Subcutaneous IL-6 Inhibitor Sarilumab vs. Standard Care in Hospitalized Patients With Moderate-To-Severe COVID-19: An Open Label Randomized Clinical Trial

Background

The use of IL-6 blockers in COVID-19 hospitalized patients has been associated with a reduction in mortality compared to standard care. However, many uncertainties remain pertaining to optimal intervention time, administration schedule, and predictors of response. To date, data on the use of subcutaneous sarilumab is limited and no randomized trial results are available.

Methods

Open label randomized controlled trial at a single center in Spain. We included adult patients admitted with microbiology documented COVID-19 infection, imaging confirmed pneumonia, fever and/or laboratory evidence of inflammatory phenotype, and no need for invasive ventilation. Participants were randomly assigned to receive sarilumab, a single 400 mg dose in two 200 mg subcutaneous injections, added to standard care or standard care, in a 2:1 proportion. Primary endpoints included 30-day mortality, mean change in clinical status at day 7 scored in a 7-category ordinal scale ranging from death (category 1) to discharge (category 7), and duration of hospitalization. The primary efficacy analysis was conducted on the intention-to-treat population.

Results

A total of 30 patients underwent randomization: 20 to sarilumab and 10 to standard care. Most patients were male (20/30, 67%) with a median (interquartile range) age of 61.5 years (56-72). At day 30, 2/20 (10%) patients died in the sarilumab arm vs. none (0/10) in standard care (Log HR 15.11, SE 22.64; p = 0.54). At day 7, no significant differences were observed in the median change in clinical status (2 [0-3]) vs. 3 [0-3], p = 0.32). Median time to discharge (days) was similar (7 [6-11] vs. 6 [4-12]; HR 0.65, SE 0.26; p = 0.27). No significant differences were detected in the rate of progression to invasive and noninvasive mechanical ventilation.

Conclusions and Relevance

Our pragmatic pilot study has failed to demonstrate the benefit of adding subcutaneous sarilumab to standard care for mortality by 30 days, functional status at day 7, or hospital stay. Findings herein do not exclude a potential effect of sarilumab in severe COVID-19 but adequately powered blinded randomized phase III trials are warranted to assess the impact of the subcutaneous route and a more selected target population.

Trial Registration

www.ClinicalTrials.gov, Identifier: NCT04357808.

Systemic effects of IL-6 blockade in rheumatoid arthritis beyond the joints

Interleukin (IL)-6 is produced locally in response to an inflammatory stimulus, and is able to induce systemic manifestations at distance from the site of inflammation. Its unique signaling mechanism, including classical and trans-signaling pathways, leads to a major expansion in the number of cell types responding to IL-6. This pleiotropic cytokine is a key factor in the pathogenesis of rheumatoid arthritis (RA) and is involved in many extra-articular manifestations that accompany the disease. Thus, IL-6 blockade is associated with various biological effects beyond the joints. In this review, the systemic effects of IL-6 in RA comorbidities and the consequences of its blockade will be discussed, including anemia of chronic disease, cardiovascular risks, bone and muscle functions, and neuro-psychological manifestations.

Engineering mesenchymal stromal cells with neutralizing and anti-inflammatory capability against SARS-CoV-2 infection

The emergence of the novel human severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to the pandemic of coronavirus disease 2019 (COVID-19), which has markedly affected global health and the economy. Both uncontrolled viral replication and a proinflammatory cytokine storm can cause severe tissue damage in patients with COVID-19. SARS-CoV-2 utilizes angiotensin-converting enzyme 2 (ACE2) as its entry receptor. In this study, we generated ACE2 extracellular domain-Fc and single-chain variable fragment-interleukin 6 (IL-6) single-chain variable fragment against IL-6 receptor (scFv-IL6R)-Fc fusion proteins to differentially neutralize viruses and ameliorate the cytokine storm. The human ACE2 (hACE2)_1-740-Fc fusion protein showed a potent inhibitory effect on pseudo-typed SARS-CoV-2 entry and a good safety profile in mice. In addition, scFv-IL6R-Fc strongly blocked IL-6 signal activation. We also established a mesenchymal stromal cell (MSC)-based hACE2_1-740-Fc and scFv-IL6R-Fc delivery system, which could serve as a potential therapy strategy for urgent clinical needs of patients with COVID-19.

Tocilizumab in COVID-19: Is the Temptation Worthwhile?

How to cite this article: Gupta S, Tomar DS. Tocilizumab in COVID-19: Is the Temptation Worthwhile? Indian J Crit Care Med 2021;25(3): 247-248.

