A Phase 2a, Randomized, Placebo-Controlled, Double Blind Multiple Ascending Dose Study in Patients With Cystic Fibrosis Carrying the 3849 +10 Kb C->T Mutation to Evaluate the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of SPL84
The goal of this clinical trial is to learn if drug SPL84 is safe for adult patients with cystic fibrosis (CF). It will also learn if the drug works to treat works to treat CF with a specific mutation (3849 +10kb C--\>T). The purpose of this research study is to test the safety and effectiveness of multiple doses of the study drug, SPL84. Researchers will compare drug SPL84 to a placebo (a look-alike substance that contains no drug) to see if drug SPL84 is safe and if it works to treat CF. In cohorts 1-3, SPL84 will be tested as a monotherapy, and in Cohort 4, SPL84 will be tested in participants who are already stable on CFTR modulator therapy. Participants will take drug SPL84 or a placebo by inhalation every week for 9 weeks (cohorts 1-3) or 12 weeks (cohort 4) and visit the clinic approximately weekly for checkups and tests.
• Diagnosis of CF and two CF causing mutations; 3849+10 Kb C-\>T mutation on one allele in the CF transmembrane conductance regulator (CFTR) gene (homozygote or compound heterozygote). Source documentation from a certified genetic laboratory is required.
• Body mass index (BMI) of ≥ 17 kg/m2.
• FEV1 40-90% predicted at screening.
• Non-smokers or vapers for at least 180 days (6 months) prior to screening, per participant report.
• Diagnosis of CF and two CF causing mutations; 3849+10 Kb C-\>T mutation on one allele in the CF transmembrane conductance regulator (CFTR) gene (homozygote or compound heterozygote). Source documentation from a certified genetic laboratory is required.
• Body mass index (BMI) of ≥ 17 kg/m2.
• FEV1 40-80% predicted at screening.
• Non-smokers or vapers for at least 180 days (6 months) prior to screening, per participant report.
• Stable adherence to standard use of Trikafta/Kaftio or Alyftrek for at least 3 months, or Alyftrek for 1 month after switching from Trikafta/Kaftio, according to prescribing information.