Phase 2b Trial of Dalcinonacog Alfa for Hemophilia B is Proceeding

Catalyst Biosciences announced the beginning of enrollment for a Phase 2b clinical trial for dalcinonacog alfa (DalcA) in people with Hemophilia B.

Hemophilia B is caused by the lack of a functional Factor IX clotting protein. Like many available therapeutics for Hemophila B, DalcA is essentially a lab-manufactured version of this protein. DalcA aims to be more stable than other available therapeutics and to be used for prophylactic (preventive) treatment, rather than only in acute situations.

DalcA also is designed to be administered either intravenously (directly into the bloodstream) or subcutaneously (under the skin), which would make it more convenient for patients to use.

In a small proof-of-concept Phase 1/2 trial (NCT03186677), patients were started on intravenous DalcA and then transitioned to subcutaneous DalcA. They were monitored primarily for adverse events (side effects), as well as the levels of Factor IX in their blood.

“The data from our Phase 1/2 clinical study demonstrated that DalcA is highly efficacious for the treatment of hemophilia B and can achieve Factor IX activity levels well above the 12% expected to prevent spontaneous bleeding,” Nassim Usman, PhD, president and CEO of Catalyst said in a press release.

The levels of Factor IX reported in the study ranged from 11.5-18% (median 16%), which is well within the typical range for mild hemophilia (5-40%), in five patients after six days.

The Phase 2b trial will include up to six individuals with hemophilia B. They will be given a single intravenous dose of DalcA, followed by daily doses of DalcA given subcutaneously for 28 days. The trial will be open-label, meaning both the clinician and the patient will know what is being administered (that is, there will be no placebo).

Patients in the Phase 2b trial will be monitored to see whether Factor IX levels can be maintained above the 12% level to prevent spontaneous bleeding. Researchers also will examine the pharmacodynamics and pharmacokinetics of DalcA — how the compound affects the body and how the body affects the compound, respectively — and will examine the safety of DalcA and monitor for the development of antibodies targeting it.

“We anticipate that this Phase 2b study will further demonstrate DalcA’s safety and efficacy as a subcutaneous prophylactic treatment option,” Usman said.

The trial is expected to conclude in late 2019. Screening for required participants has been completed, and the trial isn’t currently enrolling additional patients. However, a future Phase 3 trial is expected to recruit more participants.

DalcA has been granted orphan medicinal product designation in Europe to treat individuals with hemophilia B and orphan drug designation by the U.S. Food and Drug Administration (FDA).