Weekly bortezomib/methylprednisolone is effective and well tolerated in relapsed multiple myeloma

The standard schedule of bortezomib requires frequent infusions and is often associated with dose-dependent, adverse effects such as sensory neuropathy and thrombocytopenia. Because of the known additive effect between bortezomib and glucocorticoid, we explored weekly bortezomib/methylprednisolone in patients with relapsed multiple myeloma.

Twenty-nine patients were treated at Indiana University with bortezomib (1.3 mg/m2) and methylprednisolone (500-2000 mg) intravenously on days 1, 8, and 15 of 28-day cycles. Response was evaluated using the Blade criteria. Twenty-one patients (70%) had previous stem cell transplantation, and 13 were in third relapse or higher.

A response was observed in 18 patients (62%): 1 (3%) complete response, 1 (3%) near complete response, and 16 (55%) partial responses. Six (21%) had stable disease, and 5 (17%) had disease progression. The median time to progression, which was defined from the beginning of therapy until progression, was 6.6 months (95% confidence interval, 6.4-9.2 months). The median number of treatment cycles was 6 (range, 2-12 cycles). The median overall survival was 20.2 months (lower 95% confidence interval, 13.1 months). The most common toxicities were fatigue and gastrointestinal disturbances. Grade >or= 3 adverse effects included neuropathy (2 grade 3), gastrointestinal side effects (1 grade 3), and congestive heart failure (1 grade 3).

The weekly bortezomib/methylprednisolone regimen was well tolerated and yielded a response rate comparable with the standard schedule of bortezomib alone. Our data support further investigation of this regimen in larger patient cohorts.