The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics, and efficacy of JBT-101 in adult subjects with cystic fibrosis (CF).

An interventional, double-blind, randomized, placebo-control design will be used to test safety, tolerability, pharmacokinetics, and efficacy of JBT-101 in 70 subjects ≥ 18 and < 65 years of age with documented cystic fibrosis. There will up a screening period of up to 28 days, 84 days treatment period, and 28 days follow-up.

Inclusion Criteria:

• Documentation of a CF diagnosis as evidenced by 1 or more clinical features consistent with the CF phenotype and 1 or more of the following criteria:

  1. Sweat chloride equal to or greater than 60 mEq/L by quantitative pilocarpine iontophoresis test;
  2. Two well-characterized mutations in the CFTR gene

• FEV1 ≥ 40% predicted corrected

• Stable treatment of CF for 14 days before Visit 1

Exclusion Criteria:

• Severe or unstable CF, such as:

  1. Intravenous antibiotic treatment within 14 days before Visit 1
  2. Treatment with any corticosteroids > 10 mg per day or > 20 mg every other day oral prednisone or equivalent within 14 days before Visit 1

• Any one of the following values for laboratory tests at Screening:

  1. A positive pregnancy test (or at Visit 1);
  2. Hemoglobin < 10 g/dL
  3. Neutrophils < 1.0 x 10~9/L
  4. Platelets < 75 x 10~9/L
  5. Creatinine clearance < 50 ml/min according to modified Cockcroft-Gault equation
  6. Serum transaminases > 2.5 x upper normal limit
  7. Total bilirubin ≥ 1.5 x upper limit of normal

• Any other condition that, in the opinion of the Principal Investigator, is clinically significant and may put the subject at greater safety risk, influence response to study product, or interfere with study assessments.