Efficacy of bortezomib as first-line treatment for patients with multiple myeloma

Liquid Overlay and Collagen-Based Three-Dimensional Models for In Vitro Investigation of Multiple Myeloma

Multiple myeloma (MM) clones reside in the bone marrow (BM), which plays a role in its survival and development. The interactions between MM and their neighboring mesenchymal stromal cells (MSCs) have been shown to promote MM growth and drug resistance. However, those interactions are often missing or misrepresented in traditional two-dimensional (2D) culture models. Application of novel three-dimensional (3D) models might recapitulate the BM niche more precisely, which will offer new insights into MM progression and survival. Here, we aimed to establish two 3D models, based on MSC spheroids and collagen droplets incorporating both MM cells and MSCs with the goal of replicating the native myeloma context of the BM niche. This approach revealed that although MSCs can spontaneously assemble spheroids with altered metabolic traits, MSC spheroid culture does not support the integration of MM cells. On the contrary, collagen-droplet culture supported the growth of both cell types. In collagen, MSC proliferation was reduced, with the correlating decrease in ATP production and Ki-67 expression, which might resemble in vivo conditions, rather than 2D abundance of nutrients and space. MSCs and MMs were distributed homogenously throughout the collagen droplet, with an apparent CXCL12 expression in MSCs. In addition, the response of MM cells to bortezomib was substantially reduced in collagen, indicating the importance of 3D culture in the investigation of myeloma cell behavior, as drug resistance is one of the most pertinent issues in cancer therapy.

A Nut for Every Bolt: Subunit-Selective Inhibitors of the Immunoproteasome and Their Therapeutic Potential

At the heart of the ubiquitin-proteasome system, the 20S proteasome core particle (CP) breaks down the majority of intracellular proteins tagged for destruction. Thereby, the CP controls many cellular processes including cell cycle progression and cell signalling. Inhibitors of the CP can suppress these essential biological pathways, resulting in cytotoxicity, an effect that is beneficial for the treatment of certain blood cancer patients. During the last decade, several preclinical studies demonstrated that selective inhibition of the immunoproteasome (iCP), one of several CP variants in mammals, suppresses autoimmune diseases without inducing toxic side effects. These promising findings led to the identification of natural and synthetic iCP inhibitors with distinct chemical structures, varying potency and subunit selectivity. This review presents the most prominent iCP inhibitors with respect to possible scientific and medicinal applications, and discloses recent trends towards pan-immunoproteasome reactive inhibitors that cumulated in phase II clinical trials of the lead compound KZR-616 for chronic inflammations.

Clinical Profile of Multiple Myeloma in South India

Background: The incidence of multiple myeloma (MM) is known to be variable according to ethnicity and is increasing rapidly in Asian countries. Because of huge disparities in economy, lack of adequate health-care infrastructure and the lack of access to novel drugs in our country, treatment of multiple myeloma is still a challenge to medical field in India. Methods: This was a descriptive longitudinal study conducted in the medicine and oncology units of a tertiary care hospital in south India. During the one year period of data collection, 37 cases of multiple myeloma were diagnosed, of which 5 cases were excluded. The diagnosis of MM was made based on the International Myeloma Working Group: Criteria for the classification of monoclonal gammopathies, multiple myeloma and related disorders. The clinical and laboratory characteristics, and treatment were studied. Results: The male to female ratio was 1.3:1. The commonest symptoms noticed were fatigue 32 (100%) and bone pain 31 (96.9%). 6 (18.8%) patients had hypercalcemia and 7 (21.9%) patients had elevated serum creatinine levels. 29 (91%) of 32 had lytic lesions in the skull and 27 (84%) had lytic lesions in the spine. One patient expired during the course of the treatment. 20 (64%) of 32 patients had partial response to treatment, 7 (23%) had complete response and 4 (13%) of them had stable disease not responding to treatment. Conclusions: To conclude, the patients with multiple myeloma in the present study had a male preponderance. Most common symptoms noticed were fatigue and bone pain and majority had spine tenderness on examination. The presentation of MM is non-specific and patient can come with varied presentations at onset. The quality of life and survival in MM patients can be improved significantly if there is access to newer therapies.

