Background: The peptide drug Moli1901 activates an alternative chloride channel that is present in cystic fibrosis (CF) nasal and airway epithelia. Doing so bypasses the dysfunctional CF transmembrane regulator.
Study objective: To determine whether intranasal Moli1901 is safe, tolerable, and will induce chloride transport in healthy volunteers and CF subjects.
Design: A single-blind (to the participant), randomized, placebo-controlled, dose-escalation study of intranasal Moli1901 was performed in four healthy non-CF participants and four participants with CF. Drug or placebo was administered by intranasal superfusion, and nasal potential difference responses were continuously monitored during sequential dose escalations at 1-min intervals from 0.01 through 10 μmol/L.
Results: Neither Moli1901 nor placebo were associated with visible changes such as edema, erythema, drainage, secretions, or ulcer formation. No elevations in lactate dehydrogenase, albumin, or cell counts were observed in nasal lavage fluid after administration. No clinically significant changes in FEV1 or other toxicity parameters occurred. Changes in the nasal potential difference (NPD) induced by chloride-free, amiloride-containing Ringers solution and by subsequent superfusion with the same solution plus 10 μmol/L isoproterenol were consistent with both an acute and a sustained change in chloride transport in response to Moli1901. A similar analysis of NPD in the four CF participants demonstrated an acute response that resolved more quickly. A dose-response relationship to Moli1901 was observed in non-CF participants, but a greater range of variability within the CF participants contributed to the lack of a clear dose-response relationship in this group.
Conclusion: Moli1901 stimulates chloride transport in normal and CF nasal epithelia in vivo, but may have a shorter duration of action in CF participants.