Population Pharmacokinetics of Ipilimumab in Combination With Nivolumab in Patients With Advanced Solid Tumors

Ipilimumab is a fully human monoclonal antibody approved for the treatment of melanoma as monotherapy and for the treatment of melanoma, renal cell carcinoma, and colorectal cancer in combination with nivolumab. Ipilimumab time-varying clearance (CL) was assessed by a population pharmacokinetics (PPK) model developed using statistically significant covariates identified in a previous PPK analysis plus additional covariates. Data from 3,411 patients who received ipilimumab 0.3-10 mg/kg alone or in combination with nivolumab in 16 clinical trials were analyzed. Ipilimumab CL decreased over time; the change in CL was greater in patients treated with nivolumab combination than ipilimumab alone and in responders vs. nonresponders. Time-varying covariates including body weight, lactate dehydrogenase, albumin, and performance status were evaluated on change in ipilimumab CL. In addition, ipilimumab CL was similar across different tumor types, nivolumab dosing regimens, and lines of therapy. These data suggest an association of ipilimumab CL with disease severity.