Mark G. Kris, MD, chief of the Thoracic Oncology Service at Memorial Sloan-Kettering Cancer Center, discusses the initial trials studying dacomitinib, an irreversible pan-HER tyrosine kinase inhibitor (TKI), in patients with EGFR-mutant lung cancers.

Kris explains that dacomitinib was first studied in hopes that a greater, potentially permanent, tumor shrinkage would occur. A phase II study compared dacomitinib to reversible TKIs such as gefitinib and erlotinib as a first-line treatment for patients with lung cancers. The partial response rate was 74% among patients with EGFR deletions at exons 19 and 21. At one year, progression-free survival (PFS) rate was 77% and median PFS was 17 months.

Dacomitib may be as effective as gefitinib in terms of degree and length of tumor shrinkage, Kris believes.