Boehringer raises hope of oral drug for diabetic eye disease

People living with diabetic macular oedema (DME) currently have to undergo regular injections into their eyes to treat the condition, but an oral alternative may be on the horizon.

Boehringer Ingelheim has raised hopes of a more patient-friendly option with the start of phase 2 testing of BI 1815368, described as a potentially first-in-class medicine that is thought to reduce the permeability of newly formed blood vessels in the retina, which can leak fluid and cause vision loss in DME.

The study, dubbed THULITE, will test BI 1815368 in around 300 subjects with centre-involved DME – where blurry or distorted vision occurs in the central field of vision – and is due to generate results in 2027, according to its listing on the clinicaltrials.gov register.

DME is the top cause of vision loss in people living with diabetes, affecting around 10% of all diabetics with around 21 million cases worldwide. At the moment, treatment is carried out with intravitreal injections of VEGF-targeting drugs like Roche's Vabysmo (faricimab) and Lucentis (ranibizumab), Bayer/Regeneron's Eylea (aflibercept), and steroids, sometimes as often as once per month.

One other option is Roche's implant-based treatment Susvimo, also based on ranibizumab, which was approved for DME earlier this year and – while still an invasive treatment – only requires administration once every six months.

According to Boehringer, current treatment options are burdensome for both patients and caregivers, particularly if both eyes are affected by DME, and an oral treatment would offer a real step forward – offering the potential for at-home treatment and simultaneously addressing both eyes with, or at risk of, the disease.

"DME is one of the most challenging complications of diabetes, and as vision worsens, people may lose their independence and rely more on loved ones," commented Dario Madani, chief executive of patient advocacy group PRO RETINA, which has worked with Boehringer on its DME clinical programmes."

"Patients and caregivers may have to balance work, family obligations, and other diabetes complications, while managing their eye condition," he added. We need treatment options that could reduce this burden."

Boehringer has made developing new therapies for serious eye diseases a key pillar of its R&D strategy, and BI 1815368 is the fourth investigational compound for its eye health portfolio to move into mid-stage clinical testing.

Last year, it started the CRIMSON trial of BI 764524, an anti-Sema3A antibody pitching to become the first therapy for diabetic macular ischaemia (DMI), while in May it began the JADE trial of BI 1584862, a phospholipid modulator in development for geographic atrophy (GA). It is also developing an antibody fragment drug, codenamed BI771716, which is also a potential treatment for GA.

The privately held German group has said its pipeline is currently the best in its 139-year history, with 25 new treatments set for launch before 2030.