A Phase I/II Trial of Nivolumab Plus Ipilimumab in Children and Young Adults with Relapsed/Refractory Solid Tumors: A Children’s Oncology Group Study ADVL1412

Davis KL, Fox E, Isikwei E, Reid JM, Liu X, Minard CG, Voss S, Berg SL, Weigel BJ, Mackall CL. A Phase I/II Trial of Nivolumab plus Ipilimumab in Children and Young Adults with Relapsed/Refractory Solid Tumors: A Children’s Oncology Group Study ADVL1412. Clin Cancer Res. 2022 Dec 1;28(23):5088-5097. doi: 10.1158/1078-0432.CCR-22-2164. PMID: 36190525; PMCID: PMC10597535.

In many cancers, nivolumab in combination with ipilimumab improves response rates compared to either agent alone, but the combination has not been evaluated in childhood cancer. We conducted a Phase I/II trial of nivolumab plus ipilimumab in children and young adults with recurrent/refractory solid tumors. ADVL1412, Part C assessed safety of nivolumab plus ipilimumab at two dose levels (DL): DL1 1mg/kg of each drug and DL2 3mg/kg nivolumab plus 1mg/kg Ipilimumab. Part D evaluated response at the recommended phase 2 dose (RP2D) in Ewing sarcoma, rhabdomyosarcoma, and osteosarcoma. Part E tested DL3 (1mg/kg nivolumab plus 3mg/kg Ipilimumab) in Ewing sarcoma and rhabdomyosarcoma. Tumor response was measured using RECIST v1.1. Pharmacokinetics and PD-L1 expression on archival tissues were assessed. Fifty-five eligible patients enrolled. Based upon safety, tolerability and similar drug exposure to the same doses administered in adults, DL2 was defined as the pediatric RP2D. Among 41 patients treated at the RP2D, 2 patients experienced dose-limiting toxicities during Cycle 1 and 4 patients experienced toxicities beyond that period. Two patients had clinically significant sustained partial responses (1 rhabdomyosarcoma, 1 Ewing sarcoma) and 4 had stable disease. Among 8 patients treated at DL3, 3 DLTs occurred, all immune related adverse events; no objective responses were observed. The RP2D of nivolumab (3mg/kg) plus ipilimumab (1mg/kg) is well-tolerated in children and young adults with solid tumors and shows some clinical activity. Increased dose of ipilimumab (3mg/kg) plus nivolumab (1mg/kg) was associated with increased toxicity without clinical benefit.