Clinical Outcomes of Patients With Metastatic Cancer Receiving Immune Checkpoint Inhibitors in the Inpatient Setting

Abstract

Purpose: As indications for immune checkpoint inhibitor (ICI) therapy have increased in recent years, so has the proportion of patients eligible for this type of therapy. However, a lack of data exists about the risks and benefits of ICI therapy in hospitalized patients, who tend to be frailer and sicker than patients enrolled in clinical trials. Methods: We conducted a retrospective cohort study among hospitalized patients with metastatic solid tumors who received ICI therapy at our institution, a large academic cancer center, over the course of 4 years. We analyzed the characteristics and outcomes of these patients and identified demographic and clinical factors that could be used to predict mortality. Results: During the 4-year study period, 106 patients were treated with ICI therapy while admitted to the hospital; 66% of them had Eastern Cooperative Oncology Group (ECOG) Performance Status ≥2, which would have prevented them from enrolling in most clinical trials of ICIs. Fifty-two patients died either during admission or within 30 days of discharge; median overall survival was 1.0 month from discharge, and 15% of patients were alive 6 months after discharge. Independent predictors of death following receipt of inpatient ICI included age ≥65 years, having a cancer type other than melanoma, and prior treatment with two or more lines of therapy. Conclusions: The poor overall outcomes observed in this study may give clinicians pause when considering ICI therapy for hospitalized patients, particularly those with characteristics that are associated with a greater risk of mortality.