'Intelligent' cancer drug development boosts success rates

A new era of intelligent cancer drug development has spurred a leap in the proportion of drugs reaching patients, according to a study by Cancer Research UK scientists published in Nature Reviews Drug Discovery.

Scientists obtained data on 974 cancer drugs in clinical development, and calculated that there was a probability that 18 per cent of those entering the clinic would make it to market. Previously it was estimated that in some studies only five per cent of cancer drugs in the pipeline become standard treatments for the disease.

The research also showed that between 1995 and 2007 a family of molecularly targeted drugs called kinase inhibitors were almost three times more likely to reach patients than other types of anti-cancer drug. The researchers believe that a better understanding of the basic biology of cancer has enabled the development of this type of major new drug - which includes Herceptin for breast cancer and Glivec for leukaemia. Molecularly targeted drugs are usually less toxic, resulting in fewer side effects and they are more successful in clinical trials.

Traditional chemotherapy drugs not only target cancer cells but kill healthy cells as well which is why they result in unpleasant side effects - such as sickness, fatigue and hair loss.

Dr Ian Walker, licensing manager at Cancer Research Technology - Cancer Research UK's commercial development arm, said: "This analysis clearly demonstrates the benefits of developing molecularly targeted treatments for cancer. It highlights the fact that understanding more about the basic biology of cancer is making a real difference to the success rate of new anti-cancer drug development. It's clear that further significant achievements in cancer drug development will be dependent on continued research into new and relevant molecular targets."

Improved drug discovery processes and advances in medicinal chemistry have also contributed to better success rates of drugs in development. Furthermore, better understanding of a patient's genetic make-up and how they will respond to certain drugs has led to improvements in clinical trial design.

Co-author Professor Herbie Newell, Cancer Research UK's director of translational research, said: "These findings highlight the fact that we are working in a really exciting time for cancer drug discovery.

"Cancer Research UK invests heavily in research into the development of innovative and powerful new drugs to beat cancer and we are seeing great results in this field. We will continue to strive to improve the success rate of new cancer drugs, which will help more people survive the disease."

As drug development continues to advance, minimising the number of drugs which fail to make it to market will remain key as the cost of discovery and development of those drugs which don't reach market is borne by those that do.

Professor Newell added: "We strongly believe that both industry and academia must improve the availability of data related to failed as well as successful drug development programmes. The sharing of such information can only be beneficial for clinical, scientific and commercial reasons - and will help measure our progress as well as pinpoint areas for improvement."