Current and future roles for biosimilars in oncology – evidence from 10 years’ experience in Europe and the USA
Although licensed biosimilars are subject to rigorous regulation frameworks and close post-marketing surveillance, they are still underused in the real-world setting.
Biologics account for half the pharmacological market in oncology; however, their main drawback is their high cost. Biosimilars were developed as cheaper alternatives with the dual aims of facilitating access to novel treatments and reducing healthcare expenditures.
Biosimilars are defined by the US FDA and European Medicines Agency as highly similar biological products with no clinically meaningful differences to an existing approved reference product in terms of safety, purity, and potency. Because biosimilars are not identical to their reference biologic, biosimilarity must be demonstrated by evidence from pharmacokinetic and pharmacodynamic studies. Despite the stringent requirements for reliable scientific data and successful clinical trials for all approved biosimilars, knowledge concerning these drugs is lacking – with one quarter of oncologists reportedly able to describe a biosimilar, and one fifth of prescribers familiar with the concept.
As patents for biologics expire, more biosimilars are set to enter the oncology drugs market. The main concern of cancer clinicians over the use of biosimilars is risk of immunogenicity, as even minor differences in molecular structure, impurities, route of administration, and storage conditions between these drugs and reference products could potentially incur adverse effects. Ongoing pharmacovigilance and post-marketing safety monitoring activities – which are mandatory for all approved biologics and biosimilars – should help to dispel these worries over the long term.
Biosimilars represent significant cost savings to healthcare systems. It has been calculated that a 20% reduction in the price of six off-patent biologics would create savings of billions of euros, which when spread out would enable patients access to more treatments. However, these price forecasts also depend on the cost of reference biologics and the competition market.
For patients with cancer, biosimilars are more affordable drugs with a similar safety and toxicity profile and no clinically meaningful difference compared with their reference biologics. Current underuse of biosimilars may be attributed to lack of awareness among patients and clinicians of the benefits and challenges of these important medications. Healthcare professionals, and the public alike, should be properly educated on multiple aspects of biosimilars to ensure their successful incorporation in routine oncology care.
Healthcare practitioner knowledge concerning biosimilars is lacking. There needs to be greater educational opportunities covering all aspects of biosimilar safety and efficacy to ensure successful incorporation of biosimilars in routine oncology care.