Introduction
Cancer is a primary public health concern throughout the world and its occurrence significantly reduces people’s quality of life and leads to a range of medical problems [1, 2]. Cancer treatment has undergone tremendous changes, from previous chemotherapy and surgery to current molecular targeted drug therapy, onco-immunology therapy and combination therapy. Among them, the clinical practice of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) has significantly improved the benefit-risk ratio of cancer patients. Gefitinib, a first-generation EGFR-TKI, was authorized by the U.S. Food and Drug Administration (FDA) in 2003 and launched in China for treatment of non-small cell lung cancer (NSCLC) in February 2005. As the latest reported literature shows, gefitinib alone or chemotherapy with gefitinib plus pemetrexed may be cost-effective for patients with advanced EGFR mutated NSCLC in China [3, 4]. Evaluating the bioequivalence or substitutability of the tested formulation with the reference formulation will undoubtedly facilitate the treatment and recovery of cancer patients. The purpose of this open-label, randomized, two-period crossover, comparative pharmacokinetic study is to explore the bioequivalence of gefitinib in reference (R) or test (T) formulation in healthy Chinese subjects under fasting and fed conditions.