Immunomodulation by thalidomide and thalidomide analogues

Immunomodulatory Agents with Antivascular Activity in the Treatment of Non-Small Cell Lung Cancer: Focus on TLR9 Agonists, IMiDs and NGR-TNF

Standard treatments for nonsmall cell lung cancer (NSCLC), such as surgery, chemotherapy, and radiotherapy, often lead to disappointing results. Unfortunately, also the various immunotherapeutic approaches so far tested have not produced satisfactory results to be widely applied in the clinical practice. However, the recent development of new immunomodulatory agents may open promising therapeutic options. This paper focuses on PF3512676, lenalidomide, and NGR-TNF, that is, drugs belonging to three different classes of immunomodulatory agents, that are also capable to affect tumor blood vessels with different mechanisms, and discusses the potential role of such agents in NSCLC treatment strategy.

Effect of immunoglobulin therapy on the rate of infections in multiple myeloma patients undergoing autologous stem cell transplantation or treated with immunomodulatory agents

Multiple myeloma (MM) is associated with a significant risk of infection due to immune dysfunction. Infections are a major cause of morbidity and mortality in MM patients. There are few data available regarding the prevalence of infection in MM patients, especially in conjunction with newer generations of immunomodulatory drugs (thalidomide, bortezomib, lenalidomide) or post autologous stem cell transplantation (ASCT). Intravenous immunoglobulin (IVIG) has been used successfully to reduce infection rates in the stable phase of MM, with limited data in other stages.

We retrospectively analyzed 47 patients with MM from March 2006 to June 2009 at our institution. All patients received thalidomide and steroid therapy for at least 6 months. Nine patients received bortezomib and 11 lenalidomide subsequent to thalidomide, because of disease progression, and 22 patients underwent ASCT. The median age was 64 years (range 37–86), with a female–to-male ratio of 18:29. The median residual-serum IgG-level at time of infection was 3.2 g/L, IgA 0.3 g/L and IgM 0.2 g/L. Most patients suffered from recurrent moderate to severe bacterial infections, including the ASCT group. Fifteen patients suffered from different degrees of viral infections.

All patients except 3 received IVIG therapy with a significant decline of the rate of infection thereafter (p<001). Our analysis shows that patients with MM treated with the new immunomodulatory drugs in conjunction with steroids are at significant increased risk of infection. Employing IVIG therapy appears to be an effective strategy to prevent infection in this cohort of patients. Further studies to confirm these findings are warranted.

Thalidomide attenuates nitric oxide-driven angiogenesis by interacting with soluble guanylyl cyclase

BACKGROUND AND PURPOSE

Nitric oxide (NO) promotes angiogenesis by activating endothelial cells. Thalidomide arrests angiogenesis by interacting with the NO pathway, but its putative targets are not known. Here, we have attempted to identify these targets.

EXPERIMENTAL APPROACH

Cell-based angiogenesis assays (wound healing of monolayers and tube formation in ECV304, EAhy926 and bovine arterial endothelial cells), along with ex vivo and in vivo angiogenesis assays, were used to explore interactions between thalidomide and NO. We also carried out in silico homology modelling and docking studies to elucidate possible molecular interactions of thalidomide and soluble guanylyl cyclase (sGC).

KEY RESULTS

Thalidomide inhibited pro-angiogenic functions in endothelial cell cultures, whereas 8-bromo-cGMP, sildenafil (a phosphodiesterase inhibitor) or a NO donor [sodium nitroprusside (SNP)] increased these functions. The inhibitory effects of thalidomide were reversed by adding 8-bromo-cGMP or sildenafil, but not by SNP. Immunoassays showed a concentration-dependent decrease of cGMP in endothelial cells with thalidomide, without affecting the expression level of sGC protein. These results suggested that thalidomide inhibited the activity of sGC. Molecular modelling and docking experiments revealed that thalidomide could interact with the catalytic domain of sGC, which would explain the inhibitory effects of thalidomide on NO-dependent angiogenesis.

CONCLUSION AND IMPLICATIONS

Our results showed that thalidomide interacted with sGC, suppressing cGMP levels in endothelial cells, thus exerting its anti-angiogenic effects. These results could lead to the formulation of thalidomide-based drugs to curb angiogenesis by targeting sGC.

Caloric restriction shortens lifespan through an increase in lipid peroxidation, inflammation and apoptosis in the G93A mouse, an animal model of ALS

