This is a prospective, phase III, randomised, double-blind, placebo-controlled, multi-centre, national study to evaluate the use of doxycycline on patients with at less one risk of worsening COVID-19 disease.
As the study is double-blind, the study treatment and its placebo, will be managed by the pharmacist of the coordinating centre, CHU Nantes. The oral dose of 200 mg of doxycycline,anti-inflammatory dose, or the matching placebo, will be taken once a day, in the evening one hour beforegoing to bed, for14 days.Dispensation will be made at the inclusion/randomisation visit. No dose adjustment is required. The treatment will end if the patient is hospitalised between D0 and D14.
Six French University Hospital CHU Nantes, AP-HP [HôpitalAvicennes], CHU Bordeaux,CHU Caen, CHU Dijon and CHU Grenoble,) will include 330 patients to provide at least 280 analysable patients. The inclusion period may be 3 to 6 months depending on the recruitment rate post-deconfinement.. The treatment time is 14 days per patient and the last patient visit will be 28 days (+/- 2 days) from the start of treatment.
Patients cannot be included in any other interventional research; unless they are hospitalised, provided that there is no drug interaction with any other experimental treatment. Patients included in the study who will receive an investigational treatment (e.g. IL inhibitor or anti-IL6) during hospitalisation will be kept in the study. Their data will be analysed for the primary endpoint assessment only. Their data will not be analysed for the evaluation of secondary endpoints, except for the safety endpoint.
Male or female patients over 45 years of age suspected of COVID-19 by their treating physician or by a physician from a COVID-19 unit at a participating centre are the study population. After a positive SARS-CoV-2 PCR performed at the hospital, they may be included in the study. We chose 45 years of age as the minimum age in this study because this is the low end of the range for COVID-19+ patients likely to be admitted to intensive care units. These patients have also one or more risk factor(s) for aggravating the disease as described by the French High Council of Public Health: 70 years of age or older, cardiovascular history (stroke, coronary artery disease, complicated hypertension, cardiac surgery, NYHA III or IV heart failure), insulin-dependent diabetes which is unbalanced or secondary complicated; respiratory disease likely to decompensate for viral infection, patients with chronic renal failure on dialysis, cancer patients under treatment. We have added BMI (BMI>30) as a risk criterion, based on the recent data from the literature [10–13]. Exclusion criteria arevulnerable populations and the contraindication of the use of doxycycline. Box 1 presents all the inclusion/exclusion criteria.
The plan for the study described in this section is presented in Figure 1 and the flowchart in Figure 2. The screening is performed either by a possible network of general practitioners (GPs) associated with a participating centre; or by COVID-19 emergencies or the COVID-19 unit of the investigating centre.
A patient suspected of COVID-19,with one or more characteristic clinical signsand having one or more risk factors for aggravation of the disease are sent to the Hospital for PCR SARS-Cov2 sampling.If the PCR is positive, the investigator explains the DYNAMIC study, checks the eligibility criteria and obtains signed informed consent from the patient. The Supplementary Material file contains the French informed consent form that patients sign prior to inclusion in the trial (then updated protocol is at version 1.2on 11May 2020). Furthermore, blood samples for serology and immunological markers will be collected, stored and kept if the patient signed the biocollection informed consent. In this informed consent form, it is noted that the samples may be used for scientific research. This biocollection and its consent procedure has been registered to French Ethic Committee: CPP Ouest IV under number DC-2011-1399.After a clinical examination, patients will be randomised either in the Doxycycline arm or in the placebo arm. The patients, the investigators and their teams will be blind and will not know the treatment assigned. As Karanicolaset al. pointed out in their article, the biostatisticianswill also be masked until analyses to reduce the study bias are performed.
At 3 and 14 days, a telephone call will be made bythe hospital doctor or his/her team. A clinical assessment of the patientwill be carried outaccording to the questionnaire shown in figure 3. If necessary, a face-to-face consultation,to accurately assess the extent of the worsening of the disease, will be conducted immediately after this call.
At 7 days, a face-to-face follow-up visit will be performed. After a clinical examination, a SARS-CoV-2 qualitative PCR will be carried out. At 28 days, the end-of-study visit will be performed, also face-to-face. A blood sample will be kept for serology and other immunological markers. The patient will return any unused therapeutic units and the empty blister packs.
