A Phase II Trial of Afatinib in Patients With Metastatic or Recurrent Squamous Cell Carcinoma of Esophagus

As a 2nd generation EGFR-TKI that irreversibly binds to EGFR receptors, afatinib showed the possibility of superior effects to 1st generation TKIs such as erlotinib and gefitinib. In a phase III study LUX-lung 3 in patients with EGFR mutation-positive non-small-cell lung cancer, afatinib monotherapy showed longer progression-free disease survival time of 11.1 months than that (6.9 months) of pemetrexed/cisplatin combination therapy. Based on such the results, it is currently recommended as the standard first-line treatment for EGFR mutation-positive lung cancer, and clinical studies are also being actively conducted in other types of carcinomas characterized by EGFR gene mutation and overexpression. Thirty (30) solid cancer patients were included in a phase I trial of afatinib, and of them, a patient with esophageal cancer had partial response. Taken together, based upon the results from clinical trials of afatinib conducted so far, 7 out of 15 esophageal cancer patients achieved clinical responses of 3 months or longer. Hence, the overall results from previous studies of gefitinib and erlotinib as EGFR TKIs and our study of dacomitinib, as well as from preceding studies of afatinib - a 2nd generation EGFR TKI - suggest the possibility of an effective therapy in esophageal cancer characterized by well-known EGFR overexpression. In this phase II trial, afatinib shall be administered to patients with squamous cell carcinoma of esophagus to evaluate its effects and toxicity. Also, biomarkers to predict responses to afatinib shall be explored through further studies.