Rethinking interleukin-6 blockade for treatment of COVID-19

Interleukin-6 (IL-6) is a pleiotropic cytokine with effects in immune regulation, inflammation, and infection. The use of drugs that inhibit IL-6 biological activity has been proposed as a treatment for patients with Coronavirus Disease 2019 (COVID-19). The rationale for this approach includes commitment to the concept that inflammation is a cause of lung damage in COVID-19 and belief that IL-6 is a pro-inflammatory molecule. Observational data thought to support IL-6 inhibition include elevated circulating IL-6 levels in COVID-19 patients and association between elevated IL-6 and poor clinical outcomes. However, IL-6 has significant anti-inflammatory properties, which calls into question the rationale for employing IL-6 blockade to suppress inflammation-induced tissue injury. Also, studies suggesting a beneficial role for IL-6 in the host response to infection challenge the strategy of using IL-6 blockade to treat COVID-19. In studies of recombinant IL-6 injected into human volunteers, IL-6 levels exceeding those measured in COVID-19 patients have been observed with no pulmonary adverse events or other organ damage. These observations question the role of IL-6 as a contributing factor in COVID-19. Clinical experience with IL-6 receptor antagonists such as tocilizumab demonstrates increase in severe and opportunistic infections, raising concern about using tocilizumab and similar agents to treat COVID-19. Trials of drugs to inhibit IL-6 activity in COVID-19 are ongoing and will shed light on the role of IL-6 in COVID-19 pathogenesis. However, until more information is available, providers should exercise caution in prescribing these therapies given the potential for patient harm.

Tocilizumab for treating COVID-19: a systemic review and meta-analysis of retrospective studies

OBJECTIVES

COVID-19 has become a global epidemic, and effective therapies have not been discovered up to now. We conducted this study to explore the effectiveness and safety of tocilizumab recently used for treating COVID-19.

METHOD

A comprehensive search was conducted (up to September 27, 2020), and 19 eligible records were identified according to the inclusion and exclusion criteria. The data of the studies were extracted by 2 independent reviewers and were analyzed to evaluate the safety and availability of tocilizumab for treating COVID-19.

RESULTS

Thirteen retrospective case-control studies (n = 2285 patients) and 6 retrospective single-armed studies (n = 208) were retrieved in this study. In the comparison of tocilizumab treatment group (TCZ) and standard treatment group (ST), significant associations with a lower risk of admission to ICU, use of ventilation, and mortality (OR, 95% CI: 0.53, 0.26~1.09; 0.66, 0.46~0.94; 0.44, 0.36~0.55) were found in the tocilizumab treatment group. What is more, patients treated with tocilizumab had better clinical improvement compared with the patients treated with ST (OR, 1.24; 95% CI, 0.96~1.62). After taking tocilizumab, the patients had lower C-reactive protein (CRP), white blood cell count (WBC), aspartate aminotransferase (AST) (WMD, 95% CI: - 99.66, - 156.24~- 43.09; - 0.95, - 1.8~- 0.11; - 12.58, - 18.88~-6.29) but higher troponin (WMD, 7.61; 95% CI, 3.06~12.15) than before. In addition, tocilizumab did not have significant influence on patients' neutrophil count (Neut), lymphocyte count (Lymp), platelet count (Plt), alanine aminotransferase (ALT), and creatine (WMD, 95% CI: - 0.29, - 2.91~2.33; 0.42, - 0.23~1.07; 5.2, - 2.85~13.25; 22.49, - 2.73~47.7; - 44.78, - 93.37~3.81).

CONCLUSION

Tocilizumab may have potential effectiveness to treat COVID-19 according to the results of this study. However, more large-scale studies are needed for more accurate conclusions.

Tocilizumab, in search for a role in acute GVHD

Acute graft versus host disease (aGVHD) was first described by Barnes et al. in 1962, who reported a 'secondary disease' in mice after irradiation and infusion of allogeneic spleen cells. The disease manifested as fatal diarrhea and skin abnormalities. They postulated that aGVHD resulted from introducing immunologically competent cells into an immunocompetent host. Treatments were developed to address this problem, and most centers use calcineurin inhibitors (tacrolimus or cyclosporine) combined with mycophenolate mofetil or methotrexate to prevents aGVHD. This classic GVHD prophylaxis is associated with an incidence of acute GVHD of approximately sixty percent. Other methods of GVHD prevention, including T-cell depletion and more recently post-trasnplant cyclophosphamid, have been tested, but all have their own limitations. The most effective methods tend to be more immunosuppressive and are not clearly superior in regards to long-term survival. Acute GVHD then remains a major problem in hematopoietic stem cell allogeneic transplantation (HCT). Its initial treatment consists of high-dose glucocorticosteroids (1-2 mg/kg daily). However, only one-third of patients are cured, leaving the majority of patients requiring more therapy. Patients with glucocorticosteroid refractory acute GVHD (SR aGVHD) have a very high mortality and to date, there is no effective treatment.

The safety of live-attenuated vaccines in patients using IL-1 or IL-6 blockade: an international survey

BACKGROUND

Withholding live-attenuated vaccines in patients using interleukin (IL)-1 or IL-6 blocking agents is recommended by guidelines for both pediatric and adult rheumatic diseases, since there is a risk of infection in an immune suppressed host. However, this has never been studied. This retrospective, multicenter survey aimed to evaluate the safety of live-attenuated vaccines in patients using IL-1 or IL-6 blockade.

