Bempegaldesleukin (NKTR-214) plus nivolumab in patients with advanced solid tumors: Phase I dose-escalation study of safety, effi cacy, and immune activation (PIVOT-02)

This single-arm, phase I dose-escalation trial (NCT02983045) evaluated bempega ldesleukin (NKTR-214/BEMPEG), a CD122-preferential IL2 pathway agonist, plus nivolumab in 38 patients with selected immunotherapy-naïve advanced solid tumors (melanoma, renal cell carcinoma, and non-small cell lung cancer). Three dose-limiting toxicities were reported in 2 of 17 patients during dose escalation [hypotension ( n = 1), hyperglycemia ( n = 1), metabolic acidosis ( n = 1)]. The most common treatment-related adverse events (TRAE) were fl u-like symptoms (86.8%), rash (78.9%), fatigue (73.7%), and pruritus (52.6%). Eight patients (21.1%) experienced grade 3/4 TRAEs; there were no treatment-related deaths. Total objective response rate across tumor types and dose cohorts was 59.5% (22/37), with 7 complete responses (18.9%). Cellular and gene expression analysis of longitudinal tumor biopsies revealed increased infi ltration, activation, and cytotoxicity of CD8 + T cells, without regulatory T-cell enhancement. At the recommended phase II dose, BEMPEG 0.006 mg/kg plus nivolumab 360 mg every 3 weeks, the combination was well tolerated and demonstrated encouraging clinical activity irrespective of baseline PD-L1 status. SIGNIFICANCE: These data show that BEMPEG can be successfully combined with a checkpoint inhibitor as dual immunotherapy for a range of advanced solid tumors. Effi cacy was observed regardless of baseline PD-L1 status and baseline levels of tumor-infi ltrating lymphocytes, suggesting therapeutic potential for patients with poor prognostic risk factors for response to PD-1/PD-L1 blockade.