New technique paves way for better drugs

Swedish scientists have developed a technique to directly measure the extent to which drugs reach their targets in the cell.
The method, developed by researchers at Karolinska Institutet, could make a significant contribution to the development of new, improved drug substances.
Most drugs operate by binding to one or more proteins and affecting their function, which creates two common bottlenecks in the development of drugs; identifying the right target proteins and designing drug molecules able to efficiently seek out and bind to them.
No method has been available for directly measuring the efficiency of the drug molecules to locate and bind to its target protein.

Now researchers have developed a new tool called CETSA (Cellular Thermal Shift Assay), which utilise the concept that target proteins usually get stabilised when drug molecules bind.
"We have shown that the method works on a wide variety of target proteins and allows us to directly measure whether the drug molecules reach their targets in cells and animal models," said lead investigator Professor Par Nordlund of the Department of Medical Biochemistry and Biophysics.

"We believe that CETSA will eventually help to improve the efficiency of many drugs and contribute to better drug molecules and more successful treatments," Nordlund said.
The lack of methods to directly measure the binding of a drug to its target protein has caused a degree of uncertainty in many phases of drug development.

In some cases, where drug candidates have not lived up to expectations in clinical trials on humans, it has transpired that the drug molecules have failed to bind to the right protein.
The group behind the study believes that CETSA will be an important control stage and a complement to other methods.
In the present study, the researchers also examined processes that can lead to drug resistance in cells.
The team believes that by virtue of its ability to determine whether existing drugs are suitable for individual patients, the method is of potential value to the practice of individualised treatment.

The study was published in the journal Science.