- Anticancer treatment (chemotherapy, radiotherapy, immunotherapy, biological response modifiers, signal transduction inhibitors, etc.) within 4 weeks prior to the first dose of AP23573. The interval may be ≥ 2 weeks for hormonal therapy or signal transduction inhibitors with a half-life known to be <24 hours and must be ≥ 6 weeks for nitrosourea or mitomycin.