Key clinical point: Dexamethasone may have a detrimental effect on patients with glioblastoma who are receiving immunotherapy.

Major finding: In a multivariable analysis, baseline dexamethasone use was the strongest predictor of poor survival in glioblastoma patients receiving a checkpoint inhibitor. The hazard ratio was 2.16 (P = .003) when dexamethasone was given at less than 2 mg daily and 1.97 (P = .005) when dexamethasone was given at 2 mg or more daily, compared with no baseline dexamethasone.

Study details: A retrospective study of 181 consecutive glioblastoma patients treated with anti–PD-1 or anti–PD-L1 therapy.

Disclosures: This research was funded by grants from the National Institutes of Health and support from various foundations and institutions. The researchers disclosed relationships with many pharmaceutical companies.