Thalidomide in advanced and refractory myeloma. Thalidomide was administered to 169 patients; 76% had received 1 cycle and 53% at least 2 cycles of high-dose therapy; 67% had exhibited cytogenetic abnormalities, including 37% with abnormalities of chromosome 13. Thalidomide was administered at a starting dose of 200 mg daily, with escalation by 200 mg every 2 weeks, according to tolerance, for a maximum of 800 mg. (A) Time to different levels of myeloma protein response (reduction by at least 25%, 50%, 75%, and > 99%). At 8 months, 31% were estimated to have achieved a partial response (≥ 50% myeloma protein reduction). Most responders could be identified within 2 months using 25% or more myeloma protein reduction criteria. Superior survival (B) and event-free survival (C) were noted among 79 patients presenting without cytogenetic abnormalities (no CA). Survival was inferior in the presence of cytogenetic abnormalities (CAs), either involving chromosome 13 deletions and hypodiploidy (CA 13/hypodiploid, 51 patients) or other chromosomes (other CA, 24 patients). Fifteen patients lacked cytogenetic information.