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Azithromycin and hydroxychloroquine in hospitalised patients with confirmed COVID-19–a randomised double-blinded placebo-controlled trial

Pradeesh Sivapalan, Charlotte Suppli Ulrik, Therese Sophie Lapperre, Rasmus Dahlin Bojesen, Josefin Eklöf, Andrea Browatzki, Jon Torgny Wilcke, Vibeke Gottlieb, Kjell Erik Julius Håkansson, Casper Tidemandsen, Oliver Tupper, Howraman Meteran, Christina Bergsøe, Eva Brøndum, Uffe Bodtger, Daniel Bech Rasmussen, Sidse Graff Jensen, Lars Pedersen, Alexander Jordan, Helene Priemé, Christian Søborg, Ida E. Steffensen, Dorthe Høgsberg, Tobias Wirenfeldt Klausen, Martin Steen Frydland, Peter Lange, Asger Sverrild, Muhzda Ghanizada, Filip Krag Knop, Tor Biering-Sørensen, Jens D. Lundgren, Jens-Ulrik Stæhr Jensen, ProPAC-COVID study group
European Respiratory Journal 2021; DOI: 10.1183/13993003.00752-2021
Pradeesh Sivapalan
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Charlotte Suppli Ulrik
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Therese Sophie Lapperre
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Rasmus Dahlin Bojesen
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Josefin Eklöf
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Andrea Browatzki
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Jon Torgny Wilcke
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Vibeke Gottlieb
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Kjell Erik Julius Håkansson
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Casper Tidemandsen
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Oliver Tupper
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Howraman Meteran
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Christina Bergsøe
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Eva Brøndum
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Uffe Bodtger
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Daniel Bech Rasmussen
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Sidse Graff Jensen
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Lars Pedersen
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Alexander Jordan
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Helene Priemé
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Christian Søborg
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Ida E. Steffensen
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Dorthe Høgsberg
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Tobias Wirenfeldt Klausen
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Martin Steen Frydland
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Peter Lange
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Asger Sverrild
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Muhzda Ghanizada
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Filip Krag Knop
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Tor Biering-Sørensen
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Jens D. Lundgren
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Jens-Ulrik Stæhr Jensen,
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Abstract

Background Combining the antibiotic azithromycin and hydroxychloroquine induces airway immunomodulatory effects, with the latter also having in vitro antiviral properties. This may improve outcomes in patients hospitalised for COVID-19.

Methods Placebo-controlled double-blind randomised multicentre trial. Patients ≥18 years, admitted to hospital for≤48 h (not intensive care) with a positive SARS-CoV-2 RT-PCR test, were recruited. The intervention was 500 mg daily azithromycin for 3 days followed by 250 mg daily azithromycin for 12 days combined with 200 mg twice daily hydroxychloroquine for all 15 days. The control group received placebo/placebo. The primary outcome was days alive and discharged from hospital within 14 days (DAOH14).

Results After randomisation of 117 patients, at the first planned interim analysis, the data and safety monitoring board recommended stopping enrolment due to futility, based on pre-specified criteria. Consequently, the trial was terminated on February 1, 2021. A total of 61 patients received the combined intervention and 56 patients received placebo. In the intervention group, patients had a median of 9.0 DAOH14 (IQR, 3–11) versus. 9.0 DAOH14 (IQR, 7–10) in the placebo group (p=0.90). The primary safety outcome, death from all causes on day 30, occurred for 1 patient in the intervention group versus. 2 patients receiving placebo (p=0.52), and readmittance or death within 30 days occurred for 9 patients in the intervention group versus. 6 patients receiving placebo (p=0.57).

Conclusions The combination of azithromycin and hydroxychloroquine did not improve survival or length of hospitalisation in patients with COVID-19.

Abstract

There are no beneficial or harmful effects from the combined intervention of hydroxychloroquine and azithromycin for hospitalised patients with confirmed coronavirus disease 2019 (COVID-19).

Introduction

Early in the coronavirus disease 2019 (COVID-19) pandemic, some evidence, mainly from laboratory studies, suggested that chloroquine and its less toxic derivative hydroxychloroquine, often used as an antirheumatic drug, had an antiviral effect on coronaviridae by inhibiting several pH-dependent steps in replication and endosomal viral uptake into human cells [1]. These findings have been confirmed in laboratory studies of primate cells infected with severe acute respiratory syndrome coronavirus (SARS)-1 [2]. Hydroxychloroquine may also bind to host cell sialic acids and gangliosides with high affinity, thus protecting the cell against binding to SARS-Corona virus-2 via its spike (S) protein [3]. Administered at recommended doses, in most countries up to 400–500 mg daily, hydroxychloroquine seems safe, even when used for longer periods and costs are low [4].

Azithromycin is a macrolide antibiotic, which has proven effective in reducing airway inflammation and consequent hospitalisation-requiring exacerbations of Chronic Obstructive Pulmonary Disease (COPD), asthma and bronchiectasis [5–7]. Recently, a strong association was found in critically ill patients with acute respiratory distress syndrome (ARDS) between treatment with azithromycin and improved survival [8] as summarised with greater power in systematic meta-analyses [9, 10]. Further, hydroxychloroquine and azithromycin may act synergistically to prevent the coronavirus from binding to ganglioside receptors on human cells [11].

