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The HORNBILL study: A Phase I/IIa trial examining BI-X in patients with diabetic macular ischemia


Chirag Jhaveri, MD


Chirag Jhaveri, Quan Dong Nguyen, Sobha Sivaprasad, Maged Habib, Andrea Giani, Elizabeth Pearce

1. Chirag Jhaveri:

Retina Consultants of Austin, Austin, TX, USA

Austin Research Center for Retina, Dell Medical School, Austin, TX, USA

2. Quan Dong Nguyen:

Byers Eye Institute, Stanford University School of Medicine, Stanford, CA, USA

3. Sobha Sivaprasad:

NIHR Moorfields Biomedical Research Centre, London, UK

4. Maged Habib:

South Tyneside and Sunderland NHS Foundation Trust, Sunderland, UK

5. Andrea Giani:

Boehringer Ingelheim International GmbH, Ingelheim am Rhein, Germany

6. Elizabeth Pearce:

Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, USA


Purpose: Diabetic macular ischemia (DMI) is a complication of diabetic retinopathy (DR) that currently has no approved treatment and can result in vision loss. The HORNBILL study (NCT04424290) is investigating BI-X in subjects with proliferative DR previously treated with panretinal photocoagulation and DMI.
In the completed single rising dose (SRD) part, DMI was defined using optical coherence tomography angiography (OCTA) as any disruption in retinal vascularity in the superficial and/or deep retinal plexus. Twelve subjects received 0.5 (n=3), 1.0 (n=3), or 2.5 mg (n=6) intravitreal BI-X. The primary SRD endpoint was the number of dose-limiting events. In the ongoing multiple-dosing (MD) part, DMI was defined using OCTA as a foveal avascular zone ≥0.5 mm2. Subjects in the MD part (planned N=30) are receiving three doses of 2.5 mg BI-X or sham injection over 8 weeks (with 16 weeks’ follow-up). The primary MD endpoint is the number of subjects with drug-related adverse events (AEs).
In the SRD part no dose-limiting events or drug-related AEs were reported. There were eight AEs: five ocular and procedure related; two ocular but not procedure related; one neither ocular nor procedure related. The SRD part identified preliminary signs of efficacy: best corrected visual acuity improved by 5.3 (1.0 mg) and 4.0 letters (2.5 mg). To date, 29 subjects have been enrolled into the MD part. Recruitment is now complete.
Single doses of BI-Xwere well tolerated and showed signs of efficacy. The MD part is further evaluating the safety and efficacy of BI-X in subjects with DMI.

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