Apollo Therapeutics Reports Positive Part A Immunogenicity Data for Pan-Rhinovirus Vaccine APL-10456

Apollo Therapeutics has announced positive initial data from Part A of its Phase 1 clinical trial evaluating APL-10456, an investigational pan-rhinovirus vaccine being developed to prevent rhinovirus-driven exacerbations of chronic obstructive pulmonary disease (COPD) and asthma. Enrollment and dosing are complete across the 144-participant study, with single-dose administration demonstrating favorable tolerability and broad cross-reactive cellular immune responses.

Addressing Unmet Need and Rhinovirus Diversity

Rhinovirus is the pulmonary virus most often detected during COPD exacerbations and has been implicated in an estimated 25–50% of these events, as well as roughly half of asthma exacerbations. Apollo Therapeutics estimates that rhinovirus contributes to more than 600,000 COPD-related hospitalizations annually in the United States. Despite this burden, there are currently no approved vaccines or treatments specifically targeting rhinovirus.

Vaccine development has historically been hindered by the virus’s extensive antigenic diversity, spanning approximately 180 genetically distinct strains across three species: rhinovirus A (RV-A), rhinovirus B (RV-B), and rhinovirus C (RV-C). APL-10456 is a first-in-class, adjuvanted recombinant protein subunit vaccine that uses a protein antigen selected for high homology across rhinovirus strains. Combined with Th1-polarizing adjuvants, it is designed to elicit broadly cross-reactive cellular immune responses. Apollo has previously reported broad cross-strain immunity and rapid clearance of heterotypic rhinovirus in preclinical studies.

 Phase 1 Study Design and Favorable Safety Profile

The Phase 1 trial (NCT07399132) is a randomized, double-blind, placebo-controlled study evaluating the safety, tolerability, and immunogenicity of APL-10456 in healthy participants. Part A evaluated three single-dose levels in adults aged 18–54 years, while Part B is evaluating a two-dose regimen in adults aged 55 years and older. The study enrolled 144 participants, with enrollment and dosing completed. Additional Part B data are expected in the fourth quarter of 2026.

Part A showed a favorable initial safety and tolerability profile. The most common adverse events were mild-to-moderate injection-site reactions, with no serious adverse events reported.

Cross-Species T-Cell Responses Observed

Part A immunogenicity data showed that a single dose of APL-10456 induced rhinovirus-specific immunity, including seroconversion and Th1-skewed rhinovirus-specific cell-mediated responses. The vaccine also induced T-cell responses against peptide pools representing all three species (RV-A, RV-B, and RV-C), providing early clinical evidence supporting the vaccine’s broad, cross-reactive cellular immune approach.

“Observing that the data clearly demonstrates a single dose of APL-10456 induces T-cell responses against strains representing all three rhinovirus species is precisely the broad, cross-reactive immunity we set out to achieve,” stated Dr. Richard Butt, Chief Scientific Officer of Apollo Therapeutics.

Upcoming Development Milestones

While the Phase 1 findings provide initial evidence of safety, tolerability, and immunogenicity, clinical efficacy in preventing rhinovirus infection or reducing COPD and asthma exacerbations has not yet been established. These outcomes will require evaluation in later-stage studies involving the intended patient populations.

Additional data from Part B are expected in the fourth quarter of 2026. Apollo Therapeutics plans to advance APL-10456 into a randomized, double-blind, placebo-controlled Phase 2 trial in the first half of 2027 to evaluate the vaccine for the prevention of COPD exacerbations.

Reference

Apollo Therapeutics Announces Positive Immunogenicity Data and Cross-Species Activity from Phase 1 Trial of APL-10456, a Pan-Rhinovirus Vaccine for the Prevention of COPD Exacerbations | Apollo Therapeutics