Association of Subcutaneous or Intravenous Administration of Casirivimab and Imdevimab Monoclonal Antibodies With Clinical Outcomes in Adults With COVID-19

Learning health systems on the front lines to strengthen care against future pandemics and climate change: a rapid review

BACKGROUND

An essential component of future-proofing health systems against future pandemics and climate change is strengthening the front lines of care: principally, emergency departments and primary care settings. To achieve this, these settings can adopt learning health system (LHS) principles, integrating data, evidence, and experience to continuously improve care delivery. This rapid review aimed to understand the ways in which LHS principles have been applied to primary care and emergency departments, the extent to which LHS approaches have been adopted in these key settings, and the factors that affect their adoption.

METHODS

Three academic databases (Embase, Scopus, and PubMed) were searched for full text articles reporting on LHSs in primary care and/or emergency departments published in the last five years. Articles were included if they had a primary focus on LHSs in primary care settings (general practice, allied health, multidisciplinary primary care, and community-based care) and/or emergency care settings. Data from included articles were catalogued and synthesised according to the modified Institute of Medicine's five-component framework for LHSs (science and informatics, patient-clinician partnerships, incentives, continuous learning culture, and structure and governance).

RESULTS

Thirty-seven articles were included, 32 of which reported LHSs in primary care settings and seven of which reported LHSs in emergency departments. Science and informatics was the most commonly reported LHS component, followed closely by continuous learning culture and structure and governance. Most articles (n = 30) reported on LHSs that had been adopted, and many of the included articles (n = 17) were descriptive reports of LHS approaches.

CONCLUSIONS

Developing LHSs at the front lines of care is essential for future-proofing against current and new threats to health system sustainability, such as pandemic- and climate change-induced events. Limited research has examined the application of LHS concepts to emergency care settings. Implementation science should be utilised to better understand the factors influencing adoption of LHS approaches on the front lines of care, so that all five LHS components can be progressed in these settings.

Effectiveness of subcutaneous monoclonal antibody treatment in emergency department outpatients with COVID-19

Objectives

To evaluate whether subcutaneous neutralizing monoclonal antibody (mAb) treatment given in the emergency department (ED) setting was associated with reduced hospitalizations, mortality, and severity of disease when compared to nontreatment among mAb-eligible patients with coronavirus disease 2019 (COVID-19).

Methods

This retrospective observational cohort study of ED patients utilized a propensity score-matched analysis to compare patients who received subcutaneous casirivimab and imdevimab mAb to nontreated COVID-19 control patients in November-December 2021. The primary outcome was all-cause hospitalization within 28 days, and secondary outcomes were 90-day hospitalization, 28- and 90-day mortality, and ED length of stay (LOS).

Results

Of 1340 patients included in the analysis, 490 received subcutaneous casirivimab and imdevimab, and 850 did not received them. There was no difference observed for 28-day hospitalization (8.4% vs. 10.6%; adjusted odds ratio [aOR] 0.79, 95% confidence intervals [CI] 0.53-1.17) or 90-day hospitalization (11.6% vs. 12.5%; aOR 0.93, 95% CI 0.65-1.31). However, mortality at both the 28-day and 90-day timepoints was substantially lower in the treated group (28-day 0.6% vs. 3.1%; aOR 0.18, 95% CI 0.08-0.41; 90-day 0.6% vs. 3.9%; aOR 0.14, 95% CI 0.06-0.36). Among hospitalized patients, treated patients had shorter hospital LOS (5.7 vs. 11.4 days; adjusted rate ratio [aRR] 0.47, 95% CI 0.33-0.69), shorter intensive care unit LOS (3.8 vs. 10.2 days; aRR 0.22, 95% CI 0.14-0.35), and the severity of hospitalization was lower (aOR 0.45, 95% CI 0.21-0.97) compared to untreated.