Caloric restriction (CR) extends lifespan through a reduction in oxidative stress, delays the onset of morbidity and prolongs lifespan. We previously reported that long-term CR hastened clinical onset, disease progression and shortened lifespan, while transiently improving motor performance in G93A mice, a model of amyotrophic lateral sclerosis (ALS) that shows increased free radical production. To investigate the long-term CR-induced pathology in G93A mice, we assessed the mitochondrial bioenergetic efficiency and oxidative capacity (CS--citrate synthase content and activity, cytochrome c oxidase--COX activity and protein content of COX subunit-I and IV and UCP3-uncoupling protein 3), oxidative damage (MDA--malondialdehyde and PC--protein carbonyls), antioxidant enzyme capacity (Mn-SOD, Cu/Zn-SOD and catalase), inflammation (TNF-alpha), stress response (Hsp70) and markers of apoptosis (Bax, Bcl-2, caspase 9, cleaved caspase 9) in their skeletal muscle. At age 40 days, G93A mice were divided into two groups: Ad libitum (AL; n = 14; 7 females) or CR (n = 13; 6 females), with a diet equal to 60% of AL. COX/CS enzyme activity was lower in CR vs. AL male quadriceps (35%), despite a 2.3-fold higher COX-IV/CS protein content. UCP3 was higher in CR vs. AL females only. MnSOD and Cu/Zn-SOD were higher in CR vs. AL mice and CR vs. AL females. MDA was higher (83%) in CR vs. AL red gastrocnemius. Conversely, PC was lower in CR vs. AL red (62%) and white (30%) gastrocnemius. TNF-alpha was higher (52%) in CR vs. AL mice and Hsp70 was lower (62%) in CR vs. AL quadriceps. Bax was higher in CR vs. AL mice (41%) and CR vs. AL females (52%). Catalase, Bcl-2 and caspases did not differ. We conclude that CR increases lipid peroxidation, inflammation and apoptosis, while decreasing mitochondrial bioenergetic efficiency, protein oxidation and stress response in G93A mice.

Mechanism of action of immunomodulatory drugs (IMiDS) in multiple myeloma

Immunomodulatory drugs (IMiDs) are thalidomide analogues, which possess pleiotropic anti-myeloma properties including immune-modulation, anti-angiogenic, anti-inflammatory and anti-proliferative effects. Their development was facilitated by an improved understanding in myeloma (MM) biology and initiated a profound shift in the therapeutic approach towards MM. Despite the diverse effects of IMiDs in vitro, the relative contribution of each effect towards their ultimate anti-MM activity is still unclear. Based on in vitro data, it appears that anti-proliferative effects and downregulation of crucial cytokines are their most important anti-MM attributes. Although the co-stimulatory effects on T and NK cells have been heralded as a unique and important property of IMiDs towards enhancing anti-MM immune activity, these in vitro effects have yet to be firmly corroborated in vivo. Much is yet to be elucidated regarding the complex interplay of immunomodulatory cytokines that occurs in vivo, which ultimately dictates the net effects of IMiDs in MM-the understanding of which is necessary to facilitate optimal manipulation of these drugs in future MM management.

The ratio between CD4 + and CD8 + cells in the peripheral blood of patients with hematological malignancies is not altered by thalidomide

Thalidomide is thought to have anti-angiogenic and immunomodulatory properties, including suppression of tumor necrosis factor-alpha, effects on interleukins and interferons, down-regulation of some cell adhesion molecules, and changes in the proportion of lymphocyte subsets. It is unclear whether the clinical response to thalidomide in patients with multiple myeloma (MM), idiopathic myelofibrosis (IM), and myelodysplastic syndromes (MDS) is related to its ability to inhibit angiogenesis or its immunomodulatory effects. We examined the effect of thalidomide on T-lymphocyte subsets in 18 patients with MDS, 6 patients with MM, 4 patients with IM, and 3 patients with angioimmunoblastic lymphoma (AILD). These patients had either a relapse or progressive disease following cytotoxic chemotherapy including high-dose chemotherapy with autologous stem cell support. Thalidomide was first administered at 100 mg/day p.o. and increased to 400 mg/day. T-lymphocyte subsets (CD4+, CD8+) were measured by fluorescence-activated cell sorter (FACS) before and during treatment with thalidomide. Twenty-six of 31 patients responded to thalidomide, most of them achieving partial remission. The median concentration of CD4+ cells was 443/microl, the median of CD8+ cells was 359/microl (CD3 992/microl). In our cohort, no significant changes in absolute numbers or proportions of CD3+ (P = 0.12), CD4+ (P = 0.668), or CD8+ (P = 0.143) cells were observed following the treatment with thalidomide. Although the CD4/CD8 ratio declined from 1.6 to 1.0 during 3 months of thalidomide treatment, this had no statistical significance (P = 0.1). Our findings show that an effect of thalidomide on the T lymphocytes studied is unlikely to be of major importance for the clinical effects.

Targeted therapies in multiple myeloma

Increasing knowledge of the biology of multiple myeloma led the way for the development of novel drugs that have changed the management of the disease. New treatments target not only to the malignant plasma cell but also target the interactions of myeloma cells with their microenvironment. Several preclinical studies have identified potential targets and drugs are developed that act on pathways crucial for myeloma cell survival, proliferation, migration and drug resistance. The identification of active agents in the laboratory is followed by rationally designed clinical studies that validate these drugs, either as single agents or in combinations with other active drugs. These novel agents may be either small molecules or monoclonal antibodies targeting receptors, kinase activity of receptors or key molecules within critical pathways, intracellular maintenance mechanisms and immune modulation.

Treatment of MDS: something old, something new, something borrowed

As opposed to the treatment landscape for myelodysplastic syndromes (MDS) two decades ago, potential therapies now abound for the treatment of lower-risk and higher-risk populations. In lower-risk patients, decision tools can be used to determine the likelihood of response to erythropoiesis stimulating agents (ESAs), which have demonstrated survival advantages in retrospective studies in patients with MDS, and whether these patients should be treated initially with ESAs or non-growth factor ("active") therapies. Lenalidomide has shown good activity in transfusion-dependent patients with the del(5q) cytogenetic abnormality and modest activity in other lower-risk patients. In higher-risk patients, the DNA methyltransferase inhibitors produce complete and partial responses in 20% to 30% of patients, and for the first time, the MDS drug azacitidine has demonstrated a survival advantage when compared with conventional therapies. Newer therapies stimulate platelet production and target novel pathways, while a panoply of combination studies are underway or recently completed and that likely represent the next frontier in MDS therapy.

