Bortezomib induction and maintenance treatment in patients with newly diagnosed multiple myeloma: results of the randomized phase III HOVON-65/ GMMG-HD4 trial.

Purpose: We investigated whether bortezomib during induction and maintenance improves survival in newly diagnosed multiple myeloma (MM).

Patients And Methods: In all, 827 eligible patients with newly diagnosed symptomatic MM were randomly assigned to receive induction therapy with vincristine, doxorubicin, and dexamethasone (VAD) or bortezomib, doxorubicin, and dexamethasone (PAD) followed by high-dose melphalan and autologous stem-cell transplantation. Maintenance consisted of thalidomide 50 mg (VAD) once per day or bortezomib 1.3 mg/m(2) (PAD) once every 2 weeks for 2 years. The primary analysis was progression-free survival (PFS) adjusted for International Staging System (ISS) stage.

Results: Complete response (CR), including near CR, was superior after PAD induction (15% v 31%; P < .001) and bortezomib maintenance (34% v 49%; P < .001). After a median follow-up of 41 months, PFS was superior in the PAD arm (median of 28 months v 35 months; hazard ratio [HR], 0.75; 95% CI, 0.62 to 0.90; P = .002). In multivariate analysis, overall survival (OS) was better in the PAD arm (HR, 0.77; 95% CI, 0.60 to 1.00; P = .049). In high-risk patients presenting with increased creatinine more than 2 mg/dL, bortezomib significantly improved PFS from a median of 13 months to 30 months (HR, 0.45; 95% CI, 0.26 to 0.78; P = .004) and OS from a median of 21 months to 54 months (HR, 0.33; 95% CI, 0.16 to 0.65; P < .001). A benefit was also observed in patients with deletion 17p13 (median PFS, 12 v 22 months; HR, 0.47; 95% CI, 0.26 to 0.86; P = .01; median OS, 24 months v not reached at 54 months; HR, 0.36; 95% CI, 0.18 to 0.74; P = .003).

Conclusion: Bortezomib during induction and maintenance improves CR and achieves superior PFS and OS.