Interleukin-6 blocking agents for treating COVID-19: a living systematic review.

BACKGROUND: It has been reported that people with COVID-19 and pre-existing autoantibodies against type I interferons are likely to develop an inflammatory cytokine storm responsible for severe respiratory symptoms. Since interleukin 6 (IL-6) is one of the cytokines released during this inflammatory process, IL-6 blocking agents have been used for treating people with severe COVID-19. OBJECTIVES: To update the evidence on the effectiveness and safety of IL-6 blocking agents compared to standard care alone or to a placebo for people with COVID-19. SEARCH METHODS: We searched the World Health Organization (WHO) International Clinical Trials Registry Platform, the Living OVerview of Evidence (L·OVE) platform, and the Cochrane COVID-19 Study Register to identify studies on 7 June 2022. SELECTION CRITERIA: We included randomized controlled trials (RCTs) evaluating IL-6 blocking agents compared to standard care alone or to placebo for people with COVID-19, regardless of disease severity. DATA COLLECTION AND ANALYSIS: Pairs of researchers independently conducted study selection, extracted data and assessed risk of bias. We assessed the certainty of evidence using the GRADE approach for all critical and important outcomes. In this update we amended our protocol to update the methods used for grading evidence by establishing minimal important differences for the critical outcomes. MAIN RESULTS: This update includes 22 additional trials, for a total of 32 trials including 12,160 randomized participants all hospitalized for COVID-19 disease. We identified a further 17 registered RCTs evaluating IL-6 blocking agents without results available as of 7 June 2022.  The mean age range varied from 56 to 75 years; 66.2% (8051/12,160) of enrolled participants were men. One-third (11/32) of included trials were placebo-controlled. Twenty-two were published in peer-reviewed journals, three were reported as preprints, two trials had results posted only on registries, and results from five trials were retrieved from another meta-analysis. Eight were funded by pharmaceutical companies.  Twenty-six included studies were multicenter trials; four were multinational and 22 took place in single countries. Recruitment of participants occurred between February 2020 and June 2021, with a mean enrollment duration of 21 weeks (range 1 to 54 weeks). Nineteen trials (60%) had a follow-up of 60 days or more. Disease severity ranged from mild to critical disease. The proportion of participants who were intubated at study inclusion also varied from 5% to 95%. Only six trials reported vaccination status; there were no vaccinated participants included in these trials, and 17 trials were conducted before vaccination was rolled out. We assessed a total of six treatments, each compared to placebo or standard care. Twenty trials assessed tocilizumab, nine assessed sarilumab, and two assessed clazakizumab. Only one trial was included for each of the other IL-6 blocking agents (siltuximab, olokizumab, and levilimab). Two trials assessed more than one treatment. Efficacy and safety of tocilizumab and sarilumab compared to standard care or placebo for treating COVID-19 At day (D) 28, tocilizumab and sarilumab probably result in little or no increase in clinical improvement (tocilizumab: risk ratio (RR) 1.05, 95% confidence interval (CI) 1.00 to 1.11; 15 RCTs, 6116 participants; moderate-certainty evidence; sarilumab: RR 0.99, 95% CI 0.94 to 1.05; 7 RCTs, 2425 participants; moderate-certainty evidence). For clinical improvement at ≥ D60, the certainty of evidence is very low for both tocilizumab (RR 1.10, 95% CI 0.81 to 1.48; 1 RCT, 97 participants; very low-certainty evidence) and sarilumab (RR 1.22, 95% CI 0.91 to 1.63; 2 RCTs, 239 participants; very low-certainty evidence). The effect of tocilizumab on the proportion of participants with a WHO Clinical Progression Score (WHO-CPS) of level 7 or above remains uncertain at D28 (RR 0.90, 95% CI 0.72 to 1.12; 13 RCTs, 2117 participants; low-certainty evidence) and that for sarilumab very uncertain (RR 1.10, 95% CI 0.90 to 1.33; 5 RCTs, 886 participants; very low-certainty evidence). Tocilizumab reduces all cause-mortality at D28 compared to standard care/placebo (RR 0.88, 95% CI 0.81 to 0.94; 18 RCTs, 7428 participants; high-certainty evidence). The evidence about the effect of sarilumab on this outcome is very uncertain (RR 1.06, 95% CI 0.86 to 1.30; 9 RCTs, 3305 participants; very low-certainty evidence). The evidence is uncertain for all cause-mortality at ≥ D60 for tocilizumab (RR 0.91, 95% CI 0.80 to 1.04; 9 RCTs, 2775 participants; low-certainty evidence) and very uncertain for sarilumab (RR 0.95, 95% CI 0.84 to 1.07; 6 RCTs, 3379 participants; very low-certainty evidence). Tocilizumab probably results in little to no difference in the risk of adverse events (RR 1.03, 95% CI 0.95 to 1.12; 9 RCTs, 1811 participants; moderate-certainty evidence). The evidence about adverse events for sarilumab is uncertain (RR 1.12, 95% CI 0.97 to 1.28; 4 RCT, 860 participants; low-certainty evidence).  The evidence about serious adverse events is very uncertain for tocilizumab (RR 0.93, 95% CI 0.81 to 1.07; 16 RCTs; 2974 participants; very low-certainty evidence) and uncertain for sarilumab (RR 1.09, 95% CI 0.97 to 1.21; 6 RCTs; 2936 participants; low-certainty evidence). Efficacy and safety of clazakizumab, olokizumab, siltuximab and levilimab compared to standard care or placebo for treating COVID-19 The evidence about the effects of clazakizumab, olokizumab, siltuximab, and levilimab comes from only one or two studies for each blocking agent, and is uncertain or very uncertain. AUTHORS' CONCLUSIONS: In hospitalized people with COVID-19, results show a beneficial effect of tocilizumab on all-cause mortality in the short term and probably little or no difference in the risk of adverse events compared to standard care alone or placebo. Nevertheless, both tocilizumab and sarilumab probably result in little or no increase in clinical improvement at D28. Evidence for an effect of sarilumab and the other IL-6 blocking agents on critical outcomes is uncertain or very uncertain. Most of the trials included in our review were done before the waves of different variants of concern and before vaccination was rolled out on a large scale. An additional 17 RCTs of IL-6 blocking agents are currently registered with no results yet reported. The number of pending studies and the number of participants planned is low. Consequently, we will not publish further updates of this review.

