Table 1.

Dose escalation decision criteria

Number of patients with DLT at a given dose level	Escalation decision rule
0 out of 3	Enter 3 patients at the next dose level
≥2	Dose escalation will be stopped. This dose level will be declared the maximally tolerated dose (highest dose administered). Three (3) additional patients will be entered at the next lowest dose level if only 3 patients were treated previously at that dose.
1 out of 3	Enter up to 3 more patients at this dose level. If 0 of these 3 patients experience DLT, proceed to the next dose level. If 1 or more of this group suffer DLT, then dose escalation is stopped, and this dose is declared the maximally administered dose. Three (3) additional patients will be entered at the next lowest dose level if only 3 patients were treated previously at that dose.
≤1 out of 6 at highest dose level below the maximally administered dose	This is generally the recommended phase 2 dose. At least 6 patients must be entered at the recommended phase 2 dose.

DLT, dose-limiting toxicity.

Adapted from Storer.²⁹