In recent decades, biological medicines have revolutionized the treatment of diseases such as cancer, diabetes, Alzheimer's, rheumatoid arthritis, multiple sclerosis, among others. They are innovative products produced from living systems, such as bacteria, yeast or mammalian cells, using recombinant deoxyribonucleic acid technology.
On the other hand, biosimilars, unlike generics, are not identical to the reference drug, due to the complexity and biological variability and the fact that the biopharmaceutical manufacturing process differs depending on the manufacturer. The active ingredient, however, is the same between both, in addition to the final structure of the drug for commercialization.
The arrival of biosimilars on the market represents, for many patients, the possibility of accessing state-of-the-art, highly effective therapies at a reduced cost. The increasing prevalence of diseases such as cancer, diabetes and other chronic and rare conditions have helped the growing demand for these products.
Issues that have already been discussed in this class of drugs, such as quality and safety, have been overcome. The principles of biosimilar development are based on the totality of its evidence. Each production step must rely on scientific rigor to reduce residual uncertainties from the previous step.
Biosimilar medicines must have similarities at certain points of the molecule, while some small variations are accepted at other points. These differences are subtle and can also occur between different lots of the reference biological.
They do not affect the safety, quality, or efficacy of biosimilars, as long as strict quality standards are followed at all stages. When the National Health Surveillance Agency (Anvisa) grants the registration of a biosimilar, it concludes that there is no interference in the efficacy and safety of the drug.
For a biosimilar to be approved, it must demonstrate, through comparability studies, that any existing differences in relation to the reference biopharmaceutical do not compromise its pharmacokinetics, pharmacodynamics, efficacy or safety.
Regulatory challenges
Due to the particularities of the production process, the main regulatory agencies worldwide face the challenge of establishing rules to determine the degree of similarity of a biosimilar with its reference product to ensure that they present the same profile of quality, efficacy and safety.
However, despite all the rigorous processes adopted to compare the similarity between drugs, there are still controversial issues, especially the interchangeability, pharmacovigilance of products and safety of recurring exchanges between different products on the market.
Interchangeability
Interchangeability between products is one of the most delicate issues since the exchange of these drugs can have an impact on the patient's therapy.
The switch from a biological medicine to a biosimilar one can only occur with scientific and sure support that it will not cause harm to the patient or decrease the effectiveness of the treatment. This is even more important when considering drugs with a high capacity to form anti-drug neutralizing antibodies. Interchangeability is treated quite heterogeneously among the different countries that have biosimilar regulations.
According to Note of Clarification 003/2017/GPBIO/GGMED/ANVISA, the Agency does not consider interchangeability a regulatory issue, but rather an assignment of physicians and the Ministry of Health. According to this guideline, the specifics of each case must be taken into account, avoiding successive exchanges, in order not to compromise the pharmacovigilance and traceability of these drugs.
If the medical prescription guides the exchange of a biosimilar for a biological product (or vice versa), it is important that the patient is aware of possible adverse reactions or lack of efficacy of the product, notifying the prescribing physician or the manufacturing laboratory.
Sources:
- ICQT
- Paraná Society of Rheumatology
- Fiocruz
- Medical Archives Magazine of the Faculty of Medical Sciences of Santa Casa de São Paulo