Opinion of the Czech Society for Oncology on the possibility of biosimilar substitution

Opinion of the Czech Society for Oncology, Czech Medical Association of J.E. Purkyne (ČLS JEP) on the possibility of biosimilar substitution

Since the Committee for Medicinal Products for Human Use (CHMP) of the European Medicine Agency (EMEA) has issued its positive opinion on marketing authorisation for several products that are classified as biosimilars and have filgrastim as their main active ingredient, the introduction of copies of original biological molecules on the Czech market can be expected in the near future.

Based on the currently available information on biosimilars, the Committee of the Czech Society for Oncology (CSO) believes it is necessary to warn of certain possible risks that may be potentially associated with the use of biosimilars.

1. Since the manufacturing process of biotech products is very comprehensive and complex, it is not possible to ensure that the copy is absolutely identical to the original molecule, and these copies cannot be considered as generic drugs. As a result, potential differences may occur between the two groups, original biotech drugs and biosimilars, in the immunogenicity profile and therapeutic effect. This poses a risk of new (especially immunologically mediated) adverse reactions.
   
2. We disagree that biosimilars are interchangeable or replaceable with original biotech products, because they are not identical substances. The decision as to whether a patient should be treated with an original or biosimilar drug should be made exclusively by a qualified physician, who is sufficiently informed of the potential clinical consequences resulting mainly from
   • limited experience with biosimilars
   • the fact that most indications are registered based on extrapolations rather than on clinical studies
   • possible and barely predictable immunogenicity
   
   The automatic substitution of biosimilars is currently prohibited by the law in several countries, including France, Norway, Spain, the Netherlands, Sweden, Germany, Hungary, Finland, the United Kingdom, and Slovakia.
   
3. Biosimilars have a different administrative procedure for obtaining the positive opinion of EMEA. The marketing authorisation process for biosimilars is more complicated than that for generics. However, marketing authorisation is still provided based on limited data compared to the original product, and therefore EMEA requests that biosimilars be subject to large pharmacovigilance surveillance after being placed on specific markets. In case of a substitution of biosimilars for the original drug or vice versa during the course of the treatment, safety evaluation could be jeopardised and biased.