Important trials show positive outcomes for agents like remdesivir, anti-IL6 and convalescent plasma in milder cases and early disease stages [12–14] but these interventions seem less effective in severely ill patients [15]. On the other hand, in more severe cases, immunosuppressive pharmaceuticals like corticosteroids do show some effect [16]. Thus, antiviral treatment in the early, and less severe disease stages appears to be the window of opportunity for these drugs [17].

The present trial assessed whether a combination of azithromycin and hydroxychloroquine, both in moderate and approved (for rheumatic indications) dosing regimens, would increase the number of days alive and discharged from hospital among hospitalised patients with COVID-19.

Methods

The trial protocol and statistical analysis plan are available in Supplementary Information sections 1 and 2 and have been published previously [18, 19]. The study was approved by the ethics committees of all participating sites (H-20022574), the Danish Medicines Agency (EudraCT no 2020-001198-55) and the Danish Data Protection Agency. It was monitored in accordance with good clinical practice (GCP) by the GCP units of the participating regions in Denmark. The study was conducted in accordance with the Declaration of Helsinki [20] No financial incentive was provided to the investigators or participants. There was an independent data and safety monitoring board (DSMB), consisting of three clinicians and researchers who are experts in performing large randomised studies. Additionally, the DSMB had access to the trial statistician, Mr. Tobias Wirenfeldt Klausen, a highly skilled biostatistician, who also supervised the interim analyses. Mr. Klausen was available any time the DSMB wanted his input. He was also blinded to treatment allocation, as only the trial pharmacist had the key to unblind.

This DSMB reviewed the trial's progress and performed safety, efficacy, and data completeness evaluations during the trial. It was not possible (in the interest of timeliness) to involve patients or the public in the design, conduct, reporting, or dissemination of our research. This study is a primary analysis and is described in accordance with the consolidated standards of reporting of randomised trials (CONSORT) guidelines.

Study design and sites

The Proactive Protection with Azithromycin and hydroxyChloroquine in hospitalised patients with COVID-19 (ProPAC-COVID) study was a multicentre, double-blinded placebo-controlled, randomised clinical trial investigating whether adding 15-day treatment with azithromycin and hydroxychloroquine to standard of care could decrease the period of hospitalisation and reduce the risks of non-invasive ventilation (NIV), admittance to an intensive care unit (ICU), and death. Patients were enrolled between April 6, 2020 and December 21, 2020 at six hospitals in Denmark within the COP:TRIN collaboration (www.coptrin.dk). The dosages selected were based on well-tolerated doses used to treat other diseases (e.g. rheumatological diseases), while lowering risk of cardiac side effects. The durations were selected to ensure coverage of patients with prolonged admissions for a relatively large part of the admissions and to securely cover the entire observation period of the primary outcome. Also, durations were chosen to protect against secondary infections from Gram positive microorganisms.

Participants

Eligible patients had to be 1) at least 18 years of age, 2) admitted to hospital with a confirmed positive test for SARS-CoV-2 infection by reverse transcription polymerase chain reaction (RT-PCR), and 3) hospitalised for≤48 h. Each patient provided signed informed consent to participate. Patients were excluded if they met any of the following criteria: 1) received>5 L oxygen supply; 2) known intolerance/allergy to the study drugs; 3) neurogenic hearing loss; 4) psoriasis; 5) retinopathy; 6) maculopathy; 7) visual field changes; 8) were breastfeeding/pregnant; 9) severe liver disease (international normalised ratio>1.5 spontaneously); 10) severe gastrointestinal disease (investigator-assessed liver disease, severe ulcerative colitis or Crohn's disease, peptic ulcer disease, or cancer); 11) neurological or haematological disorder; 12) estimated glomerular filtration rate (eGFR)<45 mL·min·1.73 m2; 13) clinically significant cardiac conduction disorder/arrhythmia or a prolonged corrected QT interval (QTc; i.e., F>480 ms for males or>470 ms for females); 14) myasthenia gravis; 15) were receiving treatment with digoxin; 16) glucose-6-phosphate dehydrogenase deficiency; 17) porphyria; 18) hypoglycaemia (blood glucose<3.0 mmol/L–1); 19) unable to give informed consent; 20) severe linguistic problems that significantly hindered cooperation; or 21) were receiving treatment with ergot alkaloids. The investigator evaluated patient eligibility based on these criteria.

Randomisation and masking

The study pharmacist generated the randomisation sequence, which was then entered into the online platform REDCap electronic data-capture tools hosted by the participating Danish regions. Patients were randomised 1:1 to azithromycin plus hydroxychloroquine or matching placebo capsules. Randomisation was performed in blocks of unknown and varying size, and the final allocation was blinded and stratified for age (> 70 versus ≤ 70 years), site of recruitment, and whether the patient had any of the following chronic lung diseases (yes versus no): COPD, asthma, bronchiectasis, or interstitial lung disease. All patients and study staff were blinded to participant treatment assignments. This included outcome assessors, investigators and study nurses, as well as research and clinical staff. The DSMB remained blinded throughout and made all recommendations blinded to treatment allocations. Only the trial's chief pharmacist held the key for unblinding. Formal unblinding took place on February 1, 2021 after the DSMB recommendation had been received and acknowledged.

Intervention

Patients were randomised to one of two treatment arms: 1) 500 mg azithromycin once daily plus 200 mg hydroxychloroquine twice daily on days 1–3 and then 250 mg azithromycin once daily plus 200 mg hydroxychloroquine twice daily on days 4–15; 2) placebo instead of both types of intervention medication. Medication (both arms) was marked with neutral labels: e.g., “Azithromycin group A” and “Azithromycin group B”. An important safety consideration for both study drugs was QTc prolongation [21, 22] Therefore, trial personnel measured the QTc at least twice during the period of hospitalisation.