Conclusions

Among ED patients who presented for symptomatic COVID-19 during the Delta variant phase, ED subcutaneous casirivimab/imdevimab treatment was not associated with a decrease in hospitalizations. However, treatment was associated with lower mortality at 28 and 90 days, hospital LOS, and overall severity of illness.

Advancing Subcutaneous Dosing Regimens for Biotherapeutics: Clinical Strategies for Expedited Market Access

In recent years, subcutaneous administration of biotherapeutics has made significant progress. The self-administration market for rheumatoid arthritis has witnessed the introduction of additional follow-on biologics, while the first subcutaneous dosing options for monoclonal antibodies have become available for multiple sclerosis. Oncology has also seen advancements with the authorization of high-volume subcutaneous formulations, facilitated by the development of high-concentration formulations and innovative delivery systems. Regulatory and Health Technology Assessment bodies increasingly consider preference data in filing dossiers, particularly in evaluating novel drug delivery methods. The adoption of a pharmacokinetic-based clinical bridging approach has become standard for transitioning from intravenous to subcutaneous administration. Non-inferiority studies with pharmacokinetics as the only primary endpoint have started deviating from traditional randomization schemes, favoring the subcutaneous route and comparing with historical intravenous data. While nonclinical and computational models made progress in predicting safety and immunogenicity for subcutaneously dosed antibodies, clinical trial evidence remains essential due to inter-individual variations and the impact of formulation parameters on anti-drug antibody formation. Ongoing technological advancements and the expanding knowledge base on pharmacokinetic-pharmacodynamic correlation across specialty areas are expected to further accelerate clinical development of subcutaneous biologics.

COVID-19 in Patients with Chronic Lymphocytic Leukemia: What Have We Learned?

BACKGROUND

Chronic lymphocytic leukemia (CLL) is a prevalent hematological malignancy (HM) characterized by inherent immunodeficiency, which is further pronounced by disease-directed therapy. The COVID-19 pandemic has had devastating outcomes, and although its impact has diminished over time, it continues to be a cause of significant morbidity and mortality, particularly among immunodeficient patients.

SUMMARY

In this review, we describe mechanisms of immune dysfunction in CLL in relation to COVID-19, provide an overview of the clinical outcomes of the disease in this patient population, and identify risk factors associated with severe morbidity and mortality. Additionally, we acknowledge the influence of the rapidly evolving landscape of new disease variants. The review further delineates the humoral and cellular responses to vaccination and their clinical efficacy in preventing COVID-19 in CLL patients. Moreover, we explore potential approaches to enhance these immune responses. Pre- and post-exposure prophylaxis strategies are discussed, along with description of common agents in the treatment of the disease in both outpatient and inpatient setting. Throughout the review, we emphasize the interplay between novel therapies for CLL and COVID-19 outcomes, prevention, and treatment and describe the impact of COVID-19 on the utilization of these novel agents. This information has the potential to guide clinical decision making in the management CLL patients.

KEY MESSAGES

CLL patients are at risk for severe COVID-19 infection. Vaccinations and COVID-19 directed therapy have improved outcomes in patients with CLL, yet clinical challenges persist.

Evolving Real-World Effectiveness of Monoclonal Antibodies for Treatment of COVID-19 : A Cohort Study

BACKGROUND

Treatment guidelines and U.S. Food and Drug Administration emergency use authorizations (EUAs) of monoclonal antibodies (mAbs) for treatment of high-risk outpatients with mild to moderate COVID-19 changed frequently as different SARS-CoV-2 variants emerged.

OBJECTIVE

To evaluate whether early outpatient treatment with mAbs, overall and by mAb product, presumed SARS-CoV-2 variant, and immunocompromised status, is associated with reduced risk for hospitalization or death at 28 days.

DESIGN

Hypothetical pragmatic randomized trial from observational data comparing mAb-treated patients with a propensity score-matched, nontreated control group.

SETTING

Large U.S. health care system.

PARTICIPANTS

High-risk outpatients eligible for mAb treatment under any EUA with a positive SARS-CoV-2 test result from 8 December 2020 to 31 August 2022.

