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

Abstract

Background: 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.

Material and methods: We conducted a retrospective cohort study among hospitalized patients with metastatic solid tumors who received ICI therapy at 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; 70 (66%) had Eastern Cooperative Oncology Group Performance Status ≥2, which would have prevented them from enrolling in most clinical trials of ICIs. Fifty-two patients (49%) died either during admission or within 30 days of discharge; median overall survival was 1.0 month from discharge, and 16 patients (15%) were alive 6 months after discharge. Independent predictors of death following receipt of inpatient ICI included a diagnosis of non-small cell lung cancer relative to melanoma and prior treatment with two or more lines of therapy.

Conclusion: 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.

Implications for practice: Immunotherapy strategies for patients with cancer are rapidly evolving and their use is expanding, but not all patients will develop a response, and secondary toxicity can be significant and challenging. This is especially evident in hospitalized patients, where the economic cost derived from inpatient immune checkpoint inhibitor (ICI) administration is important and the clinical benefit is sometimes unclear. The poor overall outcomes evidenced in the ICI inpatient population in this study highlight the need to better identify the patients that will respond to these therapies, which will also help to decrease the financial burden imposed by these highly priced therapies.

Keywords: Clinical outcomes; Hospitalized patients; Immune checkpoint inhibitor; Inpatient; Metastatic cancer.

Figure 1

Flow chart of outcomes for patients treated with ICI therapy during admission to the hospital. Abbreviation: ICI, immune checkpoint inhibitor.

Figure 2

Overall survival in all patients treated with immune checkpoint inhibitor therapy during admission to the hospital. Shown is a Kaplan‐Meier estimate of overall survival, with estimated 95% confidence interval. Time 0 represents date of discharge. At 6 months after discharge, only 16 patients remained alive.