A narrative review of biosimilars: a continued journey from the scientific evidence to practice implementation.

Biologic agents have revolutionized the management of serious health conditions in the last two decades. The use of "targeted therapy" brings not only better progression free survivals and overall survivals, but also better toxicity profiles and quality of life benefits, compared to empirical palliative chemotherapy. However, given the high cost associated with biologic drugs and the sharp increases in biologic drug utilization, this drug category has significantly raised healthcare cost over the years. A similar phenomenon was previously experienced with branded simple chemical compound drugs, including chemotherapeutic agents, which was largely mitigated by the introduction of a generic approval pathway, decreasing the costs of the drugs, making them more affordable, given to the increase in competition among the drug makers. A similar opportunity presents years later with the completion of the full patent exclusivity period of many biologics. However, the ending of patent exclusivity, although enables more market competition, does not guarantee market penetration. Stakeholders, such as patients, providers and payers, must build trust and confidence in the science of biosimilars and the product specific studies leading to FDA approval in order to incorporate these products to practice and enable the biosimilar market at large to reach the potential to significantly contribute to reductions in drug cost. Dissemination of scientific and emerging biosimilar evidence is paramount in order to support stakeholder informed decision making and enable each to benefit from expanded treatment options. This paper describes the biosimilar development, approval process, and reviews a number of challenges with the marketing implementation of biosimilars.