Primary and secondary endpoints

The primary endpoint was the number of days alive and out of hospital (DAOH) within 14 days from randomisation. This outcome measure was developed by trialists to be both sensitive and clinically relevant, and it provides a method for counting days with sustained recovery without lead-time bias [23–25]. For the first secondary endpoint, each patient was placed in one of the following eight categories on day 5 and day 15, as described in our previous research [12]: 1) discharged from hospital with no restrictions on activities; 2) discharged from hospital but with restrictions on activities (may/may not be receiving long-term oxygen therapy at home); 3) hospitalised and under observation but not receiving supplemental oxygen or any other treatment; 4) hospitalised and not receiving supplemental oxygen, but receiving other treatment (which may/may not be related to COVID-19); 5) hospitalised and receiving supplemental oxygen by a method other than those described in (2) or (3), such as from a nasal catheter; 6) hospitalised and receiving NIV or oxygen from a high-flow device; 7) hospitalised and receiving mechanical ventilation or extra corporeal membrane oxygenation; or 8) dead. The trial included eight other secondary outcomes: 1) number of days in an ICU (time frame: 14 days); 2) number of days NIV was required during hospitalisation (time frame: 14 days); 3) mortality rates (time frames: 30, 90, and 365 days); 4) length of hospitalisation (time frame: 14 days); 5) DAOH (time frame: 30 days); 6) time to readmission for any reason (time frame: 30 days); 7) change in patient's pH, PaO2, or PCO2 partial pressure measurements (time frame: 4 days); and 8) time until no supplementary oxygen was required or until the patient was given “long-term oxygen therapy” (time frame: 14 days). Outcomes with follow-up >30 days will be reported later. All outcomes and analyses were conducted in strict concordance with the SAP.

Sample size calculation

The sample size for the primary outcome (DAOH within 14 days from randomisation) was calculated assuming a two-sided significance level of 5% and power (1 – β) of 80%. A group-sequential study design with one planned interim analysis at half-target recruitment was used. The standard deviation was set at 4 days [26] and the detection limit was set at 1.5 days (both directions). StudySize software (ver. 3.0; CreoStat HB, Gothenburg, Sweden) was used to calculate the sample size of 226 participants.

Statistical analysis

We compared outcomes using t-tests or Mann–Whitney U tests for continuous variables (depending on distribution), χ2 tests or Fisher's exact test for nominal variables, and log-rank tests to compare Kaplan–Meier survival curves. Cumulative event estimates were generated using hazard ratios (HRs) with 95% confidence intervals (CIs) in Cox proportional hazards models. Adjustment for continuous data was performed using multiple effects models. The primary analysis was based on intention-to-treat (ITT), and a secondary per protocol analysis was performed for both primary and secondary outcomes. A p-value<0.05 was considered statistically significant and all analyses were two-sided. We originally planned to perform an interim analysis between the groups when the study had reached 50% of the total sample size. However, in response to a subsequently retracted article by Mehra et al. [27], the Danish Medicines Agency demanded that we performed an extraordinary acute interim analysis (without unmasking) on the first 75 patients who had been recruited. This was reviewed by the DSMB, who recommended continuing to accrue patients (May 2020). The first planned interim analysis was conducted at 117 patients (50% recruited), and the trial was stopped due to futility (February 2021). Sensitivity analyses for the primary outcome included: 1) a modified ITT population of patients who received part or complete treatment with the intervention (all days); 2) a per protocol population who received both interventional drugs for all planned days; and 3) a multiple effects adjusted model for the primary outcome, in which adjustment was made for the following parameters: i) age (per year increase), ii) sex (male versus female), iii) body mass index (per unit increase), iv) oxygen therapy at inclusion (yes versus no), v) remdesivir (yes versus no), vi) any pre-existing lung disease (obstructive, interstitial or bronchiectasis: yes versus no), vii) diabetes mellitus (yes versus no), and viii) QTc across median (yes versus no). Statistical analyses were performed using SAS software (ver. 9.4; SAS Institute, Inc., Cary, NC, USA) and R software (ver. 3.4.3; R Development Core Team, Vienna, Austria).

Stopping the trial

On February 1, 2021, the trial was stopped for futility based on recommendations from the DSMB who met on January 29, 2021 and discussed the report from the first planned interim analysis. The maximum post conditional power to cross any boundary in the O'Brien–Fleming plot [28] was 0.064, which was below the threshold of 0.2 communicated from the steering committee to the DSMB prior to the meeting. The interim analyses were performed in accordance with the trial monitoring guidelines. After reviewing the post-conditional power, the remaining data in the interim analysis and the available published data, the DSMB recommended stopping the trial on grounds of futility (the DSMB recommendation is included in Supplementary Information section 4).

Results

Of the 664 patients screened, 117 were eligible for study inclusion (figure 1). Reasons for exclusion included: unable to give informed consent (18.8% of exclusions), eGFR<45 mL·min·1.73 m2 (17.9% of exclusions) and declined to participate (16.3% exclusions). Of the patients enrolled, 61 patients were randomised to the azithromycin plus hydroxychloroquine arm and 56 to the placebo arm. Participants had a median age of 65 years (interquartile range [IQR], 52–77), and 65 (56%) of them were men. The median time since symptom onset was 8 days (IQR, 4–10). Baseline characteristics of patients randomised to the intervention and placebo groups are presented in table 1, and in eTable 1 and eTable 2 in Supplementary Information section 3.

