Your correspondent Jessamy Korotoga is correct that the failure of the drug solenezium in its human trials will be disappointing to many with the horrible disease of Alzheimer’s along with their carers and loved ones. However, surely it is not in any way surprising: the unresolvable problem of species differentiation has caused many more serious problems than this in the history of medicine.
In 1928, Alexander Fleming discovered penicillin, but quickly lost interest after he injected it into rabbits, which seemed to confirm his worst fears that it would be inactivated by blood and therefore could only be used for minor exterior lesions (we now know that rabbits metabolise and excrete penicillin much more quickly than humans). That would probably have been the last of it except that the Second World War came along with the urgent need for an effective antibiotic. Two researchers, Florey and Chain, were asked to review Fleming’s work and they had an incredible stroke of luck: they chose mice to experiment on, one of the few species that reacts to penicillin the way humans do. As Florey himself stated later, if he had chosen guinea pigs he would have concluded that penicillin was far too toxic to use and would almost certainly not have proceeded further.
The most famous drug disaster is thalidomide. What is not well known is that after it had happened, the animal tests were repeated using pregnant females. A wider range of species were examined than usual, including cats, ferrets, primates and armadillos. In the overwhelming number of species no birth defects were produced. Aspirin, on the other hand, while harmless to pregant women, does produce birth defects in many species of laboratory animals.
I think the fundamental change in scientific thinking came following tests of the monoclonal antibody drug TGN1412. Three human volunteers nearly died and were permanently disabled. It transpired that the monkeys on which it had been tested had been given 500 times the human dosage without any indication of the devastating chain reactions which took place in humans. Dr David Glover, who had just retired as head of .
Cambridge Antibody Technology immediately, suggested microdosing -testing small amounts on people - as a more reliable alternative.
Given that we now have techniques such as testing on human tissue cultures, computer projections etc, surely these medieval, horrendously cruel tests should be ditched. Unfortunately, some medical charities still use their money for these “scientific” tests, but the good news is that about half have now rejected using money to this way. If you would like to ensure that any money you donate is not used for animal rersearch, Animal Aid will suppy you with a list of charites which “do” and which “don’t”.
Kevin Waddington, Queens Avenue, Lynn