Safety and immunogenicity of inactivated varicella-zoster virus vaccine in adults with hematologic malignancies receiving treatment with anti-CD20 monoclonal antibodies

Background Immunocompromised patients can experience significant morbidity and occasional mortality from complications associated with herpes zoster (HZ), but live attenuated HZ vaccine is contraindicated for these patients. Inactivated zoster vaccine (ZV_IN) is in development for prevention of HZ in immunocompromised patients. However, there are limited data in the literature regarding the effect of anti-CD20 monoclonal antibodies on vaccine-related cell-mediated immune response. This study evaluated safety and immunogenicity of ZV_IN in patients with hematologic malignancies (HM) receiving anti-CD20 monoclonal antibodies (alone or in combination chemotherapy regimens) and not likely to undergo hematopoietic cell transplant (HCT) (n = 80). Methods This was an open-label, single-arm, multicenter Phase I study (NCT01460719) of a 4-dose ZV_IN regimen (∼30 days between doses) in patients ⩾18 years old. Blood samples were collected prior to dose 1 and 28 days Postdose 4 to measure varicella zoster virus (VZV)-specific T-cell responses using interferon-γ enzyme-linked immunospot (IFN-γ ELISPOT). The primary hypothesis was that ZV_IN would elicit significant VZV-specific immune responses at ∼28 days Postdose 4, with a geometric fold rise (GMFR) >1.0. All vaccinated patients were evaluated for adverse events (AE) through 28 days Postdose 4. Results ZV_IN elicited a statistically significant VZV-specific immune response measured by IFN-γ ELISPOT at 28 days Postdose 4 (GMFR = 4.34 [90% CI:3.01, 6.24], p-value < 0.001), meeting the pre-specified success criterion. Overall, 85% (68/80) of patients reported ⩾1 AE, 44% (35/80) reported ⩾1 injection-site AE, and 74% (59/80) reported ⩾1 systemic AE. The majority of systemic AEs were non-serious and considered unrelated to vaccination by the investigator. Frequencies of AEs did not increase with subsequent doses of vaccine. No recipient of ZV_IN had rash polymerase chain reaction (PCR) positive for VZV vaccine strain. Conclusions In adults with HM receiving anti-CD20 monoclonal antibodies, ZV_IN was well-tolerated and elicited statistically significant VZV-specific T-cell responses ∼28 days Postdose 4. CLINICALTRIALS.GOV identifier: NCT01460719.