FIGURE 1
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FIGURE 1

CONSORT Diagram.

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TABLE 1

Baseline patient demographic and clinical characteristics

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TABLE 2

Primary and secondary outcomes

Primary outcome

Primary outcome assessment after randomisation was completed for 117 patients (100%). We observed no significant difference between the two randomised groups for the primary outcome of DAOH within 14 days after recruitment: median of 9.0 DAOH14 (IQR, 3–11) in the hydroxychloroquine plus azithromycin group versus 9.0 DAOH14 (IQR, 7–10) in the placebo group, p=0.91 (table 2, figure 2).

FIGURE 2
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FIGURE 2

Days alive and out of hospital at 14 days and 30 days, Median (IQR), days.

Secondary outcomes

At 15 days after randomisation, there was no significant difference between the hydroxychloroquine plus azithromycin group and the placebo group in COVID Outcomes Scale score (OR, 1.0 [95% CI, 0.5–2.2]; p=0.91; figure 3 and eTable 6 in Supplementary Information section 3). A post-hoc analysis of the ordinal outcome at day 5 was requested by the steering committee after unblinding to provide a time-updated assessment of clinical status; this analysis also suggested that the two groups were similar (OR, 0.9 [95% CI, 0.4–1.8]; figure 3 and eTable 7 in Supplementary Information section 3). We also found no differences between the groups in the prespecified subsidiary clinical outcomes (table 2, figure 2). We tested for an interaction between the trial intervention and symptom duration (< 8 days versus 8 days or above) and found no interaction (p=0.79).

FIGURE 3
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FIGURE 3

Days alive and out of hospital at 14 days and 30 days, Median (IQR), days.

Adverse event data are presented in table 3 and eTable 8 in Supplementary Information section 3. During follow-up, 1 of 61 patients (1.64%) in the hydroxychloroquine plus azithromycin group and 2 of 56 patients (3.6%) in the placebo group had a recorded QTc greater than 500 ms (table 2). Adverse events involving diarrhoea (12 versus 3), nausea (11 versus 6) and dizziness (10 versus 3) were more frequent in the hydroxychloroquine plus azithromycin patient group than in the placebo group. Conversely, adverse events involving a prolonged QTc (> 470 ms for females and>480 ms for males) were more frequent in the placebo group (4 versus 7). Only 2 serious adverse events were reported, both in the placebo group (eTable 8 in Supplementary Information section 3).

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TABLE 3

Adverse events

Discussion

The ProPAC-COVID trial was stopped at half recruitment based on prespecified futility criteria after a recommendation from the DSMB, in agreement with monitoring guidelines. Compared to placebo, the combination of azithromycin and hydroxychloroquine did not seem to have any effect on the measured outcomes. The primary outcome, DAOH within 14 days from randomisation, was similar in both arms, as was the ordinal outcome measure and the rates of death from all causes and readmissions.

Our trial is the first to report on this combination of hydroxychloroquine plus azithromycin administered in normal recommended doses for 15 days versus placebo. Other trials have reported either a mono-drug intervention versus placebo or higher doses of hydroxychloroquine plus azithromycin versus. one of these drugs.

One previous trial has reported on a dosing regimen of hydroxychloroquine similar to ours [29], albeit for a period of 5 days and without azithromycin; that trial was also stopped for futility and reported neutral results. In our trial, the study participants were generally not severely ill, which was congruent with the intention and rationale of the trial: to reduce viral replication (hydroxychloroquine) and hyperinflammation (azithromycin) before organ failure was evident. Some of the reasons that this combination of drugs failed to benefit patients with COVID-19 may include the drugs being unable to penetrate into the airway epithelium, lower potency in vivo than in vitro, and neutralisation of beneficial and harmful effects.

Although we are aware that the trial may have had insufficient power to analyse all the prespecified outcome measures, the uniform neutrality of all the analysed outcomes strongly suggests that the intervention resulted in no benefit or harm. Of special interest, we used the recommended doses of the two drugs and respected the contraindications of hydroxychloroquine and azithromycin when recruiting participants, and we did not observe changes in cardiac rhythm nor the QTc (F). Other trials investigating hydroxychloroquine/chloroquine have reported such changes, but in those trials, substantially higher doses than are recommended for other indications were used [30, 31].

Our results are consistent with those from other trials investigating the effects of hydroxychloroquine and azithromycin separately. A possibility of “neutralising” harm from drug toxicity and potential benefits against COVID-19 exists, although this is not considered to be likely, since we did not observe a higher incidence of serious adverse effects in the intervention arm. A recent placebo-controlled trial by Self et al., investigating the effects of a 5-day treatment course of hydroxychloroquine at a similar dose to our trial, was also stopped for futility (close to the target sample size) and was neutral with regards to all outcome measures [29] In the open-label RECOVERY trial [32], 500 mg of daily azithromycin for 10 days produced no benefit or harm, which was consistent with results from the COALITION II trial in which an identical azithromycin regimen was compared to placebo when added to high dose (800 mg·day–1) hydroxychloroquine. In the COALITION I trial, patients with suspected or confirmed COVID-19 were randomised to open-label treatment with i) standard care, ii) high dose hydroxychloroquine for 7 days or iii) a combination of high-dose hydroxychloroquine (800 mg daily) and high-dose azithromycin (500 mg daily) also for 7 days. The results were neutral on all outcomes, except for QTc, which was significantly longer in the two actively treated groups. Taken together, all of these trials that tested hydroxychloroquine versus standard care, azithromycin versus standard care, or azithromycin plus hydroxychloroquine have produced neutral results, except with regard to the QTc, which has been somewhat higher in patients who received high-dose hydroxychloroquine/chloroquine. Trial patients who received normal recommended doses of hydroxychloroquine/chloroquine did not exhibit prolonged QTcs.

