People with melanoma who take immune checkpoint inhibitors (ICIs) are less likely to develop colitis if they are taking vitamin D supplements at treatment initiation, a study published in the journal Cancer (22 June 2020) has suggested
Researchers analysed data on 213 patients treated for melanoma with nivolumab and/or ipilimumab, or pembrolizumab between May 2011 and October 2017, 37 of whom developed ICI colitis.
The team found that 34.1% of patients without colitis reported taking a vitamin D supplement at the time of treatment initiation, compared with 16.2% of patients with colitis.
In multivariate analysis, patients who were taking vitamin D supplements before initiating treatment had reduced odds of developing colitis (odds ratio [OR] 0.35; 95% confidence interval [CI] 0.1–0.9) compared with patients who were not taking vitamin D.
Vitamin D deficiency and immune dysregulation have been linked to the development of autoimmune colitis, but predictive markers for ICI-induced colitis are lacking, the researchers explained. They added that, to their knowledge, this was the first study to identify vitamin D as a protective factor against the development of ICI colitis.
“These results may suggest benefit in prophylactic use of vitamin D supplementation to prevent ICI colitis, as previously demonstrated in inflammatory bowel disease and graft-versus-host disease,” they concluded.