Incidence and economic burden of infections in cancer patients receiving immune checkpoint inhibitors.

Abstract

e19365 Background: Along with antitumor effects, Immune Checkpoint Inhibitors (ICPI) have shown great potential in treating chronic infections such as HIV, Hepatitis B, and malaria, in ex-vivo studies. However, several case reports and case series suggested increased infection risk in cancer patients receiving ICPI. The purpose of our study is to assess the risk of infections in cancer patients receiving ICPI. We also attempted to evaluate the role of a multidisciplinary approach (Oncology and Infectious disease specialists) and the cost associated with treatment. Methods: Records on all cancer patients over age ≥18 years old who had received at least one dose of ICPI from 2015 to 2018 at two major community teaching hospitals in the Central Massachusetts region were reviewed. Several risk factors associated with infection were identified. Two-tailed unpaired t-test was used to analyze the association between risk factors and infection. We calculated the average length of stay (LOS) and cost per admission with a multidisciplinary vs. non-multidisciplinary approach. The calculated total average cost per admission was compared with a random set of non-oncologic population admitted with similar infections noted in our study to estimate the economic burden. Results: Thirty-seven (21.8%) patients developed sixty-two episodes of infection. Microbiological confirmation was available in 13 episodes. Risk factors like COPD (P = 0.01), prior chemotherapy (P = 0.03), and steroid use (P = 0.003) were significantly associated with infections. An infection-associated mortality rate was noted to be 2.3%. With the involvement of multidisciplinary team, the average LOS increased from 5.9 to 8.1 days. Yet, the average cost per admission approximately remained the same (52,047$ vs. 54,510$). Upon comparison with a non-oncologic patient, the average cost per admission for an infection in cancer patients receiving ICPI increased from 11,527$ to 35,484$. Conclusions: Surprisingly, a significant incidence of infections and associated health care resource utilization continue to prevail in cancer patients despite the utility of ICPI. Although the economic burden due to the infections in this set of patients is remarkably high when compared to the general population, the multidisciplinary approach did not increase the hospital costs.