Purpose: To characterize efficacy and safety of bortezomib-based versus nonbortezomib-based induction regimens through an integrated analysis of data from phase III studies in transplantation-eligible patients with previously untreated myeloma.
Patients and methods: Patient-level data from the IFM 2005-01 (bortezomib-dexamethasone v vincristine-doxorubicin-dexamethasone [VAD] induction), HOVON-65/GMMG-HD4 (bortezomib-doxorubicin-dexamethasone v VAD), and PETHEMA GEM05MENOS65 (bortezomib-thalidomide-dexamethasone v thalidomide-dexamethasone) studies were pooled in an integrated analysis of efficacy and safety. Study-level data from the GIMEMA MM-BO2005 study (bortezomib-thalidomide-dexamethasone v thalidomide-dexamethasone) supplemented the integrated patient-level analysis. Key efficacy end points were post-transplantation complete plus near-complete response (CR+nCR) rate and progression-free survival (PFS).
Results: Patient-level data for 1,572 patients (bortezomib-based induction, n = 787; nonbortezomib-based induction, n = 785) were included. Post-transplantation CR+nCR rate was significantly higher following bortezomib-based versus nonbortezomib-based induction (38% v 24%; odds ratio, 2.05; P < .001); the benefit remained similar (pooled odds ratio, 1.96) when GIMEMA MM-BO2005 data were included. Median PFS was 35.9 months versus 28.6 months with bortezomib-based versus nonbortezomib-based induction, respectively (hazard ratio, 0.75; P < .001); 3-year overall survival (OS) rates were 79.7% and 74.7%, respectively (hazard ratio for OS, 0.81; P = .0402). Median duration of induction treatment was 11 weeks in both treatment groups. Rates of peripheral neuropathy during induction were 34% versus 17% (grade ≥ 3, 6% v 1%). Overall, 3% and 4% of patients died during bortezomib-based and nonbortezomib-based induction, respectively.
Conclusion: Bortezomib-based induction results in significant improvements in response and PFS/OS compared with nonbortezomib-based induction and is generally well tolerated, with a higher rate of peripheral neuropathy but no apparent increase in risk of death during induction.
Trial registration: ClinicalTrials.gov NCT00200681 NCT00461747 NCT01134484.