutations (p=0.72). Those previously treated with docetaxel (DTX) had lower PSA50 responses than untreated patients (40.4% vs 50.0%, p=0.72). Conclusions: Although many patients in our cohort identified as Black or African American, there was no significant difference in PSA response to lutetium Lu 177 vipivotide tetraxetan compared with White patients. Those with HRR mutations and prior DTX exposure had numerically lower PSA50 response rates, though differences were not statistically significant. These findings underscore the need for continued research on how patient characteristics and prior treatments influence lutetium Lu 177 vipivotide tetraxetan outcomes in advanced prostate cancer. Survival and safety data collection is ongoing. PSA50 Response to lutetium Lu 177 vipivotide tetraxetan treatment by race, homologous recombination repair (HRR) mutations, and prior docetaxel treatment (N=55). Totaln(%) PSA50 Response ≥50% Decline Yes n(%) PSA50 Response ≥50% Decline No n(%) p-value* Race Black 23(42.6) 11(47.8) 12(52.1) 0.3614 White 31(57.4) 11(35.5) 20(64.5) HRR Mutation Yes 9(18.4) 3(33.3) 6(66.7) 0.7199 No 40(81.6) 17(42.5) 23(57.5) Prior Docetaxel Treatment Yes 47(85.5) 19(40.4) 28(59.6) 0.7071 No 8(14.5) 4(50.0) 4(50.0) *Chi-square or Fisher’s Exact, as appropriate. Missing data: race (n=1), HRR mutation (n=6).