Regulatory and clinical considerations for biosimilar oncology drugs.

Biological oncology products are integral to cancer treatment, but their high costs pose challenges to patients, families, providers, and insurers. The introduction of biosimilar agents-molecules that are similar in structure, function, activity, immunogenicity, and safety to the original biological drugs-provide opportunities both to improve health-care access and outcomes, and to reduce costs. Several international regulatory pathways have been developed to expedite entry of biosimilars into global marketplaces. The first wave of oncology biosimilar use was in Europe and India in 2007. Oncology biosimilars are now widely marketed in several countries in Europe, and in Australia, Japan, China, Russia, India, and South Korea. Their use is emerging worldwide, with the notable exception of the USA, where several regulatory and cost barriers to biosimilar approval exist. In this Review, we discuss oncology biosimilars and summarise their regulatory frameworks, clinical experiences, and safety concerns.