Good treatment-free survival of monoclonal gammopathy of undetermined significance associated pure red cell aplasia after bortezomib plus dexamethasone

Pure red cell aplasia (PRCA) is a rare syndrome characterized by severe anemia and absence of erythroid precursors. PRCA associated to monoclonal gammopathy of undetermined significance (MGUS) is a scarce condition with less than five cases reported so far. There is no agreement on the treatment of MGUS associated PRCA and treatment- free survival (TFS) is an unmet clinical need. In this report, for the first time, we demonstrated two patients with MGUS associated PRCA obtained rapid remission and maintained TFS after accepting intensive short-term bortezomib plus dexamethasone. The first case was refractory to cyclosporine and prednisone, but achieved complete remission after ten doses of bortezomib. Moreover, he has kept TFS for 12 months. The other case initiated bortezomib plus dexamethasone as soon as making a definite diagnosis. She obtained complete remission after twelve doses of bortezomib and she has maintained a normal level of haemoglobin for 8 months.

Bisphosphonates for delivering drugs to bone

Advances in the design of potential bone-selective drugs for the treatment of various bone-related diseases are creating exciting new directions for multiple unmet medical needs. For bone-related cancers, off-target/non-bone toxicities with current drugs represent a significant barrier to the quality of life of affected patients. For bone infections and osteomyelitis, bacterial biofilms on infected bones limit the efficacy of antibiotics because it is hard to access the bacteria with current approaches. Promising new experimental approaches to therapy, based on bone-targeting of drugs, have been used in animal models of these conditions and demonstrate improved efficacy and safety. The success of these drug-design strategies bodes well for the development of therapies with improved efficacy for the treatment of diseases affecting the skeleton. LINKED ARTICLES: This article is part of a themed issue on The molecular pharmacology of bone and cancer-related bone diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.9/issuetoc.

Boosting Immunity against Multiple Myeloma

Despite the improvement of patient's outcome obtained by the current use of immunomodulatory drugs, proteasome inhibitors or anti-CD38 monoclonal antibodies, multiple myeloma (MM) remains an incurable disease. More recently, the testing in clinical trials of novel drugs such as anti-BCMA CAR-T cells, antibody-drug conjugates or bispecific antibodies broadened the possibility of improving patients' survival. However, thus far, these treatment strategies have not been able to steadily eliminate all malignant cells, and the aim has been to induce a long-term complete response with minimal residual disease (MRD)-negative status. In this sense, approaches that target not only myeloma cells but also the surrounding microenvironment are promising strategies to achieve a sustained MRD negativity with prolonged survival. This review provides an overview of current and future strategies used for immunomodulation of MM focusing on the impact on bone marrow (BM) immunome.

Relapsed/refractory acquired thrombotic thrombocytopenic purpura in a patient with Sjögren syndrome: Case report and review of the literature

RATIONALE

Thrombotic thrombocytopenic purpura (TTP) is a rare, fatal disorder which could be caused by autoimmune diseases. However, TTP secondary to Sjögren syndrome (SS) is extremely rare.

PATIENT CONCERNS

A 47-year- old woman with an 8-year history of SS was admitted due to skin ecchymosis and bleeding gums. Then she gradually developed fever and headache.

DIAGNOSES

Laboratory investigations suggested anemia, thrombocytopenia, increased lactic dehydrogenase, and a disintegrin-like metalloproteinase with thrombospondin motif type 1 member 13 (ADAMTS13) activity deficiency with high inhibitor titers. Acquired TTP was thus diagnosed.

INTERVENTIONS

Plasma exchange (PE) was the first choice for treatment, while glucocorticoid, cyclosporine A (CSA), rituximab, and intravenous immunoglobulin (IVIG) were used simultaneously. Bortezomib, a selective proteasome inhibitor and thereby inducing apoptosis in both B-cells and plasma cells, was added.

OUTCOMES

She was discharged from the hospital and then treated with prednisone of 40 mg/d and hydroxychloroquine. The patient remained in full remission.

