General | June 2, 2015 | Author: The Super Pharmacist
Biosimilars are defined as an emerging group of medicines in which the active substance is comparable to that of a biological reference medicine. The biosimilar and the biological reference medicine are used at the same dosage to treat the same disease (1), and the biosimilar is considered a cost-effective therapeutic equivalent of an original biopharmaceutical product. Biosimilar products can only be developed and marketed once the patent of the original product has expired and is no longer valid.
The first patent for biopharmaceuticals expired in 2001, and the production of biosimilars has been growing steadily since then, with a number of limited products currently available on the Australian market. There is increasing interest in the role of biosimilar drugs, primarily because they significantly reduce the cost of medicines to buyers and patients – it is estimated that biosimilar products will reduce prices by between 20-30% when compared to the costs of biologics. As costs will be lower, many healthcare organisations and practitioners hope that in turn this will improve access to certain medicines as they become more affordable, and that healthcare organisations can make significant savings. A number of biosimilar products are currently available on the market for the treatment of conditions such as rheumatoid arthritis and ankylosing spondylitis. Manufacturers of biosimilars must be able to demonstrate that there are no significant differences either in safety or effectiveness when compared directly with the original biologic product (2).
As an emerging pharmaceutical area, it is not clear yet how effective biosimilars are. There are some scientific concerns that, due to their slightly different molecular structure, many biosimilar medicines may not have the same side effect. Further testing, evaluation and analysis is going to be required in the field before the true rule of biosimilars in the marketplace, and as viable treatment options, are known. Many regulatory bodies, national charities, and patient interest groups are also urging patients who are prescribed biosimilars to ensure that their health professional explains the clinical trials findings to them clearly, and also that they register with clinical trials providers or regulatory bodies in order to allow them to systematically capture robust data on safety and effectiveness. This is largely due to ongoing doubts regarding the strength of the evidence for their use (commonplace in new technologies entering into the market). The way in which biosimilars are evaluated also requires some closer scrutiny, as many of the current studies are generally small-scale, covering very small numbers of individuals, and no clinical trials undertaken for each licensed indication of the biologic reference product (3). This lack of rigour within the testing methodology weakens the evidence when extrapolating data to compare the two products. As biosimilar drugs are generally new to the market, there is also a lack of available data regarding their long term safety and no evidence on the safety and effectiveness from switching to a biosimilar from a tried and tested originator drug. Additionally, much of the already conducted biosimilar research has been with ‘new’ patients who are taking the drug for the first time rather than those who have tried a wide range of other medicines first. More research will be required in these areas to further the development of biosimilar medicine, although as there is currently no statutory mandate or obligation for those conducting clinical trials to routinely collect data (or make it available), there also needs to be a more consistent and systematic way of recording this data in order to build a meaningful body of evidence (4).
At present, biosimilars and biologics are occasionally prescribed by their international non-proprietary names (INN). It is now generally recommended that all drugs are prescribed by their brand name, in line with most regulatory authority guidelines, to ensure that there is no automatic or accidental subscription to a biosimilar product when being dispensed by a pharmacist(5). This is important from a pharmacovigilance perspective, and it is essential for all patients to know what they are receiving at all times.
There is also some concern that biosimilars are being seen primarily as a more cost-effective method of prescribing drugs rather than being the best available prescribed drug for clinical reasons. As such, if biosimilar products are widely introduced to the market then it will also need to be made clear that they are only to be administered on a case by case basis, where there is clear clinical need and a strong track record of safety and effectiveness, rather than the sole purpose of cost (6). There is a danger of services or providers having a universal mandate or preference for switching to biosimilars, potentially jeopardising the safety and treatment of patients. It is also important that clinicians are clear for the reasons behind their prescribing of biosimilars, as they are different from traditional generic drugs that are clinically well understood and have a long history of regulation (7).
As such, those who are thinking about prescribing or dispensing a biosimilar should consider a number of factors, including;
1. Medicine and Healthcare products Regulatory Agency (MHRA) Glossary of MHRA terms. Available online at http://www.mhra.gov.uk/SearchHelp/Glossary/GlossaryB (last accessed 31st May 2015)
2. Locatelli F, Roger S (2006) Comparative testing and pharmacovigilance of biosimilars Nephrol Dial Transplant 21[Suppl 5]:v13–v16
3. Kelly CJ, Mir FA (2009) Economics of biological therapies Br Med J 339:b3276
4. Mellstedt H, Niederwieser D, Ludwig H (2008) The challenge of biosimilars Ann Oncol 19:411-416
5. Vermeer NS, Spierings J, Straus Gm et al (2015) Traceability of biologicals: present challenges in pharmacovigilance Expert Opin Drug Saf 14(1):63-72
6. Rak Tkaczuk KH, Jacobs IA (2014) Biosimilars in oncology: from development to clinical practice Semin Oncol 41 Suppl 3:S3-S12
7. Cortes J, Curigliano G, Dieras V (2014) Expert perspectives on biosimilar monoclonal antibodies in breast cancer Breast Canc Res Treat 144(2):233-9