Calcium Dobesilate

SARS-CoV-2 mainly infects respiratory endothelial cells, which is facilitated through its spike protein binding to heparan sulphate. Calcium dobesilate (CaD) is a well-established, widely available vasoactive and angioprotective drug interacting with heparan sulphate, with the potential to interfere with the uptake of SARS-CoV-2 by epithelial cells. The CADOVID trial aims to evaluate the efficacy and safety of CaD in reducing the SARS-CoV-2 viral load in non-hospitalised adult patients diagnosed with COVID-19, confirmed by a positive SARS-CoV-2 PCR, including its efficacy to reduce the impact of persistent COVID-19 symptoms.

This is a randomised, placebo-controlled, double-blind, monocentric phase II trial. Enrolment began in July 2022. A total of 74 adult patients will be randomly allocated to the CaD arm or the placebo group with a 1:1 ratio, respectively. Participants in the intervention arm will receive two capsules of CaD 500 mg two times per day and the placebo arm will receive two matching capsules of mannitol 312.5 mg two times per day, with a treatment period of 7 days for both arms, followed by a 77-day observational period without treatment administration. Participants will be asked to complete secured online questionnaires using their personal smartphone or other electronic device. These include a COVID-19 questionnaire (assessing symptoms, temperature measurement, reporting of concomitant medication and adverse events), a COVID-19 persistent symptoms’ questionnaire and the Short Form 12-Item (SF-12) survey. SARS-CoV-2 PCR testing will be performed on nasopharyngeal swabs collected on days 1, 4, 8 and 21. The primary endpoint is the reduction from baseline of SARS-CoV-2 viral load determined by RT-PCR at day 4.

This trial has received approval by the Geneva Regional Research Ethics Committee (2022-00613) and Swissmedic (701339). Dissemination of results will be through presentations at scientific conferences and publication in scientific journals.

NCT05305508; Clinicaltrials.gov; Swiss National Clinical Portal Registry (SNCTP 000004938).

To determine the pharmacokinetics (PK), safety, and bioequivalence profiles of 0.5‐g calcium dobesilate capsules in both fasting and fed states for the test drug and reference drug. A randomized‐sequence, single‐dose, open‐label, 2‐period crossover study was conducted in fasted and fed healthy Chinese volunteers (Chinese Clinical Trials Registry identifier: CTR202000268‐01). The fasting and fed studies, both involving 24 subjects, were conducted. A single dosage of either the reference or the test preparation was given to each eligible subject in a 1:1 ratio, followed by a 7‐day rest interval before the administration of the alternative formulation. After taking the capsules, plasma samples were taken for 48 hours, and using liquid chromatography‐tandem mass spectrometry, the calcium dobesilate level was determined. The PK parameters evaluated in the study included the maximum serum concentration (Cmax), area under the plasma concentration‐time curve (AUC) from time 0 to the last quantifiable concentration, AUC from time 0 to infinity, half‐life, time to Cmax, and terminal elimination rate constant. In addition, the safety evaluation encompassed monitoring fluctuations in vitals (temperature, pulse, and blood pressure) and laboratory tests (urinalysis, hepatic function, blood biochemistry, and hematology), as well as recording the emergence of adverse events (AEs). The geometric mean ratio (GMR) of the test/reference medications was used to assess bioequivalence by determining if the 90% confidence intervals of the GMR fell within the predefined range of 80%‐125%. AEs were assessed as safety end points. The study included 48 healthy Chinese volunteers (with n = 24 each for the fasting and the fed conditions), and no subjects dropped out for any reason. The differences in the PK metrics for the test and reference drugs for both conditions were insignificant (P > .05). For bioequivalence, irrespective of whether the food was consumed or not, the range of the 90% confidence intervals of the GMR for Cmax, AUC from time 0 to the last quantifiable concentration, and AUC from time 0 to infinity was between 80% and 125%. In the experiment, no serious AEs were recorded. Our findings revealed that the calcium dobesilate capsules used as the reference and the test drugs were both bioequivalent. Irrespective of whether the healthy Chinese volunteers consumed food or not, the PK and safety profiles were comparable.