Denecimig every two weeks shows low bleeding rates in FRONTIER4 interim analysis

A 26-week interim analysis of FRONTIER4 assessed denecimig (Mim8), an investigational subcutaneous factor VIII–mimetic bispecific antibody, given every two weeks for hemophilia A with or without inhibitors. The open-label phase 3 extension included 37 patients aged ≥12 years who had participated in the phase 2 study and at least 12 weeks of its extension. Patients received body-weight–tiered dosing. The primary endpoint was treatment-emergent adverse events; secondary endpoints included treated bleeds, injection site reactions, anti-denecimig antibodies and plasma concentrations.

Sixty treatment-emergent adverse events occurred in 20 patients. Most were mild or moderate (98.3%), considered unlikely to be related to denecimig (75.0%), and resolved within the analysis period (90.0%). None led to permanent discontinuation or were fatal. Two patients reported 14 injection site reactions. Plasma concentrations remained stable through week 26. The estimated mean annualized bleeding rate was 0.38 bleeds per patient-year, and 83.8% of patients experienced no treated bleeds.

The findings support further evaluation of every-two-week prophylaxis, but this interim analysis had no reported comparator and involved a small, selected population with prior denecimig exposure averaging 1.73 years in the phase 2 study. Longer follow-up and comparative evidence are needed to characterize safety and relative efficacy. Only the abstract was available for this assessment.