Lives unaffected by cystic fibrosis


Back to the Drug Development Pipeline

PTI-428 + PTI-801 + PTI-808

Phase Two

Phase Two

Therapeutic Approach

Restore CFTR Function

PTI-428 + PTI-801 + PTI-808 is a combination therapy combining three CFTR modulators.

PTI-801 is a corrector, a type of modulator designed to fix the defective CFTR protein so that it can move to the proper place on the cell surface. PTI-808 is a potentiator. Once CFTR protein reaches the cell surface, potentiators help facilitate the opening of the chloride channel to allow chloride and sodium (salt) to move in and out of the cell. PTI-428 is a new type of modulator called an amplifier. Amplifiers increase the amount of CFTR protein in the cell. This makes more CFTR protein available for other therapies, such correctors and potentiators, to work on.


Multiple phase 2 studies are being conducted to test the safety and effectiveness of these drugs, both alone and in combination with each other.


This program is sponsored by Proteostasis Therapeutics. The early discovery phase was partially funded by Cystic Fibrosis Foundation Therapeutics (CFFT).

Contact us about PTI-428 + PTI-801 + PTI-808 >