The US Food and Drug Administration (FDA) grants Proteostasis Therapeutics' PTI-428, a Breakthrough therapy for the treatment of cystic fibrosis patients with two copies of the F508del genetic mutation who are receiving Orkambi® as background therapy.
PTI-428 is an investigational CFTR amplifier in the development for treating CF in patients who are homozygous for the F508del mutation in the CFTR gene.
It can be used as an add-on therapy to the approved CFTR modulators or as part of PTI’s proprietary triple combination regimen that includes PTI-808, a potentiator, and PTI-801, a corrector.
PTI-428 works early during CFTR biogenesis to increase levels of newly synthesized CFTR protein, suggesting potential therapeutic benefits in combination with CFTR correctors and potentiators.
It helps to treat CF patients based on the results from a recent Phase 2, randomised, placebo controlled study, in 24 CF subjects on background treatment with Orkambi® and who were treated with either 50 mg PTI-428 once daily or placebo for 28 consecutive days.
The study results showed that treatment with PTI-428 led to mean absolute improvement in percent predicted forced expiratory volume in 1 second (ppFEV1) of 5.2 percentage points from baseline through Day 28 compared to placebo (p<0>
The Breakthrough Therapy Designation for PTI-428 showcases the strength of the recent Phase 2 study results for amplifier, which is a novel and proprietary class of CFTR modulators.
PTI-428 offers the potential for improvement in pulmonary function for patients with cystic fibrosis.
