Once- versus twice-weekly Bortezomib induction therapy with dexamethasone in newly diagnosed multiple myeloma

Outcomes with different administration schedules of bortezomib in bortezomib, lenalidomide and dexamethasone (VRd) as first-line therapy in multiple myeloma

Induction therapy for multiple myeloma with bortezomib (Velcade), lenalidomide (Revlimid), and dexamethasone (d) (VRd) was traditionally administered as bortezomib given twice weekly on a 3 week cycle. A modified schedule of weekly bortezomib has been adopted over time to decrease treatment burden for patients and reduce treatment-emergent neuropathy. This study evaluates the response rates and outcomes with different schedules of bortezomib in VRd administered for first-line treatment for patients with newly diagnosed MM (NDMM). We retrospectively analyzed patients treated with upfront VRd from June 30th 2008 to December 31st 2018, for variations of bortezomib administration. Five hundred and fifty-five (555) NDMM patients met inclusion criteria; median age 63 years and 61% men. Bortezomib was administered twice weekly every 21 days in 43%, once weekly every 21 days in 41% and once weekly every 28 days in 16%. Though peripheral sensory neuropathy was more frequent with twice weekly dosing (P = .002), this group achieved shorter time to best response (P = .01). Weekly every 21-day treatment saw higher VGPR or better rates (P = .02). However, with median follow up time of 37 months (IQR 22-56), we found no difference in PFS or OS among the groups. While small differences in response rates were found among the varying administration schedules of bortezomib administration, there was no significant effect on PFS or OS. Given that VRd remains a first line standard of care option for newly diagnosed MM, in the absence of a large trial comparing bortezomib dosing schedule modifications, these results are helpful in supporting current practices of once weekly administration.

Once-weekly bortezomib had similar effectiveness and lower thrombocytopenia occurrence compared with twice-weekly bortezomib regimen in treating patients with newly diagnosed multiple myeloma in China

The study aims to examine the treatment effect and adverse reactions of patients with newly diagnosed MM receiving different bortezomib-based regimens.This was a retrospective study of patients with newly diagnosed MM and who were treated with bortezomib-based combined chemotherapy at the Department of Hematology of the 2 affiliated hospitals of Wenzhou Medical University between July 2009 and May 2016. Cox proportion hazard multivariate analyses were carried out to assess the differences in treatment effect and adverse events between standard (1.3 mg/m on days 1, 4, 8, 11) and weekly (1.6 mg/m on days 1, 8, 15) cohorts, as well as the differences between intravenous injection and subcutaneous injection therapy. Progression-free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier method and the log-rank test.Among the 117 patients, 78 patients were treated with bortezomib standard therapy and 39 patients were treated with bortezomib weekly therapy (all with intravenous injection). In all patients, the treatment strategy was not independently associated with PFS or OS. The patients in the weekly therapy group had less thrombocytopenia events than those in the standard therapy group. The subcutaneous route had similar treatment effect as the intravenous route, but the incidence of peripheral neuropathy was lower.The once-weekly bortezomib regimen was similar in effectiveness to standard therapy in treating patients with newly diagnosed MM, but the incidence of thrombocytopenia was lower with the weekly regimen compared with the standard regimen.

Proteasome inhibitors in cancer therapy

The ubiquitin proteasome pathway was discovered in the 1980s to be a central component of the cellular protein-degradation machinery with essential functions in homeostasis, which include preventing the accumulation of misfolded or deleterious proteins. Cancer cells produce proteins that promote both cell survival and proliferation, and/or inhibit mechanisms of cell death. This notion set the stage for preclinical testing of proteasome inhibitors as a means to shift this fine equilibrium towards cell death. Since the late 1990s, clinical trials have been conducted for a variety of malignancies, leading to regulatory approvals of proteasome inhibitors to treat multiple myeloma and mantle-cell lymphoma. First-generation and second-generation proteasome inhibitors can elicit deep initial responses in patients with myeloma, for whom these drugs have dramatically improved outcomes, but relapses are frequent and acquired resistance to treatment eventually emerges. In addition, promising preclinical data obtained with proteasome inhibitors in models of solid tumours have not been confirmed in the clinic, indicating the importance of primary resistance. Investigation of the mechanisms of resistance is, therefore, essential to further maximize the utility of this class of drugs in the era of personalized medicine. Herein, we discuss the advances and challenges resulting from the introduction of proteasome inhibitors into the clinic.

