SPX-101, an investigational drug for the treatment of cystic fibrosis (CF) being developed by Spyryx Biosciences, has shown to be a safe, stable, and efficient therapy in animal models of the disease, according to results recently presented at the 30th Annual North American Cystic Fibrosis Conference (NACFC), held in Florida.

A Phase 1 clinical trial evaluating the treatment’s safety is now finishing, and the data presented supports its further development.

CF patients have difficulties in properly clearing their airways of mucus, leading to bacterial lung infections. SPX-101 mimics the function of a protein called SPLUNC-1, which plays an important role in controlling airway surface hydration and mucus clearance. By replacing SPLUNC1 activity, SPX-101 is designed to restore mucociliary clearance, and to help remove bacteria and foreign particles from the lungs.

The drug’s mechanism of action is independent of the genetic mutations causing CF, which is why SPX-101 is considered a potential disease-modifying therapy for all CF patients.

“We are excited to share these positive results with the community of researchers and physicians who are all dedicated to finding breakthrough treatments for cystic fibrosis,” John Taylor, Spyryx’s president and CEO, said in a press release. “We believe that SPX-101 represents the first therapeutic opportunity to leverage a natural, biological mechanism that is important to the maintenance of normal mucus clearance.”

Results obtained with SPX-101 were presented at NACFC 2016 as three posters.

The first poster, “SPX-101 Is A Potent Promoter Of Enac Internalization, Capable Of Regulating Mucus Hydration In Vitro And In Vivo,” showed that SPX-101 delivered by nebulization re-established a molecular pathway that controls fluid levels on the airway surface, and restored mucociliary clearance, to improve survival in animal models of CF.

The second, “The Scale-Up And Productization Of SPX-101 For Preclinical Inhaled Toxicology,” showed that SPX-101 remains stable under long-term and accelerated manufacturing conditions.

The third poster, “SPX-101 Demonstrates Safety As An Enac-Affecting Therapy For The Treatment Of Cystic Fibrosis,” demonstrated the favorable safety and tolerability profile of inhaled SPX-101 in animal models of CF, showing that the proposed clinical development plan for this therapy has an appropriate safety margin.

“These studies provide important data demonstrating low toxicity and supporting the proposed clinical doses, with no dose-limiting toxicity in the lung or systemically, and with no significant systemic bioavailability,” said Alistair Wheeler, MD, chief medical officer at Spyryx.

“We believe these non-clinical data, combined with the exciting results from the single-ascending dose portion of our Phase 1 safety study, and the pending data from the multiple-ascending dose portion of the Phase 1, supports our intention to move forward with early entry into the clinic in our Phase 2 clinical development plan,” Wheeler added.