UK MHRA approves continued enrollment in BioMarin’s phase 1/2 study of BMN 270

Following the enrollment of the initial nine patients in the study, the company suspended dosing of patients after observing increases in alanine aminotransferase (ALT) levels that crossed a pre specified threshold.

BioMarin reviewed safety and efficacy data on the nine patients with the MHRA, and depending on its review, the regulator approved to restart the trial.

The company plans to restart enrollment before the end of this year.  Depending on protocol amendments, three patients will be enrolled at a dose of 4 x 10¹³ vg/kg, and an additional three may be enrolled at this dose or the earlier tested high dose of 6 x 10¹³ vg/kg. 

BioMarin said in about six additional patients, the requirement for prophylactic corticosteroids has been removed and the threshold for beginning therapeutic corticosteroids has been increased.

The company will use safety and efficacy data from these patients to start the proposed phase 2b study in the second half of next year.

BioMarin Pharmaceutical chief medical officer Hank Fuchs said: "We are pleased that MHRA has approved the resumption of enrollment of the BMN 270 study, as well as the study amendments. 

“We believe that the amendments will allow us to optimize the design of a robust Phase 2b clinical trial, which potentially could support an accelerated approval by health authorities.”

In mouse models of hemophilia A, BMN 270 restored factor VIII plasma concentrations to levels estimated to be adequate for normal clotting in humans.

Hemophilia A is a genetic disease caused by the deficiency of clotting factor VIII. It mostly affects males, occurring in about one in 5,000 male births.