NOVEL VX-809 HYBRIDS AS CORRECTORS OF F508del- CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR (CFTR) PROTEIN

Cystic fibrosis (CF) is an autosomal recessive genetic disease that affects different organs as the lungs, the digestive system and the reproductive tract, also impacting on the growth of subjects. To date, the known CFTR gene mutations are more than 2000, but in particular the most widespread is the deletion of a phenylalanine at position 508 that involves the synthesis of a defective protein, that it is not able to lead the correct folding and is degraded early in the proteasome. When some mutated CFTR proteins reach the plasma membrane (PM), the activity of the channel is impaired. Today, in addition to symptomatic therapies, molecules have been developed against the basic defect of CFTR, in particular they are small molecules called modulators, including potentiators and correctors. The potentiators act on the gating of CFTR allowing the correct opening, while the correctors save the CFTR protein allowing it to obtain the correct conformation and stabilization at the PM. The first corrector to be approved was VX-809 called Lumacaftor (by Vertex Pharmaceuticals), for homozygous patients for the F508del-CFTR mutation. The VX-809 was then used in combination with the potentiator VX-770 in the Orkambi (by Vertex Pharamaceuticals) formulation to achieve a better effect. Since VX-809, both alone and in combination with VX-770, shows some defects, it became necessary to search new molecules with similar mechanism of action, but with fewer side effects. In this regard Vertex designed a corrector called VX-661, which acts with similar mechanism of action, but has better pharmacokinetic characteristics. Despite recent advances in drug therapy of CF and the improvement of patients' well- being, there are still many problems that arise; on the one hand, the study of active molecules against more rare mutations is necessary, on the other hand the discovery of more powerful molecules than those commercially available. In this thesis I report the synthesis, characterization and purification of molecules active as correctors, of which both biological evaluation and molecular docking studies have been carried out. In particular starting from the structure of a molecule previously synthesized by my team, called 2a, and studying its portion, I found a common backbone to be able to decorate with different functional groups for investigating the effect of each chemical group on the biological activity. Hence, I got a series of more active compounds, which showed higher potency than both the progenitor 2a (EC50 = 0,08 μM) and the commercial VX-809 (EC50 = 2,60 μM), whose activity was deepened with further biochemical assays and tested in combination with other correctors in order to study synergic or additives effects. Through a multidisciplinary approach (bioinformatic, chemistry and biochemistry), it was possible to obtain promising molecules as correctors of F508del-CFTR, in particular more potent than the 4 initial prototype, such as 34 (EC50 = 0,02 μM), 42 EC50 = 0,07 μM), 70 (EC50 = 0,06 μM), 74 (EC50 = 0,03 μM) and 81 (EC50 = 0,03μM).