Safety and effectiveness of vaccines against COVID-19 in children aged 5-11 years: a systematic review and meta-analysis.

BACKGROUND: To date, more than 761 million confirmed SARS-CoV-2 infections have been recorded globally, and more than half of all children are estimated to be seropositive. Despite high SARS-CoV-2 infection incidences, the rate of severe COVID-19 in children is low. We aimed to assess the safety and efficacy or effectiveness of COVID-19 vaccines approved in the EU for children aged 5-11 years. METHODS: In this systematic review and meta-analysis, we included studies of any design identified through searching the COVID-19 L·OVE (living overview of evidence) platform up to Jan 23, 2023. We included studies with participants aged 5-11 years, with any COVID-19 vaccine approved by the European Medicines Agency-ie, mRNA vaccines BNT162b2 (Pfizer-BioNTech), BNT162b2 Bivalent (against original strain and omicron [BA.4 or BA.5]), mRNA-1273 (Moderna), or mRNA-1273.214 (against original strain and omicron BA.1). Efficacy and effectiveness outcomes were SARS-CoV-2 infection (PCR-confirmed or antigen-test confirmed), symptomatic COVID-19, hospital admission due to COVID-19, COVID-19-related mortality, multisystem inflammatory syndrome in children (MIS-C), and long-term effects of COVID-19 (long COVID or post-COVID-19 condition as defined by study investigators or per WHO definition). Safety outcomes of interest were serious adverse events, adverse events of special interest (eg, myocarditis), solicited local and systemic events, and unsolicited adverse events. We assessed risk of bias and rated the certainty of evidence (CoE) using the Grading of Recommendations Assessment, Development and Evaluation approach. This study was prospectively registered with PROSPERO, CRD42022306822. FINDINGS: Of 5272 screened records, we included 51 (1·0%) studies (n=17 [33%] in quantitative synthesis). Vaccine effectiveness after two doses against omicron infections was 41·6% (95% CI 28·1-52·6; eight non-randomised studies of interventions [NRSIs]; CoE low), 36·2% (21·5-48·2; six NRSIs; CoE low) against symptomatic COVID-19, 75·3% (68·0-81·0; six NRSIs; CoE moderate) against COVID-19-related hospitalisations, and 78% (48-90, one NRSI; CoE very low) against MIS-C. Vaccine effectiveness against COVID-19-related mortality was not estimable. Crude event rates for deaths in unvaccinated children were less than one case per 100 000 children, and no events were reported for vaccinated children (four NRSIs; CoE low). No study on vaccine effectiveness against long-term effects was identified. Vaccine effectiveness after three doses was 55% (50-60; one NRSI; CoE moderate) against omicron infections, and 61% (55-67; one NRSI; CoE moderate) against symptomatic COVID-19. No study reported vaccine efficacy or effectiveness against hospitalisation following a third dose. Safety data suggested no increased risk of serious adverse events (risk ratio [RR] 0·83 [95% CI 0·21-3·33]; two randomised controlled trials; CoE low), with approximately 0·23-1·2 events per 100 000 administered vaccines reported in real-life observations. Evidence on the risk of myocarditis was uncertain (RR 4·6 [0·1-156·1]; one NRSI; CoE low), with 0·13-1·04 observed events per 100 000 administered vaccines. The risk of solicited local reactions was 2·07 (1·80-2·39; two RCTs; CoE moderate) after one dose and 2·06 (1·70-2·49; two RCTs; CoE moderate) after two doses. The risk of solicited systemic reactions was 1·09 (1·04-1·16; two RCTs; CoE moderate) after one dose and 1·49 (1·34-1·65; two RCTs; CoE moderate) after two doses. The risk of unsolicited adverse events after two doses (RR 1·21 [1·07-1·38]; CoE moderate) was higher among mRNA-vaccinated compared with unvaccinated children. INTERPRETATION: In children aged 5-11 years, mRNA vaccines are moderately effective against infections with the omicron variant, but probably protect well against COVID-19 hospitalisations. Vaccines were reactogenic but probably safe. Findings of this systematic review can serve as a basis for public health policy and individual decision making on COVID-19 vaccination in children aged 5-11 years. FUNDING: German Federal Joint Committee.

