Lower-dose dexamethasone (Dex)/thalidomide (Thal) and zoledronic acid (ZOL) every 3 weeks in previously untreated multiple myeloma.

e18524 Background: Although multiple myeloma (MM) is uncommon in Asia, Asian patients are often unable to tolerate full doses of Dex and/or Thal that typically result in very good partial (VGPR), near-complete (nCR) or complete response (CR) while maintaining CD34 stem cell counts. Preparative regimens achieving these responses prior to autologous hematopoietic stem cell transplantation correlate with improved outcomes in MM. Therefore, optimal regimens are needed; however, co-operative clinical studies in Asia are lacking. We investigated if q 3-week administration of ZOL (shown to exert anti-MM effects in preclinical studies) combined with low doses of Dex/Thal would be well tolerated in Asian patients and generate responses to treatment. Methods: In this co-operative multicenter phase II non-randomized single arm study in India, Singapore and Korea, previously untreated MM patients received up to 6 cycles of Dex (20 mg 1 to 4 times q wk), Thal (50 mg q wk to 100 mg q d), and ZOL (4 mg q 3 wk) (dtZ regi...