Immunomodulatory drugs Revlimid (lenalidomide) and CC-4047 induce apoptosis of both hematological and solid tumor cells through NK cell activation

Revlimid (Lenalidomide, CC-5013) and CC-4047 are IMiDs immunomodulatory drugs that have been described as having immunomodulatory properties and anti-tumor activity. Here we report proapoptotic effects of CC-5013 and CC-4047 on tumor cells in a co-culture model of PBMC and tumor cells. CC-5013 and CC-4047 enhanced PBMC activity leading to tumor cell apoptosis in K562/PBMC co-culture model. We also demonstrate that the natural killer (NK) cell population of PBMC was essential in inducing K562 apoptosis. Increases of NK and natural killer T (NKT) cell populations by CC-5013 and CC-4047 was observed along with modulation of NK cell CD56 adhesion marker. In addition, our data indicate that NK activation by CC-4047 was dependent on other cell types of PBMC. We expanded the application of K562/PBMC co-culture model to other hematological and solid tumors. In Raji/PBMC co-culture model, CC-5013 and CC-4047 dose-dependently augmented tumor cell apoptosis. Pre-treatment of Raji cells with Rituximab further enhanced apoptosis induced by CC-5013 or CC-4047-treated PBMC. Moreover, CC-5013 and CC-4047 significantly increased PC-3 prostate cancer cell apoptosis in PC-3/PBMC co-culture, either as single agent or in combination with Docetaxel. Together, the results reveal that co-culture models are suitable cellular systems to assess anti-tumor activities of these compounds. Our findings support clinical evaluation of CC-5013 and CC-4047 in relapsed NHL with Rituximab and in prostate cancer with Docetaxel.

Relationship of treatment-related cytopenias and response to lenalidomide in patients with lower-risk myelodysplastic syndromes

PURPOSE

Patients with myelodysplastic syndromes (MDS) often require treatment with growth factors (GFs) or non-GF therapies. One non-GF drug, lenalidomide, is particularly effective at achieving transfusion independence (TI) in patients with lower-risk MDS with the del(5q) cytogenetic abnormality. However, approximately half of del(5q) patients and one quarter of non-del(5q) patients treated with lenalidomide experience significant cytopenias. Lenalidomide-induced cytopenias occurring early in treatment may serve as a surrogate marker of clonal suppression and, therefore, may be predictive of a TI response.

PATIENTS AND METHODS

We analyzed 362 low-risk, transfusion-dependent patients with MDS, with or without the del(5q) abnormality, enrolled in two phase II studies (MDS-003 and MDS-002) to determine whether treatment-related cytopenias are correlated with lenalidomide response. Cytopenias were assessed during the first 8 weeks of therapy, and response was defined as TI; response predictors were explored in univariate and multivariate analyses.

RESULTS

Among patients with del(5q), 70% of those whose platelet count decreased by > or = 50% achieved TI, as compared with 42% of those whose platelet count remained stable or declined by less than 50% (P = .01). Among patients without baseline neutropenia, 82% of those whose absolute neutrophil count (ANC) decreased by > or = 75% achieved TI, as compared with 51% whose ANC remained stable or decreased by less than 75% (P = .02). These relationships were consistent in multivariate analyses. No relationship between the development of cytopenias and response could be established for lower-risk patients with MDS without del(5q).

CONCLUSION

These findings support the hypothesis that a direct cytotoxic effect of lenalidomide specific to the del(5q) clone may be indicative of a TI response.

Treatment of plasma cell dyscrasias with lenalidomide

Lenalidomide is an immunomodulatory drug, structurally related to thalidomide, with pleiotropic activity including antiangiogenic and antineoplastic properties. It is the product of advances in our understanding of the biology of myeloma cells, their interactions with the microenvironment and of the underlying molecular pathways. In preclinical and clinical studies, lenalidomide was more potent and less toxic than thalidomide. Subsequent phase II and III studies confirmed the activity of lenalidomide either as a single agent or in combination with dexamethasone in relapsed or refractory myeloma patients, whereas combinations with chemotherapy induce high response rates and durable remissions. Lenalidomide has been used successfully as an upfront treatment either with high or low dose dexamethasone or with melphalan and prednisone, resulting in high overall response and complete response rates and excellent 1-year survival. Lenalidomide causes less neuropathy than thalidomide; however, the risk of thromboembolism is high, especially in patients treated with lenalidomide and steroids. In this review, we summarize the mechanisms of action, toxicity and clinical activity, and the current role of lenalidomide in patients with multiple myeloma or other related plasma cell disorders.

Syntheses of immunomodulating androstanes and stigmastanes: Comparison of their TNF-α inhibitory activity

In a previous work our group showed that some synthetic stigmastanes may play a role in immune-mediated inflammation. In this paper we report the syntheses of a series of new steroidal compounds derived from dehydroepiandrosterone and stigmasterol, and the evaluation of their in vitro inhibitory activity of the TNF-alpha production by macrophages. A preliminary qualitative structure-activity relationship was established.