Sharing of Individual Patient-Level Data by Trialists of Randomized Clinical Trials of Pharmacological Treatments for COVID-19.

This study describes access to individual patient-level data from randomized clinical trials during the COVID-19 pandemic to determine whether the intent to share what was reported in the registry, publication, or preprint was consistent with actual data access.

Transparency and reporting characteristics of COVID-19 randomized controlled trials.

BACKGROUND: In the context of the COVID-19 pandemic, randomized controlled trials (RCTs) are essential to support clinical decision-making. We aimed (1) to assess and compare the reporting characteristics of RCTs between preprints and peer-reviewed publications and (2) to assess whether reporting improves after the peer review process for all preprints subsequently published in peer-reviewed journals. METHODS: We searched the Cochrane COVID-19 Study Register and L·OVE COVID-19 platform to identify all reports of RCTs assessing pharmacological treatments of COVID-19, up to May 2021. We extracted indicators of transparency (e.g., trial registration, data sharing intentions) and assessed the completeness of reporting (i.e., some important CONSORT items, conflict of interest, ethical approval) using a standardized data extraction form. We also identified paired reports published in preprint and peer-reviewed publications. RESULTS: We identified 251 trial reports: 121 (48%) were first published in peer-reviewed journals, and 130 (52%) were first published as preprints. Transparency was poor. About half of trials were prospectively registered (n = 140, 56%); 38% (n = 95) made their full protocols available, and 29% (n = 72) provided access to their statistical analysis plan report. A data sharing statement was reported in 68% (n = 170) of the reports of which 91% stated their willingness to share. Completeness of reporting was low: only 32% (n = 81) of trials completely defined the pre-specified primary outcome measures; 57% (n = 143) reported the process of allocation concealment. Overall, 51% (n = 127) adequately reported the results for the primary outcomes while only 14% (n = 36) of trials adequately described harms. Primary outcome(s) reported in trial registries and published reports were inconsistent in 49% (n = 104) of trials; of them, only 15% (n = 16) disclosed outcome switching in the report. There were no major differences between preprints and peer-reviewed publications. Of the 130 RCTs published as preprints, 78 were subsequently published in a peer-reviewed journal. There was no major improvement after the journal peer review process for most items. CONCLUSIONS: Transparency, completeness, and consistency of reporting of COVID-19 clinical trials were insufficient both in preprints and peer-reviewed publications. A comparison of paired reports published in preprint and peer-reviewed publication did not indicate major improvement.

Interleukin-1 blocking agents for treating COVID-19.

