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

Abstract

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 (∼30days between doses) in patients ⩾18years old. Blood samples were collected prior to dose 1 and 28days 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 ∼28days Postdose 4, with a geometric fold rise (GMFR) >1.0. All vaccinated patients were evaluated for adverse events (AE) through 28days Postdose 4.

Results: ZV_IN elicited a statistically significant VZV-specific immune response measured by IFN-γ ELISPOT at 28days 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 ∼28days Postdose 4. CLINICALTRIALS.GOV identifier: NCT01460719.

Keywords: Herpes zoster; Immunogenicity; Safety; Tolerability; Zoster vaccine.