Pharmacokinetic/Pharmacodynamic Considerations of Alternate Dosing Strategies of Tocilizumab in COVID-19

COVID-19 Drug Treatments Are Prone to Sequestration in Extracorporeal Membrane Oxygenation Circuits: An Ex Vivo Extracorporeal Membrane Oxygenation Study

Drug treatments for coronavirus disease 2019 (COVID-19) dramatically improve patient outcomes, and although extracorporeal membrane oxygenation (ECMO) has significant use in these patients, it is unknown whether ECMO affects drug dosing. We used an ex vivo adult ECMO model to measure ECMO circuit effects on concentrations of specific COVID-19 drug treatments. Three identical ECMO circuits used in adult patients were set up. Circuits were primed with fresh human blood (temperature and pH maintained within normal limits). Three polystyrene jars with 75 ml fresh human blood were used as controls. Remdesivir, GS-441524, nafamostat, and tocilizumab were injected in the circuit and control jars at therapeutic concentrations. Samples were taken from circuit and control jars at predefined time points over 6 h and drug concentrations were measured using validated assays. Relative to baseline, mean (± standard deviation [SD]) study drug recoveries in both controls and circuits at 6 h were significantly lower for remdesivir (32.2% [±2.7] and 12.4% [±2.1], p < 0.001), nafamostat (21.4% [±5.0] and 0.0% [±0.0], p = 0.018). Reduced concentrations of COVID-19 drug treatments in ECMO circuits is a clinical concern. Remdesivir and nafamostat may need dose adjustments. Clinical pharmacokinetic studies are suggested to guide optimized COVID-19 drug treatment dosing during ECMO.

Comparison of Tocilizumab vs Baricitinib in Clinical Outcomes Among Hospitalized Patients With COVID-19: Experience From a Public Hospital System in New York City

Background

Tocilizumab and baricitinib are immunomodulators that have been repurposed for the treatment of coronavirus disease 2019 (COVID-19). Whether one medication should be preferred over the other has not been established.

Methods

This multicenter retrospective cohort study comprised hospitalized patients with COVID-19 who received either tocilizumab or baricitinib. The primary outcome was improvement in respiratory status (at least 1-point reduction on the respiratory ordinal scale) at day 7 and up to day 28. Secondary outcomes included mortality, disposition, deep vein thrombosis, pulmonary embolism, or positive blood culture. Outcomes were stratified by baseline respiratory status and variant-predominating periods. Results were reported for the overall and propensity-matched cohorts.

Results

A total of 921 patients received tocilizumab and 638 received baricitinib. The propensity-matched cohort included 597 patients in each group. At day 7 in the overall and propensity-matched cohorts, significantly more patients had improvement in respiratory status in the baricitinib group. These improvements were seen in patients requiring supplemental oxygen and noninvasive ventilation/high-flow oxygen but not in patients requiring mechanical ventilation. Favorable outcomes with baricitinib were observed during the Alpha and Omicron periods. By day 28, there were no differences in the changes of respiratory status for the treatment groups in either cohort. Also, no differences were seen in mortality, disposition, development of deep vein thrombosis/pulmonary embolism, or bloodstream infections.

Conclusions

Baricitinib treatment was associated with more favorable respiratory improvement at day 7 when compared with tocilizumab, but no differences were observed up to day 28.

Disease-modifying anti-rheumatic drugs associated with different diabetes risks in patients with rheumatoid arthritis

OBJECTIVES

Patients with rheumatoid arthritis are prone to developing diabetes, which may lead to various sequelae and even cardiovascular diseases, the most common cause of death in such patients. Previous research has shown that some rheumatoid arthritis treatments may help prevent the development of diabetes. This study aimed to investigate whether patients using disease-modifying anti-rheumatic drugs (DMARDs) may have different levels of risk for diabetes and to analyse other risk factors for diabetes.

METHODS

This cohort study used data from the Chang Gung Research Database. 5530 adults with rheumatoid arthritis but without diabetes were eligible for the analysis. The endpoint of this study was new-onset diabetes, defined as an HbA1c value ≥7% during follow-up. The entire follow-up period was divided into monthly subunits. These 1-month units were then divided into methotrexate (MTX) monotherapy, any biological DMARDs (bDMARDs), MTX combination, other conventional DMARDs (cDMARDs) and non-DMARDs.

RESULTS

A total of 546 participants (9.87%) developed diabetes between 2001 and 2018. The risk of diabetes was significantly lower in the bDMARD periods (HR 0.51; 95% CI 0.32 to 0.83), MTX combination periods (HR 0.50; 95% CI 0.32 to 0.78) and other cDMARD periods (HR 0.56; 95% CI 0.37 to 0.84) than in the MTX monotherapy periods. Individual drug analysis showed that hydroxychloroquine (HR 0.52; 95% CI 0.42 to 0.65) reduced the risk of diabetes. Tumour necrosis factor-α inhibitors (HR 0.69; 95% CI 0.46 to 1.03) tended to be protective.

CONCLUSION

Patients with rheumatoid arthritis may have different levels of risk of diabetes depending on the treatment options.