INTERVENTION

Single-dose intravenous mAb treatment with bamlanivimab, bamlanivimab-etesevimab, sotrovimab, bebtelovimab, or intravenous or subcutaneous casirivimab-imdevimab administered within 2 days of a positive SARS-CoV-2 test result.

MEASUREMENTS

The primary outcome was hospitalization or death at 28 days among treated patients versus a nontreated control group (no treatment or treatment ≥3 days after SARS-CoV-2 test date).

RESULTS

The risk for hospitalization or death at 28 days was 4.6% in 2571 treated patients and 7.6% in 5135 nontreated control patients (risk ratio [RR], 0.61 [95% CI, 0.50 to 0.74]). In sensitivity analyses, the corresponding RRs for 1- and 3-day treatment grace periods were 0.59 and 0.49, respectively. In subgroup analyses, those receiving mAbs when the Alpha and Delta variants were presumed to be predominant had estimated RRs of 0.55 and 0.53, respectively, compared with 0.71 for the Omicron variant period. Relative risk estimates for individual mAb products all suggested lower risk for hospitalization or death. Among immunocompromised patients, the RR was 0.45 (CI, 0.28 to 0.71).

LIMITATIONS

Observational study design, SARS-CoV-2 variant presumed by date rather than genotyping, no data on symptom severity, and partial data on vaccination status.

CONCLUSION

Early mAb treatment among outpatients with COVID-19 is associated with lower risk for hospitalization or death for various mAb products and SARS-CoV-2 variants.

PRIMARY FUNDING SOURCE

None.

Safety and Efficacy of Combined Tixagevimab and Cilgavimab Administered Intramuscularly or Intravenously in Nonhospitalized Patients With COVID-19: 2 Randomized Clinical Trials

Importance

Development of effective, scalable therapeutics for SARS-CoV-2 is a priority.

Objective

To test the efficacy of combined tixagevimab and cilgavimab monoclonal antibodies for early COVID-19 treatment.

Design, Setting, and Participants

Two phase 2 randomized blinded placebo-controlled clinical trials within the Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV)-2/A5401 platform were performed at US ambulatory sites. Nonhospitalized adults 18 years or older within 10 days of positive SARS-CoV-2 test and symptom onset were eligible and were enrolled from February 1 to May 31, 2021.

Interventions

Tixagevimab-cilgavimab, 300 mg (150 mg of each component) given intravenously (IV) or 600 mg (300 mg of each component) given intramuscularly (IM) in the lateral thigh, or pooled placebo.

Main Outcomes and Measures

Coprimary outcomes were time to symptom improvement through 28 days; nasopharyngeal SARS-CoV-2 RNA below the lower limit of quantification (LLOQ) on days 3, 7, or 14; and treatment-emergent grade 3 or higher adverse events through 28 days.

Results

A total of 229 participants were randomized for the IM study and 119 were randomized for the IV study. The primary modified intention-to-treat population included 223 participants who initiated IM tixagevimab-cilgavimab (n = 106) or placebo treatment (n = 117) (median age, 39 [IQR, 30-48] years; 113 [50.7%] were men) and 114 who initiated IV tixagevimab-cilgavimab (n = 58) or placebo treatment (n = 56) (median age, 44 [IQR, 35-54] years; 67 [58.8%] were women). Enrollment in the IV study was stopped early based on a decision to focus on IM product development. Participants were enrolled at a median of 6 (IQR, 4-7) days from COVID-19 symptom onset. Significant differences in time to symptom improvement were not observed for IM tixagevimab-cilgavimab vs placebo or IV tixagevimab-cilgavimab vs placebo. A greater proportion in the IM tixagevimab-cilgavimab arm (69 of 86 [80.2%]) than placebo (62 of 96 [64.6%]) had nasopharyngeal SARS-CoV-2 RNA below LLOQ at day 7 (adjusted risk ratio, 1.33 [95% CI, 1.12-1.57]) but not days 3 and 14; the joint test across time points favored treatment (P = .003). Differences in the proportion below LLOQ were not observed for IV tixagevimab-cilgavimab vs placebo at any of the specified time points. There were no safety signals with either administration route.

