Table 1.

Requirements for a practical mitigator of chronic radiation-induced normal tissue injury.

Must work when therapy is started many days after exposure (3 days minimum, 7+ days preferred). Should be orally available (or a skin patch), although intramuscular or subcutaneous might be practical. Should be reasonably stable, so that it can be stockpiled. Should have efficacy in multiple organ systems. Should be FDA-approved for some indication, so that toxicity, safety, and pharmacokinetics are known.