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# FDA Approves Vertex Expanded Use for Kalydeco
- URL: https://www.fdaweb.com/fda-approves-vertex-expanded-use-for-kalydeco/
- Published: 2017-05-17T12:00:00.000Z
- Updated: 2026-09-14T22:24:04.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5138717

FDA has approved the expanded use of Vertex Pharmaceuticals’ Kalydeco (ivacaftor) for treating cystic fibrosis. This more than triples the number of rare gene mutations that the drug can treat, from 10 mutations to 33\. The agency based its decision, in part, on laboratory testing, which it used in conjunction with evidence from earlier human clinical trials. “The approach provides a pathway for adding additional, rare mutations of the disease, based on laboratory data,” an FDA [release ](https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm559212.htm?ref=fdaweb.com)says.

“Many rare cystic fibrosis mutations have such small patient populations that clinical trial studies are not feasible,” CDER director **Janet Woodcock** is quoted in the release as saying. “This challenge led us to using an alternative approach based on precision medicine, which made it possible to identify certain gene mutations that are likely to respond to Kalydeco.”

  
FDA says that results from an *in vitro* cell-based model system have been “shown to reasonably predict clinical response to Kalydeco. When additional mutations responded to Kalydeco in the laboratory test, researchers were thus able to extrapolate clinical benefit demonstrated in earlier clinical trials of other mutations.”