NEW YORK (TheStreet) -- Vertex Pharmaceuticals (VRTX) is now within weeks or even days of announcing top-line results on its two phase 3 Traffic and Transport studies for cystic fibrosis, results that will almost certainly move the stock wildly in one of two directions. Both studies are testing a combination therapy of lumacaftor and Kalydeco (ivacaftor) on CF patients with the F508del mutation, the majority of CF patients.
Judging by the FDA's history of approvals with CF, Vertex's phase 2 data for the combination therapy and the science behind the treatment, the chances of approval are high.
The Science Behind Traffic and Transport
Adam Feuerstein already discussed the phase 2 data last week, but the theory behind lumacaftor and Kalydeco working together synergistically is important to grasp in order to get a better understanding of what's going on here.
Kalydeco is already approved since 2012. The problem is, it is only effective on CF patients with the G551D mutation, which includes about 4%-5% of CF patients. This specific mutation alters one amino acid in the CFTR protein, the malfunctioning protein responsible for cystic fibrosis. While all cases of CF involve a malfunctioning CFTR protein, that protein can malfunction for different reasons due to different mutations. In the case of G551D, CFTR can still Traffic to the correct area in the cell, at the cell surface. It just can't do its job very well once there, and its job is to Transport chloride. Kalydeco helps by chemically forcing the chloride channel open, enabling a hobbled and mutated CFTR protein to do its job.