Coronavirus−19 (COVID-19) has rapidly spread throughout the world resulting in a significant amount of morbidity and mortality. Despite advances in therapy, social distancing, masks, and vaccination many places in the world continue to see an increase in the number of cases and deaths. Viremia is commonly present in severely ill patients with COVID-19 infections and is associated with organ dysfunction and poor outcomes. Exosomes released by activated cells have been implicated in the pathogenesis of COVID-19 infection. We report the experience of two cases of critically ill COVID-19 patients treated with the Hemopurifier; a lectin affinity cartridge designed to remove mannosylated viruses and exosomes. Both patients tolerated the Hemopurifier sessions without adverse effects. In the first patient removal of exosomes and exosomal microRNAs was associated with improved coagulopathy, oxygenation, and clinical recovery, while in a second patient removal of COVID-19 by the Hemopurifier cartridge was observed. The Hemopurifier is currently under further investigation in up to 40-patients in a safety and feasibility study in ICU patients with COVID-19 infection.

The Coronavirus -19 (COVID-19) pandemic due to the SARS-CoV-2 virus has now exceeded two years in duration. The pandemic has been characterized by the development of a succession of variants containing mutations in the spike protein affecting infectiousness, virulence and efficacy of vaccines and monoclonal antibodies. Resistance to vaccination and limitations in the current treatments available require the ongoing development of therapies especially for those with severe disease. The plant lectin Galanthus nivalis binds to mannose structures in the viral envelope. We hypothesized that viral binding should be unaffected by spike protein mutations. Known concentrations of seven clinically relevant SARS-CoV-2 variants were spiked in medium and passed three times over columns containing 1 gm of GNA affinity resin. Percent decrease in viral titer was compared with a control sample. Viral capture efficiency was found to range from 53 to 89% for all variants. Extrapolation indicated that an adult Aethlon Hemopurifier® would have more than sufficient binding capacity for viral loads observed in adult patients with severe COVID-19 infection.

Background: Platelet microparticles (PMP) are elevated in and associated with disease activity in a number of diseases including cancer, neurological conditions, autoimmune diseases, and infectious diseases. This finding raises the possibility of a removal of these microparticles as a therapeutic strategy. The Hemopurifier is an experimental device consisting of a plasma separator and an affinity resin containing Galanthus nivalis agglutinin (GNA) affinity resin that has previously been shown to remove extracellular vesicles in vitro and in vivo. In this proof on concept study, we sought to determine ex vivo removal of platelet-derived microparticles from healthy human plasma by the Hemopurifier. Methods: Two hundred milliliters of thawed healthy human plasma were circulated over the Hemopurifier device at a rate of 100 mL/minute. Plasma samples were taken at time points equivalent to a 4-, 6- and 8-hour clinical Hemopurifier session in a healthy adult. Microparticles were isolated from these timepoints and analyzed for treatment concentration changes. Platelet microparticle counts were determined by binding to antiCD41. Results: The Hemopurifier removed 98.5% of platelet microparticles during the equivalent of a 4-hour clinical session. Conclusions: We demonstrated that an extracorporeal device with a GNA affinity resin removes platelet microparticles from normal healthy plasma. Next steps would be demonstration of the removal of PMPs from plasma by the Hemopurifier in different disease states and characterization of the cargo within removed PMPs.

There is no proven therapy for Long COVID, a post-acute illness characterized by a myriad of diverse symptoms including fatigue, dyspnea, and brain fog following SARS-CoV-2 infection. Extracellular vesicles (EVs) have been implicated in Long COVID pathogenesis by promoting viral and inflammatory signaling with their molecular cargo. In this study, we investigated whether EV abundance and glycome characteristics are altered in plasma from people with Long COVID and whether they can be targeted for removal using a glycan-binding affinity resin. Large (100−500 nm) and small (40−200 nm) EVs were isolated from plasma of participants in the post-acute phase of COVID-19 and analyzed by nanoparticle flow cytometry to measure concentration and glycan characteristics. Plasma of those with Long COVID contained elevated levels of both large and small EVs, and mannose-positive large EVs were significantly increased in comparison to recovered controls (p < 0.05). EV capture assays using Galanthus nivalis agglutinin (GNA) affinity resin demonstrated small EV removal positively correlated with mannose-positive EV abundance (r = 0.341, p < 0.05). NanoString analyses identified seven EV-associated miRNAs significantly depleted by GNA affinity resin treatment of plasma. PROGENy pathway inference of validated miRNA-mRNA interactions suggests these reductions may lead to a downregulation of JAK-STAT signaling and upregulation of Estrogen, VEGF, and PI3K pathways, resulting in a favorable rebalancing of immune and tissue-repair networks. These findings reveal specific glycome EV-miRNA cargo signatures in Long COVID and the potential clinical benefits of a lectin capture therapeutic strategy to remove these pathogenic vesicles and their inflammatory cargo.

Background: Immunotherapy with anti-PD-1 inhibitors has revolutionized the treatment of many solid tumors, however only 30-40% of patients will have a lasting clinical response. Tumor-derived extracellular vesicles (EVs) have been implicated in the spread of solid tumors and resistance to these agents. A lectin-affinity plasmapheresis device called the Hemopurifier (HP) has been developed and shown to remove extracellular vesicle in vitro and in patients. We hypothesize that the treatment of patients who are not improving on anti-PD-1 therapies will be safe, decrease EV concentrations, and improve anti-tumor T cell activity. Methods: This safety, feasibility and dose finding study is designed in a 3+3 safety study design with three treatment cohorts. Participants who are determined to be not responding to anti-PD-1 monotherapy will be assigned to receive either one, two, or three (HP) treatments over a one-week period prior to their next scheduled dose of anti-PD-1 antibody. Advancement from one cohort to the next will be determined by a DSMB. Data collection will include adverse events, safety labs, EV concentrations and T cell measurements, repeat imaging and survival status. The primary outcome of the study will be the safety of the HP in this population with additional endpoints to include the kinetics of EV removal and rebound following HP treatment, in addition to the effects on T cell numbers and activity, Ethics and dissemination: The clinical protocol and amendment to the study protocol have been approved by the Ethics Committees and Research Governance Offices at three participating clinical sites in Australia. The Therapeutic Good Authority (TGA) has been notified. The clinical trial is listed on the Australia New Zealand Clinical Trials Registry. Informed Consent is obtained from all participants prior to any protocol procedures being performed. Australia New Zealand Registration number ACTRN12624000732583