Phase II study of bendamustine, bortezomib and dexamethasone (BBD) in the first-line treatment of patients with multiple myeloma who are not candidates for high dose chemotherapy.

The combination of bendamustine, bortezomib and dexamethasone (BBD) was evaluated as a first-line therapy for multiple myeloma. The original treatment regimen of bendamustine 80 mg/m2 , days 1, 4; bortezomib 1·3 mg/m2 , days 1, 4, 8, 11; dexamethasone 40 mg, days 1, 2, 3, 4 on a 28-day cycle (up to 8 cycles) was efficacious but determined relatively toxic in an interim analysis. The regimen was amended to bendamustine 80 mg/m2 , days 1, 2; bortezomib 1·3 mg/m2 , days 1, 8, 15; dexamethasone 20 mg, days 1, 2, 8, 9, 15, 16 every 28 days (up to 8 cycles), then maintenance 1·3 mg/m2 IV bortezomib every 2 weeks. Fifty-nine patients were enrolled. Primary endpoint was complete response (CR) rate. The original schema was given for a median of 7 cycles (range 1-8); modified schema was given for a median of 8 cycles (range 1-8) plus maintenance. Overall response was 91%, CR was 9%. Median follow-up was 19·1 months; median progression-free survival was 11·1 months and 18·9 months on the original and modified regimens, respectively. The most common Grade 3/4 adverse events were fatigue and neuropathy. The combination of BBD is tolerable and efficacious in this patient population. Modifications to decrease intensity but increase duration translated to better outcomes.