Immunomodulatory drugs in the treatment of myelodysplastic syndromes

PURPOSE OF REVIEW

The aim of this article is to discuss the proposed mechanisms of action, clinical trial data, and clinical implications for use of the immunomodulatory drugs in the treatment of myelodysplastic syndrome.

RECENT FINDINGS

The immunomodulatory drugs are a novel, nonteratogenic class of thalidomide analogues that are more potent and less toxic than the parent compound. Lenalidomide, a second generation immunomodulatory drug, has shown substantial remitting activity in myelodysplastic syndrome that is karyotype-dependent. Its biologic effects include T-cell co-stimulation, promotion of erythropoiesis, angiogenesis inhibition, and modulation of apoptosis. Results from the MDS-003 multicenter deletion 5q registration study show that lenalidomide suppresses the deletion 5q clone, and in higher risk myelodysplastic syndrome patients, may also alter the natural history of disease. Lenalidomide was approved by the US Food and Drug Administration for the treatment of International Prognostic Scoring System low or intermediate-1 risk myelodysplastic syndrome patients with chromosome 5q deletion. The most common adverse events with lenalidomide therapy are neutropenia and thrombocytopenia, the frequency of which is highest in patients with deletion 5q, in whom early clonal suppression is expected. Combination strategies are now in progress, which may improve the therapeutic potential of the immunomodulatory drugs.

SUMMARY

The immunomodulatory drugs show exciting erythropoietic activity in myelodysplastic syndrome that is karyotype-dependent.

The myelodysplastic syndromes

The myelodysplastic syndrome(s) (MDS), bone marrow stem cell malignancies that share pathogenetic overlap with acute myeloid leukemia, are characterized by peripheral blood cytopenias and, in more advanced subtypes, varied degrees of maturation arrest. Premature apoptosis of bone marrow cellular elements contributes to ineffective hematopoiesis, which is exacerbated by stromal production of inflammatory cytokines. Abrogation of the effects of these cytokines represents an area of active clinical research, particularly in the treatment of low-risk MDS. In high-risk MDS, the activation of oncogenes and the inactivation of tumor suppressor genes predominate over inhibitory cytokines as proliferation predominates over apoptosis. Agents such as thalidomide, lenalidomide and the hypomethylating drugs 5-azacytidine and decitabine have shown promising efficacy and tolerability in clinical trials, and may represent a springboard for future treatment combinations.

Immunomodulation in myelodysplastic syndromes

The myelodysplastic syndromes (MDS) - bone-marrow stem-cell malignancies that share pathogenetic overlap with acute myeloid leukemia - are characterized by peripheral-blood cytopenias and, in more advanced subtypes, varied degrees of maturation arrest. Premature apoptosis of bone-marrow cellular elements contributes to ineffective hematopoiesis, which is exacerbated by stromal production of inflammatory cytokines. Abrogation of the effects of these cytokines represents an area of active clinical research, particularly in the treatment of low-risk MDS. Agents such as thalidomide, lenalidomide, and infliximab have shown promising efficacy and tolerability in clinical trials, and may represent a springboard for future treatment combinations.

Thalidomide attenuates the development of fibrosis during post-infarction myocardial remodelling in rats

BACKGROUND

Inflammation plays a pathogenic role in the development of heart failure (HF). The aim of this study was to examine the effect of treatment with the immunomodulating drug thalidomide in a rat model for post-myocardial infarction (MI) HF.

METHODS

Rats were subjected to MI by left coronary artery ligation or sham-operated. Seven days after surgical intervention rats were randomised to treatment with thalidomide or vehicle for 8 weeks.

RESULTS

Our main findings were: (i) thalidomide treatment did not affect cardiac function or the hypertrophic response, as determined by haemodynamic measurements and heart chamber weights, respectively. (ii) HF rats treated with thalidomide had a minor reduction in septum and relative wall thickness (p<0.05), indicating an anti-remodelling effect. (iii) Thalidomide appeared to have immunostimulatory effects on the myocardium as evident by increased MIP-1alpha gene expression (p<0.05). (iv) Treating HF rats with thalidomide reduced myocardial collagen content, as assessed by markedly decreased levels of hydroxyproline ( approximately 40% reduction; p<0.05), accompanied by lower TGF-beta(1) gene expression (p<0.05).

CONCLUSION

Although thalidomide had no effect on cardiac function, our results suggest that intervention with thalidomide may have beneficial effects in post-MI HF by attenuating collagen accumulation and development of myocardial fibrosis.

Drug insight: novel small molecules and drugs for immunosuppression

Gastrointestinal diseases can result from the inadequate or excessive response of the immune system to self or innocuous antigens. Moreover, the physiologic activation of the immune system against non-self antigens is a major clinical problem in liver organ transplantation. At present, many drugs are available that suppress the activation of the immune system, although most of the currently used immunosuppressive drugs lack specificity in terms of their molecular targets and, therefore, have the potential to generate numerous side effects. The advances that have been made in understanding the molecular events that underlie the activation of the immune system have led to the development of a new generation of 'small molecules' that are endowed with immunosuppressive properties and can serve as immunomodulatory agents. Among these new small molecules, inhibitors of Janus kinase 3, p21-Rac1 and p38 mitogen-activated protein kinase represent the most innovative approach to immunosuppression, and could be a promising alternative to current immunosuppressive therapies. Here, we report on the progress that has been made in the development of small molecules in the field of gastroenterology.

