Researchers Find Drug Repurposing Signals Using EHR Analysis

Through detailed electronic health records analysis, researchers at Vanderbilt University Medical Center may have found a new and efficient method for uncovering drug benefits and for drawing more informative repurposing predictions.

In particular, VUMC officials contend that their study lends new plausibility to the hypothesis that metformin, a diabetes drug that patients generally find easy to tolerate, might have use in treating at least some types of cancer.

The study, which appears in the Journal of the American Medical Informatics Association, includes Vanderbilt faculty members Josh Denny, M.D., associate professor of biomedical informatics and medicine, and Hua Xu, adjunct associate professor of biomedical informatics, as well as colleagues at Vanderbilt, Columbia University and the Mayo Clinic.

Scanning records of some 32,000 cancer patients seen at Vanderbilt since the mid-1990s, the team trained their sights on five-year survival with and without exposure to metformin, a drug long in use as a first-line therapy for Type 2 diabetes. At the same time, patients with contraindications to metformin use were eliminated from the cohort.

The team found that use of metformin as a therapy for Type 2 diabetes was associated with: a 23 percent decrease in all-cause mortality compared with metformin-free, non-diabetic patients; a 22 percent decrease in mortality compared to other oral hypoglycemic medications; and a 39 percent decrease in mortality compared to diabetic patients receiving insulin but not metformin.

The results are adjusted for age, tobacco use, body mass index and other variables known to influence cancer survival. For good measure, the team replicated these findings in a second cohort comprised of some 79,000 cancer patients seen at Mayo Clinic. Site-specific cancers showing decreased mortality with metformin (in at least one of the two EHR cohorts) included breast, colorectal, lung and prostate.

“Our EHR allowed us to delve into details of treatment and response—cancer staging, control of cancer, the various timelines involved and cancer subtypes,” Denny said. “We’re now building on this study, pursuing opportunities for using our EHR to look at all drug exposures across a given disease—starting with cancer. We’re trying to find other signals that may look like metformin in terms of affecting patient outcomes.”

As EHR networks eventually take shape, VUMC officials said the goal would be to adapt this strategy to yet larger, more geographically dispersed cohorts. Elsewhere, meanwhile, a randomized controlled clinical trial is under way to examine metformin’s efficacy in regard to cancer treatment.

The study is available here.

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