Bortezomib-based vs non-bortezomib-based post-transplantation treatment in multiple myeloma patients: a systematic review and meta-analysis of Phase III randomized controlled trials

Objective

To evaluate the efficacy and safety of bortezomib-based vs non-bortezomib-based post-transplantation therapy in patients with multiple myeloma.

Methods

Data of relevant randomized controlled trials assessing the effect of bortezomib as post-transplantation consolidation or maintenance therapy was obtained through a comprehensive search. The outcome measures included response rate, progression-free survival, overall survival, and adverse events (AEs). The hazard ratio (HR), Cochran-Mantel-Haenszel odds ratio (OR), and 95% confidence interval (95% CI) were applied to evaluate the effect of bortezomib in relation to the end points such as progression-free survival, overall survival, response rate, and AEs.

Results

Three randomized controlled trials comprising 1,518 participants were included in this study. Pooled ORs for the rates of overall response, and complete response and near complete response, were 1.85 and 1.75, respectively. Pooled HR for progression-free survival favored bortezomib-based therapy over non-bortezomib-based therapy (0.73, 95% CI: 0.67–0.81), while no statistically significant difference could be found between the two groups regarding the pooled HR for 3-year overall survival. Moreover, incidence rates of overall adverse events and grade 3 and 4 peripheral neuropathy were similar in the bortezomib-based groups and the non-bortezomib-based groups (P=0.12 and P=0.41, respectively). The corresponding cumulative meta-analyses of the rates of overall response rate, complete response and near complete response, and grades 3 and 4 peripheral neuropathy supported the superiority of bortezomib-based maintenance therapy over consolidation therapy.

Conclusion

Bortezomib-based therapy after autologous stem cell transplantation, with tolerable AEs, could obviously improve the response as well as the outcome of multiple myeloma patients, particularly when bortezomib was administered as maintenance therapy.

The proteasome: mechanisms of biology and markers of activity and response to treatment in multiple myeloma

Since the early 1990s, the synthesis and subsequent clinical application of small molecule inhibitors of the ubiquitin proteasome pathway (UPP) has revolutionized the treatment and prognosis of multiple myeloma. In this review, we summarize important aspects of the biology of the UPP with a focus on its structure and key upstream/downstream regulatory components. We then review current knowledge of plasma cell sensitivity to proteasome inhibition and highlight new proteasome inhibitors that have recently entered clinical development. Lastly, we address the putative role of circulating proteasomes as a novel biomarker in multiple myeloma and provide guidance for future clinical trials using proteasome inhibitors.

A Phase I study of arsenic trioxide (Trisenox), ascorbic acid, and bortezomib (Velcade) combination therapy in patients with relapsed/refractory multiple myeloma

PURPOSE

This Phase I study assessed the feasibility of concomitant arsenic trioxide (ATO), ascorbic acid (AA), and bortezomib (Velcade™) (AAV) for patients with relapsed/refractory multiple myeloma.

EXPERIMENTAL DESIGN

ATO (0.25 mg/kg) and AA (1 g) were given with an escalating dose of bortezomib (1 mg/m(2) or 1.3 mg/m(2) IV bolus on days 1 and 8 of a 21-day cycle).

RESULTS

Ten patients (median age 62 years), with a median of 3 prior regimens, were enrolled. Four (40%) patients achieved clinical benefit, with one patient achieving a durable partial response. No formal DLTs were encountered.

CONCLUSION

AAV combination was feasible and demonstrated some benefits in this heavily pretreated population.