Development of new CoMFA and CoMSIA 3D-QSAR models for anti-inflammatory phthalimide-containing TNFα modulators

In the present study, we describe a new 3D-QSAR analysis of 42 previously reported thalidomide analogues, with the ability to modulate the pro-inflammatory cytokine TNFalpha, by using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Three statistically significant models were obtained. The best resulting CoMFA and CoMSIA models have conventional r(2) values of 0.996 and 0.983, respectively. The cross-validated q(2) values are 0.869 and 0.868, respectively. The analysis of CoMFA and CoMSIA contour maps provided insight into the possible sites for structural modification of the thalidomide analogues for better activity and reduced toxicity.

The neutropenia induced by the thalidomide analogue CC-4047 in patients with multiple myeloma is associated with an increased percentage of neutrophils bearing CD64

A major limitation to the treatment of multiple myeloma by the thalidomide analogue CC-4047 (Actimid) is the development of a severe neutropenia. We investigated the hypothesis that this effect may have been due to CC-4047 enhancing the removal of neutrophils from the circulation by altering the expression of surface adhesion molecules required for endothelial binding, by binding to platelets, or by enhancing apoptosis. Flow cytometric analysis was used to examine the expression of neutrophil surface molecules, platelet binding and apoptosis in whole blood samples from 19 patients with multiple myeloma who were assigned to receive either 1, 2, 5 or 10 mg of CC-4047 every other day (e.o.d.) for 28 days. CC-4047 induced dose-related decreases in neutrophil numbers and increases in the percentage of CD64-positive neutrophils, but had little, or no effect on the expression of CD11b, CD62L or CD162, neutrophil-platelet binding, or apoptosis. Relative decreases in the neutrophil count were inversely associated with relative increases in the intensity of CD64 expression on neutrophils (r=- 0.307; p=0.028). Although seven patients developed severe neutropenia, none suffered severe or recurrent bacterial infections. The percentage of CD64-positive neutrophils was still increased in eight patients who continued receiving 1-5 mg CC-4047 e.o.d. for several months afterwards, but neutrophil counts were similar to pre-treatment values.

Molecularly targeted therapy for melanoma

Effective therapy for melanoma remains an unmet goal, with most traditional therapies representing inadequate trade-offs among the several goals of specificity, efficacy, and toxicity. Targeted molecular therapeutics are tailored to genetic abnormalities that are associated with tumor progression. Modulation of aberrant signaling pathways in cancer cells has the potential to provide more effective and potentially nontoxic therapy for a broad range of cancers, including melanoma. Among the possible targets in melanoma are the Ras-MAPK and PI3K/AKT signal transduction pathways, the proteasome, histone deacetylases, methyltransferases, and melanoma-induced angiogenesis.

Hairy cell leukemia (HCL) with extensive myelofibrosis responds to thalidomide

We present a 75-year-old man who was admitted to our hospital because of splenomegaly, transfusion-dependent anemia and thrombocytopenia. The diagnosis of idiopathic myelofibrosis was suggested by the bone marrow trephine biopsy, which was hypocellular with myelofibrosis. Thalidomide was started at a daily dose of 100 mg/d and increased to 400 mg/d. Within 12 weeks, thrombocytes increased to 100.000/microl, hemoglobin normalized, lasting for about 11 months. Then, thalidomide had to be discontinued because of mild polyneuropathy. A second bone marrow biopsy showed fibrosis as well as a diffuse infiltration of the bone marrow (80%) by lymphocytes with expression of CD11c, CD19, CD20, CD103. Tartrate resistant acid phosphatase test (TRAP) was also positive. Hairy cell leukemia was diagnosed and he was administered 2-chlorodeoxyadenosine (2-CDA) achieving a complete remission.

Properties of thalidomide and its analogues: implications for anticancer therapy

Thalidomide and its immunomodulatory (IMiDs) analogs (lenalidomide, Revlimid, CC-5013; CC-4047, ACTIMID) are a novel class of compounds with numerous effects on the body's immune system, some of which are thought to mediate the anticancer and anti-inflammatory results observed in humans. Thalidomide is currently being used experimentally to treat various cancers and inflammatory diseases. It is approved for the treatment of dermal reaction from leprosy and is currently in phase III trials for multiple myeloma. Thalidomide and IMiDs inhibit the cytokines tumor necrosis factor-alpha (TNF-alpha), interleukins (IL) 1beta, 6, 12, and granulocyte macrophage-colony stimulating factor (GM-CSF). They also costimulate primary human T lymphocytes inducing their proliferation, cytokine production, and cytotoxic activity thereby increasing the T cells' anticancer activity. They induce an IL-2-mediated primary T cell proliferation with a concomitant increase in IFN-gamma production and decrease the density of TNF-alpha-induced cell surface adhesion molecules ICAM-1, VCAM-1, and E-selectin on human umbilical vein endothelial cells. Thalidomide stimulates the Th-1 response increasing IFN-gamma levels while CC-4047 increased IL-2 as well. Some of the above immunomodulatory activities along with anti-angiogenic, anti-proliferative, and pro-apoptotic properties are thought to mediate the IMiDs' antitumor responses observed in relapsed and refractory multiple myeloma and some solid tumor cancers. This has led to their use in various oncology clinical trials. The second generation IMiD, lenalidomide, has shown potential in treating the bone marrow disorders myelodysplastic syndrome and multiple myeloma. It is currently in phase II and III trials for these diseases respectively with numerous phase II trials in other hematologic and solid tumors.

