Enrollment Underway in Phase 4 Trial of Ixinity in Hemophilia B Patients Under Age 12

A Phase 4 trial investigating Ixinity as a prophylactic treatment for children under age 12 with hemophilia B has reached the halfway mark for its enrollment target, Medexus Pharmaceuticals announced.

The international study (NCT03855280), taking place at sites in Brazil, Colombia, Moldova, South Africa, and Ukraine, continues recruiting eligible patients. More information can be found here.

“We are encouraged by the steady progress of our IXINITY Phase 4 pediatric clinical trial, as we … are on track to complete enrollment by the second calendar quarter of 2021,” Khaled Mohamed, director of regulatory affairs for Medexus, said in a press release.

Hemophilia B is caused by the deficiency of factor IX (FIX), an essential blood clotting protein. Ixinity, originally developed by Aptevo Therapeutics and now under Medexus, is a replacement therapy that contains a recombinant (lab-made) version of FIX. It is given intravenously (into a vein) for routine prophylaxis, for on-demand treatment to prevent bleeding episodes, and to manage blood loss during surgery.

It was approved in the U.S. to prevent bleeding in adults and children ages 12 and older with hemophilia B in 2015.

Positive safety and tolerability with Ixinity’s use was reported in a subgroup analysis of pooled clinical trial data, including a Phase 3 study (NCT01271868), covering 12 pediatric patients younger than 12, presented at a 2017 science conference.

This analysis also showed that Ixinity’s effectiveness in controlling bleedings in children was comparable to that seen in its pivotal Phase 3 trial (NCT00768287) in an overall patient population.

“Previously reported and pooled data from Phase 3 clinical trials demonstrated IXINITY to be safe and well tolerated in preventing and controlling bleeding episodes in previously treated children under the age of 12 with hemophilia B,” said Ken d’Entremont, CEO of Medexus. “We remain determined to advance our IXINITY Phase 4 pediatric clinical trial and look forward to providing further updates as we achieve key milestones.”

The Phase 4 trial, which began dosing this year, is evaluating the safety, efficacy and pharmacokinetics — the movement of a medicine into, through, and out of the body — of Ixinity’s use in up to 22 young children with moderate to severe hemophilia B.

Enrolled patients are divided in two groups: those younger than age 6, and those ages 6 through 11.

The trial consists of three distinct phases. After an initial evaluation of the safety and pharmacokinetic properties of a single dose of Ixinity, patient move to prophylactic (preventive) treatment with Ixinity, given twice weekly at doses of 35–75 international units (IU)/kg for about six months.

In its continuation phase, children may choose to be treated for six additional months.

Its main goal is changes in patients’ annualized bleed rate over the initial six months of treatment.

“We look forward to completing this current study, which we are hopeful will allow us to expand the product label to include the U.S. pediatric population below 12 years of age,” Mohamed said.

As children are “estimated to represent one-third of the hemophilia B population, a label expansion represents a possible expansion of the potential for IXINITY. Most importantly, we look forward to providing this important, additional therapy option to the pediatric population,” d’Entremont added.