National Anti-vivisection Society

 

National Antivisection Society

SSC: problems faced in developing vaccines or therapeutics

Posted: 13 July 2007

SSC: 2) Specificity of new generation drugs/biologicals.

New generation therapeutics are often so specific that sometimes a change in a single amino acid can result in the difference between a beneficial or deleterious effect. These positive or negative effects cannot be predicted by computer models nor by testing in rodents. Often these important side effects can only be detected in specific primate model.

ADI Response:

  • It is an error to believe that the use of primate models guarantees total drug safety when used in humans, and there is evidence to demonstrate this, for example a study of animal and clinical tests reported that all the experiments (over 100, involving 3000 animals) were poorly reported. In one set of experiments to treat strokes, the animal data suggested a benefit, but the clinical trials showed no benefit and worse, possible harm83. Another study correlating animal and human trials concluded that it is “prudent to be critical and cautious about the applicability of animal data to the clinical domain” and “animal models may not adequately mimic human pathophysiology”84.
  • A study of adverse drug reactions (ADR) found that only “after drugs leave the trial setting and are used in sicker patients do their true risks become apparent”85. A paper reviewing ADR’s in 2 UK hospitals reported that these conditions totalled 6.5% of all admissions, with an estimated cost of Euros 706M a year to the UK alone86.
  • The anti-inflammatory drug Vioxx had unexpected effects on human patients, after laboratory animal tests. It has been reported that from 88-140,000 extra heart attacks may have been caused by Vioxx in the five years since its introduction87.
  • The case-fatality rate was put at 44%88, therefore fatalities would range between 38,720 and 61,600. It was found to increase the risk of heart attack by 34% compared to people on similar drugs. Many of the participants in the trials were at lower risk of cardiovascular disease than the elderly population that would use Vioxx, so the risk to the intended recipients may have been even greater – up to eight times greater89. One researcher commented that there was a “misconception amongst doctors and patients that because a drug is new, it must be better than older drugs”90.

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