One strength of the present study is that all enrolled patients had RT-PCR-confirmed COVID-19; in other trials exploring these drugs, patients with suspected but not necessarily confirmed COVID-19 were enrolled [30, 32, 33]. Additionally, the double-blind and placebo-controlled design is an important strength, especially when comparing outcomes such as the ordinal outcome and length of hospitalisation, which are heavily influenced by physician decisions. The discontinuation of the present study before full recruitment may be considered a limitation. However, we did use a relatively sensitive primary outcome. For the current study with admitted patients with lower respiratory tract infection, the sd is 3.5–4.0 [23, 34].Using this, and setting the detection limit at 1.5 days change (both ways) in DAOH, we reached the sample size, the trial was planned for. It can be discussed whether 1.5 days change is sensitive enough, however, the study group decided that if DAOH could not change at least 1.5 days, we would consider the effect to be of limited clinical value. At the time of trial termination, the chance of crossing a boundary of efficacy or harm was very low and when considered in the context of the evidence currently available, it seems unlikely that further recruitment would have demonstrated any effect. As the median time from onset of symptoms was 8 days, the study intervention could potentially have an effect if administered earlier in the course of the disease. However, this has not been studied in other trials. Our trial can not answer this question directly, however, such an effect in patients with a shorter duration of symptoms seems unlikely, as this had no effect on our results since there was no interaction between the study intervention and symptom duration regarding the primary outcome. Thus, we conclude that our trial results were neutral. The combination of azithromycin and hydroxychloroquine did not increase the likelihood of survival or discharge from hospital of patients with COVID-19. This conclusion is consistent with recent European Respiratory Society COVID-19 guidelines [35], which reported no clinical benefits associated with using hydroxychloroquine and/or azithromycin to treat patients hospitalised with COVID-19 (in the absence of bacterial infection).

Acknowledgements

We would like to thank all the relevant departments in Denmark for allowing us to recruit patients. We would also like to thank the COP:TRIN Steering Committee for their helpful advice. We also gratefully acknowledge the DSMB and chief pharmacist Kristian Østergaard Nielsen from Glostrup Pharmacy for their excellent work. In particular, we would like to thank the great team behind ProPAC COVID, especially Mohamad Isam Saeed, Jens-Kristian Bomholt-Riis, Anna Kjær Kristensen and Katja Bergenholtz.

Footnotes

  • Author contributions: Concept and design: Pradeesh Sivapalan, Charlotte Suppli Ulrik and Jens-Ulrik Jensen; acquisition, analysis and interpretation of data: Pradeesh Sivapalan, Charlotte Suppli Ulrik, Josefin Eklöf, Alexander Jordan, Therese Lapperre, Rasmus Dahlin Bojesen, Andrea Browatzki, Jon Torgny Wilcke, Vibeke Gottlieb, Kjell Erik Julius Håkansson, Casper Tidemandsen, Oliver Djurhuus Tupper, Howraman Meteran, Christina Marisa Bergsøe, Uffe Christian Steinholtz Bødtger, Daniel Bech Rasmussen, Sidse Graff Jensen, Lars Pedersen, Helene Priemé, Christian Søborg, Ida Elisabeth Steffensen, Dorthe Sandbæk Høgsberg, Martin Steen Frydland, Peter Lange, Asger Sverrild, Muzhda Ghanizada and Jens-Ulrik Jensen; drafting the manuscript: Pradeesh Sivapalan and Jens-Ulrik Jensen; critical revision of the manuscript for important intellectual content: all the authors; statistical analysis: Pradeesh Sivapalan, Jens-Ulrik Stæhr Jensen, Alexander Jordan, Tobias Wirenfeldt Klausen and Josefin Eklöf; obtaining funding: Jens-Ulrik Jensen; administrative, technical and material support: Jens-Ulrik Jensen, Vibeke Gottlieb; supervision: Jens-Ulrik Jensen, Filip Krag Knop, Tor Biering-Sørensen and Jens D. Lundgren

  • Role of the corresponding author: Initiator and study director.

  • Conflicts of interest/disclosure: PS reports fees from Boehringer Ingelheim, outside the submitted work. CSU reports fees from Boehringer-Ingelheim, AZ, GSK, TEVA, Novartis, ALK-Abello, Mundipharma, Sanofi Genzyme, Orion Pharma and Actelion, outside the submitted work. KEJH reports personal fees from AstraZeneca, Chiesi and TEVA, outside the submitted work. TBS has received research grants from GE healthcare and Sanofi Pasteur, as well as personal fees from Sanofi Pasteur, Novartis and Amgen, outside the submitted work. None of the authors have any conflicts of interest.

  • Support statement:The study was funded by The Novo Nordisk Foundation (Grant number: NNF20SA0062834). The research salary of PS was sponsored by Herlev and Gentofte Hospital, University Hospital of Copenhagen. The funders had no role in the design and conduct of the study, in the collection, management, analysis, and interpretation of the data, or in the preparation, review, or approval of the manuscript or the decision to submit the manuscript for publication. This trial was not supported in any form by the pharmaceutical industry. Dr Pradeesh Sivapalan and Dr Jens-Ulrik Jensen had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analyses.

