The safety and potential efficacy of exosomes overexpressing CD24 (EXO-CD24) in mild-moderate COVID-19 related ARDS

INTRODUCTION

EXO-CD24 are exosomes genetically manipulated to over-express Cluster of Differentiation (CD) 24. It consists of two breakthrough technologies: CD24, the drug, as a novel immunomodulator that is smarter than steroids without any side effects, and exosomes as the ideal natural drug carrier.

METHODS

A randomized, single blind, dose-finding phase IIb trial in hospitalized patients with mild to moderate Coronavirus disease 2019 (COVID-19) related Acute Respiratory Distress Syndrome (ARDS) was carried out in two medical centers in Athens. Patients received either 109 or 1010 exosome particles of EXO-CD24, daily, for five consecutive days and monitored for 28 days. Efficacy was assessed at day 7 among 91 patients who underwent randomization. The outcome was also compared in a post-hoc analysis with an income control group (n = 202) that fit the inclusion and exclusion criteria.

RESULTS

The mean age was 49.4 (± 13.2) years and 74.4% were male. By day 7, 83.7% showed improved respiratory signs and 64% had better oxygen saturation (SpO2) (p < 0.05). There were significant reductions in all inflammatory markers, most notably in C-reactive protein (CRP), lactate dehydrogenase (LDH), ferritin, fibrinogen and an array of cytokines. Conversely, levels of the anti-inflammatory cytokine Interleukin-10 (IL-10) were increased (p < 0.05). Of all the documented adverse events, none were considered treatment related. No drug-drug interactions were noted. Two patients succumbed to COVID-19. Post-hoc analysis revealed that EXO-CD24 patients exhibited greater improvements in clinical and laboratory outcomes compared to an observational income control group.

CONCLUSIONS

EXO-CD24 presents a promising therapeutic approach for hyper-inflammatory state and in particular ARDS. Its unique combination of exosomes, as a drug carrier, and CD24, as an immunomodulator, coupled with inhalation administration, warrants further investigation in a larger, international, randomized, quadri-blind trial against a placebo.

1153. Safety and Potential Efficacy of Exosomes Overexpressing CD24 (EXO-CD24) for the Prevention of Clinical Deterioration in Patients with Moderate or Severe COVID-19: A Phase II, Randomized, Single-blinded Study

Background

EXO-CD24 is a novel inhaled drug of exosomes displaying CD24, a protein with anti-inflammatory properties. We evaluated the safety and potential efficacy of EXO-CD24, in a phase II, randomized, single-blinded clinical trial of EXO-CD24 in hospitalized patients with moderate or severe COVID-19, following the preliminary safety and efficacy results of a phase 1 study (ClinicalTrials.gov: NCT04747574).

Methods

Two tertiary care hospitals in Athens, Greece participated. Patients received either 10⁹ or 10¹⁰ exosome particles per dose, once per day for 5 days and were followed for 28 days. Safety and efficacy measures (including respiratory rate < 23 b/min and pulse oximetry SpO₂≥ 94% on room air, oxygen need and levels of inflammatory biomarkers i.e. CRP, LDH, ferritin, fibrinogen and d-dimers) were compared between groups at days 3, 5 and 7. A separate analysis was conducted comparing the clinical course of treated patients with that of a control cohort (n=70 patients) matched by propensity scoring out of a similar period hospitalized cohort (n=202) that did not participate in the study.

Results

Between June 9th and August 3rd 2021, 91 patients underwent randomization: 45 in group A and 46 in group B (10⁹vs. 10¹⁰ exosome particles per dose). Mean age was 49.4 (± 13.2) years and 74.4% were male. Mean time from symptom onset to randomization was 8 days. Improvement in respiratory rate and pulse oximetry was noted in 72 out of 86 (83.7%) and 55 out of 86 (64%) analyzed patients. Day 7 inflammatory indices levels dropped at least 50% from baseline admission values in 72 out of 86 (82.8%) analyzed patients (p< 0.001). No treatment-related adverse events were reported. Comparison with the propensity score matched group showed statistically significant differences in the same parameters (p≤ 0.01 for all comparisons).

Conclusion

Our results suggest safety and potential efficacy of EXO-CD24 on clinical and laboratory parameters of moderate or severe COVID-19, that deserve further investigation in a phase 3 study. (Funded by Athens Medical Society. ClinicalTrials.gov: NCT04902183, EU Clinical Trials Register EudraCT Number 2021-002184-22).

Disclosures

All Authors: No reported disclosures.

Can steroids reverse the severe COVID-19 induced "cytokine storm"?

Severe coronavirus disease (COVID-19) is characterized by an excessive proinflammatory cytokine storm, resulting in acute lung injury and development of acute respiratory distress syndrome (ARDS). The role of corticosteroids is controversial in severe COVID-19 pneumonia and associated hyper-inflammatory syndrome. We reported a case series of six consecutive COVID-19 patients with severe pneumonia, ARDS and laboratory indices of hyper-inflammatory syndrome. All patients were treated early with a short course of corticosteroids, and clinical outcomes were compared before and after corticosteroids administration. All patients evaded intubation and intensive care admission, ARDS resolved within 11.8 days (median), viral clearance was achieved in four patients within 17.2 days (median), and all patients were discharged from the hospital in 16.8 days (median). Early administration of short course corticosteroids improves clinical outcome of patients with severe COVID-19 pneumonia and evidence of immune hyperreactivity.