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Taking people in United KingdomPhase 2

Tests BI 1815368 tablets in people with diabetic macular edema

Tests whether a tablet medicine helps adults with a diabetes-related eye condition.

Key facts

Who runs it
Boehringer Ingelheim
Where
Camberley, Gloucester, Harrow, Liverpool, London, Newcastle upon Tyne, Sunderland, and Westcliff-on-Sea, United KingdomSee the 9 sitesAlso in 8 other countries, 90 sites
Trial code
Registry title
A Study to Test Whether BI 1815368 Helps People With an Eye Condition Called Diabetic Macular Edema
Status
Recruiting
Phase
Phase 2
People taking part
300 people, planned
Started
5 Jun 2025
Expected to end
29 Mar 2028
Type of study
Interventional, 6 groupsOne group gets a placebo (a dummy treatment), for comparison.
Treatments tested
  • BI 1815368
  • Placebo
Record updated
12 November 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with diabetes who have centre-involved diabetic macular edema, an eye problem with swelling in the centre of the retina. It tests a tablet called BI 1815368 against placebo.

Age
18 years or older.
Sex
All sexes can join.
Disease stage
Centre-involved diabetic macular edema in the study eye, confirmed by an eye scan (SD-OCT) with central subfield thickness of at least 320 µm. Vision (ETDRS letter score) between 24 and 78 in the study eye.
Earlier treatment
Diabetes must be treated with stable medication for at least 30 days before Day 1. No anti-VEGF eye injection in the study eye within 8 weeks before Day 1 (16 weeks for faricimab or aflibercept 8 mg). No eye steroid treatment within 12 months before Day 1.
Biomarker or test result
HbA1c below 12% (108 mmol/mol).

Main reasons for not taking part

  • Macular edema caused by something other than diabetes in the study eye
  • Proliferative diabetic retinopathy or new vessels on the iris in the study eye
  • Past panretinal photocoagulation or vitreoretinal surgery
  • Active eye inflammation, or eye inflammation within 1 year
  • Aphakia or total absence of the posterior capsule in the study eye

The registry criteria, word for word

Show all 11 criteriaShow less

Who can take part

  • ≥18 years of age
  • Diagnosis of diabetes mellitus (DM) (type 1 or type 2), Haemoglobin A1C (HbA1c) <12% treated with stable medication for at least 30 days prior to Day 1; no already-set plans for major changes in DM medication (e.g. start of new medication) at the time of screening and baseline
  • Centre-involved diabetic macular edema (CI-DME) confirmed on spectral domain optical coherence tomography (SD-OCT) with central subfield foveal thickness (CST) ≥320 µm in the study eye at screening
  • Best corrected visual acuity (BCVA) visual acuity Early Treatment Diabetic Retinopathy Study (ETDRS) letter score in the study eye between 24 and 78 (Snellen equivalent range 20/320 to 20/32) at screening Further inclusion criteria apply

Who cannot take part

  • Intravitreal (IVT) anti-vascular endothelial growth factor (VEGF) treatment in the study eye is not allowed within 8 weeks prior to Day 1, except for faricimab or aflibercept 8 mg, for which a 16-week washout period prior to Day 1 is required. There is no limit on the total number of prior IVT antiVEGF injections, provided that the subject has demonstrated a response to prior antiVEGF treatment (at the investigator's discretion) and the anatomical integrity is confirmed by the central reading centre (CRC) at screening based on spectral domain optical coherence tomography (SD-OCT)
  • Any history of panretinal photocoagulation, vitreoretinal surgery, IVT or periocular corticosteroid treatment (within 12 months before Day 1), history of fluocinolone ophthalmic implant or dexamethasone IVT implant before Day 1, or topical steroid or nonsteroidal anti-inflammatory drug (NSAID) treatment (within 30 days before Day 1)
  • Prior macular laser photocoagulation performed more than 3 months prior to Day 1 is permitted if absence of scar-like changes within the 1-mm diameter region centred on the fovea is confirmed by the CRC at screening based on SD-OCT
  • Aphakia or total absence of the posterior capsule; Yttrium aluminium garnet (YAG) laser capsulotomy in the study eye is permitted if more than 2 months prior to Day 1 Further exclusion criteria apply
  • Active ocular inflammation or any history of intraocular inflammation within 1 year
  • Macular edema considered to be due to other causes than CI-DME in the study eye
  • Proliferative diabetic retinopathy or iris neovascularisation (including the anterior chamber angle) in the study eye

Where in United Kingdom

Also in 8 other countries, 90 sites

  • Frimley Park HospitalCamberley, United KingdomContact: Boehringer IngelheimTaking people
  • Gloucestershire Royal HospitalGloucester, United KingdomContact: Boehringer IngelheimTaking people
  • Northwick Park HospitalHarrow, United KingdomContact: Boehringer IngelheimTaking people
  • Royal Liverpool University HospitalLiverpool, United KingdomContact: Boehringer IngelheimTaking people
  • King's College HospitalLondon, United KingdomContact: Boehringer IngelheimTaking people
  • Moorfields Eye HospitalLondon, United KingdomContact: Boehringer IngelheimTaking people
  • Royal Victoria InfirmaryNewcastle upon Tyne, United KingdomContact: Boehringer IngelheimTaking people
  • Sunderland Eye InfirmarySunderland, United KingdomContact: Boehringer IngelheimTaking people
  • Southend University HospitalWestcliff-on-Sea, United KingdomContact: Boehringer IngelheimTaking people

About the trial

What the trial wants to find out

This study is open to adults 18 and older with an eye condition called diabetic macular edema. People are required to have a specific type of diabetic macular edema called centre-involved diabetic macular edema (CI-DME) to take part. The purpose of this study is to find out whether a medicine called BI 1815368 improves sight in people with CI-DME and to find the most suitable dose.

Read full original descriptionShow less

This study has 2 parts. In the first part, participants are put into 2 groups of equal size randomly, which means by chance. One group takes BI 1815368 tablets and the other group takes placebo tablets. Placebo tablets look like BI 1815368 tablets but do not contain any medicine. In the second part, participants are put into 4 groups of equal size randomly. 3 groups take different daily doses of the study medicine, BI 1815368, while 1 group takes placebo. All participants take tablets twice a day for about 11 months.

Participants are in the study for about 1 year. During this time, they visit the study site at least 16 times. Participants taking metformin have 3 additional study visits. At visits, doctors check the participant's vision and collect information on any health problems. They take detailed pictures of the eye. The changes over time are compared between the groups to see if the treatment works.

The 6 groups in the trial

  • Cohort 1: Treatment armTreatment being tested

    Treatment: BI 1815368

  • Cohort 1: Placebo armPlacebo, for comparison

    Treatment: Placebo

  • Cohort 2: Placebo armPlacebo, for comparison

    Treatment: Placebo

  • Cohort 2: Treatment arm, low doseTreatment being tested

    Treatment: BI 1815368

  • Cohort 2: Treatment arm, medium doseTreatment being tested

    Treatment: BI 1815368

  • Cohort 2: Treatment arm, high doseTreatment being tested

    Treatment: BI 1815368

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov and on the EU's official list of trials (CTIS).
Official title
A Randomised, Double-masked, Placebo-controlled Trial to Evaluate the Efficacy, Safety, and Tolerability of Oral BI 1815368 in Participants With Centre-involved Diabetic Macular Edema for 48 Weeks of Treatment (THULITE)
Plain-language title
Tests BI 1815368 tablets in people with diabetic macular edemaGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 12 November 2026.
Record updated
12 November 2026