Herpes Zoster Risk Among US Cancer Patients Following Initiation of Immunosuppressive Therapy

Justin Gatwood,1 Yong Zhu,2 Andrea Steffens,2 Stephanie J Gallagher,2 Mary C DuCharme,2 Kristin J Moore,2 Nikita Stempniewicz1 1GSK, Philadelphia, PA, USA; 2Value and Evidence Solutions, Optum Life Sciences, Eden Prairie, MN, USACorrespondence: Justin Gatwood, GSK, 2929 Walnut St, Philadelphia, PA, 19104, USA, Tel +1 908 812 0967, Email [email protected]: Cancer and immunosuppressive medications used for its treatment increase the risk for herpes zoster (HZ) among adults. This study described the incidence of HZ and its complications among United States (US) adults with specific solid tumors and hematological malignancies following initiation of immunosuppressive therapy.Patients and Methods: This retrospective cohort study used administrative claims data from October 2015 to December 2022 and included US adults with ≥ 1 immunosuppressive medication claim, ≥ 12 months continuous enrollment (baseline) prior to the first immunosuppressive medication claim, a cancer diagnosis, and no HZ diagnosis or vaccination in the baseline period. HZ incidence rates (IRs) were calculated as the number of new HZ cases per 1000 person-years at risk, stratified by cancer type and medication class. The proportions of patients with HZ-related complications such as postherpetic neuralgia, herpes zoster ophthalmicus, disseminated HZ, and HZ-related meningoencephalitis were described. A time-dependent Cox proportional hazards regression estimated adjusted hazard ratios, controlling for patient age, sex, race and ethnicity, comorbidities, prior healthcare utilization, insurance type, region, and baseline immunosuppressive medication use.Results: The overall IRs of new HZ cases in patients with a solid tumor or a hematological malignancy were 20.9 (95% confidence interval [CI]: 20.33‒21.52) and 31.1 (95% CI: 29.64‒32.52) per 1,000 person-years, respectively. HZ IR was highest in patients with non-Hodgkin lymphoma (35.4, 95% CI: 33.05‒37.77) or chronic lymphocytic leukemia (35.1, 95% CI: 31.24‒39.24). By medication class, the highest HZ IRs were associated with mycophenolic acid, azathioprine, and oral glucocorticoids. In adjusted analyses, patients were more likely to develop HZ during periods of immunosuppressive medication use versus periods without (adjusted hazards ratio [95% CI]: 3.2 [3.01‒3.39] for solid tumor, 3.2 [2.89‒3.57] for hematological malignancy).Conclusion: HZ incidence among US adults with solid tumors and hematological malignancies following immunosuppressive therapy initiation was high, reinforcing the need to prioritize HZ vaccination in these populations.Plain Language Summary: Why was the study done?Adults with cancer have a higher risk of developing herpes zoster (HZ) compared to the general population, due to both cancer and its treatments. The risk of HZ in adults by cancer type and medication class has not yet been comprehensively examined.What did the researchers do and find?This study estimated HZ incidence among United States adults with cancer following immunosuppressive therapy initiation. This study found that HZ incidence is particularly high in patients with solid tumors or hematological malignancies in the period following immunosuppressive medication initiation. Moreover, patients consistently on immunosuppressive therapy were more likely to develop HZ compared to patients with less consistent use of immunosuppressive medications. We identified mycophenolic acid, azathioprine, and oral glucocorticoids as medications associated with higher rates of HZ incidence.What do these results mean?The findings provide oncologists and hematologists with information about the risk of HZ in patients with different cancer types during periods of immunosuppressive medication use. This may also inform decision makers about the need for HZ vaccination in patients at increased risk for HZ due to both their health condition and treatment. Finally, this may provide guidance to providers by linking the need for HZ prevention with specific classes of medications, irrespective of their connection to cancer therapy. Keywords: herpes zoster, incidence, immunosuppression, solid tumor, hematological malignancy