BACKGROUND: Interleukin-1 (IL-1) blocking agents have been used for treating severe coronavirus disease 2019 (COVID-19), on the premise that their immunomodulatory effect might be beneficial in people with COVID-19. OBJECTIVES: To assess the effects of IL-1 blocking agents compared with standard care alone or with placebo on effectiveness and safety outcomes in people with COVID-19. We will update this assessment regularly. SEARCH METHODS: We searched the Cochrane COVID-19 Study Register and the COVID-19 L-OVE Platform (search date 5 November 2021). These sources are maintained through regular searches of MEDLINE, Embase, CENTRAL, trial registers and other sources. We also checked the World Health Organization International Clinical Trials Registry Platform, regulatory agency websites, Retraction Watch (search date 3 November 2021). SELECTION CRITERIA: We included randomised controlled trials (RCTs) evaluating IL-1 blocking agents compared with standard care alone or with placebo for people with COVID-19, regardless of disease severity. DATA COLLECTION AND ANALYSIS: We followed Cochrane methodology. The protocol was amended to reduce the number of outcomes considered. Two researchers independently screened and extracted data and assessed the risk of bias with the Cochrane Risk of Bias 2 tool. We rated the certainty of evidence using the GRADE approach for the critical outcomes of clinical improvement (Day 28; ≥ D60); WHO Clinical Progression Score of level 7 or above (i.e. the proportion of participants with mechanical ventilation +/- additional organ support OR death) (D28; ≥ D60); all-cause mortality (D28; ≥ D60); incidence of any adverse events; and incidence of serious adverse events. MAIN RESULTS: We identified four RCTs of anakinra (three published in peer-reviewed journals, one reported as a preprint) and two RCTs of canakinumab (published in peer-reviewed journals). All trials were multicentre (2 to 133 centres). Two trials stopped early (one due to futility and one as the trigger for inferiority was met). The median/mean age range varied from 58 to 68 years; the proportion of men varied from 58% to 77%. All participants were hospitalised; 67% to 100% were on oxygen at baseline but not intubated; between 0% and 33% were intubated at baseline. We identified a further 16 registered trials with no results available, of which 15 assessed anakinra (four completed, four terminated, five ongoing, three not recruiting) and one (completed) trial assessed canakinumab. Effectiveness of anakinra for people with COVID-19 Anakinra probably results in little or no increase in clinical improvement at D28 (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.97 to 1.20; 3 RCTs, 837 participants; absolute effect: 59 more per 1000 (from 22 fewer to 147 more); moderate-certainty evidence. The evidence is uncertain about an effect of anakinra on 1) the proportion of participants with a WHO Clinical Progression Score of level 7 or above at D28 (RR 0.67, 95% CI 0.36 to 1.22; 2 RCTs, 722 participants; absolute effect: 55 fewer per 1000 (from 107 fewer to 37 more); low-certainty evidence) and ≥ D60 (RR 0.54, 95% CI 0.30 to 0.96; 1 RCT, 606 participants; absolute effect: 47 fewer per 1000 (from 72 fewer to 4 fewer) low-certainty evidence); and 2) all-cause mortality at D28 (RR 0.69, 95% CI 0.34 to 1.39; 2 RCTs, 722 participants; absolute effect: 32 fewer per 1000 (from 68 fewer to 40 more); low-certainty evidence).  The evidence is very uncertain about an effect of anakinra on 1) the proportion of participants with clinical improvement at ≥ D60 (RR 0.93, 95% CI 0.78 to 1.12; 1 RCT, 115 participants; absolute effect: 59 fewer per 1000 (from 186 fewer to 102 more); very low-certainty evidence); and 2) all-cause mortality at ≥ D60 (RR 1.03, 95% CI 0.68 to 1.56; 4 RCTs, 1633 participants; absolute effect: 8 more per 1000 (from 84 fewer to 147 more); very low-certainty evidence). Safety of anakinra for people with COVID-19 Anakinra probably results in little or no increase in adverse events (RR 1.02, 95% CI 0.94 to 1.11; 2 RCTs, 722 participants; absolute effect: 14 more per 1000 (from 43 fewer to 78 more); moderate-certainty evidence).  The evidence is uncertain regarding an effect of anakinra on serious adverse events (RR 0.95, 95% CI 0.58 to 1.56; 2 RCTs, 722 participants; absolute effect: 12 fewer per 1000 (from 104 fewer to 138 more); low-certainty evidence). Effectiveness of canakinumab for people with COVID-19 Canakinumab probably results in little or no increase in clinical improvement at D28 (RR 1.05, 95% CI 0.96 to 1.14; 2 RCTs, 499 participants; absolute effect: 42 more per 1000 (from 33 fewer to 116 more); moderate-certainty evidence).  The evidence of an effect of canakinumab is uncertain on 1) the proportion of participants with a WHO Clinical Progression Score of level 7 or above at D28 (RR 0.72, 95% CI 0.44 to 1.20; 2 RCTs, 499 participants; absolute effect: 35 fewer per 1000 (from 69 fewer to 25 more); low-certainty evidence); and 2) all-cause mortality at D28 (RR:0.75; 95% CI 0.39 to 1.42); 2 RCTs, 499 participants; absolute effect: 20 fewer per 1000 (from 48 fewer to 33 more); low-certainty evidence).  The evidence is very uncertain about an effect of canakinumab on all-cause mortality at ≥ D60 (RR 0.55, 95% CI 0.16 to 1.91; 1 RCT, 45 participants; absolute effect: 112 fewer per 1000 (from 210 fewer to 227 more); very low-certainty evidence). Safety of canakinumab for people with COVID-19 Canakinumab probably results in little or no increase in adverse events (RR 1.02; 95% CI 0.86 to 1.21; 1 RCT, 454 participants; absolute effect: 11 more per 1000 (from 74 fewer to 111 more); moderate-certainty evidence). The evidence of an effect of canakinumab on serious adverse events is uncertain (RR 0.80, 95% CI 0.57 to 1.13; 2 RCTs, 499 participants; absolute effect: 44 fewer per 1000 (from 94 fewer to 28 more); low-certainty evidence). AUTHORS' CONCLUSIONS: Overall, we did not find evidence for an important beneficial effect of IL-1 blocking agents. The evidence is uncertain or very uncertain for several outcomes. Sixteen trials of anakinra and canakinumab with no results are currently registered, of which four are completed, and four terminated. The findings of this review are updated on the COVID-NMA platform (covid-nma.com).