METHODS

We contacted physicians involved in the treatment of autoinflammatory diseases to investigate potential cases. Patients were included if a live-attenuated vaccine had been administered while they were on IL-1 or IL-6 blockade.

RESULTS

Seventeen patients were included in this survey (7 systemic juvenile idiopathic arthritis (sJIA), 5 cryopyrin associated periodic syndrome (CAPS), 4 mevalonate kinase deficiency (MKD) and 1 familial Mediterranean fever (FMF). Three patients experienced an adverse event, of which two were serious adverse events (a varicella zoster infection after varicella zoster booster vaccination, and a pneumonia after MMR booster). One additional patient had diarrhea after oral polio vaccine. Further, seven patients experienced a flare of their disease, which were generally mild. Eight patients did not experience an adverse event or a flare.

CONCLUSION

We have described a case series of seventeen patients who received a live-attenuated vaccine while using IL-1 or IL-6 blocking medication. The findings of this survey are not a reason to adapt the existing guidelines. Prospective trials are needed in order to acquire more evidence about the safety and efficacy before considering adaptation of guidelines.

Long-term effectiveness of tocilizumab in patients with rheumatoid arthritis, stratified by number of previous treatment failures with biologic agents: results from the German RABBIT cohort

In Germany, Tocilizumab (TCZ) is used for the treatment of rheumatoid arthritis both in biologic-naïve patients and those with previous failures of biologic disease-modifying antirheumatic drugs (bDMARDs). The long-term effectiveness and retention rates of TCZ in patients with different numbers of prior bDMARD failures has rarely been investigated. We included 885 RA patients in the analyses, enrolled with the start of TCZ between 2009 and 2015 in the German biologics register RABBIT. Patients were stratified according to prior bDMARD failures: no prior bDMARD or 1, 2 or ≥ 3 bDMARD failures. We applied Kaplan–Meier methods and Cox-regression to examine treatment adherence as well as linear mixed effects models to investigate effectiveness over 3 years of follow-up. Compared to biologic-naïve patients, those with prior bDMARD failures at start of TCZ were younger but had significantly longer disease duration and more comorbidities. DAS28 at baseline and loss of physical function were highest in patients with ≥ 3 bDMARD failures. During follow-up, patients with up to two bDMARD failures on average reached low disease activity (LDA, DAS28 < 3.2). Those with ≥ 3 prior bDMARDs had a slightly lower response. However, after 3 years, nearly 50% of them achieved LDA. Treatment continuation on TCZ therapy was similar in patients with ≤ 2 bDMARD failures but significantly lower in those with ≥ 3 bDMARD failures. TCZ seems to be similarly effective in patients with no, one or two prior bDMARD failures. The majority of patients achieved LDA already after 6 months and maintained it over a period of 3 years. TCZ proved effective even in the high-risk group of patients with more than two prior bDMARD failures.

Clinical experience of IL-6 blockade in rheumatic diseases - implications on IL-6 biology and disease pathogenesis

Interleukin 6 (IL-6) plays a significant role in many rheumatological diseases and has been described as both a pro- and anti-inflammatory cytokine. IL-6 blockade has been investigated in various rheumatic diseases and a humanised anti-IL-6 receptor antibody has been licensed for use in rheumatoid arthritis, systemic and polyarticular juvenile idiopathic arthritis. The increasing clinical experience of IL-6 blockade in rheumatic diseases adds to the existing knowledge regarding the physiological and pathological roles of IL-6.

Protective role of low-dose TGF-β1 in early diabetic nephropathy induced by streptozotocin

OBJECTIVE

To determine whether low-dose TGF-β1 and/or IL-6-receptorα monoclonal antibody (anti-IL-6Rα) can be used to delay renal damage and preserve renal function by rebalancing regulatory T (Treg)/Th17 cells during the course of early diabetic nephropathy (DN) induced by streptozotocin (STZ).

METHODS

Diabetes was induced in C57BL/6 mice by multiple STZ injection. Low-dose TGF-β1 (0.1 μg/mouse/week) and/or anti-IL-6Rα (10 μg/mouse/week) were administered 6 dozes after STZ injection. After 40 days of diabetes onset, metabolic indices, renal structure, activated Akt and Stat3, Treg/Th17 balance, markers and inflammatory cytokines, and oxidative stress in glomeruli were assessed.

RESULTS

Low-dose TGF-β1, instead of causing renal damage, decreased blood glucose, ameliorated kidney hypertrophy, attenuated oxidative stress, maintained activated Stat3, and induced Treg/Th17 balance in early DN. Interestingly, low-dose TGF-β1+anti-IL-6Rα or anti-IL-6Rα alone did not attenuate DN.

CONCLUSIONS

This study provides convincing experimental evidence of the protective effects of low-dose TGF-β1 in improving metabolic disorder and slowing renal damage in early DN.