Weekly Bortezomib with or without Glucocorticosteroids Is Effective in Patients with Relapsed or Refractory Multiple Myeloma.

Well-tolerated, effective and simple regimens are warranted in multiple myeloma (MM). Bortezomib is an active novel agent for MM therapy. A phase III randomized trial in patients with relapsed and refractory MM demonstrates bortezomib to be superior to dexamethasone in time to progression and overall survival. The FDA approved schedule of bortezomib (days 1, 4, 8 and 11 infusion of a 21-day cycle) is rather inconvenient. We investigated the synergy between weekly bortezomib and glucocorticosteroids in order to the frequency of patients’ clinic visits.

Methods: Patients with relapsed or refractory MM referred to Indiana University Cancer Center were offered bortezomib 1.3 mg/m² by intravenous push and methylprednisone 500–2000 mg by intravenous infusion over 30 minutes. Treatments were given on days 1, 8 and 15 of 28-day cycles. Therapy was maintained as long as subjects’ diseases were responding and side effects were minimal. Both efficacy and tolerability of the regimen were evaluated.

Results: Thirty patients were treated on the protocol. Twenty six received bortezomib in combination with methylprednisone, while 4 received single agent bortezomib. Patient age ranged from 50–79 years (median 62); there were 15 females and 15 males. Twenty-one patients (70%) had prior high dose chemotherapy and stem cell transplantation, including 2 with prior allogeneic stem cell transplantation. Thirteen patients were in third relapse or higher. The response was evaluable in 28 patients. Eighteen patients achieved clinical response (60 %), including 1 (3%) complete response, 1 (3%) near complete response, and 16 (53%) partial response. Five (17%) had stable disease, and 5 (17%) had progression. The median number of treatment cycles was 5 (range 2 to 12). Among responders, the median number of cycles given to achieve the best response was 3 cycles (range 1–8 cycles). Major adverse effects included neuropathy (2 grade III), gastrointestinal side effects (1 grade III) and congestive heart failure (1 grade III). The updated time to progression and overall survival will be presented at the meeting.

Conclusion: Weekly bortezomib with or without steroid is a convenient and efficacious therapy for patients with heavily pretreated relapsed and refractory MM and should be further explored in a larger patient cohort.