Bortezomib and melphalan as a conditioning regimen for autologous stem cell transplantation in multiple myeloma

Bortezomib and high-dose melphalan conditioning regimen in frontline multiple myeloma: an IFM randomized phase 3 study

High-dose melphalan (HDM) and transplantation are recommended for eligible patients with multiple myeloma. No other conditioning regimen has proven to be more effective and/or safer. We previously reported in a phase 2 study that bortezomib can safely and effectively be combined with HDM (Bor-HDM), with a 32% complete response (CR) rate after transplantation. These data supported a randomized phase 3 trial. Randomization was stratified according to risk and response to induction: 300 patients were enrolled, and 154 were allocated to the experimental arm (ie, arm A) with bortezomib (1 mg/m2 intravenously [IV]) on days -6, -3, +1, and +4 and melphalan (200 mg/m2 IV) on day -2. The control arm (ie, arm B) consisted of HDM alone (200 mg/m2 IV). There were no differences in stringent CR + CR rates at day 60 posttransplant (primary end point): 22.1% in arm A vs 20.5% in arm B (P = .844). There were also no differences in undetectable minimum residual disease rates: 41.3% vs 39.4% (P = .864). Median progression-free survival was 34.0 months for arm A vs 29.6 months for arm B (adjusted HR, 0.82; 95% CI, 0.61-1.13; P = .244). The estimated 3-year overall survival was 89.5% in both arms (hazard ratio, 1.28; 95% CI, 0.62-2.64; P = .374). Sixty-nine serious adverse events occurred in 18.7% of Bor-HDM-treated patients (vs 13.1% in HDM-treated patients). The proportion of grade 3/4 AEs was similar within the 2 groups (72.0% vs 73.1%), mainly (as expected) blood and gastrointestinal disorders; 4% of patients reported grade 3/4 or painful peripheral neuropathy in arm A (vs 1.5% in arm B). In this randomized phase 3 study, a conditioning regimen with Bor-HDM did not improve efficacy end points or outcomes compared with HDM alone. The original trial was registered at www.clinicaltrials.gov as #NCT02197221.

Expression profile and biological function of miR-455-5p in colorectal carcinoma

Underexpression of microRNA-455-5p (miR-455-5p) in medullary thyroid carcinoma, melanoma, gastric cancer and additional cancer types has been reported, which may be associated with carcinoma development. The present study aimed to evaluate the expression profile and biological role of miR-455-5p in colorectal carcinoma. Carcinoma tissues and adjacent tissue specimens from 40 patients with colorectal cancer were randomly collected. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was conducted to detect the expression levels of miR-455-5p in colorectal carcinoma and adjacent normal tissues. The biological effects of miR-455-5p on selected colorectal cancer cells were assessed using bromodeoxyuridine assays, wound healing migration assays and flow cytometry. Bioinformatics analysis was implemented to predict the potential target genes of miR-455-5p in colorectal cancer. The expression levels of target genes were further validated by RT-qPCR and western blot analysis of the mRNA and protein levels. The results of the experiments demonstrated that miR-455-5p expression was downregulated in colorectal cancer tissues compared with adjacent normal tissues. In colorectal cancer cells (SW-480, HT-29 and HCT-116), miR-455-5p was observed to inhibit cell proliferation and migration while promoting cell apoptosis. Bioinformatics analysis predicted that the oncogene phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) was one of the top ranked target genes of miR-455-5p in colorectal cancer cells. This association was validated by RT-qPCR and western blotting. In vivo studies revealed that the expression level of miR-455-5p was significantly downregulated in human colorectal cancer. Further in vitro studies suggested that miR-455-5p may prevent the development of colorectal cancer by downregulating the oncogene PIK3R1. It was concluded that miR-455-5p may target and downregulate PIK3R1 in colorectal cancer.

Comparison of conditioning regimen toxicities among autologous stem cell transplantation eligible multiple myeloma patients: High-dose melphalan versus high-dose melphalan and bortezomib

Background Autologous hematopoietic stem cell transplantation (AHSCT) remains the standard of care for younger patients with multiple myeloma (MM). Currently, high-dose melphalan (HDM) is recommended as conditioning regimen before AHSCT. Preclinical data suggest that combining bortezomib and melphalan has synergistic effect against multiple myeloma cells. Bortezomib and HDM (Bor-HDM) combination as conditioning regimen has been investigated by many other investigators. Objective In this retrospective study, we aimed to compare transplant-related toxicities and hematologic recovery of HDM and Bor-HDM conditioning regimens. Method We retrospectively evaluated hematologic recovery and toxicity profile in patients with MM who received AHSCT with either HDM ( n = 114) or Bor-HDM ( n = 53) conditioning regimen. Results Nonhematologic toxicities were comparable between HDM and Bor-HDM conditioning regimen, except mucositis and diarrhea being more frequent in the Bor-HDM group. Neutrophil and platelet engraftment time and duration of hospital stay were significantly shorter for HDM regimen. Conclusions In this retrospective analysis, we observed engraftment kinetics and duration of hospitalization were significantly worse in Bor-HDM conditioning regimen with manageable toxicities. Randomized studies are needed to further compare Bor- HDM regimen to HDM in terms of response rates, toxicities, and transplant-related mortality.

