Biologic medicines, eulogized as “borrowed from nature”, have been developed from living organisms. Biologics, such as monoclonal antibodies, have emerged as a major class of therapeutics in healthcare. Concomitantly, however, the high cost of pharmaceuticals, including biologics, has become an important issue.
Market grows at amazing pace
Two compelling factors behind the high cost have been the scale of investment and the length of time involved in the development of a new drug. Nevertheless, companies are incentivized to take the necessary risk by patent protection in the market. Not surprisingly, the pharmaceutical market has grown at an amazing pace, different biologics scoring varying degrees of success, clinically and fiscally.
As can be expected, the growing market of a successful drug becomes a source of attraction and attention. Interested companies which are kept out by the patent protection barrier, keenly wait for the patent to expire. Thereafter, some of them enter the market fray with their formulated “biosimilars”. Medicines that are highly similar (not identical) to currently available biologic therapeutics (originators) are known as biosimilars. A biosimilar satisfies the same safety, purity and potency criteria as the reference product.
Easier to “copy” than “create”
Most often, it is easier to “copy” than “create”. Evidently, biosimilars have a better chance to make it to the market than a freshly developed drug. Among the leading biosimilar performers are Novartis, Pfizer, Biogen and Amgen. A rituximab biosimilar Rixathon, developed by Sandoz, a Novartis division, was approved by the European Commission in June 2017.
Rituximab is a monoclonal antibody. It recognizes human CD20 antigen present on the surface of B-cells which are a specific type of white blood cells called B-lymphocytes. B-cells are an important component of the immune system – body’s defense against harmful pathogens. The first quantities of rituximab were produced in Chinese hamster ovary (CHO) cells.
B-cell lymphoma occurs when healthy B-cells transform into fast-growing malignant cells that eventually overwhelms healthy cells. Hence, CD20 has been considered to be a suitable drug target for the treatment of certain lymphomas and autoimmune diseases.
Rituximab has been quite successful clinically as well as in the drug market. The patents on the originator product MabThera/Rituxan expired in the USA in September 2016 and in Europe in February 2013. Thereafter, some of the rituximab biosimilars have already been approved while some are in development.
Laboratory studies have shown that the active substance in Rixathon is highly similar to that in MabThera in terms of structure, purity and biological activity. Side effects of the two products are also comparable.
Late entry an economic advantage
Though entering the scene relatively later, biosimilars have the opportunity to use newer technologies. This increases the possibility of lower manufacturing costs. Some biosimilars have been developed using plants with their costs significantly reduced.
In the last decade, the plant system has been used to produce therapeutic monoclonal antibodies, Rituximab biosimilar with improved efficacy was expressed in Nicotiana benthamiana transient (non-transgenic) expression system.
On the other hand, bispecific trastuzumab/pertuzumab plant biosimilars produced in transgenic N. benthamiana displayed improved activity simultaneously against two different epitopes of the human epidermal growth factor receptor 2 (HER2/neu). Overexpression of oncogenic HER2/neu is the cause of breast cancer in a large number of patients. Trastuzumab is in the manufacturing pipeline of the Canadian biotech company PlantForm
Future ?
As for the future of the biosimilars market, experts predict that it will be essentially dominated by large, well-established companies. Proponents herald that biosimilars have the potential “to provide patients with access to more affordable, equally effective healthcare”.
Whether or not biosimilars will actually reduce healthcare costs uniformly and effectively is still debatable. What is not, is the biosimilar market growth. Different market studies have projected the growth at a compound annual growth rate (CAGR) ranging between 14 to 40 per cent from 2023 to 2032. The range is wide, yet all projections are upward.