LESSONS

We conclude that bortezomib should be considered for patients with TTP refractory to PE, steroids, and rituximab due to its efficacy and relatively favorable side effect profile.

1,2,3,4,6-Penta-O-Galloyl-Beta-D-Glucopyranoside Inhibits Proliferation of Multiple Myeloma Cells Accompanied with Suppression of MYC Expression

Multiple myeloma (MM) still remains an incurable disease, therefore discovery of novel drugs boosts the therapeutics for MM. The natural compound 1,2,3,4,6-Penta-O-galloyl-beta-D-glucopyranoside (PGG) has been shown to exhibit antitumor activities against various cancer cells. Here, we aim to evaluate antitumor effects of PGG on MM cell lines. PGG inhibited the growth of three different MM cell lines in a dose- and time-dependent manner. Cell cycle analysis revealed that PGG treatment caused cell cycle arrest in G1 phase. It also induced apoptosis which was indicated by significant increases of Annexin V positive cells, caspase 3/7 activity, and cleaved caspase 3 expression in PGG treated MM cell. Since MYC is frequently hyperactivated in MM and inhibition of MYC leads to MM cell death. We further demonstrated that PGG decreased MYC expression in protein and mRNA levels and reversed the mRNA expression of MYC target genes such as p21, p27, and cyclin D2. In addition, PGG also reduced protein expression of DEPTOR which is commonly overexpressed in MM. Unexpectedly, PGG antagonized the cytotoxic effect of bortezomib in the combination treatment. However, PGG treatment sensitized MM cells to another proteasome inhibitor MG132 induced cytotoxicity. Moreover, MYC inhibitor JQ1 enhanced the cytotoxic effect of bortezomib on MM cells. Our findings raised concerns about the combinatory use of bortezomib with particular types of chemicals. The evidence also provide useful insights into the combination of MYC and proteasome-inhibitors for MM therapy. Finally, PGG has a therapeutic potential for treatment of MM and further development is mandatory.

Management of Multiple Myeloma and Usage of Bortezomib: Perspective from India and Ukraine

Novel treatment strategies have remarkably improved the multiple myeloma (MM) patients’ survival, with associated increased costs. A joint panel meet of international experts from India and Ukraine was held in New Delhi on May 19, 2016 focusing on MM management, bortezomib role, unmet medical needs, and current challenges. The health-care system for oncology in India is majorly private vs. government-based in Ukraine. In India, electrophoresis, serum-free light chain assays, bone marrow tests, and X-rays are available modes of diagnosis. Despite of the numerous cancer centers and stem cell transplant centers, most patients do not prefer transplant owing to its high-cost and social stigma. Majority of the patients are treated with bortezomib or lenalidomide-based regimens. Most patients buy drug themselves. The expanding generic drugs market is a ray of hope for the affordable drugs. In Ukraine, immuno-fixation, bone marrow analysis, and magnetic resonance imaging are common diagnostic modalities. Due to high cost, only few patients undergo transplant. Bortezomib-based regimens are preferred in most of the patients; however, usage is limited due to high costs and lack of funds. Thalidomide-based regimens are used for maintenance therapy due to affordability. In case of relapsed MM, bortezomib is preferred in triple therapy; however, more affordable option is cyclophosphamide, thalidomide, and dexamethasone (CTD). Issues, such as cost containment, common treatment strategies, enhanced collaboration, and improved health-care access, need immediate attention. High-quality generics access will improve outcomes and support health-care cost containment. Pharmacoeconomic studies and head-to-head trials are warranted to determine the cost-effectiveness and benefit of novel therapies in MM.

Simplified response monitoring criteria for multiple myeloma in patients undergoing therapy with novel agents using computed tomography

INTRODUCTION

Multiple myeloma is a malignant hematological disorder of the mature B-cell lymphocytes originating in the bone marrow. While therapy monitoring is still mainly based on laboratory biomarkers, the additional use of imaging has been advocated due to inaccuracies of serological biomarkers or in a-secretory myelomas. Non-enhanced CT and MRI have similar sensitivities for lesions in yellow marrow-rich bone marrow cavities with a favourable risk and cost-effectiveness profile of CT. Nevertheless, these methods are still limited by frequently high numbers of medullary lesions and its time consumption for proper evaluation.

