VX-366 data

VRTX reported that a pilot Phase II trial of VX-366 in Italy showed tolerability, with no adverse events related to the agent. At the end of the 28-day treatment, levels of hemoglobin F were increased from 4.4-26 percent (mean of 6 percent) above baseline in the 7 of 12 patients who responded. At the end of a one-month follow-up, two more patients showed increased hemoglobin F, which is associated with improved symptoms of beta thalassemia and sickle cell anemia. The trial ended in 1995, and the data were presented at the Conference on Hemoglobin Switching, on Orcas Island, Washington.

Results of a Phase I trial will be published in the July Journal of Clinical Pharmacology. Escalating doses were tested (four doses from 14 to 400 mg/kg) with 4 patients receiving each dose, and 2 in each cohort treated with placebo. VX-366 was well tolerated and achieved blood levels in excess of the plasma concentrations that stimulate production of hemoglobin F. The half-life exceeded seven hours. ...