Retrospective matched-pairs analysis of bortezomib plus dexamethasone versus bortezomib monotherapy in relapsed multiple myeloma

Bortezomib-dexamethasone is widely used for relapsed myeloma in routine clinical practice, but comparative data versus single-agent bortezomib are lacking. This retrospective analysis compared second-line treatment with bortezomib- dexamethasone and bortezomib using 109 propensity score-matched pairs of patients treated in three clinical trials: MMY-2045, APEX, and DOXIL-MMY-3001. Propensity scores were estimated using logistic regression analyses incorporating 13 clinical variables related to drug exposure or clinical outcome. Patients received intravenous bortezomib 1.3 mg/m2 on days 1, 4, 8, and 11, in 21-day cycles, alone or with oral dexamethasone 20 mg on the days of/after bortezomib dosing. Median bortezomib cumulative dose (27.02 and 28.60 mg/m2) and treatment duration (19.6 and 17.6 weeks) were similar with bortezomib-dexamethasone and bortezomib, respectively. The overall response rate was higher (75% vs. 41%; odds ratio=3.467; P<0.001), and median time-to-progression (13.6 vs. 7.0 months; hazard ratio [HR]=0.394; P=0.003) and progression-free survival (11.9 vs. 6.4 months; HR=0.595; P=0.051) were longer with bortezomib-dexamethasone versus bortezomib, respectively. Rates of anygrade adverse events, most common grade 3 or higher adverse events, and discontinuations due to adverse events appeared similar between the groups. Two patients per group died of treatment-related adverse events. These data indicate the potential benefit of bortezomib-dexamethasone compared with single-agent bortezomib at first relapse in myeloma. The MMY-2045, APEX, and DOXIL-MMY-3001 clinical trials were registered at, respectively, clinicaltrials.gov identifier: 00908232, 00048230, and 00103506

Bortezomib plus melphalan and prednisone in elderly untreated patients with multiple myeloma: updated time-to-events results and prognostic factors for time to progression

New treatment options offering enhanced activity in elderly, newly diagnosed patients with multiple myeloma are required. One strategy is to combine melphalan and prednisone with novel agents. We previously reported an 89% response rate, including 32% complete responses and 11% near complete responses, in our phase 1/2 study of bortezomib plus melphalan and prednisone (VMP) in 60 newly diagnosed multiple myeloma patients with a median age of 75 years. Here, we report updated time-to-events data and the impact of poor prognosis factors on outcome

Myeloma cell dynamics in response to Treatment supports a model of hierarchical differentiation and clonal evolution

[Purpose]: Since the pioneering work of Salmon and Durie, quantitative measures of tumor burden in multiple myeloma have been used to make clinical predictions and model tumor growth. However, such quantitative analyses have not yet been performed on large datasets from trials using modern chemotherapy regimens. [Experimental Design]: We analyzed a large set of tumor response data from three randomized controlled trials of bortezomib-based chemotherapy regimens (total sample size n = 1,469 patients) to establish and validate a novel mathematical model of multiple myeloma cell dynamics. [Results]: Treatment dynamics in newly diagnosed patients were most consistent with a model postulating two tumor cell subpopulations, >progenitor cells> and >differentiated cells.> Differential treatment responses were observed with significant tumoricidal effects on differentiated cells and less clear effects on progenitor cells. We validated this model using a second trial of newly diagnosed patients and a third trial of refractory patients. When applying our model to data of relapsed patients, we found that a hybrid model incorporatingboth a differentiation hierarchy and clonal evolution best explains the response patterns. [Conclusions]: The clinical data, together with mathematical modeling, suggest that bortezomib-based therapy exerts a selection pressure on myeloma cells that can shape the disease phenotype, thereby generating further inter-patient variability. This model may be a useful tool for improving our understanding of disease biology and the response to chemotherapy regimens.The authors acknowledge the support from the Dana-Farber Cancer Institute Physical Sciences-Oncology Center (U54CA193461).Peer Reviewe

Bortezomib Induction and Maintenance Treatment Improves Survival In Patients With Newly Diagnosed Multiple Myeloma: Extended Follow-Up Of The HOVON-65/GMMG-HD4 Trial

Background We investigated if bortezomib during induction and maintenance improves survival in newly diagnosed Multiple Myeloma (MM).\r\n\r\nMethods 827 eligible patients with newly diagnosed symptomatic MM were randomized to receive induction therapy with VAD (vincristine, doxorubicin, dexamethasone; n=414) or PAD (bortezomib, doxorubicin, dexamethasone; n=413) followed by high-dose melphalan (HDM) and autologous stem cell transplant (ASCT). Maintenance consisted of daily thalidomide 50 mg (VAD) or 2-weekly bortezomib 1.3 mg/m2 i.v. (PAD) for 2 years. The primary analysis was progression-free survival (PFS) adjusted for ISS stage. We here report long-term results of this trial ( P. Sonneveld et al., J Clin Oncol 2012;30:2946-2955 ).\r\n\r\nResults The number of eligible patients, patient characteristics and disease characteristics are similar to those reported before. The response rates during protocol treatment have improved slightly since all patients have now completed treatment: CR+nCR 49% vs 35%, VGPR 26% vs 21% and ≥PR 91% vs 83% (PAD vs VAD).\r\n\r\nAfter a median follow-up of 67 months, 111 of patients treated with VAD and 131 of patients treated with PAD were progression-free and alive. Progression-free survival (PFS) defined as time from randomization until progression, relapse or death (censored at date of alloSCT, if applicable), was superior with PAD when adjusted for ISS, (HR=0.78, 95% CI [0.66-0.91], P=.002) and in multivariate analysis (HR=0.76 (95% CI [0.64-0.90], P=.001). For the secondary endpoint overall survival (OS) the PAD arm was superior when adjusted for ISS (HR=0.80, 95% CI [0.65-1.00], P=.047) as well as in multivariate analysis (HR=0.78, 95% CI [0.63-0.97], P=.027). Landmark analysis from start of maintenance for PFS did not show a significant difference between Thalidomide and Bortezomib maintenance, however, for OS the PAD arm was superior (P=.035) (HR=0.71, 95% CI [0.52-0.98]). Subgroup analysis performed on patients with renal failure at presentation (serum creatinine ≥2 mg/dL; 45 VAD, 36 PAD) showed that the PAD arm was significantly superior for PFS (HR=0.44, 95% CI [0.26-0.75], P=.003) and OS (HR=0.38, 95% CI [0.21-0.69],

Sequence analysis of β-subunit genes of the 20S proteasome in patients with relapsed multiple myeloma treated with bortezomib or dexamethasone

Variations within proteasome β (PSMB) genes, which encode the β subunits of the 20S proteasome