Conclusions

In these 2 phase 2 randomized clinical trials, IM or IV tixagevimab-cilgavimab was safe but did not change time to symptom improvement. Antiviral activity was more evident in the larger IM trial.

Trial Registration

ClinicalTrials.gov Identifier: NCT04518410.

Association of Participation in the Maryland Primary Care Program With COVID-19 Outcomes Among Medicare Beneficiaries

IMPORTANCE

Advanced primary care is a team-based approach to providing higher-quality primary care. The association of advanced primary care and COVID-19 outcomes is unknown.

OBJECTIVE

To evaluate the association of advanced primary care with COVID-19 outcomes, including vaccination, case, hospitalization, and death rates during the first 2 years of the COVID-19 pandemic.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used Medicare claims data from January 1, 2020, through January 31, 2022, and Maryland state vaccination data. All Part A and B Medicare claims for Maryland Medicare beneficiaries were included. The study population was divided into beneficiaries attributed to Maryland Primary Care Program (MDPCP) practices and a matched cohort of beneficiaries not attributed to MDPCP practices but who met the eligibility criteria for study participation from January 1, 2020, through December 31, 2021. Eligibility criteria for both groups included fee-for-service Medicare beneficiaries who were eligible for attribution to the MDPCP. A forced-match design was used to match both groups in the study population by age category, sex, race and ethnicity, Medicare-Medicaid dual eligibility status, COVID-19 Vulnerability Index score, Maryland county of residence, and primary care practice participation.

EXPOSURES

Primary care practice participation in the MDPCP.

MAIN OUTCOMES AND MEASURES

Primary outcome variables included rate of vaccination, monoclonal antibody infusion uptake, and telehealth claims. Secondary outcomes included rates of COVID-19 diagnosis, COVID-19 inpatient claims, COVID-19 emergency department claims, COVID-19 deaths, and median COVID-19 inpatient admission length of stay. Claims measures were assessed from January 1, 2020, through October 31, 2021. Vaccination measures were assessed from January 1, 2020, through March 31, 2022.

RESULTS

After matching, a total of 208 146 beneficiaries in the MDPCP group and 37 203 beneficiaries in the non-MDPCP group were included in this study, comprising 60.10% women and 39.90% men with a median age of 76 (IQR, 71-82) years. Most participants (78.40% and 78.38%, respectively) were White. There were no significant demographic nor risk measure baseline differences between the 2 groups. The MDPCP beneficiaries had more favorable primary COVID-related outcomes than non-MDPCP beneficiaries: 84.47% of MDPCP beneficiaries were fully vaccinated, compared with 77.93% of nonparticipating beneficiaries (P < .001). COVID-19-positive beneficiaries in MDPCP also received monoclonal antibody treatment more often (8.45% vs 6.11%; P < .001) and received more care via telehealth (62.95% vs 54.53%; P < .001) compared with nonparticipating counterparts. In terms of secondary outcomes, beneficiaries in the MDPCP had lower rates of COVID-19 cases (6.55% vs 7.09%; P < .001), lower rates of COVID-19 inpatient admissions (1.81% vs 2.06%; P = .001), and lower rates of death due to COVID-19 (0.56% vs 0.77%; P < .001) compared with nonparticipating beneficiaries.

CONCLUSIONS AND RELEVANCE

These findings suggest that participation in the MDPCP was associated with lower COVID-19 case, hospitalization, and death rates, and advanced primary care and COVID-19 response strategies within the MDPCP were associated with improved COVID-19 outcomes for attributed beneficiaries.

