Are Biosimilars the Future of Oncology and Haematology?

Biological drugs are vital but often high-cost components of cancer treatment. Several biosimilar versions of these drugs have been approved in Europe and/or the USA, with many more in development. However, there is some disconnect between the biosimilars that are approved for use and those accessible in clinical practice, with availability impacted by factors including patent litigation and complex healthcare insurance policies, particularly in the USA. Provided the barriers to widespread uptake can be overcome, biosimilars offer potential benefits including cost savings and improved patient access versus the reference product (RP). This article provides an up-to-date and focused perspective on the development and use of biosimilars in the haemato-oncology setting. European and US regulatory pathways governing biosimilar licensing demand that there are no clinically meaningful differences between a biosimilar and its RP. Pathways are rigorously enforced and involve comprehensive non-clinical evaluations and clinical trials in selected indications to establish the equivalence or non-inferiority of efficacy, and the comparability of safety, of the biosimilar versus its RP. 'Indication extrapolation' is only permitted if scientifically justifiable considering mechanism(s) of action, pharmacokinetics, immunogenicity and safety in relevant patient populations. Switching treatment from RP to biosimilar is supported by most available data, predominantly from indications other than cancer, and post-marketing pharmacovigilance programmes are warranted. Notably, the potential benefits of biosimilar cancer treatment may extend beyond direct cost savings: for example, the availability of biosimilars of common regimen components may help incentivise the evaluation and/or clinical use of new treatment approaches and novel drugs.