OBJECTIVE

To establish simplified response criteria by correlating size and CT attenuation changes of medullary multiple myeloma lesions in the appendicular skeleton with the course of lytic bone lesions in the entire skeleton. Furthermore to evaluate these criteria with respect to established hematological myeloma-specific parameters for the prediction of treatment response to bortezomib or lenalidomide.

MATERIALS AND METHODS

Non-enhanced reduced-dose whole-body CT examinations of 78 consecutive patients (43 male, 35 female, mean age 63.69±9.2years) with stage III multiple myeloma were retrospectively re-evaluated. On per patient basis, size and mean CT attenuation of 2-4 representative lesions in the limbs were measured at baseline and at a follow-up after a mean of 8 months. Results were compared with the course of lytical bone lesions as well with that of specific hematological biomarkers. Myeloma response was assessed according to the International Myeloma Working Group (IMWG) uniform response criteria. Testing for correlation between response of medullary lesions (Resp_med) and response of all myeloma manifestations including osteolyses (Resp_total) was performed using the corrected contingency coefficient (C_corr).

RESULTS

The correlation between Resp_med based on length diameter and transverse diameter and Resp_total was perfect (C_corr=1.0; p<0.0001) whereas the correlation based on density was moderate (C_corr=0.54; p<0.0001). The evaluation of simplified response criteria with a measurement of only 2 medullary lesions yielded the best sensitivity and specificity valued for treatment-induced changes for the length diameter evaluation with 94.4%/95.7% for prediction of progressive disease and 78.6%/93.3% for prediction of therapy response. There were no significant differences between patients treated with bortezomib and lenalidomide (p>0.05).

CONCLUSION

Measurements of size of a minimum of two medullary lesions is sufficient for response assessment and correlates very well with the course of lytic bone lesions and that of hematologic parameters.

Systematic chemical and molecular profiling of MLL-rearranged infant acute lymphoblastic leukemia reveals efficacy of romidepsin

To address the poor prognosis of mixed lineage leukemia (MLL)-rearranged infant acute lymphoblastic leukemia (iALL), we generated a panel of cell lines from primary patient samples and investigated cytotoxic responses to contemporary and novel Food and Drug Administration-approved chemotherapeutics. To characterize representation of primary disease within cell lines, molecular features were compared using RNA-sequencing and cytogenetics. High-throughput screening revealed variable efficacy of currently used drugs, however identified consistent efficacy of three novel drug classes: proteasome inhibitors, histone deacetylase inhibitors and cyclin-dependent kinase inhibitors. Gene expression of drug targets was highly reproducible comparing iALL cell lines to matched primary specimens. Histone deacetylase inhibitors, including romidepsin (ROM), enhanced the activity of a key component of iALL therapy, cytarabine (ARAC) in vitro and combined administration of ROM and ARAC to xenografted mice further reduced leukemia burden. Molecular studies showed that ROM reduces expression of cytidine deaminase, an enzyme involved in ARAC deactivation, and enhances the DNA damage-response to ARAC. In conclusion, we present a valuable resource for drug discovery, including the first systematic analysis of transcriptome reproducibility in vitro, and have identified ROM as a promising therapeutic for MLL-rearranged iALL.

Pharmacovigilance of patients with multiple myeloma being treated with bortezomib and/or thalidomide

In order to evaluate the main adverse effects of drug protocols using bortezomib and/or thalidomide for the treatment of multiple myeloma, we conducted a prospective study. Data were collected through interviews, clinical observation, and from hospital records. A total of 59 patients were included. There was a predominance of females, 36 (61%) vs 23 (39%) males, and of whites, 49 (83.1%) vs 10 (16.9%) blacks. Age ranged from 40 to 94 years, with a median of 65 years (SD=11.6). Regarding staging at diagnosis, 27 (45.7%) patients were in stage III-A, with 12 (20.3%) patients having serum creatinine ≥2 mg/dL. The main adverse effects in the bortezomib treatment group (n=40) were: neutropenia (42.5%), diarrhea (47.5%), and peripheral neuropathy in 60% of cases, with no difference between the iv (n=26) and sc (n=14) administration routes (P=0.343). In the group treated with thalidomide (n=19), 31.6% had neutropenia, 47.4% constipation, and 68.4% peripheral neuropathy. Neutropenia was associated with the use of alkylating agents (P=0.038). Of the 3 patients who received bortezomib in combination with thalidomide, only 1 presented peripheral neuropathy (33.3%). Peripheral neuropathy was the main adverse effect of the protocols that used bortezomib or thalidomide, with a higher risk of neutropenia in those using alkylating agents. Improving the identification of adverse effects is critical in multiple myeloma patient care, as the patient shows improvements during treatment, and requires a rational and safe use of medicines.

