Some type of clinical testing is expected at this point to gain market approval for most biosimilars. Large comparative clinical trials defeat the purpose of the abbreviated development program for biosimilars, according to FDA officials, and studies that merely replicate the safety and efficacy findings of the innovator product risk raising costs and delaying patient access to an alternative therapy. Instead, the biosimilar pathway permits licensure based on less than full clinical data, and is based on significant differences in developing biosimilars and innovator therapies  (Applied Clinical Trials Online)