Nivalis Therapeutics has enrolled the last patient in the larger of two Phase 2 clinical trials evaluating the company’s lead clinical candidate, N91115, for the treatment of cystic fibrosis patients with two faulty copies of the F508del mutation in the CFTR gene. The drug will be tested as an add-on therapy to FDA-approved Orkambi (lumacaftor/ivacaftor).
The last patient enrolled was also given their first study dose, the company said.
N91115 works through a novel mechanism of action, the S-nitrosoglutathione reductase (GSNOR) inhibition. This mechanism restores GSNO levels, modifying the proteins responsible for CFTR protein degradation and stabilizing the defective CFTR protein responsible for cystic fibrosis development inside the cell and at the cell surface.
Preclinical tests showed the stabilizing effect of the drug, which increased and prolonged the function of the CFTR protein and may also lead to an increase in chloride secretion.
The Phase 2 trial, “Study of N91115 in Patients With CF Homozygous for the F508del-CFTR Mutation (SNO-6),” will measure, as a primary clinical efficacy outcome, the change in forced expiratory volume in one second (FEV1; a lung function measure) from baseline — before the study — to 12 weeks after treatment with N91115. The results will be compared to a placebo treatment.
The 16-week, 138-patient study will include testing of two doses of N91115, 200 mg and 400 mg, administered to patients homozygous for the F508del-CFTR mutation and being treated with Orkambi. After 12 weeks of treatment, there will be a four-week withdrawal and follow-up period.
Colorado-based Nivalis also announced that the name “cavosonstat” has been approved for N91115 by the United States Adopted Names (USAN) Council, and the drug will now be referred to by this name.
“Completing enrollment in this Phase 2 study represents a critical milestone in our clinical development program for cavosonstat and moves us closer to our goal of bringing our novel stabilizer to people with CF,” said Nivalis President and CEO Jon Congleton, in a press release.
Congleton thanked the study participants, their families, the clinical trial sites, and the CF community for their support, adding “we look forward to the topline results of this study by the end of this year.”