Bempegaldesleukin plus Nivolumab in First-line Metastatic Urothelial Carcinoma: Results from PIVOT-02.

BACKGROUND

Despite recent changes in the treatment landscape, there remains an unmet need for effective, tolerable, chemotherapy-free treatments for patients with advanced/metastatic urothelial carcinoma (mUC), especially cisplatin-ineligible patients.

OBJECTIVE

To evaluate the immunostimulatory interleukin-2 cytokine prodrug bempegaldesleukin (BEMPEG) plus nivolumab in patients with advanced/mUC from the phase 2 multicenter PIVOT-02 study.

DESIGN, SETTING, AND PARTICIPANTS: This open-label, multicohort phase 1/2 study enrolled patients with previously untreated locally advanced/surgically unresectable or mUC (N = 41).

INTERVENTION

Patients received BEMPEG 0.006 mg/kg plus nivolumab 360 mg intravenously every 3 wk.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary objectives were safety and the objective response rate (ORR) in patients with measurable disease at baseline and at least one postbaseline tumor response assessment (response-evaluable). Secondary objectives were overall survival (OS) and progression-free survival (PFS). Exploratory biomarker analyses via univariate logistic regression were performed to test the association between potential biomarkers (CD8 tumor-infiltrating lymphocytes, tumor mutational burden, and IFN-γ gene expression profile) and response.

RESULTS AND LIMITATIONS

The ORR was 35% (13/37 evaluable patients) and the complete response rate was 19% (7/37 patients); the median duration of response was not reached. Median PFS was 4.1 mo (95% confidence interval [CI] 2.1-8.7) and median OS was 23.7 mo (95% CI 15.8-not reached). Overall, 40/41 patients (98%) experienced at least one treatment-related adverse event (TRAE); grade 3/4 TRAEs occurred in 11 patients (27%), most commonly pyrexia (4.9%; 2 patients). Exploratory biomarker analyses showed no association between biomarkers and response. Limitations include the small sample size and single-arm design.

CONCLUSIONS

BEMPEG plus nivolumab was well tolerated and showed antitumor activity as first-line treatment in patients with locally advanced/mUC.

PATIENT SUMMARY

We investigated an immune-stimulating prodrug called bempegaldesleukin plus the antibody nivolumab as the first therapy for patients with advanced or metastatic cancer of the urinary tract. This combination had manageable treatment-related side effects and was effective in a subset of patients. This trial is registered at ClinicalTrials.gov as NCT02983045.