VZV vaccine reduces HZ incidence after HSCT

Nineteen patients in the V212 consistency lot group had moderate-to-severe pain, as did 61 placebo-treated patients.

V212 conferred an estimated 83.7% (95% CI, 0.446-0.952) reduction in the incidence of post-herpetic neuralgia (PHN). Three patients in the V212 consistency lot group and 18 patients in the placebo group had PHN.

PHN was defined as pain in the area of the HZ rash with a “worst pain in the last 24 hours” score of 3 or greater (on a 0-10 scale) on the ZBPI that persists or appears 90 days or beyond after HZ rash onset following HSCT.

Patients who received V212 also saw an estimated 73.5% (95% CI, 0.498-0.860) reduction in “other” HZ complications. Twelve patients in the V212 consistency group and 44 in the placebo group had such complications.

“Other” complications included hospitalization or prolongation of hospitalization due to HZ, disseminated HZ (including disseminated HZ rash or VZV viremia), visceral HZ, ophthalmic HZ, neurological impairment due to HZ, and the administration of intravenous acyclovir therapy for the treatment of HZ post-HSCT.

Safety

All patients who received at least 1 dose of the vaccine or placebo and had follow-up data were included in the safety analysis. Patients were followed for AEs up to 28 days after the fourth vaccination dose.

AEs occurred in 97% of patients who received the vaccine (consistency and high-antigen groups assessed together) and 96.9% of placebo-treated patients. Vaccine-related AEs occurred in 32.6% and 12.6%, respectively.

“Of course, in this population of autologous stem cell transplant patients, adverse events of any type were very common in almost all patients,” Dr Winston said. “However, vaccine-related adverse events were greater in the vaccine recipients compared to the placebo patients, but this was primarily due to an increased incidence of injection-site adverse events in the vaccine recipients.”

Injection-site reactions occurred in 191 vaccinated patients and 36 placebo-treated patients.

The most common systemic AEs—in vaccinated and placebo-treated patients, respectively—were diarrhea (60.1% and 61.9%), nausea (56.5% and 57.8%), pyrexia (49.8% and 46.9%), mucosal inflammation (39.7% and 41.7%), thrombocytopenia (36.4% and 38.4%), febrile neutropenia (33.9% and 28.3%), vomiting (32.6% and 36.6%), anemia (26.6% and 24.4%), neutropenia (25.1% and 23.5%), decreased appetite (23.1% and 23.8%), fatigue (21.8% and 20.7%), hypokalemia (21.3% and 19.9%), and constipation (16.1% and 18.4%).

The incidence of serious AEs was 32.9% in vaccinated patients and 32.7% in the placebo group. The incidence of serious vaccine-related AEs was 0.8% and 0.9%, respectively.

The most common serious AEs—in vaccinated and placebo-treated patients, respectively—were infection (12.3% and 11.9%), relapsed malignancy (7.8% for both), febrile neutropenia (5.3% and 4.9%), pyrexia (3.2% and 4.0%), gastrointestinal disorders (3.2% and 3.6%), respiratory failure (2.7% and 2.2%), cardiac disorders (1.7% and 1.6%), and mucositis (1.2% and 0.9%).

Death occurred in 6.2% of vaccinated patients and 6.3% of placebo-treated patients. Three percent and 3.1%, respectively, discontinued the study due to AEs.