Clinical Results with a B Cell Activating Anti-CD73 Antibody for the Immunotherapy of COVID-19 (preprint)

Robust polyclonal humoral immune responses have the potential to generate a diverse set of antibodies to neutralize and eliminate viruses such as SARS-CoV-2 and protect against transmission, re-infection and the evolution of variants that evade immunity. CD73 is present on subsets of human B and T cells where it plays a role in lymphocyte activation and migration. CD73 also functions as an ectoenzyme that converts AMP into immunosuppressive adenosine. We have developed a humanized anti-CD73 antibody, mupadolimab (CPI-006), that blocks CD73 enzymatic activity and activates CD73POS B cells, thereby inducing differentiation into plasmablasts, immunoglobulin class switching, and antibody secretion independent of the adenosine modulatory activity. These effects suggest mupadolimab may enhance the magnitude, diversity, and duration of anti-viral responses in patients with COVID-19. This hypothesis was tested in a dose escalation phase 1 trial in 29 hospitalized patients with COVID-19. Single doses of 0.3 mg/kg - 5 mg/kg mupadolimab were well tolerated with no drug related adverse events. Doses greater than 0.3 mg/kg resulted in rapid generation of IgG and IgM to SARS-CoV-2 significantly above titers measured in convalescent controls, with elevated IgG titers sustained for more than 6 months beyond presentation of symptoms. Based on these findings, a randomized double-blind, placebo-controlled Phase 3 study in hospitalized patients was initiated. The primary endpoint was proportion of patients alive and free from respiratory failure within 28 days. This trial was discontinued early during the period of waning COVID-19 incidence after enrolling 40 patients. Although underpowered, results from this trial suggest improvement in the primary and key secondary endpoints in patients treated with single doses of 2 mg/kg and 1 mg/kg compared to placebo. The presumed mechanism of action, stimulation of B cells, may represent a novel approach to immunotherapy of COVID-19 and other viral infections.

Implementation of SARS-CoV-2 monoclonal antibody infusion sites at three medical centers in the United States: Strengths and challenges assessment to inform COVID-19 pandemic and future public health emergency use (preprint)

Background: The COVID-19 pandemic caught the globe unprepared without targeted medical countermeasures, such as therapeutics, to target the emerging SARS-CoV-2 virus. However, in recent months multiple monoclonal antibody therapeutics to treat COVID-19 have been authorized by the U.S. Food and Drug Administration (FDA) under Emergency Use Authorization (EUA). Despite these authorizations and promising clinical trial efficacy results, monoclonal antibody therapies are currently underutilized as a treatment for COVID-19 across the U.S. Many barriers exist when deploying a new infused therapeutic during an ongoing pandemic with limited resources and staffing, and it is critical to better understand the process and site requirements of incorporating monoclonal antibody infusions into pandemic response activities. Methods: We examined the monoclonal antibody infusion site process components, resources, and requirements during the COVID-19 pandemic using data from three initial infusion sites at medical centers in the U.S. supported by the National Disaster Medical System. A descriptive analysis was conducted using process assessment metrics to inform recommendations to strengthen monoclonal antibody infusion site implementation. Results: The monoclonal antibody infusion sites varied in physical environment and staffing models due to state polices, infection control mechanisms, and underlying medical system structure, but exhibited a common process workflow. Sites operationalized an infusion process staffing model with at least two nurses per ten infusion patients. Monoclonal antibody implementation success factors included tailoring the infusion process to the patient community, strong engagement with local medical providers, batch preparing the therapy before patient arrival, placing the infusion center in proximity to emergency services, and creating procedures resilient to EUA changes. Infusion process challenges stemmed from confirming patient SARS-CoV-2 positivity, strained staff, scheduling needs, and coordination with the pharmacy for therapy preparation. Conclusions: Infusion site processes are most effective when integrated into the pre-existing pandemic response ecosystems and can be implemented with limited staff and physical resources. As the pandemic and policy tools such as EUAs evolve, monoclonal antibody infusion processes must also remain adaptable, as practice changes directly affect resources, staffing, timing, and workflows. Future use may be aided by incorporating innovative emergency deployment techniques, such as vehicle and home-based therapy administration, and by developing drug delivery mechanisms that alleviate the need for observed intravenous infusions by medically-accredited staff.