A premature end-of-study visit corresponds to the end-of-study visit (D28 visit), with the exception of serology if the premature exit occurs before 14 days. For included patients who are hospitalised before 28 days, the experimental treatment is stopped as soon as they are hospitalised and they are considered as a failure. Clinical data related to hospitalisation will be reported in the CRF. For patients hospitalised after 28 days and until 90 days post-treatment, follow-up will be carried out until discharge. This follow-up will allow the collection of vigilance data, some hospitalisation data (date of end of hospitalisation, length of hospitalisation in intensive care unit, duration of mechanical respiratory assistance, possible death).
During the trial, any drug judged to be necessary for the well-being of the patient, which should not interfere with the evaluation of the test drug, may be administered at the discretion of the investigator. Absorption of doxycycline is impaired by antacids containing aluminium, calcium, as well as magnesium, bismuth subsalicylate and iron-zinc-containing preparations. The study drug should be taken at a different time to antacids. Other prohibited treatments are those prohibited by the SCP of doxycyclineand are listed in exclusion criteria (see Box1).However, in the absence of a change in the therapeutic management of a patient arriving at hospital according to the treatment arm, it is not necessary to include a blinding procedure in this protocol.Treatment will be stopped if hospitalisation.
Objectives and statistics
The main objective is to evaluate the decrease in the percentageof patients with respiratory aggravation (oxygen saturation rate ≤ 93% in room air) after at least 48 hours of experimental treatment or requiring hospitalisation for COVID-19. The 48-hour delay allows a more objective attribution of the clinical course to advanced treatment. The embedded second main objective is to evaluate the decrease in the percentage of patients requiring mechanical ventilator support.
The secondary objectives are to evaluate:
- the decrease in the percentage of patients with SARS-CoV-2 positive PCR at 7 days after the start of experimental treatment,
- the decrease of the total length of hospital stay,
- the decrease of the length of hospitalisation in the intensive care unit,
- the decrease of the duration of mechanical ventilatory assistance,
- the decrease of the rate of deaths related to SARS-CoV-2 infection,
- an assessment of the safety of doxycycline.
The main criterion is an efficacy criterion corresponding to the percentage of patients with clinical respiratory aggravation (SaO2 ≤ 93%) after at least 48 hours of treatment and the percentage of patients hospitalised for COVID-19 after at least 48 hours of experimental treatment. The criterion corresponding to the embedded second main objective corresponds to the percentage of patients requiring mechanical ventilator assistance. These three criteria aremonitored in the 2 arms from 48hoursof treatment to 28 days corresponding to the end-of-study visit.
For the secondary outcomes:
Efficacy: These outcomes correspond to the report of the:
- Number of positive SARS-CoV-2 PCR tests at the inclusion visit and D7,
- Total length of hospital stay,
- Total length of hospital stay in the intensive care unit,
- Duration of mechanical ventilator assistance,
- Number of deaths related to SARS-CoV-2 infection.
Safety: Report of the number of Adverse Events (AE) and Serious Adverse Events (SAE) over 28 days
Apart from the first and the last secondary criterion, the other criteria will be noted at 28 days. If the patient is hospitalised during the duration of the study,this data will be noted 3 months after the beginning of the treatment. For all these secondary outcomes, percentages will be calculated.
The DYNAMIC study is a superiority study of doxycycline efficacy. Theembedded testing strategy will be used to successively test:
- the decrease in the percentage of patients presenting, after at least 48 hours of treatment, a respiratory aggravation (SaO2 93%) or requiring hospitalisation related to the SARS-CoV-2 infection,
- a decrease in the percentage of patients requiring mechanical ventilator assistance if the first null hypothesis is rejected.
An intermediate futility analysis will be carried out, after 100 patients have been evaluated, with the objective of being able to stop the clinical trial if there is no probability that the null hypothesis will be rejected at the end of the full study. The one and only response to this analysis is whether or not to stop the trial because of lack of efficacy. The Peto method will be used with an alpha risk at the intermediate analysis of 1 per thousand and at the final analysis of 5% .As already quoted, the biostatistician will be part of the masked team. He will give the results of this intermediate analysis to the Data and Safety Monitoring Committee (DMSC), which may unblind or not depending on the results.
