When immunotherapy was given changed melanoma survival odds

Researchers at Emory University's Winship Cancer Institute reviewed records of nearly 300 metastatic melanoma patients receiving immune checkpoint inhibitors, asking a question mostly studied in mice before: whether getting the infusion earlier or later in the day affected how well the treatment worked.

Patients who received 20 percent or more of their infusions after 4:30 in the afternoon had worse overall survival than those who mostly received morning or early-afternoon infusions. In matched groups, median survival was 4.8 years with later infusions and had not yet been reached with earlier ones, roughly double the risk of death, a difference that held up after adjusting for other factors.

This was a single-institution, retrospective look at existing records, not a randomized trial, so doctors cannot yet be certain that shifting appointment times would itself change outcomes rather than reflecting some other difference between patients. The finding builds on earlier mouse studies of circadian immune rhythms, and a prospective trial scheduling infusion times deliberately is a needed next step before clinics change scheduling practices.

The clock on the wall may matter too.