Chemotherapy for glioblastoma (GBM) may work better in the morning, according to a study published in Neuro-Oncology Advances. Researchers assessed whether timing of maintenance temozolomide (TMZ) administration affects GBM patient outcomes. The analysis included 166 patients with newly diagnosed GBM from 2010 through 2018 who had surgery, had chemoradiation, and were prescribed TMZ for either the morning or evening. Patients were followed for a median of 5.07 years. Patients taking TMZ in the morning showed longer overall survival (OS) compared with those taking TMZ in the evening (median OS, 1.43 vs 1.13 years), with a significant year 1 restricted mean survival time difference (RMST; −0.09). In an analysis of O6-methylguanine-DNAmethyltransferase-methylated patients, median OS was 6 months longer for patients taking TMZ in the morning, with significant RMST differences at years 1 to 2.5. Among all patients, superiority of morning TMZ at years 1, 2, and 5 was supported by RMST difference regression in an adjusted analysis. “Many oncologists give it in the evening because patients tend to report fewer side effects then,” a coauthor said in a statement. “We saw that in our study as well. But it could be that the increased side effects—which we can manage with other therapies—are a sign that the drug is working more effectively.”