Combined Pan-HER and ALK/ROS1/MET Inhibition with Dacomitinib and Crizotinib in Advanced Non-Small Cell Lung Cancer: Results of a Phase I Study

Abstract

Introduction: This phase I study investigated the activity of the irreversible pan-human epidermal growth factor receptor inhibitor dacomitinib in combination with the mesenchymal-epithelial transition factor/anaplastic lymphoma kinase/ROS proto-oncogene 1, receptor tyrosine kinase inhibitor crizotinib in advanced non-small cell lung cancer.

Methods: Patients with progression after at least one line of chemotherapy or targeted therapy received dacomitinib once daily and crizotinib once daily or twice daily, with doses escalated until intolerable toxicity; the expansion cohorts received the maximum tolerated dose of the combination. The primary objective was to define the recommended phase II dose; secondary objectives included assessment of safety and activity of the combination in epidermal growth factor receptor inhibitor-resistant patients and correlation with tumor biomarkers.

Results: Seventy patients were treated in the dose-escalation (n = 33) and expansion phases (n = 37), with the maximum tolerated dose defined as dacomitinib, 30 mg once daily, plus crizotinib, 200 mg twice daily. Grade 3 or 4 treatment-related adverse events were reported in 43% of patients: the most common were diarrhea (16%), rash (7%), and fatigue (6%). There were 16 deaths; none were considered treatment related. One patient (1%) had a partial response; 46% had stable disease. Most of the tumor samples analyzed had activating epidermal growth factor receptor gene (EGFR) mutations (18 of 20 [90%]); 50% (10 of 20) had a concurrent resistance mutation. Only one sample showed MMNG HOS Transforming gene (MET) amplification (the patient had progressive disease), whereas 59% (13 of 22) and 47% (14 of 30) had high levels of expression of epidermal growth factor receptor and mesenchymal-epithelial transition factor on the basis of H-scores, respectively. There was no apparent association between biomarker expression and antitumor activity.

Conclusion: The combination of dacomitinib and crizotinib showed limited antitumor activity in patients with advanced non-small cell lung cancer and was associated with substantial toxicity.

Keywords: Biomarkers; Crizotinib; Dacomitinib; EGFR TKI resistance; Non–small cell.