Cancer Med: Biomarkers can improve the success rate of cancer drugs

Significant progress has been made in the development of new anti-cancer drugs in recent decades, such as Herceptin, a targeted drug for the treatment of women diagnosed with HER2-positive breast cancer. Despite these successes, cancer remains the second leading cause of death after heart disease, with nearly 90% of all anti-cancer drugs tested in clinical trials failing.

Ayson Parker, professor of biology at the University of Toronto, asked a simple but important question: "Is there any way to improve the risk of clinical trial failure?"

To find the answer, Parker launched a large-scale research project seven years ago to determine whether the use of predictive biomarkers (which help assess a patient's possible response to a specific treatment) improves the likelihood that a new cancer drug will be approved clinically. In a study published in Cancer Medicine, Parker and his co-authors provide the first systematic statistical evidence that biomarkers can significantly improve oncological outcomes when new drugs are tested.

This new study compares the success rate of drug approval in biomarker-based clinical trials with the results of four cancers without biomarkers: breast cancer, melanoma, non-small cell lung cancer and colorectal cancer. “Our overall analysis of these four cancers shows that drugs tested in biomarker-based trials are almost five times more likely to be approved by regulatory authorities,” Parker said. “Strong evidence supports the use of biomarkers to improve test results for new cancer drugs.”

The greatest benefit was seen in new drug testing against breast cancer, where biomarker-based trials were 12 times more likely to be successful. The success rate of melanoma drugs using biomarkers increased eightfold, while the success rate of lung cancer drugs increased sevenfold. Although drugs for colorectal cancer have not shown overall benefit, the investigators believe that this situation may change in the future with the introduction of more biomarkers for colorectal cancer.

Parker assessed the performance of well-established and novel exploratory biomarkers. The second key finding of the study suggests that the use of new biomarkers can also improve the success rate of oncology clinical trials before they are properly validated. This is surprising and encouraging as some experts believe that the use of unproven new biomarkers may increase the risk of failure. He explained: “The data show that exploratory biomarkers still have a fourfold benefit compared with no biomarkers. This suggests that drug developers can take advantage of new biomarkers because the broad interests of biomarkers are so powerful.”