Biologicals have become an integral part of cancer treatment both as therapeutic agents and as supportive care agents. It is important to know that biologics are large, complex molecular entities requiring extensive immunogenicity testing and pharmacovigilance strategies to ensure no immune response is evoked in the body. Oncology's pharmacological market is dominated by biologics; however, their high development and manufacturing costs are burdensome to healthcare systems. Biologics, being the most expensive prescription drugs on the market, limit accessibility for necessary treatment for many patients.

As biologics patents expire, the development of biosimilars is underway in an effort to lower costs and enable patients to access new cancer therapies. Regulatory guidelines for biosimilars have now been established and are constantly being revised to address any issues, facilitating their robust development. Moreover, many scientific societies offer guidance to help stakeholders better understand current regulations and biosimilars' safety. Despite the potential cost benefits, lack of knowledge about biosimilars and the possibility of immunogenicity have created an uncertain environment for healthcare professionals and patients. In this review, we provide an overview of relevant legislation and regulations, pharmacoeconomics, and stakeholder perceptions regarding biosimilars. The article also describes biosimilars in development, as well as the ones currently available on the market.