<qa>  How many patients receive escalating doses of bortezomibCohorts of 3-6 patients receive escalating doses of bortezomib until the maximum tolerated dose MTD is determined. The MTD is defined as the dose preceding that at which at least 2 of 6 patients experience dose-limiting toxicity. Once the MTD is determined, an additional cohort of up to 12 patients is treated at the MTD. 