Biopharmaceutical drugs are broadly defined as:
”Those medicines produced using a living system or genetically modified organism. These drugs are different from traditional chemical medicines in many ways. Size of the molecule is one of the most obvious distinctions: the molecules of a biopharmaceutical medicine are much larger, have far more complex spatial structures and are much more diverse (“heterogeneous”) than the chemical molecules which make up classical drugs.”
The Biosimilar drugs:
Biosimilar drugs are follow-on versions of original biopharmaceutical medicines. Biosimilar medicines are intended to have the same mechanism of action for the same diseases as the original biopharmaceutical drugs.
The term “bio generic” will be misleading for off patent biopharmaceutical products, as no two biopharmaceutical products could possibly be exactly identical. This is mainly because of the following reason:
“Whereas generics of chemistry based medicines are identical in the molecular structure and therefore copies of the original product, based on a strict definition of “sameness”, a corresponding definition cannot be established for biosimilar medicines because of their nature and the complexity of their manufacturing process. Here post-translational modifications are dependent of the host cell and the process.”
Thus the common terminologies used to describe such products when the original products go off-patent are follow-on biologics and biosimilars.
Manufacturing Conditions of biosimilars ultimately define the final product:
Unlike chemical drugs, the manufacturing conditions and the process followed to produce biopharmaceutical drugs largely define the final product and its quality. Any alteration to the manufacturing process may result in a completely different product. Additionally proteins are relatively unstable. Thus additional measures in their storage, formulation and delivery are very critical.
Key concerns with the existing regulatory approval process for Biosimilar drugs:
• Small changes in the manufacturing process of biosimilar drugs could significantly affect the safety and efficacy of the molecule.
• Due to the very nature of a biologic it is virtually impossible for two different manufacturers to manufacture two identical biopharmaceutical drugs. Identical host expression systems, processes and equivalent technologies need to be demonstrated in extensive comparability trials. Thus, as stated above, a ‘bio generic’ cannot exist.
• As against the situation applicable for generics of chemical molecules which can be replicated, biosimilar drugs cannot be replicated. At the most such biopharmaceuticals can be at the most “similar” but not “identical” to the original reference products. To ensure desired efficacy and safety of biosimilar products, these products should only be approved after charting out a formal and well validated regulatory pathway for the biosimilar drugs in India.
• Currently biosimilar drugs are given marketing approval by the regulator without such guidelines for large molecule biological and following just the bioequivalence model as specified in the Schedule Y of the Drugs and Cosmetics Act (D&CA) of India for small molecule chemical entities only, as the current Drugs and cosmetics Acts of India, very unfortunately, do not differentiate between large and small molecular drugs. This could, in turn, endanger patients’ safety with serious medical consequences.
Although, Central Drugs Standard Control Organization (CDSCO) and the Drugs Controller General of India (DCGI) are responsible for approvals of the new drug applications, health being a state subject, respective state regulatory authorities are responsible for granting manufacturing license to the pharmaceutical manufacturers.
Pharmaceutical manufacturers setting up facilities in the states, where regulatory oversight and incidences of weaker enforcement are common, will be able to market their products, including biosimilars, across the country. It is alleged that there are hardly any regulatory control over the mistakes or offences committed by the State Drug authorities who permit manufacture of drugs even unapproved by the DCGI. The existing issue of mushrooming of various irrational Fixed Dose Combinations (FDC) products in India will vindicate this point.
The Government’s response to this public health concern:
Express Pharma in its June 30, 2009 edition reported Dr M K Bhan, Secretary, Government of India, DBT, saying, “The first question is do we have written guidelines available to people? Currently, we have a large committee of about 30 people in the Review Committee on Genetic Manipulation (RCGM) which frequently discusses the current FDA and EMEA guidelines and makes sure that it is updated as per the guidelines in case by case approvals.”
He acknowledged, to make sure that the product is identical or original is harder for biological than for chemical entities and said, “So the next question is, what is the degree of difficulty you create to be sure that some of the products in the in vitro laboratories and the strength of the biomolecule, are to be characterized in details, and the other side is how expensive should the chemical evaluation be? At this moment, RCGM is seeing the issues and is in touch with both the FDA and the EMEA, and they are taking case by case decisions while trying to standardize the minimum information that is required to show how companies have characterized their products.”
“If we ask a big established company on this issue they will tell us to be strict, whereas a smaller company will suggest otherwise. What we are trying to do is being very scientific and come to a conclusion,” reported Express Pharma quoting Dr. Bhan.
The current practice:
Much water has flown down the bridge since the above interview was published. Nothing much has changed on ground regarding this critical issue, thus far. The industry sources allege that even today regulatory approval of biosimilar drugs (large molecules) are granted based on Phase III clinical trials, as specified in the schedule Y of the Drugs and Cosmetics Acts for the small molecules (chemicals) and that too conducted mostly on just 40 to 45 patients. At times the number of patients studied is even lesser. Immunogenicity study, which is so important for biosimilar drugs is, more often than not, overlooked. This could seriously compromise patients’ safety with such category of drugs.
Conclusion:
It is, indeed, quite surprising that in our country there is still no separate transparent and published guidelines for regulatory approval of Biosimilar drugs even when the World Health Organization (WHO) has come out with the same and India had actively participated in that exercise.
The question, therefore, comes to my mind whether the Biosimilar drugs manufactured in India would conform to international quality and safety standards, like in the U.K or what has been recently announced in the USA? If not, who will address the safety concerns of the patients administering these life saving medicines?
Such a concern gets vindicated by widely reported serious quality problems, detected by the drugs regulatory authorities, at some large and well known Biosimilar drug’s manufacturing units in India, in not too distant past and also from the condition of some vaccine manufacturing units in our country. The recent example of WHO cancelling the pre-qualification of ‘Shan 5’ (Shanta Biotech) vaccines for quality related problems, perhaps may help opening the eyes of our regulators, on the related patients’ safety issues arising out of regulatory laxity.
This issue assumes even greater importance considering the very recent development of the Department of Biotechnology (DBT) unfolding an interesting scheme to encourage development of biosimialr dugs in India by offering financial support to the domestic pharmaceutical and biopharmaceutical industry.
The proposed new regulatory pathway for the marketing approval of Biosimilar drugs in India will immensely help paving the way for the Biopharmaceuticals drugs manufacturers in India to adequately prepare themselves to grab a significant share of the fast emerging Biosimilar drugs markets, particularly, in Europe and the USA, in the years to come.
The Ministry of Health and the Department of Biotechnology of the Government of India should, therefore, urgently and jointly consider amending the Drugs & Cosmetics Acts of India accordingly and establish robust regulatory guidelines for marketing approval of biosimilar drugs in the country, acknowledging the widespread concern for patients’ safety.
By Tapan Ray
Disclaimer: The views/opinions expressed in this article are entirely my own, written in my individual and personal capacity. I do not represent any other person or organization for this opinion.