Ixinity Soon To Be Available in Larger Vial and Trial Likely in Younger Children with Hemophilia B, Aptevo Says

Aptevo Therapeutics provided an update on Ixinity, its hemophilia B therapy, that includes developing a larger 3,000 IU vial assay for patient convenience.

The company also plans to initiate a Phase 4 clinical trial in a pediatric patients, and to apply for Ixinity’s approval outside of the United States.

Hemophilia B results from a deficiency in clotting factor IX. Ixinity is an intravenously therapeutic that contains recombinant (made in the lab) coagulation factor IX (trenonacog alfa), which is targeted to compensate for a lack of factor IX.

Currently, Ixinity is indicated for hemophilia B patients ages 12 and older for control or prevention of bleeding episodes and for perioperative management (around the time of surgery).

“We reached an important milestone in our IXINITY program this year as IXINITY became cash flow positive for our organization,” Mike Adelman, senior vice president of commercial operations for Aptevo, said in a press release.

“With our manufacturing process stabilized and our commercial efforts in the U.S. now solidly on track, Aptevo is intensifying its focus on additional market expansion opportunities for IXINITY both within and outside the U.S. market,” added Adelman.

The response from the hemophilia B community regarding Ixinity indicates that a bigger vial size would be more convenient for patients, particularly from a dosing perspective, and would lead to more widespread use of the therapy.

Development and manufacturing of the new 3000 IU vial assay for Ixinity is underway, and Aptevo anticipates it being available to patients in mid-2019.

A Phase 4, or post-marketing, clinical trial of Ixinity is in the planning stages, and is expected to enroll about 20 pediatric hemophilia B patients under age 12 at one or more sites in the U.S.

Results previously released indicate that Ixinity is safe and well-tolerated in younger children, with outcomes comparable to those of the overall patient population evaluated in the pivotal clinical trial of Ixinity (NCT00768287). That Phase 2/3 study included patients starting at 5 years old.

At a 2017 scientific conference, the company reported that 11 of 12 patients under age 12 in the pivotal trial were given Ixinity infusions as prophylactic (preventive) treatment. In this group, the median number of bleeding episodes was 1.0, and the median annualized bleeding rate was 0.3.

According to a report released by the World Federation of Hemophilia, about 33% of hemophilia B patients in the United States are under 13 years of age.

Aptevo did not specify in its release those countries in which it also hopes to market Ixinity, which is now available only in the U.S. But Adelman said his company is “closely evaluating opportunities to license or partner distribution and marketing rights” for the therapy, a possibility “we are now positioned to pursue.”