The Food and Drug Administration (FDA) has granted approval of a new indication for Temodar (temozolomide). The drug, used concurrently with radiotherapy and as maintenance therapy after radiotherapy, can extend the lives of adult patients newly diagnosed with glioblastoma multiforme (GBM), the most common form of malignant brain cancer.
GBM is usually fatal. The annual incidence of GBM is four to five cases per 100,000 persons with 8,000 to 10,000 new cases diagnosed per year in North America.
The new approval of Temodar for GBM was based on efficacy and safety data from a large randomized controlled study conducted by the European Organization for Research and Treatment of Cancer (EORTC) in patients with newly diagnosed GBM. Patients were randomized to treatment with radiation alone or to treatment with radiotherapy plus temozolomide. In the multicenter trial of 573 patients, median survival was improved by two and a half months in the temozolomide group, a significant benefit. The median survival was 14.6 months with radiotherapy plus temozolomide and 12.1 months with radiotherapy alone.
Temodar was previously granted accelerated approval in 1999 for the treatment of adult patients with another form of brain tumor (anaplastic astrocytoma) in relapse after chemotherapy with nitrosourea and procarbazine.
Accelerated approval is a regulatory mechanism that allows approval of certain new drug products that treat serious or life-threatening illnesses and that may provide a meaningful therapeutic benefit to patients over existing treatments. Products approved through this route have been studied using an endpoint that is thought be reasonably likely to predict clinical benefit. After such accelerated approvals, the company must continue the clinical trials to determine whether or not the endpoint used as the basis for the accelerated approval indeed did predict a clinical benefit for the patient. If so, the product with an accelerated approval then will receive a traditional approval.
Based on the clinically important outcome in the GBM study, (GBM and anaplastic astrocytoma are closely related tumors) the anaplastic astrocytoma indication is now approved under traditional procedures, and the accelerated approval requirements no longer apply.
Side effects for Temodar reported include nausea, vomiting, headaches, fatigue, and anorexia. Preventive treatment for pneumocystis carinii pneumonia (PCP) is required when Temodar is administered with radiotherapy.
Temodar is manufactured by the Schering-Plough Corporation, Kenilworth, N.J.