uniQure gains on Factor IX activity data for hemophilia B gene therapy

uniQure N.V. (NASDAQ:QURE) added $8.13 (36%) to $30.93 on Thursday after reporting that all three patients who received hemophilia B gene therapy AMT-061 in a dose-confirmation Phase IIb trial achieved and sustained therapeutic levels of Factor IX activity. The company has started enrollment in the Phase III HOPE-B trial of AMT-061 in about 50 hemophilia B patients, and expects to begin dosing in 1Q19.

In the three severe hemophilia B patients in the open-label, U.S. Phase IIb trial, a single IV dose of 2x10^13 vector capsids (vc) per kg AMT-061 led to a mean Factor IX activity level of 31% of normal at six weeks after treatment as measured by an activated partial thromboplastin time (aPTT) assay. uniQure said the level exceeds the threshold for Factor IX levels generally considered sufficient to significantly reduce the risk of bleeding events, and cited epidemiological data showing that activity above 12% of normal is associated with substantial reduction or elimination of spontaneous bleeds and factor usage...