Outcomes of multiple myeloma patients receiving bortezomib, lenalidomide, and carfilzomib.

New classes of drugs including the proteasome inhibitors (PI) bortezomib and, more recently, carfilzomib and the immunomodulatory agent lenalidomide have shown improved outcomes for multiple myeloma (MM) patients during the past decade. However, most of the studies reporting outcomes for patients receiving these drugs have relied on older data sets derived from large institutions that included patients not receiving their treatment at those facilities and represented only those eligible for clinical trials or were from sites where treatment options were limited. We have analyzed data from 258 MM patients who have received treatment with at least one of three agents: bortezomib, carfilzomib, and lenalidomide in a single clinic specializing in MM with respect to their responses and other outcomes to treatment regimens including these agents. Response rates were similar between these three drugs when used for the first time and again during subsequent treatment regimens. As expected, the clinical benefit rates (CBRs) were better for patients receiving their first treatment when compared to their use in subsequent treatment regimens. The CBRs were similar during their 2nd, 3rd, and 4th treatments containing these agents. Many patients refractory to these agents showed responses to regimens containing these same drugs when used in different combinations. In addition, patients refractory to one PI often responded to the other PI. The results of this study demonstrate that novel agents can be used repeatedly in novel combinations with significant clinical benefit for patients with MM.

Serum B-cell maturation antigen: a novel biomarker to predict outcomes for multiple myeloma patients.

B-cell maturation antigen is expressed on plasma cells. In this study, we have identified serum B-cell maturation antigen as a novel biomarker that can monitor and predict outcomes for multiple myeloma patients. Compared to healthy donors, patients with multiple myeloma showed elevated serum B-cell maturation antigen levels (P<0.0001). Serum B-cell maturation antigen levels correlated with the proportion of plasma cells in bone marrow biopsies (Spearman's rho = 0.710; P<0.001), clinical status (complete response vs partial response, P=0.0374; complete response vs progressive disease, P<0.0001), and tracked with changes in M-protein levels. Among patients with non-secretory disease, serum B-cell maturation antigen levels correlated with bone marrow plasma cell levels and findings from positron emission tomography scans. Kaplan-Meier analysis demonstrated that serum B-cell maturation antigen levels above the median levels were predictive of a shorter progression-free survival (P=0.0006) and overall survival (P=0.0108) among multiple myeloma patients (n=243). Specifically, patients with serum B-cell maturation antigen levels above the median level at the time of starting front-line (P=0.0043) or a new salvage therapy (P=0.0044) were found to have shorter progression-free survival. Importantly, serum B-cell maturation antigen levels did not show any dependence on renal function and maintained independent significance when tested against other known prognostic markers for multiple myeloma such as age, serum ß2 microglobulin, hemoglobin, and bone disease. These data identify serum B-cell maturation antigen as a new biomarker to manage multiple myeloma patients.

Improved clinical outcomes for multiple myeloma patients treated at a single specialty clinic.

Despite recent advances made in its treatment, multiple myeloma (MM) remains an incurable B cell malignancy. Thus, the objective for treating these patients is to prolong overall survival (OS) and preserve patients' quality of life. We have analyzed data from 264 consecutive MM patients who had their initial visit between July 1, 2004 and December 1, 2014 and have received treatment in a single clinic specializing in MM. We determined their progression-free survival (PFS, OS, and 5-year OS). The PFS for frontline (n = 165 treatments), salvage (n = 980), and all treatments (n = 1145) were 13.9, 4.6, and 5.5 months, respectively. The median OS of all patients was 98 months with a 5-year survival of 74%. The results of this study show a marked improvement in OS for unselected MM patients compared with historical data. There were no significant differences in OS between patients with different International Staging System (ISS) stages. Younger patients (<65 years old) showed a longer OS. The results of this study should help physicians predict outcomes for MM patients and be encouraging for patients with this B cell malignancy.

Levels of uninvolved immunoglobulins predict clinical status and progression-free survival for multiple myeloma patients.

Multiple myeloma (MM) is characterized by the enhanced production of the same monoclonal immunoglobulin (M-Ig or M protein). Techniques such as serum protein electrophoresis and nephelometry are routinely used to quantify levels of this protein in the serum of MM patients. However, these methods are not without their shortcomings and problems accurately quantifying M proteins remain. Precise quantification of the types and levels of M-Ig present is critical to monitoring patient response to therapy. In this study, we investigated the ability of the HevyLite (HLC) immunoassay to correlate with clinical status based on levels of involved and uninvolved antibodies. In our cohort of MM patients, we observed that significantly higher ratios and greater differences of involved HLC levels compared to uninvolved HLC levels correlated with a worse clinical status. Similarly, higher absolute levels of involved HLC antibodies and lower levels of uninvolved HLC antibodies also correlated with a worse clinical status and a shorter progression-free survival. These findings suggest that the HLC assay is a useful and a promising tool for determining the clinical status and survival time for patients with multiple myeloma.

A novel angiogenesis model for screening anti-angiogenic compounds: the chorioallantoic membrane/feather bud assay.

Enhanced angiogenesis is a hallmark of solid tumors and hematological malignancies. Anti-angiogenic therapeutic approaches have recently been shown to be effective for the treatment of certain cancers. Endothelial cells migrating to tumors provide them with new blood vessels that are critical for their growth and survival. We have developed a novel and rapid method to evaluate the anti-angiogenic activity of new agents consisting of a combined chorioallantoic membrane (CAM) and feather bud (FB) assay. Unlike previous assays, this new assay assesses the effects of drugs on the ability of tissues to attract and develop their own blood supply. The CAM already has a well-developed vascular network that is capable of providing blood vessels to the non-vascularized FB, allowing for this tissue to develop feathers. As a result, the exposure of the FB to drugs for 2 days followed by attachment to the CAM for 4 days allows evaluation of the compound's ability to impact blood vessel and feather formation within the CAM-attached FB tissue. Feather formation is determined as well as expression of endothelial cell genes and proteins analyzed. Using agents with known anti-angiogenic activity including fumagillin, minocycline, zoledronic acid, doxorubicin and agents lacking anti-angiogenic activity such as melphalan, we have shown that the CAM/FB assay can accurately and rapidly assess the ability of agents to prevent blood vessel and feather development within non-vascularized tissues.

Pleiotrophin produced by multiple myeloma induces transdifferentiation of monocytes into vascular endothelial cells: a novel mechanism of tumor-induced vasculogenesis.

Enhanced angiogenesis is a hallmark of cancer. Pleiotrophin (PTN) is an angiogenic factor that is produced by many different human cancers and stimulates tumor blood vessel formation when it is expressed in malignant cancer cells. Recent studies show that monocytes may give rise to vascular endothelium. In these studies, we show that PTN combined with macrophage colony-stimulating factor (M-CSF) induces expression of vascular endothelial cell (VEC) genes and proteins in human monocyte cell lines and monocytes from human peripheral blood (PB). Monocytes induce VEC gene expression and develop tube-like structures when they are exposed to serum or cultured with bone marrow (BM) from patients with multiple myeloma (MM) that express PTN, effects specifically blocked with antiPTN antibodies. When coinjected with human MM cells into severe combined immunodeficient (SCID) mice, green fluorescent protein (GFP)-marked human monocytes were found incorporated into tumor blood vessels and expressed human VEC protein markers and genes that were blocked by anti-PTN antibody. Our results suggest that vasculogenesis in human MM may develop from tumoral production of PTN, which orchestrates the transdifferentiation of monocytes into VECs.