Testing a common diabetes drug for people with cystic fibrosis-related diabetes

This trial is testing whether metformin, a widely used diabetes medication, can help people with cystic fibrosis-related diabetes who are already taking newer CF drugs called CFTR modulators. The researchers want to see if the medication can improve how your body handles blood sugar and support your overall health. You would take the medication at gradually increasing doses over several weeks, along with a vitamin B12 supplement to prevent a known side effect.

People with cystic fibrosis who take newer CF medications sometimes develop diabetes as a side effect, even though the CF drugs are helping their lungs. This trial exists to find out whether this medication could help manage that diabetes and potentially improve how the CF medications work in your body.