Safety Profile of Molnupiravir in the Treatment of COVID-19: A Descriptive Study Based on FAERS Data

Concerns have been raised about the actual benefit and safety of molnupiravir, a new antiviral treatment for coronavirus disease 2019 (COVID-19). In order to provide additional evidence to support its use, we aimed to evaluate the real safety profile based on post-marketing pharmacovigilance data. Molnupiravir safety data were captured from the FDA Adverse Event Reporting System (FAERS). We performed a descriptive analysis of the baseline demographic characteristics of patients who experienced at least one adverse drug reaction (ADRs) related to molnupiravir, and then evaluated those most frequently reported. As of 31 March 2022, 612 reports of ADRs related to molnupiravir were submitted to the FDA, 301 (49.18%) were related to females and 281 (45.92%) to males. Most reports (524; 85.62%) were submitted by healthcare professionals and 345 (56.37%) concerned serious outcomes. The most common reported ADRs were diarrhoea (57; 4.51%), rash (36; 2.85), nausea (29; 2.30%), and COVID-19 pneumonia (22; 1.74%). The most frequent adverse reactions reported with molnupiravir in the U.S. post-marketing experience are consistent with the safety evaluation of the antiviral medicine. Even if no evident safety concerns emerged, an unexpectedly high rate of serious adverse reactions together with a few cases of potential new adverse reactions occurred.

Referrals, access, and equity of monoclonal antibodies for outpatient COVID-19: A qualitative study of clinician perspectives

Neutralizing monoclonal antibody treatments for non-hospitalized patients with COVID-19 have been available since November 2020. However, they have been underutilized and access has been inequitable. To understand, from the clinician perspective, the factors facilitating or hindering monoclonal antibody referrals, patient access, and equity to inform development of clinician-focused messages, materials, and processes for improving access to therapeutics for COVID-19 in Colorado. We interviewed 38 frontline clinicians with experience caring for patients with COVID-19 in outpatient settings. Clinicians were purposely sampled for diversity to understand perspectives across geography (i.e., urban versus rural), practice setting, specialty, and self-reported knowledge about monoclonal antibodies. Interviews were conducted between June and September 2021, lasted 21 to 62 minutes, and were audio recorded and transcribed verbatim. Interview transcripts were then analyzed using rapid qualitative analysis to identify thematic content and to compare themes across practice settings and other variables. Clinicians perceived monoclonal antibodies to be highly effective and were unconcerned about their emergency use status; hence, these factors were not perceived to hinder patient referrals. However, some barriers to access - including complex and changing logistics for referring, as well as the time and facilities needed for an infusion - inhibited widespread use. Clinicians in small, independent, and rural practices experienced unique challenges, such as lack of awareness of their patients' COVID-19 test results, disconnect from treatment distribution systems, and patients who faced long travel times to obtain treatment. Many clinicians held a persistent belief that monoclonal antibodies were in short supply; this belief hindered referrals, even when monoclonal antibody doses were not scarce. Across practice settings, the most important facilitator for access to monoclonal antibodies was linkage of COVID-19 testing and treatment within care delivery. Although clinicians viewed monoclonal antibodies as safe and effective treatments for COVID-19, individual- and system-level barriers inhibited referrals, particular in some practice settings. Subcutaneous or oral formulations may overcome certain barriers to access, but simplifying patient access by linking testing with delivery of treatments that reduce morbidity and mortality will be critical for the ongoing response to COVID-19 and in future pandemics.

Effectiveness of Subcutaneous Casirivimab and Imdevimab in Ambulatory Patients with COVID-19

INTRODUCTION

Data on real-world effectiveness of subcutaneous (SC) casirivimab and imdevimab (CAS+IMD) for the treatment of coronavirus disease 2019 (COVID-19) are limited. The objective of this study was to assess the effectiveness of SC CAS+IMD versus no antibody treatment among patients with COVID-19.

