ASCO: Velcade in untreated patients

Abstract No: 7504

Citation: Journal of Clinical Oncology, 2006 ASCO Annual Meeting Proceedings Part I. Vol 24, No. 18S (June 20 Supplement), 2006: 7504

Author(s): K. Anderson, P. Richardson, A. Chanan-Khan, R. Schlossman, N. Munshi, A. Oaklander, L. Heffner, H. Hassoun, D. Avigan, A. Amato

Abstract:

Background: Bortezomib is effective in relapsed and/or refractory MM. This trial evaluated its efficacy and safety as monotherapy in previously untreated MM.

Methods: Pts with untreated, symptomatic MM were eligible, with pts receiving concomitant steroids, platelet count <>9/L, or grade > 2 peripheral neuropathy [PN] excluded. Endpoints included response rate (RR), time to progression, safety, incidence/severity of PN, and effect of dose modifications on PN. Pts received bortezomib 1.3 mg/m² (d1, 4, 8, 11 every 21d) for 8 cycles. Comprehensive neurologic evaluation including electrophysiologic testing [NCS] and skin biopsy was performed in a subset of pts (n = 34).

Results: Sixty-six pts (47% with stage III MM) were treated and 60 pts are evaluable for response, with an overall RR of 38% (CR 10%, PR 28%). PN was reported in 55% (36/65) pts (23 grade 1, 12 grade 2). One pt with grade 3 PN was discontinued. Other common treatment-associated adverse events reported to date include grade 1-2 fatigue in 21% (6/29), and rash in 17% (5/29) pts. Preliminary analysis shows PN improved or resolved in 75% (6/8 pts, with available follow-up data) with dose reduction. At baseline, small-fiber neuropathy (SFN) was seen in 52% (17/33) and large fiber axonal neuropathy (LFN) occurred in 9% (3/34) pts by NCS. SFN worsened in 41% (7/17) pts with baseline SFN. After completion of treatment, new SFN was seen in 33% (8/24) pts and LFN in 17% (4/24) pts by NCS.

Conclusion: Single agent bortezomib is active in newly diagnosed MM pts (CR 10%), has manageable toxicity and offers a steroid-sparing approach. Underlying SFN appears more common in MM than previously appreciated and can also develop during bortezomib therapy, with symptomatic PN improving with dose modification.