Phase I Dose-Escalation Trial — 3+3 Design & Maximum Tolerated Dose

Before a new cancer drug can be tested for whether it works, a Phase I trial has to answer a narrower question first: how much of it can a patient safely receive? This simulator runs the classic 3+3 dose-escalation design used across oncology drug development — small cohorts of patients are dosed up a fixed ladder of dose levels, and a strict rule decides after every cohort whether to escalate, expand, or stop, until the trial converges on a Maximum Tolerated Dose. Each simulated patient's dose-limiting toxicity is sampled from a hidden logistic dose-toxicity curve you control via a midpoint dose and steepness, so you can watch the rule-based algorithm — which only ever sees small binary outcomes, never the curve itself — home in on (or misjudge) the real safety boundary, then reveal the ground truth to see how it did.