Boehringer Ingelheim has announced its antibody BI 764524 has shown positive results in the HORNBILL Phase 1/2a trial of patients with diabetic macular ischemia (DMI).

BI 764524 is a humanised monoclonal anti-Sema3A antibody. It is designed to re-vascularise ischemic areas and minimise leakage in the retina.

HORNBILL study evaluated the tolerability of BI 764524 in individuals with diabetic retinopathy (DR) with DMI who have previously been treated with pan-retinal photocoagulation.

The Phase 1/2a trial comprised a single rising dose (SRD) followed by a multiple-dose (MD) segment in which BI 764524 was administered via intravitreal injection.

In the non-randomised, open-label, SRD part, 12 patients were administered with 0.5mg, 1mg, or 2.5mg intravitreal BI 764524 doses.

Its primary endpoint was defined as the number of patients with dose-limiting events (DLEs) and secondary endpoints were the number of patients with drug-related adverse events (AEs) and any ocular AEs.

The randomised, masked, sham-controlled MD part administered three intravitreal 2.5mg BI 764524 doses or a sham injection at four-week intervals in 31 patients.

The primary endpoint was the number of patients with drug-related AEs and secondary endpoints included change from baseline in the foveal avascular zone (FAZ) area, number of patients with ocular AEs, best corrected visual acuity (BCVA), and central retinal thickness (CRT).

According to the results, BI 764524 was well received upon intravitreal administration of both single and multiple doses.

It successfully met its primary safety endpoints and demonstrated initial indications of potential effectiveness.

Additionally, the study met its predetermined criteria for early efficacy by stabilising the foveal avascular zone area compared to the sham at week 16.

Boehringer Ingelheim said the results indicate a potential positive impact of BI 764524 on retinal non-perfusion, with the potential to impede the progression of capillary loss.

The forthcoming CRIMSON trial, a Phase 2b study, will further evaluate the safety and efficacy of BI 764524 in patients with DR, with recruitment slated to commence later this year.

Boehringer Ingelheim retinal health head Ulrike Graefe-Mody said: “Today’s results are an important step towards achieving our aspiration of developing precision therapies delivering the right treatment for the right patient at the right time to prevent vision loss before irreversible damage occurs.”