Ingelheim, Germany, July 7, 2025 – Boehringer Ingelheim announced today the commencement of the Phase II THULITE clinical trial. This study will assess the effectiveness, safety, and how well patients tolerate BI 1815368 as a potential oral treatment for improving vision in individuals with diabetic macular edema (DME).1
DME is a primary cause of vision impairment among people with diabetes, affecting over 21 million individuals worldwide, which accounts for up to 10% of those with diabetes.2,3,4 Current DME treatments necessitate frequent visits to a retina specialist for eye injections, with each appointment addressing only one eye. This places a significant burden on patients and their caregivers, particularly when both eyes require treatment.5,6
“DME stands out as one of the most difficult complications of diabetes, potentially leading to a loss of independence and increased reliance on family as vision deteriorates,” stated Dario Madani, CEO of PRO RETINA, whose members participate in Boehringer’s DME Clinical Program Steering Committee. “Patients and caregivers often have to juggle work, family duties, and other diabetes-related issues while managing their eye condition. We need treatment options that can alleviate this burden.”
In DME, fluid leaks into the macula, the central part of the retina vital for the clear vision needed for daily activities.3 BI 1815368 aims to treat and prevent this fluid leakage by reducing the permeability of newly formed blood vessels. Unlike existing DME treatments, it is administered orally, offering the possibility of at-home treatment and simultaneous treatment of both eyes, whether they are affected by DME or at risk.
“An oral medication for DME could significantly advance its management,” said Charles C. Wykoff, M.D., Ph.D., the trial’s Principal Investigator, Director of Research at Retina Consultants of Texas, and Chair of Research at Retina Consultants of America. “A safe and effective systemic treatment would provide a crucial alternative to repeated intravitreal injections. It could also promote earlier, more consistent care, improve treatment adherence, and enhance patients’ quality of life.”
“At Boehringer Ingelheim, we are dedicated to a future where early intervention leads to lasting outcomes that prevent vision loss. We aim to achieve this partly through the development of oral treatments, empowering patients to take greater control of their condition,” explained Dr. Patrick Bussfeld, Global Head of Medicine, Eye Health at Boehringer Ingelheim. “By systemically targeting the disease pathway, we also have the potential to prevent DME in one eye while treating it in the other.”
BI 1815368 is the fourth investigational compound in Boehringer Ingelheim’s Eye Health portfolio to progress to Phase II clinical trials.7,8 It is a component of Boehringer’s broader clinical program focused on diabetic retinal disease, which also includes BI 764524, a Sema3A antibody currently under evaluation in the CRIMSON Phase II trial for diabetic retinopathy.
About BI 1815368
BI 1815368 is an investigational drug designed to reduce retinal vascular hyperpermeability, thereby treating existing exudation and preventing future exudation. Boehringer Ingelheim discovered and developed the compound as part of its research and development efforts in retinal conditions.
About diabetic retinal disease
Diabetic retinal disease encompasses all diabetes-related changes in the retina (the back of the eye), including damage to retinal blood vessels (diabetic retinopathy or DR), swelling in the retina (diabetic macular edema or DME), reduced blood supply to the macula (diabetic macular ischemia or DMI), and damage to retinal nerve cells that aid in vision (diabetic retinal neuropathy or DRN).9
About diabetic macular edema (DME)
DME is a type of diabetic retinal disease characterized by fluid leakage (exudation) into the retina due to increased permeability of existing blood vessels, resulting from inflammatory processes caused by diabetes. Exudation in the fovea of the eye typically leads to significant vision loss that can become permanent and progressive.10
About Boehringer Ingelheim
Boehringer Ingelheim is a biopharmaceutical company involved in both human and animal health. As a leading investor in research and development, the company is dedicated to creating innovative therapies that improve and extend lives in areas of significant unmet medical need. Operating independently since its founding in 1885, Boehringer adopts a long-term approach, incorporating sustainability throughout its value chain. Our approximately 54,500 employees serve over 130 markets to contribute to a healthier and more sustainable future. Learn more at .
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References
- ClinicalTrials.Gov. A Study to Test Whether BI 1815368 Helps People With an Eye Condition Called Diabetic Macular Edema. Available at: . Accessed: June 2025.
- James H B Im, Ya-Ping Jin, et al. Prevalence of diabetic macular edema based on optical coherence tomography in people with diabetes: A systematic review and meta-analysis. Survey of Ophthalmology. 2022;67:1244-51.
- International Diabetes Federation. Clinical Practice Recommendations for Managing Diabetic Macular Edema. Available at: . Accessed June 2025.
- Prevent Blindness. Diabetic Macular Edema (DME). Available at: . Accessed June 2025.
5. Watane A, Tabano D, Cox O, et al. Investigating nAMD and DME treatment burden on recipients and caregivers in the UK. Investigative Ophthalmology & Visual Science. 2023;64(4196).
- 6. Jampol LM, Glassman AR and Sun J. Evaluation and Care of Patients with Diabetic Retinopathy. The New England Journal of Medicine. 2020 Apr 23;382:1629-37.
- Abramoff, MD, Fort PE, Han IC, et al. Investigative Ophthalmology & Visual Science. 2018;59:519-27.
- Sakini ASA, Hamid AK, Alkhuzai, ZA, et al. Diabetic macular edema (DME): dissecting pathogenesis, prognostication, diagnostic modalities along with current and futuristic therapeutic insights. International Journal of Retina and Vitreous. 2024;10:83.
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