Bortezomib vs. dexamethasone in relapsed multiple myeloma: A phase 3 randomized study

6511 Background: Bortezomib (Velcade, Millennium Pharmaceuticals), a novel proteasome inhibitor, is effective in refractory multiple myeloma (MM). For the APEX Study Group we present the interim results of an international, randomized phase 3 study conducted at 95 sites. Methods: Between June 2002 and Oct 2003 669 patients (pt) with relapsed MM previously treated with 1–3 prior therapies were randomized to bortezomib (Vc) (327 pts) 1.3 mg/m2 IV days 1,4,8,11 q 3 weeks for 8 cycles followed by 1.3 mg/m2 IV days 1,8,15,22 q 5weeks for 3 cycles versus dexamethasone (D) (330 pts) 40 mg po days 1–4, 9–12, 17–20 q 5 weeks for 4 cycles followed by 40mg po days 1–4 every 28 days for 3 cycles. The primary endpoint was time to progression (TTP) using EBMT criteria for progressive disease (PD). Secondary endpoints were overall survival (OS), incidence of ≥grade 3 infection and time to skeletal event (TSE). Pt progressing on D were offered Vc on a companion study. Results: Median age was 62 with no apparent differenc...