  • Data sharing statement: It is the opinion of the COP:TRIN steering committee that knowledge sharing increases the quantity and quality of scientific results. Requests for trial information can be submitted to the project management team (Jens-Ulrik Jensen, Charlotte Ulrik and Pradeesh Sivapalan) who will consider the request. Any reasonable requests will then be discussed with the COP:TRIN Steering Committee.

  • The members of the writing group (Pradeesh Sivapalan, Charlotte Suppli Ulrik, Therese Sophie Lapperre, Rasmus Dahlin Bojesen, Josefin Eklöf, Andrea Browatzki, Jon Torgny Wilcke, Vibeke Gottlieb, Kjell Erik Julius Håkansson, Casper Tidemandsen, Oliver Tupper, Howraman Meteran, Christina Bergsøe, Eva Brøndum, Uffe Bodtger, Daniel Bech Rasmussen, Sidse Graff Jensen, Lars Pedersen, Alexander Jordan, Helene Priemé, Christian Søborg, Ida E. Steffensen, Dorthe Høgsberg, Tobias Wirenfeldt Klausen, Martin Steen Frydland, Peter Lange, Asger Sverrild, Muhzda Ghanizada, Filip Krag Knop, Tor Biering-Sørensen, Jens D. Lundgren, and Jens-Ulrik Stæhr Jensen, [protocol chair, Copenhagen COP:TRIN lead]) of the and ProPAC-COVID Study Group assume responsibility for the overall content and integrity of this article. The affiliations of the members of the writing group are listed in the Appendix.

  • This article has supplementary material available from erj.ersjournals.com

  • Data availability: It is the opinion of the COP:TRIN steering committee that knowledge sharing increases the quantity and quality of scientific results. Requests for trial information can be submitted to the project management team (Jens-Ulrik Jensen, Charlotte Ulrik and Pradeesh Sivapalan) who will consider the request. Any reasonable requests will then be discussed with the COP:TRIN Steering Committee.

  • Support Statement: (Funded by The Novo-Nordisk Foundation, grant no. NNF20SA0062834; ProPAC-COVID: ClinicalTrials.gov number, NCT04322396).

  • Received March 15, 2021.
  • Accepted May 22, 2021.
  • Copyright ©The authors 2021
http://creativecommons.org/licenses/by/4.0/

This version is distributed under the terms of the Creative Commons Attribution Licence 4.0.

