Biosimilar medicines are highly similar to FDA approved reference biologics. The sponsor’s intended use claim plays an important role in the use of biosimilar medicines in specialty therapy categories such as immunology, endocrinology, oncology. The new biosimilar products approved by the FDA, play a pivotal role in the clinical treatments of patients suffering from life-threatening diseases such as cardiac myopathies, carcinoma, sarcoma, lymphoma. The US biosimilar approval process requires a thorough characterization of the new biosimilars with a clinically meaningful outcome. Sponsors of new biosimilars follow the appropriate ICH guidelines in regard to clinical PK/PD, safety and efficacy studies. The FDA guidances for extrapolation and interchangeability state that data derived from clinical studies should be adequate to demonstrate purity, potency, safety and the intended clinical use of the new biosimilar in comparison to previously approved licensed biologics. This article emphasizes the FDA’s quality system approach to the design of studies for clinical applications for designated specialty therapy categories.