Interleukin-6 blocking agents for treating COVID-19: a living systematic review.

BACKGROUND: Interleukin 6 (IL-6) blocking agents have been used for treating severe coronavirus disease 2019 (COVID-19). Their immunosuppressive effect might be valuable in patients with COVID-19 characterised by substantial immune system dysfunction by controlling inflammation and promoting disease tolerance. OBJECTIVES: To assess the effect of IL-6 blocking agents compared to standard care alone or with placebo on efficacy and safety outcomes in COVID-19. We will update this assessment regularly. SEARCH METHODS: We searched the World Health Organization (WHO) International Clinical Trials Registry Platform (up to 11 February 2021) and the L-OVE platform, and Cochrane COVID-19 Study Register to identify trials up to 26 February 2021. SELECTION CRITERIA: We included randomised controlled trials (RCTs) evaluating IL-6 blocking agents compared with standard care alone or with placebo for people with COVID-19, regardless of disease severity. DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methodology. The protocol was amended to reduce the number of outcomes considered. Two review authors independently collected data and assessed the risk of bias with the Cochrane Risk of Bias 2 tool. We rated the certainty of evidence with the GRADE approach for the critical outcomes such as clinical improvement (defined as hospital discharge or improvement on the scale used by trialists to evaluate clinical progression or recovery) (day (D) 28 / ≥ D60); WHO Clinical Progression Score of level 7 or above (i.e. the proportion of participants with mechanical ventilation +/- additional organ support OR death) (D28 / ≥ D60); all-cause mortality (D28 / ≥ D60); incidence of any adverse events; and incidence of serious adverse events. MAIN RESULTS: We identified 10 RCTs with available data including one platform trial comparing tocilizumab and sarilumab with standard of care. These trials evaluated tocilizumab (nine RCTs including two platform trials; seven were reported as peer-reviewed articles, two as preprints; 6428 randomised participants); and two sarilumab (one platform trial reported as peer reviewed article, one reported as preprint, 880 randomised participants). All trials included were multicentre trials. They were conducted in Brazil, China, France, Italy, UK, USA, and four were multi-country trials. The mean age range of participants ranged from 56 to 65 years; 4572 (66.3%) of trial participants were male. Disease severity ranged from mild to critical disease. The reported proportion of participants on oxygen at baseline but not intubated varied from 56% to 100% where reported. Five trials reported the inclusion of intubated patients at baseline. We identified a further 20 registered RCTs of tocilizumab compared to placebo/standard care (five completed without available results, five terminated without available results, eight ongoing, two not recruiting); 11 RCTs of sarilumab (two completed without results, three terminated without available results, six ongoing); six RCTs of clazakisumab (five ongoing, one not recruiting); two RCTs of olokizumab (one completed, one not recruiting); one of siltuximab (ongoing) and one RCT of levilimab (completed without available results). Of note, three were cancelled (2 tocilizumab, 1 clazakisumab). One multiple-arm RCT evaluated both tocilizumab and sarilumab compared to standard of care, one three-arm RCT evaluated tocilizumab and siltuximab compared to standard