New approaches in the treatment of myelofibrosis

Myelofibrosis with myeloid metaplasia (MMM) is a chronic clonal neoangiogenesis disorder characterized by bone marrow fibrosis and neoangiogensis with extramedullary hematopoiesis. Identification of prognostic factors associated with MMM have not impacted the treatment of the disease, which continues to be palliative with the exception of allogeneic stem cell transplantation (SCT) for potential long-term disease-free survival in selected patients. Additional insights into the pathophysiology of MMM have resulted in the use of novel therapeutic strategies in the treatment of this disease. The rationale for the investigation of these agents in MMM and the status of clinical trials with various modalities such as angiogenesis inhibitors (e.g., thalidomide), tyrosine kinase inhibitors (e.g., imatinib mesylate), farnesyl transferase inhibitors (e.g., R115777), and other agents are reviewed, in addition to the potential roles of autologous and allogeneic SCT.

Thalidomide for the treatment of idiopathic myelofibrosis

Except rare instances of allogeneic stem cell transplantation, treatment of idiopathic myelofibrosis (IMF) is only palliative and based on cytostatic treatment (hydroxyurea and anagrelide), androgen therapy, steroids and splenectomy. Thalidomide is an anti-angiogenic and immunomodulatory drug with a wide spectrum of activities, which are not clearly understood. Current data suggest that the action of thalidomide is related to several different mechanisms, including suppression of tumor necrosis factor, effects on basic fibroblast growth factor, vascular endothelial growth factor, interleukins and interferons, downregulation of selected cell surface adhesion molecules, and changes in the lymphocyte subsets. We administered thalidomide to 16 patients with IMF (15 men, one women) who had transfusion-dependent anemia, thrombocytopenia or symptomatic splenomegaly. Median age was 59 yr (range: 52-78). Patients received thalidomide at an escalating dose from 100 to 400 mg/d (median 300 mg). The drug was discontinued in four patients because of progressive disease (two) or polyneuropathy (two). Other adverse effects were obstipation (10), fatigue (eight) and edema (two). Clinical response has now been observed for a median duration of 9 months (range: 3-20). Fifteen patients are evaluable. Anemia improved in six of 10 patients who were anemic. Platelet counts improved in five of seven patients with thrombocytopenia. Splenomegaly regressed in three of 13 patients. Lactate dehydrogenase (LDH) decreased in seven of 12 patients, but increased in four patients. LDH levels were not correlated with clinical response. In summary, thalidomide appears useful in the treatment of IMF.

Novel agents for cutaneous T-cell lymphoma

Several novel therapies have recently emerged for the treatment of hematologic malignancies; several agents have demonstrated activity against T-cell lymphomas in vitro or in early clinical trials. This article discusses how these therapies may be implemented in the treatment of patients who have advanced or refractory cutaneous T-cell lymphoma.

Thalidomide Inhibits Tumor Necrosis Factor-α Production and Antigen Presentation by Langerhans Cells

Thalidomide is an effective treatment for several inflammatory and autoimmune disorders including erythema nodosum leprosum, Behcet's syndrome, discoid lupus erythematosus, and Crohn's disease. Thalidomide is believed to exert its anti-inflammatory effects, at least in part, by inhibiting tumor necrosis factor-alpha (TNF-alpha) production by monocytes. We studied the effects of thalidomide on epidermal Langerhans cells (LC). LCs are epidermal antigen-presenting dendritic cells that play important roles in skin immune responses. Using the murine epidermis-derived dendritic cell lines, XS106A from A/J mice and XS52 from BALB/c mice as surrogates for LC, we found that thalidomide inhibited TNF-alpha production in a concentration-dependent manner. Northern blot analysis revealed that thalidomide significantly decreased the peak-induced mRNA level of TNF-alpha in XS106A cells and XS52 cells. We then examined the effect of thalidomide on fresh LC enriched to approximately 98% using positive selection of Ia+ cells with antibodies conjugated to magnetic microspheres. TNF-alpha production was reduced by 67.7% at a thalidomide concentration of 200 microg per mL. Thalidomide also had a profound inhibitory effect on the ability of LC to present antigen to a responsive TH1 clone. Thalidomide inhibits TNF-alpha production and the antigen-presenting ability of epidermal LCs. These mechanisms may contribute to the therapeutic effects observed with this agent.

Single agent thalidomide in patients with relapsed or refractory acute myeloid leukaemia

Thalidomide is a putative anti-angiogenesis agent that has significant anti-tumour activity in haematological malignancies with increased bone marrow angiogenesis, including multiple myeloma (MM) and myelodysplastic syndromes (MDS). Increased levels of the mitogen for angiogenesis, vascular endothelial growth factor (VEGF), correlate with worse survival in acute myeloid leukaemia (AML). A phase II trial of thalidomide was conducted in patients with relapsed- or refractory-AML previously treated with cytarabine-containing regimens. A total of 16 patients with refractory- or relapsed-AML were treated with thalidomide 200-800 mg orally daily (median dose 400 mg daily) for a median of 27 d (range, 3-94 d). Overall, one patient (6%) achieved complete remission (CR) lasting for 36 months, and two patients had a transient reduction in marrow blasts from 8% and 7% to less than 5% in both cases. There was no correlation between reduction in levels of angiogenesis markers and response. Toxicities related to thalidomide were significant, and precluded dose escalation beyond 400 mg orally daily in most patients. Although there appears to be some evidence of biological activity, single agent thalidomide is not an optimal choice of therapy for salvaging patients with relapsed- or refractory-AML. Thalidomide analogues with more potent immunomodulatory activities and more favourable toxicity profiles may offer more promise as anti-AML therapy.