METHODS

This retrospective cohort study linked Komodo Health and CDR Maguire Health and Medical data. Patients diagnosed with COVID-19 in ambulatory settings (August 1-October 30, 2021) treated with SC CAS+IMD were exact- and propensity score-matched to fewer than five untreated treatment-eligible patients and followed for the composite endpoint of 30-day all-cause mortality or COVID-19-related hospitalization. Kaplan-Meier estimators were used to calculate outcome risk overall and across subgroups. Cox proportional-hazards models were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI).

RESULTS

Of 13,522 patients treated with CAS+IMD, 12,972 were matched to 41,848 untreated patients. The 30-day composite outcome risk was 1.9% (95% CI 1.7-2.2) and 4.4% (95% CI 4.2-4.6) in the treated and untreated cohorts, respectively; treated patients had a 49% lower relative risk of the composite outcome (aHR 0.51; 95% CI 0.46-0.58) and a 67% relative risk of 30-day mortality (aHR 0.33, 95% CI 0.18-0.60). Effectiveness was consistent across vaccination status and various subgroups.

DISCUSSION

Patients with COVID-19 benefitted from treatment with SC CAS+IMD versus untreated patients. The results were consistent across subgroups of patients, including older adults, immunocompromised patients, and patients vaccinated against COVID-19. Results were robust across numerous sensitivity analyses.

CONCLUSION

SC CAS+IMD is effective in reducing 30-day COVID-19-related hospitalization or mortality in real-world outpatient settings during the Delta-dominant period.

Monoclonal Antibodies for Treatment of SARS-CoV-2 Infection During Pregnancy : A Cohort Study

BACKGROUND

Monoclonal antibody (mAb) treatment decreases hospitalization and death in high-risk outpatients with mild to moderate COVID-19. However, no studies have evaluated adverse events and effectiveness of mAbs in pregnant persons compared with no mAb treatment.

OBJECTIVE

To determine the frequency of drug-related adverse events and obstetric-associated safety outcomes after treatment with mAb compared with no mAb treatment of pregnant persons, and the association between mAb treatment and a composite of 28-day COVID-19-related hospital admission or emergency department (ED) visit, COVID-19-associated delivery, or mortality.

DESIGN

Retrospective, propensity score-matched, cohort study.

SETTING

UPMC Health System from 30 April 2021 to 21 January 2022.

PARTICIPANTS

Persons aged 12 years or older with a pregnancy episode and any documented positive SARS-CoV-2 test (polymerase chain reaction or antigen test).

INTERVENTION

Bamlanivimab and etesevimab, casirivimab and imdevimab, or sotrovimab treatment compared with no mAb treatment.

MEASUREMENTS

Drug-related adverse events, obstetric-associated safety outcomes among persons who delivered, and a risk-adjusted composite of 28-day COVID-19-related hospital admission or ED visit, COVID-19-associated delivery, or mortality.

RESULTS

Among 944 pregnant persons (median age [interquartile range (IQR)], 30 years [26 to 33 years]; White (79.5%; n = 750); median Charlson Comorbidity Index score [IQR], 0 [0 to 0]), 552 received mAb treatment (58%). Median gestational age at COVID-19 diagnosis or treatment was 179 days (IQR, 123 to 227), and most persons received sotrovimab (69%; n = 382). Of those with known vaccination status, 392 (62%) were fully vaccinated. Drug-related adverse events were uncommon (n = 8; 1.4%), and there were no differences in any obstetric-associated outcome among 778 persons who delivered. In the total population, the risk ratio for mAb treatment of the composite 28-day COVID-19-associated outcome was 0.71 (95% CI, 0.37 to 1.4). The propensity score-matched risk ratio was 0.61 (95% CI, 0.34 to 1.1). There were no deaths among mAb-treated patients compared with 1 death in the nontreated control patients. There were more non-COVID-19-related hospital admissions in the mAb-treated persons in the unmatched cohort (14 [2.5%] vs. 2 [0.5%]; risk ratio, 5.0; 95% CI, 1.1 to 21.7); however, there was no difference in the propensity score-matched rates, which were 2.5% mAb-treated vs. 2% untreated (risk ratio, 1.3; 95% CI, 0.58% to 2.8%).