Signaling mechanisms of bortezomib in TRAF3-deficient mouse B lymphoma and human multiple myeloma cells

Bortezomib, a clinical drug for multiple myeloma (MM) and mantle cell lymphoma, exhibits complex mechanisms of action, which vary depending on the cancer type and the critical genetic alterations of each cancer. Here we investigated the signaling mechanisms of bortezomib in mouse B lymphoma and human MM cells deficient in a new tumor suppressor gene, TRAF3. We found that bortezomib consistently induced up-regulation of the cell cycle inhibitor p21(WAF1) and the pro-apoptotic protein Noxa as well as cleavage of the anti-apoptotic protein Mcl-1. Interestingly, bortezomib induced the activation of NF-κB1 and the accumulation of the oncoprotein c-Myc, but inhibited the activation of NF-κB2. Furthermore, we demonstrated that oridonin (an inhibitor of NF-κB1 and NF-κB2) or AD 198 (a drug targeting c-Myc) drastically potentiated the anti-cancer effects of bortezomib in TRAF3-deficient malignant B cells. Taken together, our findings increase the understanding of the mechanisms of action of bortezomib, which would aid the design of novel bortezomib-based combination therapies. Our results also provide a rationale for clinical evaluation of the combinations of bortezomib and oridonin (or other inhibitors of NF-κB1/2) or AD 198 (or other drugs targeting c-Myc) in the treatment of lymphoma and MM, especially in patients containing TRAF3 deletions or relevant mutations.

Blocking the ZZ domain of sequestosome1/p62 suppresses myeloma growth and osteoclast formation in vitro and induces dramatic bone formation in myeloma-bearing bones in vivo

We reported that p62 (sequestosome 1) serves as a signaling hub in bone marrow stromal cells (BMSC) for the formation of signaling complexes, including NFκB, p38MAPK, and JNK, that are involved in the increased osteoclastogenesis and multiple myeloma (MM) cell growth induced by BMSC that are key contributors to myeloma bone disease (MMBD), and demonstrated that the ZZ-domain of p62 (p62-ZZ) is required for BMSC enhancement of MMBD. We recently identified a novel p62-ZZ inhibitor, XRK3F2, that inhibits MM cell growth and BMSC growth enhancement of human MM cells. In the current study we evaluate the relative specificity of XRK3F2 for p62-ZZ, characterize XRK3F2’s capacity to inhibit growth of primary MM cells and human MM cell lines, and test the in vivo effects of XRK3F2 in the immunocompetent 5TGM1 MM model. We found that XRK3F2 induces dramatic cortical bone formation that is restricted to MM containing bones and blocked the effects and upregulation of TNFα, an OBL differentiation inhibitor that is increased in the MM bone marrow microenvironment and utilizes signaling complexes formed on p62-ZZ, in BMSC. Interestingly, XRK3F2 had no effect on non-MM bearing bone. These results demonstrate that targeting p62 in MM models has profound effects on MMBD.

