NX-13 activation of NLRX1 reduces intracellular reactive oxygen species and decreases inflammation in animal models of colitis. A phase 1a trial demonstrated a gut-selective pharmacokinetic (PK) profile with good tolerability. This phase Ib study aimed to evaluate the safety, tolerability, and PK of NX-13 in patients with active ulcerative colitis (UC).
We conducted a multicenter, randomized, double-blinded, placebo-controlled trial of NX-13 in patients with active UC. Patients with a Mayo Clinic Score of 4-10 were randomly assigned (3:3:3:1 ratio) to three NX-13 oral dose groups (250mg Immediate Release (IR), 500mg IR, or 500mg Delayed Release (DR) or placebo) once daily for 4 weeks. Safety and PK were the primary and secondary objectives, respectively.
Thirty-eight patients (11 females) were recruited and randomized to placebo (5), NX-13 250mg IR (11), NX-13 500mg IR (11), or NX-13 500mg DR (11) and received at least one dose. There were no Serious Adverse Events (SAEs) or deaths during the trial. One patient (500mg DR, 1/11) withdrew for worsening of UC and a second (500mg IR, 1/11) on the last day of treatment after a panic attack associated with atrial fibrillation. In the efficacy population (36 patients), clinical improvement in rectal bleeding and stool frequency scores relative to placebo were seen as early as week 2 and endoscopic response was seen at week 4.
NX-13 was generally safe and well tolerated with early signs of rapid symptom and endoscopic improvement. This novel mechanism of action warrants further investigation. ClinicalTrials.gov: NCT04862741.
© The Author(s) 2023. Published by Oxford University Press on behalf of European Crohn’s and Colitis Organisation.
