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# Fast Track for Triple Combination for Cystic Fibrosis.
- URL: https://www.fdaweb.com/fast-track-for-triple-combination-for-cystic-fibrosis/
- Published: 2018-04-04T12:00:00.000Z
- Updated: 2026-09-14T23:57:20.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5141148

FDA has granted Proteostasis Therapeutics a fast track designation for its triple combination product for cystic fibrosis, consisting of cystic fibrosis transmembrane conductance regulator (CFTR) modulators known as PTI-428, PTI-801 and PTI-808\. All three drug candidates were discovered internally at the company and are “designed to act synergistically through complementary mechanisms of action which address specific dysfunctions of the CFTR protein, the underlying cause of the disease,” the company says. The three modulators have active INDs at FDA and are currently in clinical trials in patients in the U.S. and Europe.