Thalidomide in the treatment of multiple myeloma

Animal models of chemotherapy-induced peripheral neuropathy for hematological malignancies: A review

Chemotherapy is one of the main treatments for hematologic malignancies. However, chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common long-term toxic reactions in chemotherapy, and the occurrence of CIPN affects patients' quality of life and can cause interruption of chemotherapy in severe cases, thus reducing the efficacy of chemotherapy. We currently summarize the existing CIPN animal models, including the characteristics of several common animal models such as bortezomib-induced peripheral neuropathy, vincristine-induced peripheral neuropathy, and oxaliplatin-induced peripheral neuropathy. It was found that CIPN may lead to behavioral, histopathological, and neurophysiological changes inducing peripheral neuropathy. However, the mechanism of CIPN has not been fully elucidated, especially the prevention and treatment protocols need to be improved. Therefore, this review article summarizes the progress of research on CIPN animal models and the possible mechanisms and treatment of CIPN.

The prognostic and predictive value of IKZF1 and IKZF3 expression in T-cells in patients with multiple myeloma

Purpose: While recent studies described the role of IKZF1/3 proteins in multiple myeloma (MM) cells, few have highlighted the significance of IKZF1/3 expression in T-cells. In this study we examine the prognostic and predictive value of IKZF1/3 expression in T-cells in patients with MM stage III. Experimental design: We analysed the IKZF1/3 expression levels in T-cells from 45 MM stage I (MMI) and 50 newly diagnosed MM stage III (MMIII) patients, according to Durie-Salmon staging system, by flow cytometry to examine their prognostic and predictive value. We also combined in vivo observations with in vitro assays to determine the effect of IKZF1/3 expression on the T-cell immunophenotype and anti-tumour T-cell response in 162 MMIII patients. Results: We found that high IKZF3, but not IKZF1, expression in T-cells correlates with superior overall survival in MMIII patients treated with immunomodulatory drugs (thalidomide, lenalidomide and pomalidomide). Moreover, we show that higher IKZF3 expression in T-cells inhibits myeloma-specific T-cell response in vitro and that the immunophenotype of patients with high IKZF3 expression shows features that are contrary to the changes induced by immunomodulatory drugs. Although we observed higher IKZF3 expression levels in T-cells from patients with MMIII compared to MMI, IKZF3 expression was unaffected by the tumour microenvironment. Conclusion: In conclusion, IKZF3 expression in T-cells is a predictive value for clinical outcome in MMIII patients treated with immunomodulatory drugs due to its profound modulation of T-cell functionality.

Impact of pomalidomide therapy in multiple myeloma: a recent survey

Pomalidomide (Pomalyst(®)) is a synthetic compound derived by modifying the chemical structure of thalidomide to improve its potency and reduce its side effects and third drug in the class of immunomodulatory drugs. Pomalidomide is under global development with Celgene Corporation, was approved by the U.S. Food and Drug Administration on February 8, 2013 to treat patients with relapsed and refractory multiple myeloma (MM) who have received at least two prior therapies including bortezomib and lenalidomide. In October 2009, it has found orphan designation for the treatment of relapsed and refractory MM by the EMA, and on August 2013, marketing authorization has issued in Europe by gaining a positive response. It inhibits myeloma cell growth and angiogenesis directly. Pomalidomide is the latest myeloma cell growth inhibitor to be approved in both USA and EU. The predominant side effects are thrombocytopenia, neuropathy, and deep vein thrombosis. Pomalidomide is also being investigated in patients with amyloidosis, prostate cancer, small cell lung cancer, pancreatic cancer, graft-versus-host disease, and Waldenstrom's macroglobulinemia. This article reviews the available information on pomalidomide with respect to its clinical pharmacology, mechanism of action, pharmacokinetics, pharmacodynamics, metabolism, pre-clinical studies, and clinical trials.

Clinical and genetic factors associated with venous thromboembolism in myeloma patients treated with lenalidomide-based regimens

Lenalidomide has significant antimyeloma activity but it is associated with a significant risk of venous thromboembolism (VTE). In this study, we assessed clinical and genetic risk factors that may predispose for VTE in myeloma patients who were treated with lenalidomide-based regimens. We analyzed common clinical and selected genetic factors in 200 consecutive, unselected myeloma patients who were treated with lenalidomide-based regimens in a single institution. Twelve patients (6%) developed a VTE (nine deep venous thrombosis and three pulmonary embolism). All VTEs occurred in patients who were receiving aspirin prophylaxis; no patient who received LMWH or acenocoumarol had a VTE. The frequency of VTEs was 9.4% in previously untreated and 4.5% in previously treated patients. VTEs were more frequent in patients >65 years (8.1% vs. 1.6%) especially among patients receiving aspirin as prophylaxis (10.4% vs. 1.8% for patients ≤65 years). In patients who received prophylaxis with low dose aspirin a single-nucleotide polymorphism in NFκB1 (rs3774968) gene was associated with increased risk of VTE (OR 3.76, 95%CI 1-16, P = 0.051). None of the patients who developed VTEs had common genetic variations that are associated with increased risk of VTEs in the general population, such as FVLeiden and FIIG20210A. Our data indicated that LMWH or vitamin K antagonists (with a target INR 2-3) effectively reduce the risk of VTEs. In patients who received prophylaxis with aspirin genetic variants of genes that are involved directly or indirectly in inflammatory response may be associated with increased risk of VTE.

