This review gives clear insight on Biosimilars. Biosimilars - the follow-on biologicals is the new area for a pharmaceutical industry to consider whether it suits its expertise, its business interest and offers for it opportunities for growth. This review explores Biosimilar Drug Development from the view-point of a biopharmaceutical company and proposes key points that a company needs to consider through the process of planning biosimilar drug development. It examines significant developments in the biosimilars market and will arm the reader with scientific, regulatory and strategic information needed to face new opportunities as well as the challenges of the biosimilars revolution.