Structural Insight into the Resistance of the SARS-CoV-2 Omicron BA.4 and BA.5 Variants to Cilgavimab.

We have recently revealed that the new SARS-CoV-2 Omicron sublineages BA.4 and BA.5 exhibit increased resistance to cilgavimab, a therapeutic monoclonal antibody, and the resistance to cilgavimab is attributed to the spike L452R substitution. However, it remains unclear how the spike L452R substitution renders resistance to cilgavimab. Here, we demonstrated that the increased resistance to cilgavimab of the spike L452R is possibly caused by the steric hindrance between cilgavimab and its binding interface on the spike. Our results suggest the importance of developing therapeutic antibodies that target SARS-CoV-2 variants harboring the spike L452R substitution.

Treatment of chronic or relapsing COVID-19 in immunodeficiency.

BACKGROUND: Patients with some types of immunodeficiency can experience chronic or relapsing infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This leads to morbidity and mortality, infection control challenges, and the risk of evolution of novel viral variants. The optimal treatment for chronic coronavirus disease 2019 (COVID-19) is unknown. OBJECTIVE: Our aim was to characterize a cohort of patients with chronic or relapsing COVID-19 disease and record treatment response. METHODS: We conducted a UK physician survey to collect data on underlying diagnosis and demographics, clinical features, and treatment response of immunodeficient patients with chronic (lasting ≥21 days) or relapsing (≥2 episodes) of COVID-19. RESULTS: We identified 31 patients (median age 49 years). Their underlying immunodeficiency was most commonly characterized by antibody deficiency with absent or profoundly reduced peripheral B-cell levels; prior anti-CD20 therapy, and X-linked agammaglobulinemia. Their clinical features of COVID-19 were similar to those of the general population, but their median duration of symptomatic disease was 64 days (maximum 300 days) and individual patients experienced up to 5 episodes of illness. Remdesivir monotherapy (including when given for prolonged courses of ≤20 days) was associated with sustained viral clearance in 7 of 23 clinical episodes (30.4%), whereas the combination of remdesivir with convalescent plasma or anti-SARS-CoV-2 mAbs resulted in viral clearance in 13 of 14 episodes (92.8%). Patients receiving no therapy did not clear SARS-CoV-2. CONCLUSIONS: COVID-19 can present as a chronic or relapsing disease in patients with antibody deficiency. Remdesivir monotherapy is frequently associated with treatment failure, but the combination of remdesivir with antibody-based therapeutics holds promise.

Recent updates in the clinical trials of therapeutic monoclonal antibodies targeting cytokine storm for the management of COVID-19.

Clinical studies have identified a cytokine storm in the third stage of disease progression in critical ill patients with coronavirus disease 2019 (COVID-19). Hence, effectively suppressing the uncontrolled immune response of the host towards the invaded viruses in a cytokine storm is a critical step to prevent the deterioration of patient conditions and decrease the rate of mortality. Therapeutic monoclonal antibodies (mAbs) are found to be effective for the management of acute respiratory distress syndrome in patients with COVID-19. In this review, we compiled all therapeutic mAbs targeting cytokine storm, which are in clinical trials for its repurposing in the management of COVID-19. Compilation of clinical trial data indicated that therapeutic monoclonal antibodies targeting interleukins (IL-6, IL-1ra, IL-8, IL-1ß, IL-17A, IL-33), interferon-gamma, tumor necrosis factor-alpha, P-selectin, connective tissue growth factor, plasma kallikrein, tumor necrosis factor superfamily 14, granulocyte macrophage colony stimulating factor, colony stimulating factor 1 receptor, C-C chemokine receptor type 5, cluster of differentiation 14 and 147, vascular endothelial growth factor, programmed cell death protein-1, Angiopoietin - 2, human factor XIIa, complementary protein 5, natural killer cell receptor G2A, human epidermal growth factor receptor 2, immunoglobulin-like transcript 7 receptor, complement component fragment 5a receptor and viral attachment to the human cell were under investigation for management of severely ill patients with COVID-19. Among these, about 65 clinical trials are targeting IL-6 inhibition as the most promising one and Tocilizumab, an IL-6 inhibitor is considered to be the potential candidate to treat cytokine storm associated with the COVID-19.

Evaluation of SARS-CoV-2 Serological Testing in Patients with Multiple Myeloma and Other Hematologic Malignancies on Monoclonal Antibody Therapies.

BACKGROUND: Patients with hematological malignancies (HM), including multiple myeloma (MM), frequently suffer from immune deficiency-associated infectious complications because of both the disease and the treatment. Alarming results from China and the UK confirm the vulnerability of HM patients to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-driven coronavirus disease 2019 (COVID-19). Given that the immunoassay interference from the endogenous monoclonal immunoglobulin (M paraprotein) and treatment antibodies continually challenges the MM management, it is critical to evaluate the SARS-CoV-2 serology tests for suspected interference/cross-reactivity. METHODS: We compared the degree of interference in three SARS-CoV-2 serology assay platforms in HM patients with and without COVID-19 and on various therapeutic monoclonal antibody (t-mAb) treatments. Further, we confirmed the cross-reactivity in pooled samples from normal and COVID-19 + samples spiked with respective antibodies in vitro. RESULTS: None of the 93 HM patient samples with or without t-MAbs showed cross-reactivity on any of the three serology platforms tested. CONCLUSIONS: The tested three serologic assays for SARS-CoV-2 are specific and do not have cross-reactivity with M-components or t-MAbs indicating that they can be used safely in oncology practice and in research exploring the immunologic response to COVID-19 in patients with HM.