Characterization of a new small bowel adenocarcinoma cell line and screening of anti-cancer drug against small bowel adenocarcinoma

Small bowel adenocarcinoma (SBA) is a rare, aggressive malignancy with a poor prognosis, and the mechanisms of carcinogenesis in SBA remain unclear. Our aims were to investigate the molecular mechanisms underlying SBA and to identify treatments by establishing and characterizing an SBA cell line and performing anti-cancer drug screening. SIAC1 cells, established from jejunal SBA, showed epithelial characteristics and formed organoids in 3D culture. SIAC1 cells had a heterozygous β-catenin deletion mutation, resulting in a stable β-catenin protein with enhanced Wnt/β-catenin activity. SIAC1 cells lacked MLH1 and MSH6 expression, and target genes such as TGFBR2 and ACVR2 showed frameshift mutations. Among 10 clinical SBA samples, 2 (20%) had interstitial deletions in β-catenin, expression of mismatch repair protein was aberrant in 4 (40%), and heterozygous frameshift mutations of three target genes were found in all 10 samples. On screening assay using 140 compounds, eribulin significantly inhibited SIAC1 cell growth both in vitro and in vivo by inhibition of the Wnt/β-catenin pathway via enhanced degradation of β-catenin. In conclusion, we established an SBA cell line with molecular characteristics similar to those of clinical SBA samples, including β-catenin deletion and mismatch repair protein deficiency, that will be useful for SBA research. Eribulin might be a candidate for SBA treatment due to its inhibitory effect on Wnt/β-catenin signaling.

Proteasome inhibitors in progressive renal diseases

Proteasome (PS) is a sophisticated protein degradation machinery comprising a 20S proteolytic core particle provided with caspase-like, trypsin-like and chymotrypsin-like activities on ubiquitinilated proteins. The products of this selective, complex, controlled and strictly coordinated system play a crucial role in cell cycle progression and apoptosis; activation of transcription factors, cytokines and chemokines; degradation and generation of MHC class I-presented peptides. PS has recently emerged as a promising drug target in cancer therapy, and bortezomib has been approved for refractory multiple myeloma. PS proteolysis is crucial for the degradation of the inhibitory protein IkB of nuclear factor kB (NF-kB), and hence, an interesting field of research has been developed on possible benefits of drugs with anti-PS activity in disease conditions with hyper-expression of NF-kB. PS inhibitors are being adopted in pilot studies in antibody-mediated renal rejection and in AL amyloidosis, with increasing scientific interest in possible applications in lupus, IgA nephropathy, idiopathic nephrotic syndrome and renal fibrosis. The most often used PS inhibitor, bortezomib, has a severe peripheral neurotoxicity, and the search for effective and less toxic PS-targeted drugs is a challenging area also in nephrology.

Bortezomib and IL-12 produce synergetic anti-multiple myeloma effects with reduced toxicity to natural killer cells

The aim of this study was to examine the hypothesis that a combination of proteasome inhibition by bortezomib and immune therapy with interleukin-12 (IL-12) can produce enhanced antitumor efficacy relative to the effects of either of these agents alone. A mouse xenograft model of myeloma was developed. The mice were randomly divided into saline control (NS), IL-12 (0.4 µg/animal; intraperitoneal), bortezomib (0.75 mg/kg; intravenous), and bortezomib+IL-12 groups. Effects of treatments on tumor growth were assessed by before and after treatment comparisons and group comparisons. The effects of various treatments on the number of peripheral blood lymphocytes and natural killer (NK) cells were assessed by complete blood count and flow cytometry analysis. The cell-killing function of NK cells in splenocytes was evaluated using the lactate dehydrogenase release assay. IL-12 treatment alone produced a mild decrease in tumor volume compared with control (P>0.05). Bortezomib alone resulted in substantial inhibition of tumor growth at varying time points, reaching ~65 and ~60% reduction in tumor volume after 15 and 21 days of therapy, respectively. At the same time points, the combination therapy produced ~75 and ~84% decreases in tumor growth, respectively, which were significantly greater than the reduction produced by bortezomib monotherapy. Tumors resumed growth upon termination of bortezomib treatment at 2 weeks, although the tumor volume was still significantly smaller than that in the time-matched NS and IL-12 animals. This rebound of tumor growth was completely prevented with the combination therapy, and tumor volume continued to decrease throughout the time course. The percentage and total number of NK cells were significantly decreased after bortezomib monotherapy and combination therapy; however, they remained unaltered after IL-12 treatment compared with no treatment. Further, combination therapy significantly restored the bortezomib-induced functional impairment of the cell-killing capability of NK cells, relative to bortezomib alone. We conclude that the bortezomib-IL-12 combination therapy offers superior antitumor efficacy over monotherapy with either bortezomib or IL-12 in a mouse model of myeloma. Restoration of bortezomib-induced functional impairment of NK cells by IL-12 may be a mechanism for the synergetic effects of the two agents. Therefore, a combination of the two agents may represent a more rational therapeutic approach for myeloma.

