The sixth group in the trial (NCT03186677) of the therapy that Catalyst calls CB 2679d (ISU304) will include up to five people with moderate to severe hemophilia B. They will receive one intravenous administration of the treatment, followed by nine injections.
“The addition of this sixth cohort will allow us to build on the progressive increase in Factor IX activity levels — from severe to mild hemophilia — that we observed after six daily subcutaneous [injected] doses in Cohort 5 of this Phase 1/2 trial,” Nassim Usman, the CEO of Catalyst, said in a press release. “The Cohort 6 design will also allow us to evaluate the benefits of a single IV loading dose.”
Korean regulators’ decision was based on results showing that the blood clotting factor was effective in the fifth group, who received injections of it for six consecutive days.
The key finding was that the treatment increased by 16 percent the activity of blood clotting factor IX (FIX) — the one that’s missing in hemophilia B. The new formulation also stayed in the body longer than other versions.
During the treatment, and for five days afterward, researchers discovered no antibodies that could counter the therapy’s effectiveness. The main adverse effects were injection site reactions, including pain, skin irritation and redness.
The findings suggested that long-term use of injected CB 2679d “has the potential to maintain FIX activity in the high mild hemophilia to normal range,” the researchers wrote.
The company expects preliminary results in the sixth group by the third quarter of 2018, and additional findings by the fourth quarter. Catalyst will use the information to help design future trials, including a Phase 2b study expected to start in the third quarter of 2018, Usman said.
The Phase 1/2 trial is being conducted in three centers in South Korea in collaboration with ISU Abxis.