A Phase 2 interventional study of DME lactose pill and DME levosulpiride in Diabetic Macular Edema and Diabetic Retinopathy, sponsored by Carmen Clapp. Recruiting at 2 sites in Mexico. Open to participants aged 40 Years to 69 Years. Per ClinicalTrials.gov, last updated 2025-11-18.
Sponsored by Carmen Clapp · Phase 2, Interventional, and Treatment
This is a randomized, double-blind, placebo-controlled trial to evaluate the safety and efficacy of levosulpiride to improve retinal alterations due to diabetic macular edema and diabetic retinopathy
Diabetic retinopathy (DR) and diabetic macular edema (DME) are the primary cause of irreversible blindness and visual impairment in working-age adults. Nearly 80% of patients with diabetes will experience some degree of DR and DME 15-20 years after diagnosis. Altered blood parameters (glucose, lipids, and pressure) influence disease development and progression; however, the combined values of these parameters account for only 10% of the risk of DR. Laser therapy is effective for preserving sight but is poor for reversing visual loss. Anti-angiogenic therapies are effective and less destructive but require frequent intravitreal delivery, which raises the risk of infection and ocular complications. Therefore, the prevention and treatment of DR and DME should include other modifiable factors. Data from preclinical studies support a protective role for the serum levels of the hormone prolactin. The trial investigates a new specific therapy for DR and DME based on elevating the circulating levels of prolactin with the prokynetic, dopamine D2 receptor blocker, levosulpiride. It is a prospective, randomized clinical study in patients with DR and DME in which ophthalmologic and health parameters evaluated before and after starting the study medication will determine the efficacy and safety of treatment.
Patient registries: Patients are enrolled at the time of a routine health care service. The caregiver and patient together, in a standardized uniform manner for every patient, will collect the data. Data collection procedures are clearly described and include protocols, policies, and the formatted listing of all the data elements, their full definitions and validation rules. All personnel involved in data collection are qualified registry trained. The same physicians, laboratory technicians, and graduate students will evaluate and collect the data from all patients. An individual fully knowledgeable of all protocols, policies, procedures, and definitions in the registry will be designated as Accountable for Data Quality. This individual (coordinator) should ensure that all collected data are complete, accurate, and valid. Data logically inconsistent will be confronted to information in external database. Data collected on formatted paper forms are entered into a computer and electronic registries carefully reviewed by a third party to identify missing data, invalid or erroneous entries, and inconsistent data. Any data review activity and remediation efforts will be documented. Amelioration of data problems may include querying the personnel uploading the data, the coordinator, the interviewer, or the patient. The proposed sample size and study duration are the minimum required and are based on biological models of DR and on clinical experience evaluating primary data associated with the study. These parameters may have to be modified to accommodate the sample size required to obtain clinically important differences and their statistical evaluation, access to eligible patients, lack of adherence to therapy at specific calendar dates (holidays), etc. Statistical methods include those evaluating continuous and categorical variables, incidence and prevalence, the association between a risk factor and outcome, and the relative contribution of confounding factors.
Exclusion Criteria:
Patients with DME will be randomized to take a lactose pill (placebo).
Drug: DME lactose pill
Patients with DME will be randomized to take levosulpiride.
Drug: DME levosulpiride
Patients with non-proliferative DR will be randomized to take a lactose pill (placebo)
Drug: DR lactose pill
Patients with non-proliferative DR will be randomized to take levosulpiride
Drug: DR levosulpiride
Patients with proliferative DR (undergoing medically prescribed vitrectomy 7 days after starting the study) will be randomized to take a lactose pill (placebo).
Drug: DR vitrectomy lactose pill
Patients with proliferative DR (undergoing medically prescribed vitrectomy 7 days after starting the study) will be randomized to take levosulpiride.
Drug: DR vitrectomy levosulpiride
Patients with DME that will receive intravitreal antiangiogenic therapy with ranibizumab will be randomized to take a lactose pill (placebo)
Drug: DME plus ranibizumab lactose pill
Patients with DME that will receive intravitreal antiangiogenic therapy with ranibizumab will be randomized to take levosulpiride
Drug: DME plus ranibizumab levosulpiride
Patients with DME will take placebo orally 3 times a day (TID) for 8 weeks.The placebo is taken on top of standard therapy for diabetes and blood pressure control.
Also known as: placebo, sugar
Patients with DME will take levosulpiride (75 mg/day) orally TID for 8 weeks. Levosulpiride is taken on top of standard therapy for diabetes and blood pressure control.
Also known as: dopamine D2 receptor blocker
Patients with non-proliferative DR will take a lactose pill (placebo) orally TID for 8 weeks. The placebo is taken on top of standard therapy for diabetes and blood pressure control.
