July 22, 2015: Discovering an Old Drug’s New Tricks
I often write about how the inefficiencies so prevalent in the translational process can be turned into opportunities when viewed through the lens of innovation. A striking example is a current statistic in drug development: 80 percent of drugs that enter human testing are never approved for use. One common reason is that clinical studies fail to show effectiveness in treating the disease or condition — the “indication” — the drug was designed to treat. This is frustrating to the patients who might benefit from the new drugs, the doctors who would use them and the pharmaceutical companies that developed them.
But turned on its head, this problem presents a great opportunity to advance translation and health. It turns out that given the connectedness of human biology, a single drug might be effective in treating several different diseases. And the 80 percent statistic means that for every approved new drug, there are four investigational drugs that have undergone years of development and could be rapidly tested in a new indication. Many anecdotal examples of this “repurposing” strategy exist. But the question remains: How do we systematically identify new diseases that these approved and investigational drugs might treat?
NCATS is taking multiple approaches to solving this problem, two of which reached milestones recently. For the first, scientists used the Center’s high-throughput screening capabilities to test every drug ever approved for human use as well as many investigational medicines — compiled in the NCATS Pharmaceutical Collection — to identify possible new treatments for hepatitis C infection and multiple sclerosis. A collaboration with researchers from NIH’s National Institute of Diabetes and Digestive and Kidney Diseases found that chlorcyclizine, an over-the-counter allergy drug, stopped hepatitis C virus infection in cells and animals, leading to a clinical trial now ongoing at the NIH Clinical Center. And through another collaboration with NIH-funded researchers at Case Western Reserve University, we discovered that a combination of two drugs currently used to treat fungal infections and eczema may hold promise as a treatment for multiple sclerosis.
A second NCATS program focused on repurposing, Discovering New Therapeutic Uses for Existing Molecules, matches NIH-funded researchers with investigational pharmaceutical compounds to identify new indications. This month, NCATS is awarding nearly $3 million to four academic research groups to test whether drugs from pharmaceutical companies AstraZeneca and Sanofi may be effective for treating type 2 diabetes, acute myeloid leukemia (an aggressive blood cancer), glioblastoma (one of the most aggressive brain tumors in adults) and Chagas disease (a neglected tropical disease that causes heart, digestive and neurological problems).
Drug repurposing has enormous potential to get more treatments to more patients more quickly; NCATS’ programs are making this potential a reality.
Christopher P. Austin, M.D.
National Center for Advancing Translational Sciences