Q&As on Iressa's (gefitinib) New Labeling (cont.)
4. What is a surrogate endpoint?
A surrogate endpoint is a laboratory finding or physical sign that may not be a direct measurement of how a patient feels, functions, or survives, but is still considered reasonably likely to predict therapeutic benefit for the patient. In the case of Iressa, accelerated approval was based on demonstration of response measured by tumor shrinkage in approximately 10% of patients with non-small cell lung cancer who had already received standard treatments.
5. How was accelerated approval applied to Iressa?
Iressa was approved on the basis of a surrogate endpoint which was approximately a 10% tumor response rate (tumor shrinkage) in clinical studies in patients with advanced lung cancer. This tumor response suggested that the drug was reasonably likely to have a valuable effect on survival or symptoms.
6. Who can receive Iressa under the Iressa Access Program?
Prescriptions for Iressa will be limited the following patient populations:
7. Will any new patients be able to obtain Iressa?
New patients may be able to obtain Iressa under the Iressa Access Program if they are eligible to participate in a non-Investigational New Drug Application (non-IND) clinical trial approved by an IRB prior to June 17, 2005 (no new patients can be started after June 17, 2005). New patients may also qualify for enrollment in clinical trials for Iressa that are conducted under an IND.
8. What is an IND?
An Investigational New Drug (IND) application is a submission from a company that FDA uses to oversee clinical research and the use of investigational drugs involving patients.
9. What is the reason for the Iressa Access Program?
FDA has carefully reviewed data from the completed clinical studies of Iressa, including the confirmatory trial that was required by the agency as part of the drug's accelerated approval. The confirmatory trial enrolled patients with advanced non-small cell lung cancer (NSCLC) who had failed one or two prior chemotherapy regimens. In this large study, 1,692 patients were randomly assigned to receive either Iressa (gefitinib) or placebo. The results of the study showed no significant survival benefit for those patients treated with Iressa. Three other studies of Iressa in patients with lung cancer have also failed to demonstrate improved survival. However, AstraZeneca continues to examine the data and intends to pursue additional clinical studies. Other approved treatments for non-small cell lung cancer have been shown to improve survival in clinical trials. Given the results of these studies, it is not reasonable to start new patients on Iressa.