Association of body mass index and tumor response in metastatic urothelial carcinoma treated with enfortumab vedotin: data from the ULTRA-Japan consortium.

BACKGROUND

Enfortumab vedotin (EV), an antibody-drug conjugate (ADC) targeting Nectin-4, has been available as standard care for metastatic urothelial carcinoma (mUC) patients who have progressed after platinum-based chemotherapy and checkpoint inhibitors (CPIs). However, the association between body mass index (BMI) and clinical outcomes for EV remains unknown.

METHODS

We analyzed the records of 123 mUC patients who received EV. The cohort was divided into low BMI (< 22, n = 65) and high BMI (≥ 22, n = 58) groups. Propensity score matching was performed to reduce clinical bias between the two groups.

RESULTS

In the total cohort (n = 123), the objective response rate (ORR) and disease control rate (DCR) were 46% and 68%, respectively. The ORR was significantly higher in the higher BMI group (62%, n = 58) compared to the lower BMI group (32%, n = 65). Among the pair-matched cohort (n = 100), despite reducing potential bias, the ORR remained significantly higher in the higher BMI group than in the lower BMI group (64% vs. 32%, p = 0.002). Both overall survival (OS) and radiographic progression-free survival (r-PFS) were longer in the higher BMI group compared to the lower BMI group (median OS: not reached vs. 8 months, p = 0.035; median r-PFS: 10 vs. 4 months, p < 0.001). On multivariate analyses, a higher BMI (≥ 22) was an independent predictor for achieving objective response and favorable OS in mUC patients treated with EV.

CONCLUSIONS

The findings of this study suggest a potential association between high BMI and improved tumor response to EV in mUC patients with disease progression after platinum-based chemotherapy and CPIs.