Role of thalidomide in the treatment of patients with multiple myeloma

The first of the so-called "novel agents" (thalidomide, lenalidomide, and bortezomib), thalidomide has demonstrated activity as a single agent and in combination with other agents in patients with relapsed and/or refractory MM. The combination of melphalan, prednisone, and thalidomide (MPT) has become a standard treatment option for newly diagnosed patients who are ineligible for high-dose chemotherapy with autologous stem cell transplantation (ASCT). For patients intending to undergo ASCT, the combination of thalidomide, dexamethasone and cyclophosphamide can be used as a non-myelosuppressive induction regimen. Treatment with thalidomide is associated with an increased risk of developing peripheral neuropathy, which can be managed with dose reductions and discontinuation, and venous thromboembolism, which warrants thromboprophylaxis. While its adverse event profile may preclude prolonged use as maintenance therapy, thalidomide is an effective and well-tolerated salvage therapy option. Ongoing trials continue to evaluate novel thalidomide-based regimens to further optimize the use of thalidomide in the management of MM.

Clinical study of thalidomide combined with dexamethasone for the treatment of elderly patients with newly diagnosed multiple myeloma

OBJECTIVE

To investigate the relationship between the efficacy and safety of different doses of thalidomide (Thal) plus dexamethasone (Dex) as the initial therapy in elderly patients with newly diagnosed multiple myeloma (MM).

METHODS

Clinical data of 28 elderly patients with newly diagnosed MM who underwent the TD regimen as the initial therapy were analyzed retrospectively. The patients were divided into two groups according to the maximal sustained dose of Thal: lower dose (group A) and higher dose (group B). The overall response rate (ORR), progression free survival (PFS), overall survival (OS), and adverse events (AES) were compared between the two groups.

RESULTS

A total of 28 patients were followed up with a median of 18 months. The ORR was 60.1%. The median response time and PFS were 2.0 and 17.0 months, respectively. The mean sustained dose of Thal in group B was significantly higher than group A (292.9 mg v 180.4 mg, P=0.01). There was no significantly difference in ORR (57.1% v 64.3%, P=1.00) and PFS (9.63months v 17.66 months, P=0.73) between groups A and B. During the follow up, only five patients died (<40%) and, therefore, median OS values were not available. It is estimated, however, that the mean survival time in the two groups was 35.6 and 33.4 months (P>0.05), respectively. All of the patients tolerated the treatment well. The incidence of AES in patients with a grading above 3 in group B was significantly higher than in group A (P=0.033).

CONCLUSIONS

The TD regimen results in a high response rate and manageable AES as the initial therapy in elderly patients with MM. TD should be considered as the front line regimen for the treatment of elderly patients with MM in areas with financial constraints. The clinical response can be achieved at a low dose Thal with minimal toxicity.

Emerging drugs for Waldenström's macroglobulinemia

INTRODUCTION

Waldenström's macroglobulinemia (WM) is a rare but distinct B-cell lymphoproliferative disorder characterized by lymphoplasmacytic bone marrow infiltration and IgM monoclonal paraproteinemia. Alkylators or nucleosides analogs, often in combination with rituximab, are the most commonly used drugs, but WM will relapse and even salvage treatments may fail.

AREAS COVERED

We present recent advances on the treatment of WM, focusing on drugs that are under clinical investigation and for which data indicate promising activity and positive future prospects. Bortezomib is a proteasome inhibitor that eventually becomes a major treatment option for WM. Everolimus and perifosine which target mTOR (mammalian target of rapamycin) and Akt, respectively, of the PI3K/AKT/mTOR pathway showed some activity. Bendamustine, a novel alkylating agent is active, especially in combination with rituximab. Immunomodulatory drugs can act synergistically with rituximab but are toxic. Targeting surface antigens of the lymphoplasmatic cells have shown promising results.

EXPERT OPINION

Combinations of novel drugs with established agents are feasible and increase response rates but whether there will be an increase in the survival of patients with WM needs further investigation. The toxicity profile is an important determinant for the feasibility of these drugs in patients with WM.

