21 October 2020
by Humane Society International
In recent years many scientists have questioned why animals are still being used for testing potential drugs aimed at treating human diseases, including cancer. There is an increasing body of evidence showing that the predictive value of animals to attest safety and efficacy of medicines for humans is very low. In fact, animal testing represents a major obstacle in the drug development pipeline and is the main reason drug attrition rates are so high. For cancer, in particular, more than 95% of potential drugs fail in clinical trials.
But are failing animal models truly being replaced by the more predictive, human biology-based tools? To investigate this, a group of researchers at Humane Society International, led by Dr Lindsay Marshall, analyzed research funding, numbers of papers published and clinical trials for breast, lung and colorectal cancers across the European Union and in the US between 2014 and 2019. The group compared research using animal-dependent methods—so-called “xenograft” models in which patient tumor biopsies are injected into an animal—and human “organoids”, which use patient tumor samples to create in vitro models that more closely resemble a patient’s tumor.