149. Immunogenicity, Safety, and Post-hoc Efficacy Assessment of the Adjuvanted Recombinant Zoster Vaccine in Adults with Hematologic Malignancies: A Phase 3, Randomized Clinical Trial

BACKGROUND: Patients with hematologic malignancies treated with anticancer immunosuppressive therapies (ITs) are at increased risk of herpes zoster (HZ). In a previous report of this phase 3, observer-blind, multicenter trial (NCT01767467), the adjuvanted recombinant zoster vaccine (RZV) was shown to be immunogenic and well-tolerated in ≥18 years of age patients with hematologic malignancies who completed or were undergoing anticancer IT.(1) Here we report end-of-study results from the same trial. METHODS: Participants were randomized 1:1 to receive 2 doses of RZV or placebo (PL) 1–2 months apart, either ≥10 days before or after a cancer therapy cycle, or 10 days to 6 months after cancer therapy ended. Humoral and cell-mediated immune (CMI) responses were evaluated at 1 month and 12 months post-dose 2 (month 2 and month 13, respectively). Confirmatory objectives were to evaluate humoral response rate to RZV and to compare humoral immune responses to RZV and PL at month 2 excluding either subjects with chronic lymphocytic leukemia and non-Hodgkin B-cell lymphoma (NHBCL), or only those with NHBCL. Efficacy against HZ was explored in a post-hoc analysis of confirmed HZ cases. Solicited and unsolicited adverse events (AEs) were recorded for 7 and 30 days after each dose, respectively. Serious AEs (SAEs) and potential immune-mediated diseases (pIMDs) were recorded throughout the study. RESULTS: Of the 562 (RZV: 283, PL: 279) treated participants, 415 (RZV: 217, PL: 198)/310 (RZV: 168, PL: 142) were included in the according-to-protocol (ATP) cohort for humoral immunogenicity/immune persistence. The ATP sub-cohort for CMI included 132 (RZV: 69, PL: 63) participants at month 2 and 100 (RZV: 54, PL: 46) at month 13. All confirmatory immunogenicity objectives were met (Table 1). RZV efficacy against HZ, assessed post-hoc, was 87.2% (Table 2). RZV was more reactogenic than PL. The occurrence of unsolicited AEs, SAEs, and pIMDs was similar between the study groups (Table 3). CONCLUSION: RZV induced robust humoral and cellular immune responses and showed an effect in the reduction of HZ incidence in patients with hematologic malignancies who completed or were undergoing anticancer IT. No safety concerns were identified. Reference 1. Oostvogels et al. IDWeek2017, abs 1344. [Image: see text] [Image: see text] [Image: see text] Funding. GlaxoSmithKline Biologicals SA. DISCLOSURES: A. F. Dagnew, GSK: Employee and Shareholder, Salary. J. Murphy, GSK: Investigator, Research support. S. A. McNeil, GSK group of companies: Grant Investigator, Research grant and Research support. B. Salaun, GSK group of companies: Employee and Shareholder, Salary. E. Di Paolo, GSK group of companies: Employee, Salary. L. Campora, GSK group of companies: Employee and Shareholder, Salary. M. López-Fauqued, GSK group of companies: Employee, Salary. M. El Idrissi, GSK group of companies: Employee, Salary. A. Schuind, GSK: Employee, Salary. T. C. Heineman, GSK group of companies: Consultant, Employee and Shareholder, Consulting fee and Salary. P. Van Den Steen, GSK: Employee and Shareholder, Restricted shares and Salary. L. Oostvogels, GSK: Employee, Salary and Stock and stock options.