Vertex falls after ending development of liver disease drug VX-864

Vertex Pharmaceuticals is trading lower after the company announced that VX-864 will not advance into late-stage development. Vertex said that in a Phase 2 proof-of-concept study, VX-864 achieved statistically significant increases in mean functional alpha-1 antitrypsin levels of 2.2 to 2.3 micromolar from baseline in people with alpha-1 antitrypsin deficiency with the PiZZ genotype, across three dose groups of VX-864 compared to placebo. It added, however: "Although results provide proof-of-mechanism, the magnitude of treatment effect observed in this study is unlikely to translate into substantial clinical benefit. As such, Vertex will not advance VX-864 into late-stage development and instead will advance additional novel small molecule correctors with the potential for increased clinical efficacy into the clinic." Vertex shares in after-hours trading are down 11%, or $24.77, to $192.00.