The US Food and Drug Administration (FDA) has given fast track designation to a triple combination programme in cystic fibrosis (CF) patients developed by biopharma Proteostasis Therapeutics.

Proteostasis specialises in the development and production of therapies targeted at CF and other diseases caused by dysfunctional protein processing. The company’s triple combination programme for CF treatment includes a cystic fibrosis transmembrane conductance regulator (CFTR) amplifier, a third generation corrector and a potentiator, known as PTI-428, PTI-801 and PTI-808, respectively.

All three components were discovered by Proteostasis and are designed to act synergistically through complementary actions which address specific dysfunctions of the CFTR protein, the underlying cause of the disease. PTI-428, PTI-801, and PTI-808 have active Investigational New Drug designations under the FDA and are currently in clinical trials in patients in the US and Europe.

Proteostasis plans to initiate a study into the triple combination programme this quarter. The programme has already received endorsement and a high strategic fit score from the Therapeutics Development Network (TDN), the Clinical Trial Network (CTN), the drug development arms of the Cystic Fibrosis Foundation (CFF) and the European CF Society (ECFS).

“Fast Track designation represents another positive step for the development of our triple combination therapy and underscores the serious unmet need that remains for the vast majority of CF patients,” Proteostasis CEO Meenu Chhabra said.

“We believe this designation, together with other recent designations from regulators and CF organisations following review of our results with PTI-428, PTI-801 and PTI-808, is recognition of the potential of these programmes in this disease.

“We believe combinations of CFTR modulators hold the promise of improving treatment efficacy for different segments of the CF population, including F508del heterozygotes and F508del homozygotes, where patients have limited access to treatment, are underserved by existing treatments or see a declining benefit in lung function over time.”

The FDA’s fast track programme is designed to simplify and accelerate the development of new drugs created to treat serious or life-threatening conditions. These medications often address a gap in the medical market, providing potential treatments for those with limited options. Under the fast track designation, investigational drugs are eligible for more frequent communications with the FDA regarding development plans and clinical trial design. Fast-tracked therapies may also be eligible for priority review if certain criteria are met.