Embryopathic effects of thalidomide and its hydrolysis products in rabbit embryo culture: evidence for a prostaglandin H synthase (PHS)-dependent, reactive oxygen species (ROS)-mediated mechanism

Thalidomide (TD) causes birth defects in humans and rabbits via several potential mechanisms, including bioactivation by embryonic prostaglandin H synthase (PHS) enzymes to a reactive intermediate that enhances reactive oxygen species (ROS) formation. We show herein that TD in rabbit embryo culture produces relevant embryopathies, including decreases in head/brain development by 28% and limb bud growth by 71% (P<0.05). Two TD hydrolysis products, 2-phthalimidoglutaramic acid (PGMA) and 2-phthalimidoglutaric acid (PGA), were similarly embryopathic, attenuating otic vesicle (ear) and limb bud formation by up to 36 and 77%, respectively (P<0.05). TD, PGMA, and PGA all increased embryonic DNA oxidation measured as 8-oxoguanine (8-oxoG) by up to 2-fold (P<0.05). Co- or pretreatment with the PHS inhibitors eicosatetraynoic acid (ETYA) or acetylsalicylic acid (ASA), or the free-radical spin trap phenylbutylnitrone (PBN), completely blocked embryonic 8-oxoG formation and/or embryopathies initiated by TD, PGMA, and PGA. This is the first demonstration of limb bud embryopathies initiated by TD, as well as its hydrolysis products, in a mammalian embryo culture model of a species susceptible to TD in vivo, indicating that all likely contribute to TD teratogenicity in vivo, in part through PHS-dependent, ROS-mediated mechanisms.

Thalidomide inhibits activation of caspase-1

Thalidomide is an efficient anti-inflammatory and anti-angiogenic drug, but its therapeutic use is problematic due to a strong teratogenic activity. Nevertheless, thalidomide was approved for the treatment of inflammatory skin diseases and certain types of cancer, and it is extensively tested for several other indications. Recently, we demonstrated that active caspase-1, whose activation is dependent on inflammasome complexes, is required for unconventional protein secretion of proinflammatory cytokines such as IL-1 and of the proangiogenic fibroblast growth factor 2. In this study, we show that pharmacological doses of thalidomide strongly reduced the secretion of both proteins. Thalidomide-treated cells also released less of other leaderless proteins, which require caspase-1 activity for their secretion. In line with these findings, the drug inhibited activation and activity of caspase-1 in cultured cells but not in vitro. The latter finding suggests that the pharmacological activity is exerted by a metabolite of the drug. The anti-inflammatory activity of thalidomide was also mediated via caspase-1 in mice. These findings represent a novel mechanism by which thalidomide exerts its pharmacological activity and suggest that inhibition of the activity of IL-1 might represent a novel strategy to substitute thalidomide.

Thalidomide affects the skeletal system of ovariectomized rats

Apart from having written an inglorious chapter in the history of medicine, thalidomide is currently being intensely studied because of its multidimensional activity. The aim of this study was to examine the effects of thalidomide on the skeletal system in ovariectomized and non-ovariectomized rats. The experiments were carried out with female Wistar rats, divided into eight groups: sham-operated control rats; sham-operated rats receiving thalidomide at doses of 15, 30 or 60 mg/kg, po; ovariectomized control rats; ovariectomized rats receiving thalidomide at doses of 15, 30 or 60 mg/kg, po. The drug was administered for 4 weeks. Body mass gain and the mass of the uterus, liver, spleen and thymus were studied. Macrometric parameters and content of mineral substances, calcium and phosphorus in the femur, tibia and L-4 vertebra and histomorphometric parameters of the femur and tibia were examined. In the femur, the mechanical properties of the whole bone and of the femoral neck were examined. Thalidomide did not affect the skeletal system of the non-ovariectomized rats. Bilateral ovariectomy induced osteoporotic skeletal changes in mature female rats. The effects of thalidomide on the skeletal system of ovariectomized rats depended on the dose used. With a dose of 15 mg/kg, po, thalidomide counteracted some osteoporotic changes induced by estrogen deficiency. With a dose of 60 mg/kg, po, thalidomide intensified the destructive effects of estrogen deficiency on the rat skeletal system.

Initial therapy in multiple myeloma: investigating the new treatment paradigm

The development of three novel chemotherapeutic agents - thalidomide, lenalidomide, and bortezomib - has resulted in a fundamental shift in the management of multiple myeloma. Despite this tremendous advancement, the selection of initial treatment must still be made with a degree of uncertainty as a true standard therapy has yet to be established. Although challenging, the relative abundance of therapeutic options, when taken into consideration with unique patient characteristics, creates the potential for individualization of care.For patients eligible for autologous stem cell transplantation, various combinations of novel agents with dexamethasone or traditional chemotherapy have supplanted the previous standard regimen consisting of vincristine, doxorubicin, and dexamethasone. In elderly patients or others that are deemed ineligible for the transplant procedure, the addition of a novel agent to melphalan-prednisone has demonstrated significant improvements in response rates. Due to the immaturity of the available data, it is perhaps best to regard the era of novel agents with a degree of rational enthusiasm, as the ultimate impact on patient care remains undetermined. Although further research is clearly implicated, recent advancements have resulted in significant progress toward obtaining optimum outcomes in a historically challenging disease.

Role of thalidomide in previously untreated patients with multiple myeloma

Thalidomide represents one of the most relevant therapeutic advances for patients with multiple myeloma over the last 10 years. Despite some toxicities, it has demonstrated significant efficacy in elderly patients, as well as in the setting of younger subjects receiving autologous stem cell transplantation. Here, we report and discuss the clinical results achieved with thalidomide alone or in combination with dexamethasone or other drugs, such as melphalan, cyclophosphamide, doxorubicin and bortezomib, in previously untreated myeloma patients.