CF Foundation Therapeutics to Give Up to $5M to Spyryx for Phase 2 Trial of SPX-101

Cystic Fibrosis Foundation Therapeutics (CFFT) will increase funding to support Spyryx Biosciences‘ Phase 2 trial assessing SPX-101 in people with cystic fibrosis. The funding is part of an award Spyryx received in 2015 from CFFT, the Cystic Fibrosis Foundation‘s nonprofit drug discovery and development affiliate.

The revised funding agreement states that Spyryx will receive up to $5 million to support the trial, named HOPE-1.

SPX-101 is a drug designed to increase the amount of liquid on the airway surfaces (airway hydration), which makes clearing mucus easier — a feature that’s defective in patients with cystic fibrosis. The drug acts on epithelial sodium channels (ENaC), and so SPX-101 acts independently of the underlying genetic mutations that cause cystic fibrosis.

Data from a recent Phase 1 trial of the drug in healthy volunteers showed the drug to be safe and well tolerated. The data was presented as an E-poster at the European Cystic Fibrosis Society (ECFS) Conference held June 7-10 in Spain.

The trial recruited 32 adults without a history of lung disease and with a normal lung function. They were treated twice-daily for up to 14 days with one of four doses of SPX-101 — 10 mg, 30 mg, 60 mg, or 120 mg — or placebo. The inhaled drug was administered using the eFlow nebulizer system (PARI Pharma, Starnberg, Germany), which is also an investigational product.   

The presentation, “Safety and Pharmacokinetics of 14-Day Dosing with SPX-101 in Healthy Human Subjects,” demonstrated that the participants did not experience changes in lung function. They also did not experience abnormal serum potassium levels or bronchoconstriction (airway constriction) and no serious adverse events.

“The data from the Phase 1 study validate the safety of SPX-101’s novel mechanism of action via the internalization of epithelial sodium channels with a small, inhaled peptide,” Alistair Wheeler, MD, chief medical officer of Spyryx, said in a press release.

“Our ability to deliver the peptide without significant systemic exposure or any reports of hyperkalemia [high potassium levels] are key to advancing the program into a meaningful efficacy study,” Wheeler added. “We are thrilled that CFFT has generously provided additional funding to support our Phase 2 study. We remain committed to bringing this new potential treatment to people living with CF and look forward to further evaluating this innovative peptide.”

SPX-101 is currently undergoing a small Phase 1b trial (NCT03056989) in patients with cystic fibrosis. In preclinical testing, the drug improved survival and mucus clearance in a mouse model of cystic fibrosis.