A major meta-analysis finds that administering immunotherapy earlier in the day is associated with significantly longer survival in patients with advanced solid tumors.
The systematic review, published in JAMA Network Open, analyzed 29 studies involving over 6,000 patients. Researchers found that earlier infusion of immune checkpoint inhibitors (ICIs) was linked to a 40% improvement in overall survival and a 38% improvement in progression-free survival.
The benefit was most pronounced in non-small cell lung cancer, gastric cancer, renal cell carcinoma, small cell lung cancer, and biliary tract cancer. In non-small cell lung cancer, the finding was supported by randomized clinical trial data-the gold standard of evidence.
Experts point to circadian biology as a possible mechanism. Immune cell activity, including T-cell responses and cytokine production, fluctuates naturally throughout the day. Aligning treatment with these rhythms-a concept known as chronotherapy-could enhance anti-tumor immunity.
However, researchers caution that clinical implementation is premature. Most data is retrospective, definitions of “early” vs. “late” varied across studies, and heterogeneity was high. Prospective randomized trials are needed to confirm whether timing has a causal effect on outcomes and to establish standardized scheduling protocols.