Adverse Metaphase Cytogenetics Can Be Overcome by Adding Bortezomib and Thalidomide to Fractionated Melphalan Transplants

Purpose: To determine whether a reduction in the intensity of Total Therapy (TT) reduces toxicity and maintains efficacy.Experimental Design: A total of 289 patients with gene expression profiling (GEP70)-defined low-risk multiple myeloma were randomized between a standard arm (TT4-S) and a light arm (TT4-L). TT4-L employed one instead of two inductions and consolidations. To compensate for potential loss of efficacy of TT4-L, bortezomib and thalidomide were added to fractionated melphalan 50 mg/m²/d for 4 days.Results: Grade ≥3 toxicities and treatment-related mortalities were not reduced in TT4-L. Complete response (CR) rates were virtually identical (P = 0.2; TT4-S, 59%; TT4-L, 61% at 2 years), although CR duration was superior with TT4-S (P = 0.05; TT4-S, 87%; TT4-L, 81% at 2 years). With a median follow-up of 4.5 years, there was no difference in overall survival (OS) and progression-free survival (PFS). Whereas metaphase cytogenetic abnormalities (CAs) tended to be an adverse feature in TT4-S, as with predecessor TT trials, the reverse applied to TT4-L. Employing historical TT3a as training and TT3b as test set, 51 gene probes (GEP51) significantly differentiated the presence and absence of CA (q < 0.0001), seven of which function in DNA replication, recombination, and repair. Applying the GEP51 model to clinical outcomes, OS and PFS were significantly inferior with GEP51/CA in TT4-S; such a difference was not observed in TT4-L.Conclusions: We identified a prognostic CA-linked GEP51 signature, the adversity of which could be overcome by potentially synergizing anti-multiple myeloma effects of melphalan and bortezomib. These exploratory findings require confirmation in a prospective randomized trial. Clin Cancer Res; 23(11); 2665-72. ©2016 AACR.

Multiple myeloma

Autologous stem cell transplant (ASCT) remains an integral part of the treatment strategy for many myeloma patients. The role of allogeneic stem cell transplant continues to be defined. There is increasing evidence that posttransplant maintenance therapy can significantly improve outcomes. It is predicted that with more routine use of cytogenetic and gene expression profiling in the future, we will be better able to identify those subgroups of patients who are expected to benefit most from early versus late versus no ASCT and those who will benefit from allogeneic stem cell transplant.

Bortezomib, dexamethasone, and high-dose melphalan as conditioning for stem cell transplantation in young Japanese multiple myeloma patients: a pilot study

Autologous stem cell transplantation is recommended for younger patients with newly diagnosed multiple myeloma because of a high complete response rate and better survival. Bortezomib shows a synergistic effect with melphalan and has no prolonged hematologic toxicity, and the complete response rate after autologous stem cell transplantation is improved by combining bortezomib with melphalan for conditioning. Twelve patients were enrolled in a phase 2 study between February and November 2010, receiving bortezomib (1 mg/m(2) × 4), dexamethasone (20 mg/body × 8), and melphalan (200 mg/m(2)) for conditioning. No toxic deaths occurred. Neutrophils (absolute neutrophil count ≥0.5 × 10(9)/L) and platelets (≥20 × 10(9)/L without transfusion) recovered after a median of 5 days (range: 4-6 days) and 7 days (range: 4-8 days), respectively. No patient was admitted for exacerbation of peripheral neuropathy. Four patients obtained a stringent complete response, three patients obtained a complete response, and three patients showed a very good partial response. These results suggest that this conditioning regimen is safe and promising for young Japanese multiple myeloma patients. A prospective multicenter trial of this regimen combined with suitable induction and consolidation therapy should be performed.

Bortezomib with high dose melphalan conditioning for autologous transplant is safe and effective in patients with heavily pretreated and high risk multiple myeloma

There are no uniform guidelines for the treatment of relapsed refractory multiple myeloma (MM), however autologous stem cell transplant (SCT) remains an important treatment modality. Although a number of modifications to high dose melphalan (HDM) conditioning have been evaluated, improvement in overall survival has not been demonstrated. We now report our experience of 23 patients with heavily pretreated MM (median lines of prior treatment 3 [range 1-6]) who underwent SCT with bortezomib and high dose melphalan (BorHDM). The overall response rate (at least partial response [PR]) was 65.4%. Median overall survival (OS) was 24 months. A subset of patients who relapsed ≤ 12 months after initial SCT had significantly longer OS after BorHDM SCT compared to a historical control group who received HDM conditioning alone (14.5 vs. 8 months, respectively, p = 0.011). In summary, BorHDM SCT produces very good response rates in heavily pretreated MM, and may increase survival in the salvage setting in patients who relapse early after initial SCT. We propose that its use should be explored as part of a tandem approach in patients undergoing initial SCT who are at high risk of early relapse.

The future of proteasome inhibitors in relapsed/refractory multiple myeloma

The ubiquitin-proteasome pathway was first validated as a target for cancer therapy with the demonstration of the activity of the boronic acid proteasome inhibitor (PI) bortezomib (Velcade) against relapsed and relapsed/refractory multiple myeloma. Another generation of PIs is now entering the clinical arena; this includes intravenous agents such as carfilzomib, CEP-18770, and marizomib, and oral drugs such as MLN9708 and ONX 0912. These novel agents will likely first be used for patients with disease that has either relapsed or been refractory to prior therapy (including bortezomib-based regimens) because of their ability to overcome drug resistance, or will be used in patients who are intolerant of, or are not candidates for bortezomib. Preclinical studies also suggest that PIs may act synergistically with other conventional and novel agents, or even with one another in rationally designed combination regimens. In addition, other inhibitors that selectively target only the immunoproteasome and not the constitutive proteasome, as well as agents that bind to noncatalytic proteasome subunits, are emerging as potential drug candidates. Taken together, it seems likely that we have only begun to appreciate the full potential of inhibition of the proteasome. This article extrapolates our current knowledge into an algorithm for the future use of these inhibitors against multiple myeloma.