References

  1. ↵
    1. Savarino A,
    2. Boelaert JR,
    3. Cassone A, et al.
    Effects of chloroquine on viral infections: an old drug against today's diseases? Lancet Infect Dis 2003; 3: 722–727. doi:10.1016/S1473-3099(03)00806-5
    OpenUrlCrossRefPubMedWeb of Science
  2. ↵
    1. Vincent MJ,
    2. Bergeron E,
    3. Benjannet S, et al.
    Chloroquine is a potent inhibitor of SARS coronavirus infection and spread. Virol J 2005; 2: 69. doi:10.1186/1743-422X-2-69
    OpenUrlCrossRefPubMed
  3. ↵
    1. Fantini J,
    2. Di Scala C,
    3. Chahinian H, et al.
    Structural and molecular modelling studies reveal a new mechanism of action of chloroquine and hydroxychloroquine against SARS-CoV-2 infection. Int J Antimicrob Agents 2020; 55: 105960. doi:10.1016/j.ijantimicag.2020.105960
    OpenUrlCrossRefPubMed
  4. ↵
    1. Lee SJ,
    2. Silverman E,
    3. Bargman JM
    . The role of antimalarial agents in the treatment of SLE and lupus nephritis. Nat Rev Nephrol 2011; 7: 718–729.
    OpenUrlCrossRefPubMed
  5. ↵
    1. Albert RK,
    2. Connett J,
    3. Bailey WC, et al.
    Azithromycin for prevention of exacerbations of COPD. N Engl J Med 2011; 365: 689–698. doi:10.1056/NEJMoa1104623
    OpenUrlCrossRefPubMedWeb of Science
    1. Gibson PG,
    2. Yang IA,
    3. Upham JW, et al.
    Effect of azithromycin on asthma exacerbations and quality of life in adults with persistent uncontrolled asthma (AMAZES): a randomised, double-blind, placebo-controlled trial. Lancet 2017; 390: 659–668. doi:10.1016/S0140-6736(17)31281-3
    OpenUrlCrossRefPubMed
  6. ↵
    1. Altenburg J,
    2. de Graaff CS,
    3. Stienstra Y, et al.
    Effect of azithromycin maintenance treatment on infectious exacerbations among patients with non-cystic fibrosis bronchiectasis: the BAT randomised controlled trial. JAMA 2013; 309: 1251–1259. doi:10.1001/jama.2013.1937
    OpenUrlCrossRefPubMedWeb of Science
  7. ↵
    1. Kawamura K,
    2. Ichikado K,
    3. Takaki M, et al.
    Adjunctive therapy with azithromycin for moderate and severe acute respiratory distress syndrome: a retrospective, propensity score-matching analysis of prospectively collected data at a single center. Int J Antimicrob Agents 2018; 51: 918–924. doi:10.1016/j.ijantimicag.2018.02.009
    OpenUrlPubMed
  8. ↵
    1. Chalmers JD,
    2. Boersma W,
    3. Lonergan M, et al.
    Long-term macrolide antibiotics for the treatment of bronchiectasis in adults: an individual participant data meta-analysis. Lancet Respir Med 2019; 7: 845–854. doi:10.1016/S2213-2600(19)30191-2
    OpenUrl
  9. ↵
    1. Hiles SA,
    2. McDonald VM,
    3. Guilhermino M, et al.
    Does maintenance azithromycin reduce asthma exacerbations? An individual participant data meta-analysis. Eur Respir J 2019; 54. doi:10.1183/13993003.01381-2019
  10. ↵
    1. Fantini J,
    2. Chahinian H,
    3. Yahi N
    . Synergistic antiviral effect of hydroxychloroquine and azithromycin in combination against SARS-CoV-2: What molecular dynamics studies of virus-host interactions reveal. Int J Antimicrob Agents 2020; 56: 106020. doi:10.1016/j.ijantimicag.2020.106020
    OpenUrl
  11. ↵
    1. Beigel JH,
    2. Tomashek KM,
    3. Dodd LE, et al.
    Remdesivir for the Treatment of Covid-19 - Final Report. N Engl J Med 2020; 383: 1813–1826. doi:10.1056/NEJMoa2007764
    OpenUrlCrossRefPubMed
    1. Nugroho CW,
    2. Suryantoro SD,
    3. Yuliasih Y, et al.
    Optimal use of tocilizumab for severe and critical COVID-19: a systematic review and meta-analysis. F1000Res 2021; 10: 73. doi:10.12688/f1000research.45046.1
    OpenUrl
  12. ↵
    1. Casadevall A,
    2. Dragotakes Q,
    3. Johnson PW, et al.
    Convalescent Plasma Use in the United States was inversely correlated with COVID-19 Mortality: Did Convalescent Plasma Hesitancy cost lives? medRxiv 2021.
  13. ↵
    1. Group A-TL-CS,
    2. Lundgren JD,
    3. Grund B, et al.
    A neutralizing monoclonal antibody for hospitalised patients with Covid-19. N Engl J Med 2021; 384: 905–914. doi:10.1056/NEJMoa2033130
    OpenUrlPubMed
  14. ↵
    1. Group RC,
    2. Horby P,
    3. Lim WS, et al.
    Dexamethasone in Hospitalised patients with Covid-19. N Engl J Med 2021; 384: 693–704. doi:10.1056/NEJMoa2021436
    OpenUrlCrossRefPubMed
  15. ↵
    1. Cantini F,
    2. Goletti D,
    3. Petrone L, et al.
    Immune therapy, or antiviral therapy, or both for COVID-19: a systematic review. Drugs 2020; 80: 1929–1946. doi:10.1007/s40265-020-01421-w
    OpenUrl
  16. ↵
    1. Sivapalan P,
    2. Ulrik CS,
    3. Bojesen RD, et al.
    Proactive prophylaxis with Azithromycin and HydroxyChloroquine in hospitalised patients with COVID-19 (ProPAC-COVID): a structured summary of a study protocol for a randomised controlled trial. Trials 2020; 21: 513. doi:10.1186/s13063-020-04409-9
    OpenUrl
  17. ↵
    1. Sivapalan P,
    2. Ulrik CS,
    3. Lappere TS, et al.
    Proactive prophylaxis with azithromycin and hydroxychloroquine in hospitalized patients with COVID-19 (ProPAC-COVID): a statistical analysis plan. Trials 2020; 21: 867. doi:10.1186/s13063-020-04795-0
    OpenUrl
  18. ↵
    1. World Medical A
    . World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. JAMA 2013; 310: 2191–2194. doi:10.1001/jama.2013.281053
    OpenUrlCrossRefPubMedWeb of Science
  19. ↵
    1. Roden DM,
    2. Harrington RA,
    3. Poppas A, et al.
    Considerations for drug interactions on QTc in exploratory COVID-19 treatment. Circulation 2020: 141: e906–e907. doi:10.1161/CIRCULATIONAHA.120.047521
    OpenUrlPubMed
  20. ↵
