Assessment of the Efficacy of Calcium Dobesilate vs. Placebo on SARS-CoV-2 Viral Load Amongst Outpatients With COVID-19. (COVID-19)
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ClinicalTrials.gov Identifier: NCT05305508 |
Recruitment Status :
Not yet recruiting
First Posted : March 31, 2022
Last Update Posted : April 1, 2022
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Condition or disease | Intervention/treatment | Phase |
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COVID-19 Virus Disease | Drug: Calcium Dobesilate Drug: Mannitol | Phase 2 |
This study is a phase II, randomized, double-blind, placebo-controlled, monocenter trial. The study will assess the efficacy and safety of CaD compared to placebo in reducing SARS-CoV-2 viral load in non-hospitalized adult patients diagnosed with COVID-19, as well as monitoring symptoms severity, progression of the disease to severe form, and persistence of symptoms.
The treatment period is seven consecutive days, followed by a 12-weeks observational period without treatment administration.
Enrolled patients will be randomized, in a ratio of 1:1 into the following treatment groups: - IMP arm: patients will receive 2 x 2 capsules of Calcium Dobesilate (CaD) 500 mg (total of 2000 mg) daily for seven consecutive days
- Placebo arm: patients will receive 2 x 2 capsules of matching placebo (Mannitol 500 mg) daily for seven consecutive days.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 74 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Masking Description: | The central pharmacy of the HUG is responsible for preparation of the randomization list and of the blinding of the study treatments. Randomization will be done in variable-sized blocks (size 4) in random sequence. Pharmacists will be un-blinded. Care providers and/or outcome assessors, nurses, clinical research associates, investigators and patients will be blinded. Participants will be allocated to either the treatment group (CaD) or placebo group at Day 1 visit through randomization process, and will be dispensed the full treatment regimen on-site, including instructions on intake and explanations of side-effects. The investigators will receive from the central pharmacy of the HUG all the study treatments and the participant's allocated treatment randomization number. Thus, the subjects who meet the eligibility criteria will dynamically be randomized at 1:1 ratio and be assigned either to the CaD or to the placebo arms during Day 1 visit. |
Primary Purpose: | Treatment |
Official Title: | A Randomized, Placebo-controlled, Double-blind, Monocenter, Phase II Trial to Assess the Efficacy of Calcium Dobesilate (CaD) vs. Placebo on SARS-CoV-2 Viral Load Amongst Outpatients With COVID-19. |
Estimated Study Start Date : | May 2022 |
Estimated Primary Completion Date : | January 2023 |
Estimated Study Completion Date : | March 2023 |

Arm | Intervention/treatment |
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Placebo Comparator: placebo
The comparator (placebo, Mannitol 500 mg) will be administered orally twice a day for 7 days.
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Drug: Mannitol
The comparator (placebo, Mannitol 500 mg) will be administered orally twice a day for 7 days. |
Experimental: Calcium Dobesilate
The CaD (Calcium Dobesilate 500 mg) will be administered orally twice a day for 7 days.
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Drug: Calcium Dobesilate
The treatment (CaD, Calcium Dobesilate 500 mg) will be administered orally twice a day for 7 days. |
- Primary Outcome [ Time Frame: baseline and day 4 ]Reduction from baseline of RT-PCR SARS-CoV-2 viral load at day 4, defined by Polymerase Chain Reaction (PCR) threshold cycles. PCR reaction happens in cycles of amplification. Inclusion criteria to enter in the study is a RT-PCR positive for SARS-CoV-2, which correspond to 25 cycles (or lower) of the RT-PCR test. The participant will be tested at day 4 after treatment to evaluate if the viral load has decreased. To do that, another RT-PCR SARS-CoV-2 will be performed. A higher value of RT-PCR cycles compared to the one obtained when the participat was diagnosed COVID-19 positive, is considered a reduction from baseline.
- SARS-CoV-2 Viral Load at day 8 [ Time Frame: baseline and day 8 ]Reduction from baseline of RT-PCR SARS-CoV-2 viral load at day 8.
- SARS-CoV-2 Viral Load negativity [ Time Frame: day 4, 8 and 21 ]Proportion of patients with viral load negativity or very low viral load (defined by PCR threshold cycles >32) at days 4, 8 and 21.
- Symptoms [ Time Frame: day 4, 8 and 21 ]
Time to acute symptom resolution after randomisation to treatment.
Proportion of participants with acute symptom resolution at days 4, 8, 21.
- Symptoms resolution [ Time Frame: day 4, 8 and 21 ]Proportion of participants with acute symptom resolution at days 4, 8, 21.
- Persistent COVID-19 symptoms [ Time Frame: day 84 ]Proportion of patients with persistent symptoms (≥1 of the following symptoms: fatigue, headache, intermittent fever, palpitations/tachycardia, sleep disturbance, anxiety, blurred vision, depression, brain fog (difficulty concentrating), loss of memory, dizziness, tinnitus (and other hearing issues), altered smell, altered taste, shortness of breath, chest pain, cough, myalgia (and spasms), neuralgias, arthralgia (joint pain), paraesthesia, nausea, vomiting, diarrhea, constipation, abdominal pain, menstrual and period problems as well as new onset of allergies) at day 84 (week 12).
- Mental and physical score [ Time Frame: baseline and 84 ]SF12 score at day 21 and day 84 (week 12) compared to day 1 (baseline).