Also known as: placebo, sugar
Patients with non-proliferative DR will take levosulpiride (75 mg/day) orally TIDfor 8 weeks. Levosulpiride is taken on top of standard therapy for diabetes and blood pressure control.
Also known as: dopamine D2 receptor blocker
Patients with proliferative DR (undergoing medically prescribed vitrectomy 7 days after starting the study medication) will have to take a lactose pill (placebo) orally TID for one week. The last placebo pill will be taken on the morning of the day vitrectomy is performed. The placebo is taken on top of standard therapy for diabetes and blood pressure control.
Also known as: placebo, sugar
Patients with proliferative DR (undergoing medically prescribed vitrectomy 7 days after starting the study medication) will take levosulpiride (75 mg/day) orally TID for one week. The last pill will be taken on the morning of the day vitrectomy is performed. Levosulpiride is taken on top of standard therapy for diabetes and blood pressure control.
Also known as: dopamine D2 receptor blocker
Patients with DME with conventional intravitreal antiangiogenic therapy with ranibizumab (0.5 mg every 4 weeks for 12 weeks) will take a lactose pill (placebo) orally TID for 24 weeks. The placebo is taken on top of standard therapy for diabetes and blood pressure control.
Also known as: placebo, sugar
Patients with DME with receive intravitreal antiangiogenic therapy with ranibizumab (0.5 mg every 4 weeks for 12 weeks) will take a levosulpiride (75 mg/day) orally TID for 24 weeks. The study medication is taken on top of standard therapy for diabetes and blood pressure control.
Also known as: dopamine D2 receptor blocker
Visual acuity
Number of letters recognized in the Early Treatment Diabetic Retinopathy Study (ETDRS) chart test after correcting for any refractive error (myopia, hyperopia, or astigmatism)
Time frame: 5 minutes
Retinal thickness
Retinal thickness is evaluated by non-invasive optical coherence tomography (OCT) imaging via qualitative and quantitative analyses. For qualitative analyses, OCT images approaching the histological level of retinal morphology are interpreted based on normal and diseased features (hyper-reflective or hypo-reflective lesions, shadowing, and anatomical changes). Quantitative analysis evaluates retinal reflective signals and their correlation with retinal morphology by computer image-processing algorithms (retinal thickness map, volume, area, 1, 3, and 6 mm ETDRS circle diameters).
Time frame: Pupils are dilated (eye drops) for 10 to 15 minutes and optical coherence tomography (OCT) images recorded during 5 minutes.
Retinal hard exudates and hemorrhages
Number, size, and location of retinal hard exudates and hemorrhages evaluated by indirect ophthalmoscopy
Time frame: Pupils are dilated (eye drops) for 10 to 15 minutes and fundus images recorded during 5 minutes
Retinal microaneurisms, leakage area, cotton-wool spots, venous beading, microvascular and vascular abnormalities
Location, intensity, and source of above alterations evaluated by fundus fluorescein angiography imaging qualitative and quantitative analysis of hyper-fluorescent or hypo-fluorescent regions.
Time frame: Pupils are dilated (eye drops) for 10 to 15 minutes and fundus images recorded before and at different times (0.5 to 5 minutes) after fluorescein injection.
Prolactin serum levels
ng/ml levels of prolactin quantified in serum samples using the IMMULITE 2000 XPi immunoassay system
Time frame: 1-2 minutes (duration of blood withdrawal)
Prolactin vitreous levels
ng/ml levels of prolactin quantified in vitreous samples using the IMMULITE 2000 XPi immunoassay system
Time frame: 2 minutes (duration of vitreous withdrawal during medically prescribed vitrectomy)
Vasoinhibin vitreous levels
Optical density values of vasoinhibins obtained by the immunoprecipitation-Western blot analysis of vitreous samples
Time frame: 2 minutes (duration of vitreous withdrawal during medically prescribed vitrectomy)
Pyruvic glutamic transaminase (TGP) and thyroid stimulating hormone (TSH) serum levels
U/L (TGP) and uU/mL (TSH) quantified in serum samples by the Bioclin Kinetic Transaminase ALT (TGP) Kit and the automatic quimioluminescent evaluator (TSH)
Time frame: 1-2 minutes (duration of blood withdrawal)
Blood glycated hemoglobin and creatinine serum levels
Glycated hemoglobin (evaluated by boronate affinity chromatography) and creatinine (evaluated by the Jaffe reaction) levels are expressed as % and mg/dL, respectively.
Time frame: 1-2 minutes (duration of blood withdrawal)
Blood pressure
Systolic and diastolic values in mmHg
Time frame: 5 minutes
Plan to share: Undecided — It is yet undecided whether case reports will be published in medical journals throughout the course of the study. No identifier linking participants in the study to research records will be made public or reported.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.