Some cancer therapies may be more effective when given earlier in the day, aligning treatment with the body's natural rhythms, a Chinese study found, confirming earlier evidence.

Researchers randomly assigned 210 patients with newly diagnosed advanced non-small cell lung cancer to receive four treatments with Merck's Keytruda and Eli Lilly's Tyvyt, either before or after 3 p.m.

In the group that received treatment before 3 p.m., tumors remained under control for a median 11.3 months, whereas they began to progress at a median 5.7 months in patients treated after 3 p.m.

Median overall survival was 28 months with earlier treatment versus 17 months for those who got later infusions, Dr. Yongchang Zhang of Central South University in Changsha and colleagues reported.

After accounting for individual risk factors, the odds of earlier death were 58% lower with earlier-in-the-day treatment, the researchers wrote in Nature Medicine.

The researchers note that circadian rhythms - the 24-hour cycles governing biological processes - are known to influence immune cells. Earlier retrospective studies have reported improvements in the efficacy of immunotherapies like Keytruda and Tyvyt when given earlier in the day.

Larger studies are still needed to confirm the findings, the researchers acknowledged.

Writing in China’s Journal of the National Cancer Center, a separate team reports that earlier peer-reviewed lab studies showed profound impacts of circadian rhythms on tumor growth and immune cell activity during treatment with drugs that work on the immune system like Keytruda, the world's top-selling prescription medicine.

“Circadian regulation is a critical yet underappreciated factor influencing how tumors interact with the immune system,” study leader Dr. Peng Luo of Southern Medical University in Guangzhou said in a statement.

“By aligning immunotherapy with the body’s natural rhythms, we may significantly enhance treatment outcomes.”