Indeed a great post, a newly developed drug is uncertain of the side effects, may cause hypersensitivity reaction in some person while the other person might be cured too, the liver toxicity has to be monitored and the experiments on mice are not reliable too. Its challenging job to find a new drug and to be accepted by nationals pharmaceuticals too.
Yes, one had been comment that how the mice is being treated would also affect the experimental result. Yet, it is difficult and impossible to have human experiment at the very begining