LIMITATIONS

Drug-related adverse events were patient and provider reported and potentially underrepresented. Symptom severity at the time of SARS-CoV-2 testing was not available for nontreated patients.

CONCLUSION

In pregnant persons with mild to moderate COVID-19, adverse events after mAb treatment were mild and rare. There was no difference in obstetric-associated safety outcomes between mAb treatment and no treatment among persons who delivered. There was no difference in 28-day COVID-19-associated outcomes and non-COVID-19-related hospital admissions for mAb treatment compared with no mAb treatment in a propensity score-matched cohort.

PRIMARY FUNDING SOURCE

No funding was received for this study.

James G, Zeltner M, Platt T. Impact of a subcutaneous casirivimab and imdevimab clinic in outpatients with symptomatic COVID-19: A single-center, propensity-matched cohort study

PURPOSE

To evaluate the success of a clinic for subcutaneous administration of casirivmab and imdevimab (REGEN-COV; Regeneron) for treatment of patients with symptomatic mild to moderate coronavirus disease 2019 (COVID-19) in terms of preventing disease progression and healthcare utilization.

METHODS

This retrospective single-center, propensity-matched cohort study examined healthcare utilization outcomes for patients who received subcutaneous casirivimab and imdevimab at a pharmacist-led clinic of an academic health system. Eligible patients were treated between August 1, 2021, and January 5, 2022, and were at high risk for COVID-19 disease progression. Treatment patients were propensity matched with high-risk control patients with a diagnosis of COVID-19 in the same timeframe who did not receive casirivimab and imdevimab. Patients were followed for 30 days for collection of data on inpatient admissions, emergency department visits, and mortality. Risk of a 30-day healthcare utilization event was assessed and tested for statistical significance utilizing McNemar's test.

RESULTS

A total of 585 patients who received treatment with subcutaneous casirivimab and imdevimab were matched with 585 patients who did not receive casirivimab and imdevimab therapy. Patients who received casirivimab and imdevimab had significantly lower risk of a 30-day all-cause inpatient admission event than untreated patients (relative risk reduction, 62.4%; P < 0.0001). Treated patients also had a significantly lower risk of 30-day all-cause emergency department visit than untreated subjects (relative risk reduction, 36.5%; P = 0.0021). There were 6 mortality events in the untreated group and no mortality events in the treatment group.

CONCLUSION

This study provides evidence for the effectiveness of a subcutaneous casirivimab and imdevimab clinic in preventing progression of symptomatic mild to moderate COVID-19.

Neutralizing monoclonal antibodies against SARS-CoV-2 for COVID-19 pneumonia in a rituximab treated patient with systemic sclerosis—A case report and literature review

Patients with immune-mediated diseases (IMID) such as systemic sclerosis (SSc), who are treated with B cell depleting treatments, are at risk for developing severe COVID-19 due to inadequate humoral immune response. During B cell depletion, therapeutic substitution of neutralizing monoclonal antibodies against the SARS-CoV-2 spike protein (mAbs) might be helpful to prevent severe COVID-19. It has been shown, that in non-IMID patients mABs reduce SARS-CoV-2 viral load and lower the risk of COVID-19 associated hospitalization or death. However, there are limited data on the effect of mAbs in IMID patients after exposure, especially in patients treated with B cell depleting agents. Herein, we report a case of a rituximab treated SSc patient who developed COVID-19 and was successfully treated with a combination of mAbs (casirivimab/imdevimab). With this case we show that IMID patients may benefit from post-exposure administration of mAbs. In our case treatment with neutralizing autoantibodies was safe and a possible contributor in protecting the patient from mechanical ventilation and eventually death. We frame this case within the current evidence from the literature and provide a perspective on the future potential role of mAbs for treating IMID patients suffering from COVID-19.