The analysis will be stratified by centre and number of severity factors (1 versus ≥2). The severity factors are ≥ 70 years, BMI > 30, cardiovascular history (stroke, coronary artery disease, complicated hypertension, cardiac surgery, NYHA III or IV heart failure), insulin-dependent diabetic patients who are unbalanced or have complications secondary to their disease, respiratory disease likely to decompensate for viral infection, patients with chronic renal failure on dialysis, cancer patients on treatment at the time of inclusion. Randomisation will be carried out for each centre in order to balance the treatment arms.
A Modified Intent to Treat analysis will be applied. It will include all eligible randomised patients who have signed the consent for the trial. It will exclude patients who withdrew their consent prior to the assessment of the first primary endpoint, randomised patients who were inappropriately included (inclusion or exclusion criteria not met) and patients who did not receive any dose of treatment.
A per-protocol analysis will also be implemented, including all patients evaluated in their treatment group and having received more than 75% of the total treatment dose.
For the main criteria (percentage of patients), we will use a Mantel-Haenszel test to compare stratified percentages across centres and the number of risk factors. For the quantitative secondary criteria, a mixed linear model will be used to take into account the risk factors and the centre effect (random factor). The statistical software used will be R, version 3.8 or later. The significance thresholds will be set at 5%.
It is estimated,among eligible patients in the study, that 25% of patients will present pulmonary signs with SaO2£93% and/or will require hospitalisation. It is hypothesised that with doxycycline, this rate would increase to 12%. Indeed, the article concerning the effect of doxycycline on dengue patients: "Dengue Patients Treated With Doxycycline Showed Lower Mortality Associated with a Reduction in IL-6 and TNF Levels" , shows that the group on doxycycline has a lower mortality than those in the untreated group (11.2% [13/116] vs 20.9% [24/115], respectively, p=0.05). In addition, doxycycline administration resulted in a significant drop in IL6 and TNF. These results therefore confirm our hypothesis of a 12% reduction
For the second embedded hypothesis, it is estimated that 23% (source: https://www.data.gouv.fr/fr/datasets/donnees-hospitalieres-relatives-a-lepidemie-de-covid-19/) of the hospitalisedpatients are admitted to intensive care units. With the recruitment we have, we will have a power of 80% to show a decrease of 23 to 10%.
Under these hypotheses, with a 5% alpha risk in a bilateral situation and a power of 80%, we would have to evaluate 280 patients in total in both arms. If the first hypothesis is rejected, the power of the test of the second hypothesis would then be 83.5%. Three hundred and thirty (330) patients will be included to compensate for study exits and non-assessable patients.
Randomisation will be stratified by centre and by severity factors (1 versus ≥2). It will be performed according to a 1:1 ratio and balanced by blocks. The random numbers will be generated by computer. Subjects are randomised into blocks as the allocation progresses, a block being a sub-group of predetermined size within which there is a random allocation of patients. The software used for the randomisation is SAS version 9.4. The randomisation key is known only to the biostatistician and the data managers, to make it impossible for the investigator to assign a particular treatment. It should be noted that the biostatistician who carries out the randomisation is different to the biostatistician who will carry out the statistical analysis.
Adverse event management
For doxycycline, the main adverse events (AEs) expected are skin disorders (photosensitivity reaction, rash), immune system disorders (urticaria, rash, pruritus, angioedema, anaphylactic reaction) or digestive disorders (nausea, epigastralgia, diarrhaea, anorexia, glossitis, enterocolitis, anal or genital candidiasis). There have been no reports of overdosage. Those reported for other tetracyclines, following renal impairment (hepatic toxicity, hyperazotemia, hyperphosphataemia, acidosis), are unlikely to occur with doxycycline, due to the lack of a change in blood levels in relation to the functional value of the kidney. Concerning the placebo, the main expected effects are digestive disorders (excess gas, feeling of abdominal bloating, abdominal cramps and pain, diarrhaea). As regards the pathology, patients with an uncomplicated viral infection of the upper respiratory tract may have non-specific symptoms such as fever, fatigue, cough (with or without discharge), anorexia, malaise, muscle aches, sore throat, dyspnea, nasal congestion or headache. Rarely, patients may also experience diarrhaea, nausea and vomiting [7,49], and loss of taste or smell .The disease can worsen to pneumonia, acute respiratory distress syndrome , sepsis and septic shock .
