Drug candidates undergoing phase I-II trials have a low success rate (less than 12%) to pass all the trial phases necessary to obtain final approval.
Dawa zilizoteuliwa katika majaribio ya Awamu ua I-II zina kiwango cha chini cha mafanikio (chini ya asilimia 12%) kupita katika awamu za majaribio ili kupata idhini ya mwisho.