Researchers have discovered that administering immunotherapy drugs for lung cancer in the morning can significantly improve patient survival rates. This approach leverages the body's circadian rhythms, which influence immune cell activity. The findings suggest a simple timing adjustment could enhance treatment effectiveness without added costs.
Cancer treatments may work better when aligned with the body's natural 24-hour cycles, known as circadian rhythms. These rhythms regulate cell division, hormone release, and immune responses, but they are often disrupted in cancer cells, which divide continuously.
Efforts to time chemotherapy have focused on reducing side effects by targeting it when healthy tissues are less active. Now, attention is turning to immunotherapy drugs like immune checkpoint inhibitors, which enhance T-cells' ability to attack tumors. T-cells are naturally more active in the morning, potentially amplifying the drugs' effects if given early.
A study by Zhe Huang and colleagues at Central South University in Changsha, China, earlier this year examined non-small cell lung cancer (NSCLC) patients receiving pembrolizumab with chemotherapy. Those treated before 11:30 a.m. showed nearly double the survival rate compared to afternoon treatments.
Building on this, the team analyzed data from 397 small cell lung cancer patients treated with atezolizumab or durvalumab plus chemotherapy between 2019 and 2023. Patients receiving infusions before 3 p.m. had longer progression-free and overall survival. After adjusting for confounding factors, early treatment linked to a 52 percent lower risk of cancer progression and a 63 percent lower risk of death.
"Compared with patients treated later in the day, those treated before 3pm had significantly longer progression-free survival and overall survival," said Yongchang Zhang, a team member.
The NSCLC trial indicated morning dosing increased circulating T-cell numbers and activation, while late-day dosing reduced them. Mouse studies further show tumor-infiltrating T-cells vary in function over 24 hours, influenced by nearby cells' clocks.
Similar benefits appear in renal cell carcinoma and melanoma studies. "This study further supports the growing number of reports... describing better results with early time of day of immunotherapy drugs administration," noted Pasquale Innominato at the University of Warwick, UK.
While randomized trials with larger samples are needed, experts like Seline Ismail-Sutton emphasize chronotherapy's potential as a low-cost precision medicine tool. However, individual chronotypes—such as early birds versus night owls—vary, and biomarkers to assess them are in development. Adjusting infusion times remains a practical, cost-free option for hospitals.