Guardian writer Joshua Pederson describes his 12-year-old son's fight with an aggressive tumour and his family's alarm at prediction market Kalshi's plan to let users bet on clinical trial outcomes and FDA drug approvals. His son is currently enrolled in a trial combining chemotherapy and immunotherapy after his cancer, first diagnosed almost two years ago, returned following a period of remission, making the prospect of outsiders wagering on treatments' success deeply unsettling to the family.

Kalshi's pilot programme will initially include contracts on whether an anti-cancer drug wins approval and whether an Alzheimer's drug trial meets its goals. Chief executive Tarek Mansour has defended the move as "surfacing information" in an industry he calls information-constrained, offering a public probability reflecting evidence rather than sponsors' messaging. Pederson acknowledges some sympathy with this argument, given how daunting it was to choose between eligible trials for his son, but rejects the idea that a betting market could substitute for expert oncologists, and notes wider concerns that such markets could actively harm life-saving research.