Tuesday, October 30, 2018

Why patent drugs

Dr Schreitmueller

BIG pharmaceutical companies have often been accused of “extending” their drug patents for as long as possible, depriving many patients of cheaper generic versions of drugs that could potentially save their lives or improve their conditions.

Called evergreening, NGOs had said these companies tend to “extend” drug patent just before the 20-year expiry period by making only a slight modification.

Dr Thomas Schreitmueller, Regulatory Policy Head at Roche Global, argues this is not necessarily the case. While this may be the contention for generic drugs, it is not for biological products, says Dr Schreitmueller who is based in Basel, Switzerland, citing the difference between trastuzumab and trastuzumab emtansine. While Trastuzumab can slow or stop the growth of breast cancer, the newer trastuzumab emtansine can kill breast cancer cells, he says. With trastuzumab, patients will still have to get a separate chemotherapy to kill the cancer cells but with the newer trastuzumab emtansine, patients do not need to go for a separate chemotherapy, Dr Schreitmueller explains.

In this case, he tells The Star in an interview, “You clearly change the purpose of the molecule. And this is different from ever-greening.”

Dr Schreitmueller points to another example of innovation – the first generation Interferon alfa-2a for treating Hepatitis C, which is made of pure protein, but years later, the protein was modified by pegylation (chemical modification to the protein). This changed the pharmacokinetic (bodily absorption, distribution, metabolism, and excretion of drugs) profile of the product.
With the pegylation immunogenicity in patients being lower, the dosing frequency could be lowered, he says, adding that the “new” product also shows a higher efficacy compared with the former version.

According to Dr Schreitmueller, an originator product is more expensive than a biosimilar because when developing the use for the antibody for treating each of the diseases or condition (indications), the originator company will have to carry out clinical studies for each of the indications while this is not required for biosimilar products.

A biosimilar company may extrapolate positive data from one clinical similarity assessment in one indication to all other indications of the originator product, besides the needed demonstration of analytical and preclinical similarities, he says.

In developing a new drug for 10 indications, a pharmaceutical company may have to do more than 10 clinical studies while a manufacturer of a biosimilar product (a biologic medical product that is almost identical copy of an original) may have to do only two, he says.

There is also a low risk of failing to demonstrate safety and efficacy for the biosimilar product as this was already demonstrated by the originator product, he says.

Dr Schreitmueller also points out that a high level of similarity between a biosimilar and the originator product was important to mitigate the risk of interchangeability (switching), particularly with cancer products.

“You cannot do with biologics what you may do with synthetic drugs that are not immunogenic because if the patient has developed an immune response to the biosimilar after a switch and thus, does not work anymore, this immune response may also neutralise the originator product and it also will not work anymore for the patient.

“So there is no point switching back to the originator product,” he says.

However, he says for rheumatoid arthritis, patients may switch to other treatments if one fails because there are many other options available.

In view of such delicate situation with biologics and biosimilars, Dr Schreitmueller urges the Malaysian authorities to be more transparent in its regulatory decision making by coming up with an objective evaluation report and not leave the education of the products to companies or other stakeholders.

This is crucial for physicians and patients to make unbiased treatment decisions, he stresses.
“In Europe, whenever the European Medicine Agency (EMA) approved a pharmaceutical product, it will publish an evaluation report.

“In the report, the physicians, patients and other stakeholders are able to find information such as the results of the clinical studies, preclinical and analytical studies with conclusion from EMA as well as the reason why a certain product is approved.”

Pharma co-vigilant (monitoring of side-effects) is also important after a product is released into the market, he adds.

Asked how pharmaceutical companies can address the issue of high drug cost that is inaccessible to many patients and and put a burden on health care systems, Dr Schreitmueller says in cases without competition, it would be useful to identify specific patients where the drugs would work with a high likelihood, such as through tumour gene analysis.

“Currently, we may have a drug, such as for lung cancer approved, but it may not work on all lung cancer patients.

“If we are able to treat only a specifically identified population, a sub group, this will make the system more efficient and achieve cost effectiveness,” he says.

In cases where we have competition such as biosimilars, the Government buying several products from the same molecule instead of allowing only single win contract, enables and maintains competition.

On NGOs arguing that most of the discovered compounds were researched in public universities – thus paid by tax payers and should not cause drugs developed to be too expensive – Dr Schreitmueller points out that these institutions are not necessarily involved in the costly development efforts leading to a safe and effective product, which are usually done by the pharmaceutical companies. - The Star

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