Food Intervention to Reduce Immunotherapy ToXicity

The FORX (Food intervention to Reduce immunotherapy toXicity) trial will assess whether supplementing dietary fiber intake by providing weekly boxes containing 30 different plants to patients with solid tumors starting immune checkpoint inhibitor therapy affects the incidence of immune related adverse events.

Immune checkpoint inhibitor (ICI) therapy has revolutionized cancer treatment but can give rise to immune related adverse events (irAEs) that are currently not preventable. These irAEs impact patients' quality of life and oncological treatment course. The gut plays an essential role in immune homeostasis and gut dysbiosis is implicated in (auto)inflammatory conditions. The FORX trial investigates whether the composition of the gut microbiome can be altered to improve ICI tolerance. It has been shown that healthy volunteers who ingest at least 30 different plants (vegetables, fruits, nuts) weekly, have a more diverse microbiome than those who consume 10 or less. A fiber-rich diet has been associated with improved outcome of ICI treatment. This trial is the first prospective trial to translate these findings into a concrete dietary advice. The diets of patients with a solid tumor who start ICI will be supplemented by weekly boxes containing 30 different plants during the first 12 weeks of their treatment. The increased fiber intake is expected to strengthen the gut microbiome and reduce the incidence of irAEs. Stool and blood samples will clarify the microbial and cytokine signatures associated with irAEs. The FORX trial will provide valuable insights in the interaction between the gut microbiome and autoimmunity and serve as a basis for nutritional advice and the development of targeted probiotics. It will empower cancer patients and improve their quality of life.