Effectiveness of Casirivimab-Imdevimab and Sotrovimab During a SARS-CoV-2 Delta Variant Surge: A Cohort Study and Randomized Comparative Effectiveness Trial

Importance

The effectiveness of monoclonal antibodies (mAbs), casirivimab-imdevimab and sotrovimab, is unknown in patients with mild to moderate COVID-19 caused by the SARS-CoV-2 Delta variant.

Objective

To evaluate the effectiveness of mAb against the Delta variant compared with no mAb treatment and to ascertain the comparative effectiveness of casirivimab-imdevimab and sotrovimab.

Design, Setting, and Participants

This study comprised 2 parallel studies: (1) a propensity score-matched cohort study of mAb treatment vs no mAb treatment and (2) a randomized comparative effectiveness trial of casirivimab-imdevimab and sotrovimab. The cohort consisted of patients who received mAb treatment at the University of Pittsburgh Medical Center outpatient infusion centers and emergency departments from July 14 to September 29, 2021. Participants were patients with a positive SARS-CoV-2 test result who were eligible to receive mAbs according to emergency use authorization criteria.

Exposure

For the trial, patients were randomized to either intravenous casirivimab-imdevimab or sotrovimab according to a system therapeutic interchange policy.

Main Outcomes and Measures

For the cohort study, risk ratio (RR) estimates for the primary outcome of hospitalization or death by 28 days were compared between mAb treatment and no mAb treatment using propensity score-matched models. For the comparative effectiveness trial, the primary outcome was hospital-free days (days alive and free of hospitalization) within 28 days after mAb treatment, where patients who died were assigned -1 day in a bayesian cumulative logistic model adjusted for treatment location, age, sex, and time. Inferiority was defined as a 99% posterior probability of an odds ratio (OR) less than 1. Equivalence was defined as a 95% posterior probability that the OR was within a given bound.

Results

A total of 3069 patients (1023 received mAb treatment: mean [SD] age, 53.2 [16.4] years; 569 women [56%]; 2046 had no mAb treatment: mean [SD] age, 52.8 [19.5] years; 1157 women [57%]) were included in the prospective cohort study, and 3558 patients (mean [SD] age, 54 [18] years; 1919 women [54%]) were included in the randomized comparative effectiveness trial. In propensity score-matched models, mAb treatment was associated with reduced risk of hospitalization or death (RR, 0.40; 95% CI, 0.28-0.57) compared with no treatment. Both casirivimab-imdevimab (RR, 0.31; 95% CI, 0.20-0.50) and sotrovimab (RR, 0.60; 95% CI, 0.37-1.00) were associated with reduced hospitalization or death compared with no mAb treatment. In the clinical trial, 2454 patients were randomized to receive casirivimab-imdevimab and 1104 patients were randomized to receive sotrovimab. The median (IQR) hospital-free days were 28 (28-28) for both mAb treatments, the 28-day mortality rate was less than 1% (n = 12) for casirivimab-imdevimab and less than 1% (n = 7) for sotrovimab, and the hospitalization rate by day 28 was 12% (n = 291) for casirivimab-imdevimab and 13% (n = 140) for sotrovimab. Compared with patients who received casirivimab-imdevimab, those who received sotrovimab had a median adjusted OR for hospital-free days of 0.88 (95% credible interval, 0.70-1.11). This OR yielded 86% probability of inferiority for sotrovimab vs casirivimab-imdevimab and 79% probability of equivalence.

Conclusions and Relevance

In this propensity score-matched cohort study and randomized comparative effectiveness trial, the effectiveness of casirivimab-imdevimab and sotrovimab against the Delta variant was similar, although the prespecified criteria for statistical inferiority or equivalence were not met. Both mAb treatments were associated with a reduced risk of hospitalization or death in nonhospitalized patients with mild to moderate COVID-19 caused by the Delta variant.

Trial Registration

ClinicalTrials.gov Identifier: NCT04790786.