Herpes zoster vaccine safe, effective after HSCT
SALT LAKE CITY — Use of herpes zoster vaccine following an autologous hematopoietic stem cell transplant showed a vaccine efficacy of 68% with a clinically acceptable safety profile, according to study results presented at the BMT Tandem Meetings.
“Immunocompromised individuals, including autologous hematopoietic stem cell transplant recipients, are at increased risk [for] herpes zoster,” Javier de la Serna, MD, PhD, hematologist at Hospital 12 de Octubre in Madrid, and colleagues wrote. “The risk is highest in the first year after transplantation, with an 8% to 30% herpes zoster incidence in autologous HSCT recipients.”
The herpes zoster subunit vaccine — which contains recombinant varicella zoster virus gE and AS01B Adjuvant System — has a greater than 90% vaccine efficacy for adults aged older than 50 years. The vaccine is approved for this population in the U.S. and Canada.
In a previous study, the herpes zoster vaccine showed increased immune responses among patients who received autologous HSCT.
In the phase 3 ZOE-HSCT trial, de la Serna and colleagues studied the effect of the herpes zoster vaccine on prevention of herpes zoster, postherpetic neuralgia and herpes zoster-related complications; they also assessed the safety of the vaccine.
The researchers randomly assigned 1,846 patients aged at least 18 years (mean age, 55 years) 1:1 to receive two doses of the herpes zoster vaccine or placebo 1 to 2 months apart, 50 to 70 days after HSCT.
Researchers used polymerase chain reaction assay positive for varicella zoster virus to confirm suspected herpes zoster episodes. When assay results were indeterminate or missing, three committee members had to agree to confirm herpes zoster episodes.
Median follow-up was 21 months.
Researchers confirmed at least one episode of herpes zoster among 49 patients (30 per 1,000 person-years) in the vaccine cohort and among 135 patients (94.3 per 1,000 person-years) in the placebo cohort.
The vaccine prevented herpes zoster with a vaccine efficacy of 68.17% (95% CI, 22.54-99.76) and prevented postherpetic neuralgia with a vaccine efficacy of 89.27% (95% CI, 22.54-99.76).
The vaccine also prevented herpes zoster complications with an efficacy of 77.76% (95% CI, 19.05-95.93) and herpes zoster-related hospitalizations with an efficacy of 84.7% (95% CI, 32.15-96.55).
Dose 2 compliance appeared similar between the two groups (vaccine, 94.7%; placebo, 93.3%).
Patients who received the vaccine had more local solicited adverse events (85.8%; 95% CI, 83.3-88 vs. 10.4%; 95% CI, 8.5-12.6) and more general solicited adverse events — including fatigue, gastrointestinal symptoms, headache, myalgia, shivering and/or fever — (42.1%; 95% CI, 38.8-45.4 vs. 16.8%; 95% CI, 14.4-19.4).
Incidences of unsolicited (vaccine, 39%; vs. placebo, 38.2%), severe (28.5% vs. 26.1%) and fatal (12.8% vs. 12.4%) adverse events appeared similar between the groups. Researchers also reported similar rates of potential immune-mediated disease (1.4% vs. 0.9%) and relapses (25.9% vs. 27.4%).
“Administered to adults early after autologous HSCT, herpes zoster subunit vaccine effectively prevented herpes zoster (independent of age) and postherpetic neuralgia. The safety profile of herpes zoster subunit vaccine in this population was clinically acceptable,” the researchers wrote in the abstract. – by Cassie Homer
de la Serna J, et al. Abstract LBA2. Presented at: BMT Tandem Meetings; Feb. 21-25, 2018; Salt Lake City.
Disclosures: HemOnc Today could not confirm the authors’ relevant financial disclosures at the time of reporting.