OPTION 2: A Trial to Assess the Safety and Efficacy of MS1819 in Enteric Capsules in Patients With Cystic Fibrosis

This is a Phase 2, open-label, multicenter, 2, 2x2 crossover study assessing the safety and efficacy of MS1819, 2240 mg/day vs porcine PERT, and 4480 mg/day vs porcine PERT given at the same dose and dosing regimen that was being administered during the pre-study period. MS1819 will be administered in enteric capsules.

MS1819 will be assessed in a 2x2 crossover including approximately 30 patients completing both periods. Fifteen patients will be randomized to the MS1819 2240 mg/day vs PERT arm, and 15 patients will be randomized to the MS1819 4480 mg/day vs PERT arm. Patients in each arm will further be randomized to receive either the sequence consisting of MS1819 for 3 weeks followed by PERT for another 3 weeks or the opposite sequence of treatments, PERT for 3 weeks followed by MS1819 for another 3 weeks.The coefficient of fat absorption (CFA) will be measured at the end of each 3 week study period. Patients enrolled into the extension phase (EP) will be composed of patients who have completed the crossover phase of OPTION 2.

Inclusion criteria

• Cystic fibrosis, based on 2 clinical features consistent with CF, plus either a new/historic sweat chloride ≥60 mmol/L (measured while not on a CFTR modulator) or genotype.
• Under stable dose of porcine PERT
• A fair or better nutritional status
• Fecal elastase <100 µg/g
• Standard-of-care medications including CFTR modulators are allowed

Exclusion criteria

• History or diagnosis of fibrosing colonopathy
• Any chronic diarrheal illness unrelated to pancreatic insufficiency
• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) level ≥5 ×upper limit of normal (ULN), or total bilirubin level ≥1.5 ×ULN at the Screening visit
• Feeding via an enteral tube during 6 months before screening
• Forced expiratory volume ≤30% at the Screening visit