Questions on Oncologic Investigational Agent Guidance
The National Cancer Institute says it has four concerns about an FDA guidance that requires studies of oncologic investigational agents to enroll additional patients on multiple dose levels to assess activity for dose optimization, before the therapy’s clinical effectiveness has been established and before the tolerability of therapy has been determined to be unacceptable. The comment letter says the concerns are:
- most agents in Phase 1 studies will not be developed into marketable agents and will not be shown to provide benefits for patients;
- most investigational drugs that are developed into marketed agents are tolerable at the dose used in Phase 3 studies and the guidance focuses on a small minority of approved oncologic agents;
- the guidance does not contain clear criteria for defining tolerability and does not describe how the precision of its measure can be determined; and
- the supposition that a biologically effective dose … is related to the clinical effectiveness of an investigational agent is pure conjecture for most agents.