Dermatologic and nondermatologic uses of thalidomide

OBJECTIVE

To review published data on thalidomide, with emphasis on current knowledge about mechanism of action, new and/or potential dermatologic and nondermatologic therapeutic applications, well-known and emerging adverse effects, and current indications for its safe use.

DATA SOURCES

Review articles, in vitro research studies, references from retrieved articles, case reports, and clinical trials were identified from a computerized literature search using MEDLINE and OVID (1966-January 2003) and on the Cochrane Clinical Trials Register (January 2003). Information available from meetings' abstract books, Internet, or pharmaceutical companies was also considered.

STUDY SELECTION AND DATA EXTRACTION

All articles identified as relevant, including those from non-English literature, were considered in an attempt to provide to the reader both the theoretical basis and practical guidelines for thalidomide pharmacotherapy.

DATA SYNTHESIS

Thalidomide has hypnosedative, antiangiogenic, antiinflammatory, and immunomodulatory properties. Moreover, it has been shown to selectively inhibit the production of tumor necrosis factor-alpha and reduce the expression of various integrin receptors on the membrane of leukocytes and other cell types in a dose-dependent fashion. Controlled trials demonstrated the efficacy of thalidomide in a number of diseases, including erythema nodosum leprosum, lupus erythematosus, aphthosis, graft-versus-host disease, prurigo nodularis, and actinic prurigo. Single case reports or studies in small series have also suggested a possible role for thalidomide in numerous other dermatologic and nondermatologic disorders. Possibly severe and sometimes irreversible risks related to the clinical use of thalidomide include teratogenicity and neurotoxicity.

CONCLUSIONS

Although teratogenicity and neurotoxicity are significant adverse effects requiring cautious use, thalidomide is an effective therapeutic modality in a variety of difficult-to-treat disorders and, providing careful selection of patients, should offer an acceptable risk-to-benefit ratio.

Effective immunomodulatory treatment of Escherichia coli experimental sepsis with thalidomide

Thalidomide, an agent which inhibits biosynthesis of tumor necrosis factor alpha (TNF-alpha) and which is used to treat a variety of chronic inflammatory conditions, was investigated as therapy for experimental sepsis. Sepsis was induced by intraperitoneal injection of 10(7) CFU of Escherichia coli per kg of body weight to 80 Wistar rats divided into four groups. Group A consisted of 24 control animals that did not receive any pretreatment, group B consisted of 18 vehicle-treated control animals pretreated with seed oil, group C consisted of 30 rats administered thalidomide diluted in seed oil at a dose of 50 mg/kg 30 min before bacterial challenge, and group D consisted of eight animals that were not challenged with E. coli but that were used for white blood cell count determination. Sepsis was determined by measurement of vital signs before and 6 h after bacterial challenge. After 6 h the animals were killed and blood was sampled for culture; white blood cell count determination; and determination of endotoxin (lipopolysaccharide), TNF-alpha, interleukin-1beta (IL-1beta), and IL-6 levels. The levels of these cytokines were also estimated in the supernatants of human monocytes pretreated with thalidomide after exposure to the isolate. Sepsis developed in all vehicle-treated control animals and controls by 6 h after bacterial challenge but in only 10 animals (33.3%) pretreated with thalidomide (P < 0.0001). Six hours after bacterial challenge all animals had similar levels of endotoxemia, IL-1beta, and IL-6. The mean white blood cell count for groups A, B, and C were 5,631.1, 2,638.9, and 8,169.3 cells/ micro l, respectively (P value between groups, <0.0001); the TNF-alpha levels were 77.3, 107.2, and 26.1 pg/ml, respectively (P values between groups, <0.0001). Pretreatment of human monocytes with thalidomide prevented the secretion of TNF-alpha and IL-1beta but not that of IL-6. It is concluded that thalidomide exerts a considerable anti-inflammatory effect by preventing evolution to sepsis and by decreasing the level of production of TNF-alpha and therefore deserves to be further evaluated in research for the therapy of sepsis.

Thalidomide after allogeneic haematopoietic stem cell transplantation: activity in chronic but not in acute graft-versus-host disease

Thalidomide was used to treat acute (n=21) or chronic (n=59) graft-vs-host disease (GVHD) in 80 haematopoietic stem cell allograft recipients after failure to respond to the combination of cyclosporine and corticosteroids with or without other agents. The median time to onset of acute GVHD was 11 days, and thalidomide was started at a median of 48 days post transplant. In addition to corticosteroids and cyclosporine, 13 patients had also received other agents before thalidomide. None of the patients responded and all died of acute GVHD. For chronic GVHD (limited in 13, extensive in 46), thalidomide was started at a median of 385 days post transplant. In addition to corticosteroids and cyclosporine, 34 patients received azathioprine concomitantly. In all patients, thalidomide was added to the ongoing immunosuppressive regimen. The median duration of therapy with thalidomide was 60 days (range, 11-1210; <2 weeks in 11). In total, 13 patients (22%) had complete response, eight (14%) partial response and 38 (64%) no response. Response rates were comparable for limited (39%) and extensive (33%) chronic GVHD. At a median of 53 months, 19 patients are alive, 13 without evidence of chronic GVHD. Survival was significantly better in patients who responded to thalidomide. The principal causes of death were progressive chronic GVHD (n=29) and relapsed leukaemia (n=7). In conclusion, thalidomide has no activity in acute GVHD, but has some activity in chronic GVHD in combination with other agents.

