Canadian Cancer Trials Group (CCTG) IND215: A phase Ib study of Selumetinib in patients with untreated advanced or metastatic NSCLC who are receiving standard chemotherapy regimens.

Introduction Selumetinib (AZD6244, ARRY-142886) is a potent inhibitor of MEK1/2, thereby inhibiting phosphorylation of ERK2. We investigated the toxicity and the recommended phase II dose of the combination of selumetinib with two platinum based first line chemotherapy combinations in non-small cell lung cancer. Methods This was a phase I trial of escalating doses of selumetinib with carboplatin (AUC 6), paclitaxel (200 mg/m2) (cohort 1) or pemetrexed (500 mg/m2) and cisplatin (75 mg/m2) (cohort 2) in patients with chemotherapy naïve, advanced or metastatic NSCLC. Patients enrolled on cohort 2 had non-squamous histology. Dose escalation of selumetinib proceeded using a 3 + 3 design: 50 mg b.i.d. days 2-19 (dose level 1); 75 mg b.i.d. days 2-19 (dose level 2); and 75 mg b.i.d. continuously. Adverse events were evaluated using CTC AE v4 and response by RECIST 1.1. Results Thirty-nine patients were enrolled (cohort 1 n = 16; cohort 2, n = 23). There were no dose limiting toxicities in either cohort and the recommended phase II dose for both regimens was standard doses of carboplatin, paclitaxel or pemetrexed and cisplatin with continuous selumetinib at a dose of 75 mg b.i.d. Most adverse events were grade 1 or 2 and were predominantly diarrhea, nausea, stomatitis, peripheral edema, neutropenia, and skin rash. Response rate was 37.5% for cohort 1 and 30.4% for cohort 2. Conclusion Selumetinib at a dose of 75 mg b.i.d continuously can be safely combined with paclitaxel and carboplatin or pemetrexed and cisplatin in patients with advanced or metastatic NSCLC. This trial provided the dose for the regimens used in a randomized phase II trial in NSCLC (CCTG IND.219).