Spyryx Biosciences has reported positive results from the first cohort of Hydration for Optimal Pulmonary Effectiveness (HOPE-1) Phase ll clinical trial of SPX-101 to treat patients with cystic fibrosis (CF).
The exploratory, randomised, placebo-controlled, 28-day trial has so far enrolled 46 adult CF patients who are independent of CFTR mutation type. The trial aims to enrol a total of 90 patients.
The trial’s first cohort compared a high dose (120mg), a low dose (60mg) and placebo in patients with baseline percent predicted forced expiratory volume in 1 second (ppFEV1) of 40%-80%.
During the trial, SPX-101 was given by nebulisation through a new, silent, rapid and portable nebuliser, ENaC, while ppFEV1 was measured at days seven, 14 and 28.
The cohort’s primary efficacy endpoint was the absolute change from baseline in ppFEV1 after 28 days.
The new results have shown that at day 28, a dose-related benefit was witnessed with the high dose showing a placebo adjusted increase of 5.2% in ppFEV1.
It was also found that with the high dose, ppFEV1 separation from placebo was achieved by day seven and it continued through the treatment period.
In the subgroup of moderate patients with baseline pp FEV1, less than 55% of the high dose response at day 28 was observed at 8.3%. SPX-101 was also reported to be safe and well tolerated with the most common adverse events being cough and sputum production.
HOPE-1 principal investigator Isabelle Fajac said: “There is urgent need for an effective and safe treatment to promote airway clearance for all patients with CF, regardless of their genetic mutation.
“The data shows that with this novel mechanism – internalisation of ENaC – it is possible to inhibit ENaC in the airways without impacting potassium concentrations in the blood, and this has been a goal in research for the past 30 years.
“This data is also very promising in terms of respiratory benefit gained from ENaC inhibition.”
Spyryx plans to complete the Phase ll trial soon and start preparations for the Phase lll trial of SPX-101 for CF next year.