Financial Daily from THE HINDU group of publications
Friday, Aug 09, 2002
Corporate - Research & Development
Suspended diabetes drug trials: What's in store?
HYDERABAD, Aug. 8
AS many as 2,500 diabetic patients in over 30 countries were subjected to clinical trials of the controversial anti-diabetic drug. The trials have now been suspended.
The drug, DRF 2725, had been licensed to the Danish drug major, Novo Nordisk, by Dr Reddy's Laboratories Ltd. This was stated by Dr Reddy's Executive Vice-Chairman and Chief Executive Officer, Mr G.V.Prasad. He, however, did not specify how many of those patients belonged to India.
Novo Nordisk detected tumours in rats treated with DRF 2725 in February. But clinical trials continued till July this year.
While stating that Dr Reddy's Labs was not directly involved in conducting the clinical trials, Mr Prasad, however, admitted that urine bladder tumours were detected in a number of rats treated with the drug early this year itself. The detection of urine bladder tumours in rats treated with DRF 2725 forced Novo Nordisk to suspend clinical trials.
Asked as to why the clinical trials were continued till July when the tumours in rats were detected early this year itself, Mr Prasad said: "Many of the pharmaceuticals on the market today have, however, been shown to cause tumours in trials involving rats. Therefore, the rat findings alone were not alarming.''
Further, Mr Prasad said, "The American and European health authorities, including the Danish Laegemiddlestyrelsen, did not question the continuation of the clinical studies after having been informed by Novo Nordisk of tumour findings in the rats.''
It was only after finding tumours in mice also that Novo Nordisk decided not to continue trials in humans.
According to Mr Prasad, "Only the investigators conducting the trials are permitted to contact trial participants directly. Pharmaceutical companies do not know who the trial participants are and cannot contact them.''
The detection of tumours in rats during February this year was informed to all the stakeholders concerned, including patients, through investigators and the patients were asked to re-assess their continued participation in clinical trials, Mr Prasad said. Stating that the process of informing the patients and the ethics committees was currently under way and was being followed closely by Novo Nordisk, Mr Prasad said it takes a year to know whether any of these patients suffered any harm due to DRF 2725. The majority of patients were exposed to DRF 2725 for less than six months and only very few were exposed for a period of seven months. "Risk, if at all, is very small,'' he said.
According to Mr Prasad, DRF 2725 falls under the category of non-genotoxic carcinogens which require long exposure time to pose a risk to humans, normally many years of exposure. However, he added that Novo Nordisk would suggest the patients to have a urine test sample taken one year after they stop taking the drug to determine whether they suffered any harm.
`No universal guidelines'
The Deputy Drug Controller General of India, Dr M. Venkateswarlu, when contacted, told Business Line that the regulatory framework for conducting clinical trials simultaneously on both animals and human beings varied from country to country and there were no universal guidelines on the issue. There is no single global regulatory body to approve clinical trials across the world and the drug discovery companies will have to obtain approvals from the regulators of individual countries.
Further, according to him, the development of adverse effects on rats during the clinical trials need not necessarily indicate human relevance. Whenever a drug research company finds such developments in rats, they suspend the clinical trials on human beings and initiate risk benefit analysis.
They proceed for clinical trials on intermediate species such as cats, monkeys and chimpanzees based on the results.
This process enables them to decide whether the findings in rats detected at the initial stages would be of any human relevance later, Dr Venkateswarlu said.
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