Modified HyperCVAD Versus Bortezomib-HyperCAD in Patients With Relapsed/Refractory Multiple Myeloma.

INTRODUCTION: Multiple myeloma (MM) is an incurable plasma cell malignancy, in which aggressive relapses might require salvage cytotoxic infusional chemotherapy. Several clinical trials that reported the efficacy of bortezomib led to institutional practice changes in which vincristine was replaced with bortezomib in the modified hyperCVAD regimen, creating a new treatment regimen, named "bortezomib-hyperCAD." PATIENTS AND METHODS: We retrospectively describe the effectiveness and tolerability of 2 chemotherapy regimens among 33 patients with relapsed and/or refractory MM. Patients who received ≥ 1 cycle of modified hyperCVAD or bortezomib-hyperCAD between 2011 and 2015 were assessed. RESULTS: The median number of cycles administered in each arm was 2. The overall response rate was 40% (6 partial responses) in the modified hyperCVAD group and 44.4% (1 complete response, 1 very good partial response, and 6 partial responses) in the bortezomib-hyperCAD group (Fisher exact P = .80). Median progression-free survival (PFS) and median overall survival (OS) for patients in the modified hyperCVAD group was 6.3 months and 11.1 months, respectively. This was comparable with patients in the bortezomib-hyperCAD group, who had a median PFS of 6.6 months and a median OS of 13.8 months (log rank P = .54 and .66, respectively). There was no statistically significant association between treatment arm and febrile neutropenia, emergency department visits, hospitalizations, or peripheral neuropathy (all Fisher exact P values > .05). CONCLUSION: Overall effectiveness and tolerability outcomes were similar between modified hyperCVAD and bortezomib-hyperCAD, with both regimens showing an impressive response rate among refractory and heavily pretreated patients with relapsed MM.

Small molecule inhibitor screen identifies synergistic activity of the bromodomain inhibitor CPI203 and bortezomib in drug resistant myeloma.

PURPOSE: Despite significant therapeutic progress in multiple myeloma, drug resistance is uniformly inevitable and new treatments are needed. Our aim was to identify novel, efficacious small-molecule combinations for use in drug resistant multiple myeloma. EXPERIMENTAL DESIGN: A panel of 116 small molecule inhibitors was used to screen resistant myeloma cell lines for potential therapeutic targets. Agents found to have enhanced activity in the bortezomib or melphalan resistant myeloma cell lines were investigated further in combination. Synergistic combinations of interest were evaluated in primary patient cells. RESULTS: The overall single-agent drug sensitivity profiles were dramatically different between melphalan and bortezomib resistant cells, however, the bromodomain inhibitor, CPI203, was observed to have enhanced activity in both the bortezomib and melphalan resistant lines compared to their wild-type counterparts. The combination of bortezomib and CPI203 was found to be synergistic in both the bortezomib and melphalan resistant cell lines as well as in a primary multiple myeloma sample from a patient refractory to recent proteasome inhibitor treatment. The CPI203-bortezomib combination led to enhanced apoptosis and anti-proliferative effects. Finally, in contrast to prior reports of synergy between bortezomib and other epigenetic modifying agents, which implicated MYC downregulation or NOXA induction, our analyses suggest that CPI203-bortezomib synergy is independent of these events. CONCLUSION: Our preclinical data supports a role for the clinical investigation of the bromodomain inhibitor CPI203 combined with bortezomib or alkylating agents in resistant multiple myeloma.

The StcE protease contributes to intimate adherence of enterohemorrhagic Escherichia coli O157:H7 to host cells.

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a diarrheal pathogen that causes attaching and effacing (A/E) lesions on intestinal epithelial cells. Strains of the O157 serogroup carry the large virulence plasmid pO157, which encodes the etp type II secretion system that secretes the genetically linked zinc metalloprotease StcE. The Ler regulator controls expression of many genes involved in A/E lesion formation, as well as StcE, suggesting StcE may be important at a similar time during colonization. Our laboratory has previously demonstrated that StcE cleaves C1-esterase inhibitor, a regulator of multiple inflammation pathways. Here we report two new substrates for StcE, mucin 7 and glycoprotein 340, and that purified StcE reduces the viscosity of human saliva. We tested the hypothesis that StcE contributes to intimate adherence of EHEC to host cells by cleavage of glycoproteins from the cell surface. The fluorescent actin stain (FAS) test was used to observe the intimate adherence represented by fluorescently stained bacteria colocalized with regions of bundled actin formed on HEp-2 cells. An E. coli O157:H7 strain with a stcE gene deletion was not affected in its ability to generally adhere to HEp-2 cells, but it did score threefold lower on the FAS test than wild-type or complemented strains. Addition of exogenous recombinant StcE increased intimate adherence of the mutant to wild-type levels. Thus, StcE may help block host clearance of E. coli O157:H7 by destruction of some classes of glycoproteins, and it contributes to intimate adherence of E. coli O157:H7 to the HEp-2 cell surface.