of care and consequently they appear in each respective comparison. Tocilizumab versus standard care alone or with placebo a. Effectiveness of tocilizumab for patients with COVID-19 Tocilizumab probably results in little or no increase in the outcome of clinical improvement at D28 (RR 1.06, 95% CI 1.00 to 1.13; I2 = 40.9%; 7 RCTs, 5585 participants; absolute effect: 31 more with clinical improvement per 1000 (from 0 fewer to 67 more); moderate-certainty evidence). However, we cannot exclude that some subgroups of patients could benefit from the treatment. We did not obtain data for longer-term follow-up (≥ D60). The effect of tocilizumab on the proportion of participants with a WHO Clinical Progression Score of level of 7 or above is uncertain at D28 (RR 0.99, 95% CI 0.56 to 1.74; I2 = 64.4%; 3 RCTs, 712 participants; low-certainty evidence). We did not obtain data for longer-term follow-up (≥ D60). Tocilizumab reduces all-cause mortality at D28 compared to standard care alone or placebo (RR 0.89, 95% CI 0.82 to 0.97; I2 = 0.0%; 8 RCTs, 6363 participants; absolute effect: 32 fewer deaths per 1000 (from 52 fewer to 9 fewer); high-certainty evidence). The evidence suggests uncertainty around the effect on mortality at ≥ D60 (RR 0.86, 95% CI 0.53 to 1.40; I2 = 0.0%; 2 RCTs, 519 participants; low-certainty evidence). b. Safety of tocilizumab for patients with COVID-19 The evidence is very uncertain about the effect of tocilizumab on adverse events (RR 1.23, 95% CI 0.87 to 1.72; I2 = 86.4%; 7 RCTs, 1534 participants; very low-certainty evidence). Nevertheless, tocilizumab probably results in slightly fewer serious adverse events than standard care alone or placebo (RR 0.89, 95% CI 0.75 to 1.06; I2 = 0.0%; 8 RCTs, 2312 participants; moderate-certainty evidence). Sarilumab versus standard care alone or with placebo The evidence is uncertain about the effect of sarilumab on all-cause mortality at D28 (RR 0.77, 95% CI 0.43 to 1.36; 2 RCTs, 880 participants; low certainty), on all-cause mortality at ≥ D60 (RR 1.00, 95% CI 0.50 to 2.0; 1 RCT, 420 participants; low certainty), and serious adverse events (RR 1.17, 95% CI 0.77 to 1.77; 2 RCTs, 880 participants; low certainty). It is unlikely that sarilumab results in an important increase of adverse events (RR 1.05, 95% CI 0.88 to 1.25; 1 RCT, 420 participants; moderate certainty). However, an increase cannot be excluded No data were available for other critical outcomes. AUTHORS' CONCLUSIONS: On average, tocilizumab reduces all-cause mortality at D28 compared to standard care alone or placebo and probably results in slightly fewer serious adverse events than standard care alone or placebo. Nevertheless, tocilizumab probably results in little or no increase in the outcome clinical improvement (defined as hospital discharge or improvement measured by trialist-defined scales) at D28. The impact of tocilizumab on other outcomes is uncertain or very uncertain. With the data available, we were not able to explore heterogeneity. Individual patient data meta-analyses are needed to be able to identify which patients are more likely to benefit from this treatment. Evidence for an effect of sarilumab is uncertain and evidence for other anti-IL6 agents is unavailable. Thirty-nine RCTs of IL-6 blocking agents with no results are currently registered, of which nine are completed and seven trials were terminated with no results available. The findings of this review will be updated as new data are made available on the COVID-NMA platform (covid-nma.com).