Efficacy of crizotinib in children with relapsed/refractory ALK-driven tumors including anaplastic large cell lymphoma and neuroblastoma: A Children's Oncology Group phase I consortium study.

Abstract

9500 Background: Genetic aberrations in the anaplastic lymphoma kinase (ALK) gene are found in anaplastic large cell lymphoma (ALCL), neuroblastoma (NB) and other tumors.Crizotinib,a small molecule inhibitor of ALK and c-Met, is active in non-small cell lung cancers (NSCLC) harboring an ALK translocation. We performed a phase 1 dose-escalation and pharmacokinetic (PK) trial of crizotinib in patients (pts) with refractory solid tumors and ALCL. Methods: Crizotinib was administered bid without interruption in 28 day cycles using the rolling-six design. Six dose levels (100, 130, 165, 215, 280, 365 mg/m2/dose) have been evaluated (A1). Pts with confirmed ALK fusion proteins, mutations or amplification (A2) could enroll at one dose level lower than part A1 and those with NB could enroll on a separate stratum (A3). PK studies were performed on day 1 and at steady state (SS). ALK genomic status in tumor tissue was evaluated and qPCR was used to measure NPM-ALK fusion transcript in bone marrow and blood samples of ALCL pts. Results: 70 pts were enrolled, 57 fully evaluable for toxicity, [median (range) age 9.9 yrs (1.1–21.3)]: 29 on A1, 18 on A2, and 10 on A3. In A1, 2/7 pts developed DLT (grade 3 dizziness, grade 5 intra-tumoral hemorrhage) at 215 mg/m2 and 1/6 pts developed DLT (grade 4 liver enzyme elevation) at 365 mg/m2. In A2, 1 grade 4 DLT (neutropenia) occurred at 165 mg/m2; in A3, no DLTs occurred. Mean (±SD) Cave (=AUC0-12h/12h) of crizotinib at SS was 466±114 ng/mL at 215 mg/m2/dose (n=5), 443±121 ng/mL at 280 mg/m2/dose (n=8), and 720±230 ng/mL at 365mg/m2/dose (n=4). Response data for pts with ALCL (six at 165 mg/m2, two at 280 mg/m2) approved for release by the Data Safety Monitoring Committee demonstrates 7/8 (88%) complete response (CR) rate to date. RT-PCR data for 6 of these pts at 57 time points was obtained and will be described. In addition, 2 pts with NB have had CRs, one with a documented ALK mutation. One patient with an inflammatory myofibroblastic tumor and one with NSCLC had PRs. Conclusions: Inhibition of ALK in pediatric pts with ALK-driven tumors occurs with minimal toxicity and is associated with objective anti-tumor activity.