Patients are randomized to receive thalidomide at 1 of 2 doses for 12 weeks initially, with response assessed at weeks 2, 4, 8, and 12. Patients failing the low dose will be eligible to increase the dose to the higher dose. Treatment may continue indefinitely. After 12 weeks, patients continuing treatment are evaluated every 2 months for up to 6 additional months, then every 6 months thereafter.