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Ages Eligible for Study: | 16 Years and older (Child, Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Documented COVID-19 diagnosis (SARS-CoV-2 positivity as assessed by PCR) ≤3 days of symptom appearance, with a CT<25.
- Symptoms related to Day 1 ≤ 5 days.
- Participant presents at least one of the following acute COVID-19 symptoms: nasal congestion or runny nose, sore throat, headache, myalgia, dry/productive cough, fever, chills, abdominal symptoms (nausea, vomiting, diarrhea, abdominal pain), fatigue, chest pain, palpitations, and shortness of breath.
- Participant is aged ≥ 16 years of age.
- Participant has provided an appropriate signed Informed consent.
Exclusion Criteria:
- Known hypersensitivity or allergy to any of the study products to be administered.
- Participation in any other investigational device or drug study within 30 days preceding study screening visit.
- Treatment with Calcium Dobesilate or related molecules (e.g., ethamsylate) within 30 days preceding screening visit, or current treatment with any other investigational agent(s).
- Breastfeeding, unless If the patient agrees to stop breastfeeding
- Treatment with any investigational, emergency use authorization-approved, or approved drug for COVID-19, such as, but not limited to: monoclonal antibody treatment, direct or indirect antiviral treatment, and others according to local guidelines.
- Any kind of disorder or medical conditions that, in the opinion of the investigators, may be associated with increased risk to the participant, may affect patients' compliance, or may interfere with study assessments or outcomes.
- Inability to follow and comply with study procedures.
- Participant has hospitalization criteria according to local guidelines (Sat < 95%, RR >25) at the time of screening or is admitted to hospital prior to randomization
- Participant is, in the opinion of the investigators, likely to deteriorate in the next 24-48h and require hospitalization

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05305508
Contact: Hervé SPECHBACH, MD | +41 22 372 95 22 | herve.spechbach@hcuge.ch | |
Contact: Julien Salamun, MD | +41 22 372 51 06 | julien.salamun@hcuge.ch |
Switzerland | |
Division and Department of Primary Care Medicine, Geneva University Hospitals | |
Geneva, Switzerland, 1211 | |
Contact: Hervé Spechbach, MD +41 22 372 95 22 herve.spechbach@hcuge.ch | |
Contact: Julien Salamun, MD +41 22 372 51 06 julien.salamun@hcuge.ch | |
Principal Investigator: Hervé Spechbach, MD | |
Sub-Investigator: Julien Salamun, MD | |
Sub-Investigator: Alexandra Calmy, MD, PhD | |
Sub-Investigator: Idris Guessous, Pr |
Principal Investigator: | Hervé SPECHBACH, MD | HUG |
Publications:
Responsible Party: | Hervé SPECHBACH, Principal Investigator, Associate Assistant Physician at Primary Care Medicine department HUG, Geneva University Hospitals, University Hospital, Geneva |
ClinicalTrials.gov Identifier: | NCT05305508 |
Other Study ID Numbers: |
2022-00000 |
First Posted: | March 31, 2022 Key Record Dates |
Last Update Posted: | April 1, 2022 |
Last Verified: | March 2022 |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Calcium Dobesilate Viral load COVID-19 symptoms |
COVID-19 Virus Diseases Respiratory Tract Infections Infections Pneumonia, Viral Pneumonia Coronavirus Infections Coronaviridae Infections Nidovirales Infections RNA Virus Infections Lung Diseases |
Respiratory Tract Diseases Mannitol Calcium Dobesilate Calcium Calcium-Regulating Hormones and Agents Physiological Effects of Drugs Diuretics, Osmotic Diuretics Natriuretic Agents Hemostatics Coagulants |