A135 Bortezomib International Observational Study in Multiple Myeloma: Baseline Characteristics

analysis, we included patients with follow-up period of 12 weeks or death. Results: 489 patients (56% male, median age, 64 years) were enrolled as of August 29, 2008. In the year before bortezomib therapy, PN was seen in 127 (26%) patients. At baseline, just before initiation of bortezomib therapy, 110 (22%) patients had PN due to previous MM treatment. Most PN cases at baseline were grade 1. Sixty-seven percent of patients started bortezomib in combination with other therapies such as dexamethasone, thalidomide, lenalidomide, and/or prednisone. Of 253 patients with no PN at baseline and 12-week follow-up, newonset PN was largely grade 1 (21%) or grade 2 (16%). Grade 3 and 4 PN developed in 24 (9%) and 4 (2%) patients, respectively. Of the 82 patients with PN at baseline and 12-week follow-up, 42 (51%) had PN improvement or resolution at any time during bortezomib therapy, 15(18%) had PN worsening, and 25 (30%) patients had no change in PN. Conclusion: In this international observational study PN was observed in 1 of 4 patients prior to bortezomib therapy. Consistent with clinical trial data, most cases with new-onset PN during bortezomib therapy were mild or moderate in severity. Despite the presence of baseline PN, more than half of these patients had improvement or stabilization of PN during bortezomib therapy.