P3.02c-102 Safety and Tolerability of Abemaciclib Combined with LY3023414 or with Pembrolizumab in Patients with Stage IV NSCLC: Topic: IT Clinical

Abstract

Currently, treatment options are limited for patients with advanced and/or metastatic NSCLC particularly after initial treatment. In a prior phase 1 study, abemaciclib, a CDK4 & 6 inhibitor, demonstrated single-agent anti-tumor activity when dosed orally on a continuous schedule, with an acceptable safety profile in patients with previously treated metastatic NSCLC (NCT01394016). PI3kinase is an escape pathway after CDK inhibition in tumor models and aberrant immunity is a hallmark of cancer, providing the rationales to combine abemaciclib with PI3K and with checkpoint inhibitors. An ongoing Phase 1b multicenter, open-label, 3+3 dose-escalation trial with an expansion phase is investigating abemaciclib in combination with multiple single-agent options in metastatic NSCLC (NCT02079636). Here we report preliminary results for two arms of the study. In Part D, abemaciclib was administered orally on a continuous schedule every 12 hours (q12h) in combination with the PI3K/mTOR inhibitor, LY3023414, at 100, 150, or 200 mg q12h. In Part E, abemaciclib was administered in combination with the anti-PD-1 antibody, pembrolizumab (200 mg I.V. infusion q3 weeks). Patients with late stage NSCLC and 1-3 prior therapies without central nervous system metastasis were treated until disease progression or other discontinuation criteria were met. Primary endpoints for each cohort included safety/tolerability and identification of the recommended phase 2 dose. Safety assessments followed the Common Terminology Criteria for Adverse Events (NCI-CTCAE v4.0). Parts D and E began enrolling patients on April 13, 2015 and April 29, 2016, respectively. As of August 24, 2016, Parts D and E escalation included, respectively, 22 [male (64%)/Caucasian (77%)/stage IV (91%)/adenocarcinoma (91%)] and 6 patients [male (33%)/Caucasian (100%)/stage IV (67%)/adenocarcinoma (100%)]. ECOG PS was ≤1 in both cohorts. In Part D, 1 patient on dose level-2 (DL-2) experienced a dose limiting toxicity (DLT) (G4 thrombocytopenia). Evaluation of additional dose levels is ongoing. Seventeen patients (77%) experienced ≥1 treatment-related emergent adverse event (TRAE). Common TRAEs were nausea (50%), diarrhea (50%), vomiting (36%), fatigue (32%), and decreased appetite (27%). In Part E, no DLTs or deaths occurred in the two dosing cohorts evaluated. Four patients (67%) experienced ≥1 TRAE with 75% G1/2. Common TRAEs included fatigue (50%), diarrhea and proteinuria, (33%, each). The majority of previously treated advanced/metastatic NSCLC patients administered abemaciclib with LY3023414 or with pembrolizumab had manageable and tolerable adverse events, similar to those of the single agents.