Elicio Therapeutics Announces Preclinical Data for ELI-005 COVID-19 Vaccine Candidate Demonstrating 265-Fold Higher Neutralizing Antibody Levels Than Convalescent Patients

Compiled by S.Li

On August 19 (local time), Elicio Therapeutics, a next-generation immunotherapy development company based in Cambridge, Massachusetts, announced preclinical data for its COVID-19 vaccine candidate, ELI-005. The company stated that this protein subunit vaccine possesses a unique ability to elicit robust T-cell responses against COVID-19 and effectively induce neutralizing antibodies. Given the transient nature of antibody responses to COVID-19, durable protection can be achieved through long-lasting, effective, and balanced antiviral T-cell responses following administration of ELI-005.

The core findings of the ELI-005 study in mice are as follows:

The number of T cells detected in peripheral blood was 25 times that of the standard vaccine (>40% of cells were CD8-positive), forming a first line of defense against COVID-19 in lung tissue (>70% of cells were CD8-positive) and respiratory tract fluids;

Induces a coronavirus protein-neutralizing antibody response that is 265 times higher than that in convalescent COVID-19 patients;

No signal of vaccine-associated enhanced respiratory disease (VAERD) risk was observed; under the effect of ELI-005, a Th1 T-cell (interferon-γ, tumor necrosis factor-α) and Th1 antibody (IgG2bc) response profile was established;

Compared with young mice, aged mice can maintain effective antibody and T cell responses;

Viral protein antigens at doses less than one-tenth of the standard dose can sustain effective immune responses, indicating that ELI-005 could reduce the supply required for global COVID-19 vaccination.

This study demonstrates that biweekly administration of the ELI-005 vaccine induces a balanced immune response across both antibody and T-cell mechanisms. Multifunctional CD4+ and CD8+ T cells migrate to the lungs and secrete effector molecules into respiratory fluids, thereby establishing a first line of defense against COVID-19. No signals indicating a risk of vaccine-associated enhanced respiratory disease (VAERD) were observed in the trial. Effective immune responses are maintained with viral protein antigen doses less than one-tenth of the standard dose, thus requiring lower manufacturing capacity for global distribution of ELI-005.

ELI-005 consists of two components. The first component, ELI-004, is an amphiphilic adjuvant structured as a hydrophobic albumin-binding lipid linked to a hydrophilic immunostimulatory CpG DNA oligonucleotide (AMP-CpG). This design enables efficient lymph node targeting; by binding to tissue albumin, AMP-CpG is naturally transported into the lymph nodes via albumin flow. Existing evidence demonstrates that, compared with traditional CpG and other benchmark adjuvants, ELI-004 improves lymph node delivery efficiency by at least 10-fold, thereby significantly enhancing immune cell delivery and immune responses. The second component is the receptor-binding domain (RBD) of the COVID-19 Spike protein, which previous studies have identified as a target for T cells and coronavirus-neutralizing antibodies.

Amid the vigorous global race to develop COVID-19 vaccines, pharmaceutical companies and researchers worldwide are racing against time to combat this pandemic. The promising preclinical data for ELI-005 reported by Elicio Therapeutics have drawn significant attention; however, the path to clinical development remains long, and more robust evidence is needed to substantiate the potential of this dark-horse candidate.

Reference Source: Lymph Node Targeting COVID-19 Vaccine Induces Up To 25-Fold More T Cells Over Benchmark Vaccines and >265-Fold Greater Antibody Levels Than Recovering Patients