Light chain multiple myeloma, clinic features, responses to therapy and survival in a long-term study

Background

We intended to investigate the long-term clinical characteristics, responses to therapy and survival in patients with lightchain multiple myeloma (MM).

Methods

Ninety-six patients were enrolled into the study. There were 42 κ-chain MM patients and 54 λ-chain MM patients. All the patients werestage III in the Durie-Salmonstaging system. Among them, 66 patients received Velcade (bortezomib) treatment and the other 30 did not.

Results

The main symptoms of these patients included bone pain (77.1%), weakness and fatigue (12.5%), foamy urine (8.3%) and extramedullaryplasmocytomas (33.3%). The overall response rate (ORR) was 95.5% in patients treated with Velcade and 60%in the patients without. The median survival times were 23 months in patients treated with Velcade and 12 months in patients without. The median time of progression-free survival (PFS) was nine months in patients treated with Velcade and five months in patients without. The one-year PFS and two-year PFS were 37% and 25%, 27% and 9% for patients treated with Velcade, or without, respectively. The three-year overall survival (OS) and five-year OS were 33% and 24%, 28% and 9% for patients treated with Velcade, or without, respectively. There was no significance in OS between the two groups (P = 0.335). But there was significant difference in PFS between the two groups (P = 0.036).

Conclusions

Our long-term study demonstrated that patients with lightchain myeloma appeared to have more aggressive disease courses and poor outcomes, which could be improved by treatment with Velcade.

Bortezomib for chronic relapsing thrombotic thrombocytopenic purpura: a case report

BACKGROUND

Acquired thrombotic thrombocytopenic purpura (TTP) is an autoimmune disorder characterized by a severe deficiency of ADAMTS13 activity. Although therapeutic plasma exchange (PLEX) is the standard of care, 30% to 50% patients develop exacerbation or relapse, requiring immunomodulatory agents. Of these agents, glucocorticoids, rituximab, and cyclosporine A are the most frequently used.

CASE REPORT

We report a case of chronic relapsing TTP in a patient who had eight relapses over a 14-year period. After her seventh relapse, the patient demonstrated only partial response to glucocorticoids, two courses of rituximab, and cyclophosphamide. The eighth relapse occurred 58 days after her last PLEX and subsequent to this she received a course of bortezomib (Velcade, Millennium Pharmaceuticals, Inc.). After treatment with bortezomib the patient demonstrated a complete response with a progressive increase in ADAMTS13 activity from less than 5% to 22% accompanied by undetectable inhibitor, and she has remained PLEX free for more than 169 days.

CONCLUSION

Bortezomib may serve as an adjunct treatment in patients with acquired TTP who exhibit an incomplete response or are refractory to conventional management.

Tetravalent antibody-scTRAIL fusion proteins with improved properties

We applied the immunoglobulin E (IgE) heavy-chain domain 2 (EHD2) as the covalently linked homodimerization module to generate antibody-scTRAIL fusion proteins. By fusing a humanized single-chain fragment variable (scFv) directed against EGFR to the N-terminus of the EHD2 and a single-chain derivative of TRAIL (scTRAIL) to the C-terminus of the EHD2, we produced a dimeric, tetravalent fusion protein. The fusion protein retained its binding activity for EGFR and TRAIL receptors. In vitro, the targeted antibody-scTRAIL fusion protein exhibited an approximately 8- to 18-fold increased cytotoxic activity compared with the untargeted EHD2-scTRAIL fusion protein. This resulted in increased antitumor activity in a subcutaneous Colo205 xenograft tumor murine model. In summary, the scFv-EHD2-scTRAIL fusion protein combines target cell selectivity with an increased TRAIL activity leading to improved antitumor activities.