Phase 1, randomized, rater and participant blinded placebo-controlled study of the safety, reactogenicity, tolerability and immunogenicity of H1N1 influenza vaccine delivered by VX-103 (a MIMIX microneedle patch [MAP] system) in healthy adults

Background The MIMIX platform is a novel microneedle array patch (MAP) characterized by slowly dissolving microneedle tips that deploy into the dermis following patch application. We describe safety, reactogenicity, tolerability and immunogenicity for MIMIX MAP vaccination against influenza. Methodology The trial was a Phase 1, exploratory, first-in-human, parallel randomized, rater, participant, study analyst-blinded, placebo-controlled study in Canada. Forty-five healthy participants (18 to 39 years of age, inclusive) were randomized in a 1:1:1 ratio to receive either 15 mu g or 7.5 mu g of an H1N1 influenza vaccine, or placebo delivered via MIMIX MAP to the volar forearm. A statistician used a computer program to create a randomization scheme with a block size of 3. Post-treatment follow-up was approximately 180 days. Primary safety outcomes included the incidence of study product related serious adverse events and unsolicited events within 180 days, solicited application site and systemic reactogenicity through 7 days after administration and solicited application site erythema and/or pigmentation 14, 28, 56 and 180 days after administration. Immunogenicity outcomes included antibody titers and percentage of seroconversion (SCR) and seroprotection (SPR) rates determined by the hemagglutination inhibition (HAI) assay. Exploratory outcomes included virus microneutralization (MN) titers, durability and breadth of the immune response. The trial was registered with ClinicalTrials.gov, number NCT 06125717. Findings Between July 7, 2022 and March 13, 2023 45 participants were randomized to a treatment group. One participant was lost to follow up in the 15 mu g group and 1 participant withdrew from the 7.5 mu g dose group. Safety analyses included n = 15 per group, immunogenicity analyses included n = 14 for the 15 mu g and 7.5 mu g treatment groups and n = 15 for the placebo group. No SAEs were reported in any of the treatment groups. All treatment groups reported solicited local events within 7 days after vaccination, with mild (Grade 1) erythema being the most frequent symptom reported. Other local symptoms reported included mostly mild (Grade 1) induration/swelling, itching, pigmentation, skin flaking, and tenderness. Within 7 days after vaccination, 2 participants (4.4%) reported moderate (Grade 2) erythema, 1 participant (2.2%) reported moderate (Grade 2) induration/swelling, and 1 participant (2.2%) reported moderate (Grade 2) itching. There was an overall reduction in erythema and pigmentation reported on Days 15, 29, 57, and 180 among all treatment groups. Systemic symptoms reported within 7 days after vaccination, included mild (Grade 1) fatigue reported among all treatment groups, and mild (Grade 1) headache reported by 1 participant in the 7.5 mu g treatment group. No study drug related severe symptoms were reported in the study. Group mean fold rises in HAI titers ranged between 8.7 and 12-fold, SCRs were >76% and SPRs were >92% for both VX-103 dose groups thereby fulfilling serological criteria established by the EMA and FDA for seasonal influenza vaccines. Longitudinal assessments demonstrate persistence of the immune response through at least Day 180. Conclusions The MIMIX MAP platform is safe, well tolerated and elicits robust antibody responses.