    1. Mercuro NJ,
    2. Yen CF,
    3. Shim DJ, et al.
    Risk of QT interval prolongation associated with use of Hydroxychloroquine with or without concomitant azithromycin among hospitalised patients testing positive for coronavirus disease 2019 (COVID-19). JAMA Cardiol 2020; 5: 1036–1041. doi:10.1001/jamacardio.2020.1834
    OpenUrl
  21. ↵
    1. Sivapalan P,
    2. Lapperre TS,
    3. Janner J, et al.
    Eosinophil-guided corticosteroid therapy in patients admitted to hospital with COPD exacerbation (CORTICO-COP): a multicentre, randomised, controlled, open-label, non-inferiority trial. Lancet Respir Med 2019.
    1. Freund Y,
    2. Cachanado M,
    3. Delannoy Q, et al.
    Effect of an Emergency department care bundle on 30-Day hospital discharge and survival among elderly patients with acute heart failure: The ELISABETH randomised clinical trial. JAMA 2020; 324: 1948–1956. doi:10.1001/jama.2020.19378
    OpenUrl
  22. ↵
    1. Ariti CA,
    2. Cleland JG,
    3. Pocock SJ, et al.
    Days alive and out of hospital and the patient journey in patients with heart failure: Insights from the candesartan in heart failure: assessment of reduction in mortality and morbidity (CHARM) program. Am Heart J 2011; 162: 900–906. doi:10.1016/j.ahj.2011.08.003
    OpenUrlCrossRefPubMed
  23. ↵
    1. Sivapalan P,
    2. Lapperre TS,
    3. Janner J, et al.
    Eosinophil-guided corticosteroid therapy in patients admitted to hospital with COPD exacerbation (CORTICO-COP): a multicentre, randomised, controlled, open-label, non-inferiority trial. Lancet Respir Med 2019; 7: 699–709. doi:10.1016/S2213-2600(19)30176-6
    OpenUrl
  24. ↵
    1. Mehra MR,
    2. Desai SS,
    3. Ruschitzka F, et al.
    Hydroxychloroquine or chloroquine with or without a macrolide for treatment of COVID-19: a multinational registry analysis. Lancet 2020.
  25. ↵
    1. O'Brien PC,
    2. Fleming TR
    . A multiple testing procedure for clinical trials. Biometrics 1979; 35: 549–556. doi:10.2307/2530245
    OpenUrlCrossRefPubMedWeb of Science
  26. ↵
    1. Self WH,
    2. Semler MW,
    3. Leither LM, et al.
    Effect of Hydroxychloroquine on Clinical Status at 14 Days in hospitalised patients with COVID-19: a randomised clinical trial. JAMA 2020; 324: 2165–2176. doi:10.1001/jama.2020.22240
    OpenUrlPubMed
  27. ↵
    1. Group RC,
    2. Horby P,
    3. Mafham M, et al.
    Effect of Hydroxychloroquine in Hospitalised patients with Covid-19. N Engl J Med 2020; 383: 2030–2040. doi:10.1056/NEJMoa2022926
    OpenUrlPubMed
  28. ↵
    1. Borba MGS,
    2. Val FFA,
    3. Sampaio VS, et al.
    Effect of high vs low doses of chloroquine diphosphate as adjunctive therapy for patients hospitalised with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection: a randomised clinical trial. JAMA Netw Open 2020; 3: e208857. doi:10.1001/jamanetworkopen.2020.8857
    OpenUrl
  29. ↵
    1. Horby P
    . Azithromycin in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial. Lancet 2021.
  30. ↵
    1. Cavalcanti AB,
    2. Zampieri FG,
    3. Rosa RG, et al.
    Coalition Covid-19 Brazil II. Hydroxychloroquine with or without Azithromycin in Mild-to-Moderate Covid-19. N Engl J Med 2020; 383: 2041–2052. doi:10.1056/NEJMoa2019014
    OpenUrlPubMed
  31. ↵
    1. Walters JA,
    2. Tan DJ,
    3. White CJ, et al.
    Systemic corticosteroids for acute exacerbations of chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2014(9): CD001288.
    OpenUrl
  32. ↵
    1. Chalmers JD,
    2. Crichton ML,
    3. Goeminne PC, et al.
    Management of hospitalised adults with coronavirus disease 2019 (COVID-19): a European Respiratory Society living guideline. Eur Respir J 2021; 57. doi:10.1183/13993003.00048-2021
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Azithromycin and hydroxychloroquine in hospitalised patients with confirmed COVID-19–a randomised double-blinded placebo-controlled trial
Pradeesh Sivapalan, Charlotte Suppli Ulrik, Therese Sophie Lapperre, Rasmus Dahlin Bojesen, Josefin Eklöf, Andrea Browatzki, Jon Torgny Wilcke, Vibeke Gottlieb, Kjell Erik Julius Håkansson, Casper Tidemandsen, Oliver Tupper, Howraman Meteran, Christina Bergsøe, Eva Brøndum, Uffe Bodtger, Daniel Bech Rasmussen, Sidse Graff Jensen, Lars Pedersen, Alexander Jordan, Helene Priemé, Christian Søborg, Ida E. Steffensen, Dorthe Høgsberg, Tobias Wirenfeldt Klausen, Martin Steen Frydland, Peter Lange, Asger Sverrild, Muhzda Ghanizada, Filip Krag Knop, Tor Biering-Sørensen, Jens D. Lundgren, Jens-Ulrik Stæhr Jensen,
European Respiratory Journal Jan 2021, 2100752; DOI: 10.1183/13993003.00752-2021

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Azithromycin and hydroxychloroquine in hospitalised patients with confirmed COVID-19–a randomised double-blinded placebo-controlled trial
Pradeesh Sivapalan, Charlotte Suppli Ulrik, Therese Sophie Lapperre, Rasmus Dahlin Bojesen, Josefin Eklöf, Andrea Browatzki, Jon Torgny Wilcke, Vibeke Gottlieb, Kjell Erik Julius Håkansson, Casper Tidemandsen, Oliver Tupper, Howraman Meteran, Christina Bergsøe, Eva Brøndum, Uffe Bodtger, Daniel Bech Rasmussen, Sidse Graff Jensen, Lars Pedersen, Alexander Jordan, Helene Priemé, Christian Søborg, Ida E. Steffensen, Dorthe Høgsberg, Tobias Wirenfeldt Klausen, Martin Steen Frydland, Peter Lange, Asger Sverrild, Muhzda Ghanizada, Filip Krag Knop, Tor Biering-Sørensen, Jens D. Lundgren, Jens-Ulrik Stæhr Jensen,
European Respiratory Journal Jan 2021, 2100752; DOI: 10.1183/13993003.00752-2021
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