All serious adverse events (SAEs), whether expected or unexpected, require the completion of a SAE report. The investigator must ensure that the information entered in this report is accurate and clear. The SAE should be reported immediately (within 24 hours of being highlighted by the investigator) to the sponsor. After receiving an unexpected SAE report, the sponsor notifies the authorities. Furthermore, a Data and Safety Monitoring Committee (DSMC) has been set up. It is a consultative committee responsible for reviewing the safety of a study on behalf of the sponsor and the coordinator/principal investigator of the study. Members of the Committee who are competent in the field of clinical trials (pathology methodology and pharmacovigilance) are not involved in the study.
The DSMC is a referral point for pharmacovigilance if a SUSAR or an SAE poses particular analytical difficulty or if a doubt arises about the risk/benefit of the study. Moreover, it will make a decision on the outcome of the futility analysis. In the event of early termination of the study by decision of the DSMC or the Study Sponsor, the regulatory authorities and the Ethical Review Board will be informed by post within a maximum of 15 days. In any event, written confirmation will be sent to the coordinating investigator of the study (specifying the reasons for early termination) and to the principal investigator of each centre, if applicable. All patients in the study will be informed and will be required to attend their early discharge visit.
Ethical, regulatory and dissemination aspects
The clinical study will be conducted in accordance with the relevant versions of the French Public Health Code, national and international good clinical practice (GCP) guidelines, and the Declaration of Helsinki, each in the applicable version.
In accordance with French law, the study protocol was submitted to the French regulatory authority (ANSM).This clinical study was submitted to and approved by the Ethical Review Board of Boulogne-Billancourt(Comité de Protection des Personnes – CPP Ile de France VIII) on 13 May 2020. Requests for substantial modifications should be addressed by the sponsor for approval or notification to the ANSM and/or the Ethical Review Board concerned in compliance with Law 2004-806 of 9 August, 2004 and its implementing decrees.The amended protocol should be a dated and updated version. If necessary, the information form and consent form should be amended.The updated protocol is version 1.2 on 11 May 2020. The trial is not yet recruiting and the anticipated date of enrolment of the first participant is expected on 1 June 2020. The anticipated study completion is anticipated to be on 1 January 2021.
All the submissions/declarations were made by the Sponsor Department at CHU Nantes, which of course, manages the quality of the data collected. The data collected during the study will be processed electronically in accordance with the requirements of the CNIL, the French Data Protection Authority (in compliance with the French Reference Methodology MR001).The data-sharing will be only between the investigators. However, the datasets analysed during the current study will be available from the corresponding author on reasonable request.
An electronic Case Report Form (eCRF) shall be drawn up for each included patient. The identification of the subject will be performed using the first letter of the family name, the first letter of the first name, the centre number and the inclusion number. This code should be the only information featuring on the eCRF enabling a retrospective link to the patient. The investigator, or their team, shall also encode the patient data on any documents that may be in their possession (imaging, biology test reports, etc.) attached to the eCRF. At the end of the study, database reconciliation is carried out between the CRF database and the safety database. This reconciliation is performed before database locking. Similarly, an annual reconciliation is carried out when updating the Annual Safety Report (ASR).
As required, the sponsor has provided an insurance policy to cover the financial consequences of its civil liability in accordance with the regulations. This protocol was created thanks to a Scientific Committee. The Scientific Committee is coordinated by Prof. B Dréno and its membership comprises external and internal experts in COVID-19 pathology,a general practitioner, experts in clinical trials and a methodologist. An inspection or audit may take place as part of this study, performed by the Sponsor and/or by the regulatory authorities. Inspectors will check the documents, logistics, records and any other resources that the authorities consider to be associated with the clinical trial and that may be located at the trial site itself.
The trial results will be published in international, medical and scientific journals and presented at national and international conferences. The investigators will follow the rules and guidelines of the International Committee for Medical Journal Editors (ICMJE). In practice, the Scientific Committee will be among the authors of the publication, as will the investigators who included the patients in the trial.