Pharmacokinetics and tolerability of prefilled syringe and auto-injector presentations of MSB11456: results of a randomized, single-dose study in healthy adults

BACKGROUND

Tocilizumab is a monoclonal immunoglobulin G interleukin-6 receptor antagonist. MSB11456 is a proposed tocilizumab biosimilar.

OBJECTIVE

To determine the pharmacokinetic equivalence of a single subcutaneous injection of MSB11456, when delivered via autoinjector (AI) and prefilled syringe (PFS), in healthy adult subjects.

RESEARCH DESIGN AND METHODS

In this randomized, open-label, single fixed-dose, crossover study, 91 subjects received subcutaneous administration of tocilizumab 162 mg via AI and PFS presentations. The primary endpoint pharmacokinetic parameters were analyzed using analysis of variance. Safety data were summarized descriptively.

RESULTS

There were no differences in pharmacokinetic parameters between presentations, and safety parameters were comparable. The 90% confidence intervals for the geometric least squares mean ratios of all primary pharmacokinetic parameters were contained within the predefined 80.00% to 125.00% bioequivalence limits, indicating pharmacokinetic equivalence between the AI and PFS.

CONCLUSIONS

MSB11456 administration via AI was bioequivalent to administration via PFS. MSB11456 can be administered by AI or PFS, increasing the available range of self-injection devices.

TRIAL REGISTRATION

The trial is registered at EudraCT, number 2020-003419-86.

Pharmacokinetics of a proposed tocilizumab biosimilar (MSB11456) versus US-licensed tocilizumab: results of a randomized, double-blind, single-intravenous dose study in healthy adults

BACKGROUND

Tocilizumab, a recombinant monoclonal immunoglobulin G, targets the interleukin-6 receptor. MSB11456 is a proposed tocilizumab biosimilar.

OBJECTIVES

To assess pharmacokinetic equivalence of intravenous MSB11456 to US-licensed tocilizumab.

RESEARCH DESIGN AND METHODS

In this double-blind, parallel-group, single-dose study, 128 healthy adults were randomized to a single one-hour 8 mg/kg IV infusion of either MSB11456 or US-licensed tocilizumab. Blood samples were collected pre-dose and at regular intervals up to day 48 post-dose. The primary endpoint pharmacokinetic parameter was analyzed using analysis of variance (ANOVA) model on the natural logarithm of the endpoint (AUC_0-last), with treatment as a fixed effect. Immunogenicity and safety data were summarized descriptively.

RESULTS

Subjects received either MSB11456 (N = 62) or US-licensed tocilizumab (N = 66). Pharmacokinetic bioequivalence, defined as 90% confidence intervals for the geometric least squares mean ratio entirely contained within the 80.00% to 125.00% equivalence limits, was demonstrated between MSB11456 and US-licensed tocilizumab for the primary and secondary pharmacokinetic endpoints. Anti-drug antibody responses, frequency of neutralizing antibodies against tocilizumab, and safety profiles showed no notable between-treatment differences. Safety was comparable between treatments.

CONCLUSIONS

Pharmacokinetic similarity of MSB11456 and US-licensed tocilizumab was demonstrated, with comparable immunogenicity and safety profiles, supporting MSB11455 as a biosimilar to US-licensed tocilizumab. The trial is registered at EudraCT, number 2019-003484-22.

CHARACTERISTICS OF OLOKIZUMAB PHARMACOKINETICS IN PATIENTS WITH NOVEL CORONAVIRUS INFECTION COVID-19

The aim of the article is to study pharmacokinetic characteristics of intravenous olokizumab in patients with moderate COVID-19 to relieve a hyperinflammation syndrome.

Materials and methods. The pharmacokinetic study was conducted as a part of a phase III clinical study (RESET, NCT05187793) on the efficacy and safety of a new olokizumab regimen (intravenous, at the doses of 128 mg or 256 mg) in COVID-19 patients. Plasma concentrations of olokizumab were determined by the enzyme immunoassay. The population analysis was performed using a previously developed pharmacokinetic model based on a linear two compartment.

Results. The pharmacokinetic analysis included the data from 8 moderate COVID-19 patients who had been administrated with olokizumab intravenously at the dose of 128 mg. According to the analysis results in this population, there was an increase in the drug clearance, compared with the data obtained in healthy volunteers and the patients with rheumatoid arthritis: 0.435, 0.178 and 0.147 l/day, respectively. The parameters analysis within the framework of a population pharmacokinetic model showed that the main factors for the increased olokizumab clearance are a high body mass index. In addition, the presence of COVID-19 itself is an independent factor in increasing the drug clearance.

Conclusion. After the intravenous olokizumab administration, an increase in the drug clearance is observed in moderate COVID-19 patients against the background of the disease course. The main contribution to the increased clearance is made by the characteristics of the population of COVID-19 patients associated with the risk of a severe disease and inflammation. When administered intravenously at the dose of 128 mg, a therapeutically significant olokizumab level was maintained throughout the acute disease phase for 28 days.

Impact of COVID-19 and Antibiotic Treatments on Gut Microbiome: A Role for Enterococcus spp

OBJECTIVE

Several studies showed the substantial use of antibiotics and increased risk of antimicrobial resistant infections in patients with COVID-19. The impact of COVID-19-related treatments and antibiotics on gut dysbiosis has not been clarified.

