Single-agent bortezomib in previously untreated multiple myeloma (MM): Results of a phase II multicenter study

7504 Background: Bortezomib is effective in relapsed and/or refractory MM. This trial evaluated its efficacy and safety as monotherapy in previously untreated MM. Methods: Pts with untreated, symptomatic MM were eligible, with pts receiving concomitant steroids, platelet count 2 peripheral neuropathy [PN] excluded. Endpoints included response rate (RR) [Blade criteria], time to progression, safety, incidence/severity of PN, and effect of dose modifications on PN. Pts received bortezomib 1.3 mg/m2 (d1, 4, 8, 11 every 21d) for 8 cycles. Comprehensive neurologic evaluation including electrophysiologic testing [NCS] and skin biopsy was performed in a subset of pts (n = 34). Results: Sixty-six pts (47% with stage III MM) were treated and 60 pts are evaluable for response, with an overall RR of 38% (CR 10%, PR 28%). PN was reported in 55% (36/65) pts (23 grade 1, 12 grade 2). One pt with grade 3 PN was discontinued. Other common treatment-associated adverse events reported to date inclu...