Positive results from Factor IX-CTP comparative study in hemophilic mice

PROLOR Biotech, Inc., today reported positive results from a comparative study of its biobetter longer-acting version of the hemophilia drug Factor IX (Factor IX-CTP) in Factor IX-depleted hemophilic mice.  The study was designed to measure the potential increase in clotting activity and duration of therapeutic effect of PROLOR's long-acting CTP-modified Factor IX when compared with commercially available recombinant Factor IX.  Factor IX is indicated for the treatment of acute bleeding episodes and as therapy for prevention of bleeding in hemophilia B patients.

In the study, Factor IX-CTP, when compared with commercially available Factor IX, demonstrated a significantly longer duration of clotting activity in the hemophilic mice model.  Bleeding episodes were also significantly shorter and less intense for the group treated with Factor IX-CTP.  In addition, none of the animals treated with Factor IX-CTP had any spontaneous re-bleeding events, compared with a 50% incidence of re-bleeding events for the group treated with commercial Factor IX and an 83% incidence of re-bleeding events for the untreated group.

The new study results support previous preclinical studies that demonstrated significant improvements in the half-life of Factor IX-CTP compared to commercially available Factor IX.

"We believe that this study further validates CTP as a leading platform for developing long-acting therapeutic proteins, demonstrating that the fundamental ability of CTP to extend duration of therapeutic effect while increasing biological activity is consistent across various types of proteins," noted Shai Novik, President of PROLOR.  "The utility of CTP has previously been validated for non-enzyme proteins, such as Merck's hormone therapy Elonva® and PROLOR's human growth hormone, interferon beta and erythropoietin.  With this successful Factor IX study, we have now additionally confirmed the applicability of CTP technology for the development of biobetter enzymes."

"We believe there is great need among hemophilia patients and their physicians for therapies that will provide prolonged protection from bleeding," said Dr. Abraham Havron, CEO of PROLOR.  "The encouraging efficacy seen in our preclinical hemophilia study, together with the impressive half-life extension seen in our previous studies, show that Factor IX-CTP may be able to reduce the number of injections needed by hemophilia B patients to once-weekly or less."

Dr. Havron added, "We believe that these results further confirm the clinical potential of Factor IX-CTP to become an important long-acting therapy for the treatment of acute bleeding episodes and for prevention of bleeding in hemophilia B patients.  We are moving forward with our plan to initiate our first clinical study of Factor IX-CTP in hemophilia in early 2012."