DESIGN

The prospective cohort study included hospitalized COVID-19 patients (April-December 2020). The gut microbiome composition was analysed by 16S sequencing. The gut diversity and changes in opportunistic bacteria (OBs) or symbionts were analysed according to clinical parameters, laboratory markers of disease progression, type of non-antibiotic COVID-19 treatments (NACT) and type, WHO AWaRe group, and duration of antibiotic therapy (AT).

RESULTS

A total of 82 patients (mean age 66 ± 13 years, 70% males) were enrolled. The relative abundance of Enterococcus was significantly correlated with duration of hospitalization, intensive care unit stay, O2 needs, and D-dimer, ferritin, and IL-6 blood levels. The presence of Enterococcus showed the highest number of correlations with NACT, AT, and AT + NACT (e.g., hydroxychloroquine ± lopinavir/ritonavir) and increased relative abundance with AWaRe Watch/Reserve antibiotics, AT duration, and combinations. Abundance of Dorea, Agathobacter, Roseburia, and Barnesiella was negatively correlated with AT and corticosteroids use. Patients with increased IL-6, D-dimer, and ferritin levels receiving AT were more likely to show dysbiosis with increased abundance of Enterococcus and Bilophila bacteria and decreased abundance of Roseburia compared with those not receiving AT.

CONCLUSION

Microbiome diversity is affected by COVID-19 severity. In this context, antibiotic treatment may shift the gut microbiome composition towards OBs, particularly Enterococcus. The impact of treatment-driven dysbiosis on OBs infections and long-term consequences needs further study to define the role of gut homeostasis in COVID-19 recovery and inform targeted interventions.

Reduced fixed dose tocilizumab 400 mg IV compared to weight-based dosing in critically ill patients with COVID-19: A before-after cohort study

Background

Interleukin-6 inhibitors reduce mortality in severe COVID-19. British Columbia began using tocilizumab 8 mg/kg (maximum 800 mg) in January 2021 in critically ill patients with COVID-19, but due to drug shortages, decreased dosing to 400 mg IV fixed dose in April 2021. The aims of this study were twofold: to compare physiological responses and clinical outcomes of these two strategies, and examine the cost-effectiveness of treating all patients with 400 mg versus half the patients with 8 mg/kg and the other half without tocilizumab.

Methods

This was a single-centre, before-after cohort study of critically ill COVID-19 patients treated with tocilizumab, and a control cohort treated with dexamethasone only. Physiological responses and clinical outcomes were compared between patients receiving both doses of tocilizumab and those receiving dexamethasone only. We built a decision tree model to examine cost-effectiveness.

Findings

152 patients were included; 40 received tocilizumab 8 mg/kg, 59 received 400 mg and 53 received dexamethasone only. Median CRP fell from 103 mg/L to 5.2 mg/L, 96 mg/L to 6.8 mg/L and from 81.3 mg/L to 48 mg/L in the 8 mg/kg, 400 mg tocilizumab, and dexamethasone only groups, respectively. 28-day mortality was 5% (n=2) vs 8% (n=5) vs 13% (n=7), with no significant difference in all pair-wise comparison. At an assumed willingness-to-pay threshold of $50,000 Canadian per life-year, utilizing 400 mg for all patients rather than 8 mg/kg for half the patients is cost-effective in 51.6% of 10,000 Monte Carlo simulations.

Interpretation

Both doses of tocilizumab demonstrated comparable reduction of inflammation with similar 28-day mortality. Without consideration of equity, the net monetary benefits of providing 400 mg tocilizumab to all patients are comparable to 8 mg/kg to half the patients. In the context of ongoing drug shortages, fixed-dose 400 mg tocilizumab may be a practical, feasible and economical option.

Funding

This work was supported by a gift donation from Hsu & Taylor Family to the VGH Foundation, and the Yale Bernard G. Forget Scholarship.

Drug dosing in hospitalized obese patients with COVID-19

Obesity is highly prevalent in hospitalized patients admitted with COVID-19. Evidence based guidelines are available for COVID-19-related therapies but dosing information specific to patients with obesity is lacking. Failure to account for the pharmacokinetic alterations that exist in this population can lead to underdosing, and treatment failure, or overdosing, resulting in an adverse effect. The objective of this manuscript is to provide clinicians with guidance for making dosing decisions for medications used in the treatment of patients with COVID-19. A detailed literature search was conducted for medications listed in evidence-based guidelines from the National Institutes of Health with an emphasis on pharmacokinetics, dosing and obesity. Retrieved manuscripts were evaluated and the following prioritization strategy was used to form the decision framework for recommendations: clinical outcome data > pharmacokinetic studies > adverse effects > physicochemical properties. Most randomized controlled studies included a substantial number of patients who were obese but few had large numbers of patients more extreme forms of obesity. Pharmacokinetic data have described alterations with volume of distribution and clearance but this variability does not appear to warrant dosing modifications. Future studies should provide more information on size descriptors and stratification of data according to obesity and body habitus.