FDA Approves Thalomid (thalidomide) to Treat Multiple Myeloma
On May 26, 2006, the U.S. Food and Drug Administration granted accelerated approval for thalidomide (Thalomid, Celgene Corporation) in combination with dexamethasone for the treatment of newly diagnosed multiple myeloma (MM) patients. Because of thalidomide’s known teratogenicity, the FDA is controlling Thalidomide’s marketing in the United States via the System for Thalidomide Education and Prescribing Safety (S.T.E.P.S.) program. This mandatory registry includes authorized patients, prescribers and pharmacies, extensive patient education regarding thalidomide’s safety, and is designed to prevent fetal exposure to thalidomide during pregnancy.
Thalidomide was evaluated in 207 patients with newly diagnosed MM in one open-label, multi-center, cooperative group trial. Patients were randomized to 4 cycles of thalidomide 200 mg daily plus dexamethasone (Thal/Dex) or to dexamethasone (Dex) alone. Response rates based on serum or urine paraprotein measurements were significantly higher in the combination arm than Dex alone (51.5% vs. 35.6%, respectively, p = 0.025). After completing treatment, patients were encouraged to undergo stem cell transplantation.
The incidence of grade 3 or 4 adverse events was 84.3% on the Thal/Dex arm and 73.5% on the Dex alone arm. The most common toxicities associated with thalidomide were somnolence, constipation, neuropathy, venous thromboembolism (VTE), and rash.
The incidence of VTE was significantly higher in the Thal/Dex arm than with Dex alone (22.5% vs. 4.9%, respectively, p = 0.002). Prophylactic antithrombotic therapy prescribed with thalidomide may reduce VTE; however, the decision to prescribe antithrombotic therapy should be made after a careful assessment of the patient’s underlying risk factors.
This approval is based on objective response rates and is approved under accelerated approval regulations (Subpart H) requiring further clinical trials to demonstrate thalidomide’s clinical benefit in the treatment of multiple myeloma.
Full prescribing information, including clinical trial information, safety, dosing, drug-drug interactions and contraindications is available at Drugs@FDA.