In almost 90 per cent of cases, novel drugs tested on humans by pharmaceutical companies do not work as intended and must be scrapped. Often the drugs do not work, while at worst, test subjects die. New research from the University of Southern Denmark now shows that this number can be reduced. The secret is to test the drug on cells grown as 3D structures.
In 1993, five out of 15 liver patients who participated in a medical trial following the American Federal Drug Administration's (FDA's) instructions died. The patients had been treated with the substance fialuridin that should treat them for the disease hepatitis B. The substance was tested in the laboratory and on animals and had been evaluated as safe for human testing.
Surprisingly it turned out that the substance was acutely lethal to humans and led to extensive liver failure. Five patients died and two others only survived because they received a liver transplant.
When researchers develop new medicines, there are not just billions of dollars and years of research on the line. Patient safety is also at stake.
Now, new research from the University of Southern Denmark shows that the safety for people participating in medical experiments can be improved.
"With our new technique the pharmaceutical industry can better avoid harmful or even fatal effects on medical test subjects," says cell researcher Stephen Fey from the University of Southern Denmark.
When a new drug is developed, its individual active substances are first tested for adverse effects. All substances in the world are potentially deadly if the dose is high enough - this was first stated by the German-Swiss scientist Paracelsus (1493 - 1541) in the Renaissance. The challenge is to find substances that have a positive, healing effect and not a toxic or deadly one.
The substances are often tested on human liver cells in the laboratory. If liver cells do not respond negatively to the substance, scientists move to testing animals and finally humans. But despite all this work, only 10 per cent of the substances being tested on humans actually work as intended. 90 per cent do not. At worst, they are toxic, and in extreme cases, test subjects die.
"The success rate can be better than the 10 per cent", explains Stephen Fey, associate professor in the Department of Biochemistry and Molecular Biology at the University of Southern Denmark.
Together with his colleague Krzysztof Wrzesinski, postdoc at the same place, he is the leading scientist behind the groundbreaking discovery. The researchers' work is published in two articles in the journal Toxicology Research, issues 2 and 3, 2013.
"The breakthrough is that now we can test drugs on human liver cells that are more natural than the cell lines used by the pharmaceutical industry. Laboratory cells today do not have much in common with the natural cells that live in the human body, "says Stephen Fey.
In a human body, cells are able to communicate with each other and exchange valuable information. If cells that think they are alone they behave differently than they do when other cells are around. The isolated cells spend all their energy on multiplying and therefore can no longer perform their advanced functions.
The reason that laboratories work with cells that poorly communicate with each other, is not laziness, nor ignorance. In order to keep the cells alive, you have to expose them to a rather rough treatment that removes their ability to communicate. If you leave the cell line inside a container and feed them, they multiply and become overcrowded - the problem is that they will pile up on top of each other. This will prevent the bottom cells from getting oxygen and nutrients and this will eventually kill them.