Thalidomide and its derivatives: emerging from the wilderness

Forty years on from its worldwide withdrawal, thalidomide is currently undergoing a remarkable renaissance as a novel and powerful immunomodulatory agent. Over the last decade it has been found to be active in a wide variety of inflammatory and malignant disorders where conventional therapies have failed. Recently, considerable progress has been made in elucidating its complex mechanisms of action, which include both anticytokine and antiangiogenic properties. However, in addition to its well known teratogenic potential, it has a significant side effect profile that leads to cessation of treatment in up to 30% of subjects. In response to this, two new classes of potentially safer and non-teratogenic derivatives have recently been developed. This review summarises the biological effects, therapeutic applications, safety profile, and future potential of thalidomide and its derivatives.

Immunomodulatory analogs of thalidomide inhibit growth of Hs Sultan cells and angiogenesis in vivo

We have previously shown that thalidomide and its potent immunomodulatory derivatives (IMiDs) inhibit the in vitro growth of multiple myeloma (MM) cell lines and patient MM cells that are resistant to conventional therapy. In this study, we further characterize the effect of these drugs on growth of B cell malignancies and angiogenesis. We established a beige-nude-xid (BNX) mouse model to allow for simultaneous in vivo measurement of both anti-tumor and anti-angiogenic effects of thalidomide and its analogs. Daily treatment (50 mg/kg/d) with thalidomide or IMiDs was nontoxic. The IMiDs were significantly more potent than thalidomide in vivo in suppressing tumor growth, evidenced by decreased tumor volume and prolonged survival, as well as mediating anti-angiogenic effects, as determined by decreased microvessel density. Our results therefore show that the IMiDs have more potent direct anti-tumor and anti-angiogenic effects than thalidomide in vivo, providing the framework for clinical protocols evaluating these agents in MM and other B cell neoplasms.

Antimyeloma efficacy of thalidomide in the SCID-hu model

To determine the mechanism of thalidomide's antimyeloma efficacy, we studied the drug's activity in our severe combined immunodeficiency-human (SCID-hu) host system for primary human myeloma. In this model, tumor cells interact with the human microenvironment to produce typical myeloma manifestations in the hosts, including stimulation of neoangiogenesis. Because mice are not able to metabolize thalidomide efficiently, SCID-hu mice received implants of fetal human liver fragments under the renal capsule in addition to subcutaneous implants of the fetal human bone. Myeloma cell growth in these mice was similar to their growth in hosts without liver implant, as assessed by change in levels of circulating human immunoglobulins and by histologic examinations. Thalidomide given daily by peritoneal injection significantly inhibited myeloma growth in 7 of 8 experiments, each with myeloma cells from a different patient, in hosts implanted with human liver. In contrast, thalidomide exerted an antimyeloma effect only in 1 of 10 mice without liver implants. Microvessel density in the untreated controls was higher than in thalidomide-responsive hosts but not different from nonresponsive ones. Expression of vascular endothelial growth factor by myeloma cells and by other cells in the human bone, determined immunohistochemically, was not affected by thalidomide treatment in any experiment. Our study suggests that thalidomide metabolism is required for its antimyeloma efficacy. Although response to thalidomide was strongly associated with decreased microvessel density, we were unable to conclude whether reduced microvessel density is a primary result of thalidomide's antiangiogenic activity or is secondary to a lessened tumor burden.

Association between the tumor necrosis factor locus and the clinical outcome of Leishmania chagasi infection

A periurban outbreak of visceral leishmaniasis (VL) caused by the protozoan Leishmania chagasi is ongoing outside Natal, northeast Brazil. Manifestations range from asymptomatic infection to disseminated visceral disease. Literature reports suggest that both genetic and environmental factors influence the outcome of infection. Due to the association of the tumor necrosis factor (TNF) locus with other infectious diseases, we examined whether polymorphic alleles at this locus are associated with the outcome of L. chagasi infection. Neighborhoods with ongoing transmission were identified through patients admitted to local hospitals. Altogether, 1,024 individuals from 183 families were classified with the following disease phenotypes: (i) symptomatic VL, (ii) asymptomatic infection (positive delayed-type hypersensitivity [DTH+]), or (iii) no evidence of infection (DTH-). Genotypes were determined at a microsatellite marker (MSM) upstream of the TNFB gene encoding TNF-beta and at a restriction fragment length polymorphism (RFLP) at position -307 in the promoter of the TNFA gene encoding TNF-alpha. Analyses showed that the distribution of TNFA RFLP alleles (TNF1 and TNF2) and the TNF MSM alleles (TNFa1 to TNFa15) differed between individuals with VL and those with DTH+ phenotypes. TNF1 was transmitted more frequently than expected from heterozygous parents to DTH+ offspring (P = 0.0006), and haplotypes containing TNF2 were associated with symptomatic VL (P = 0.0265, transmission disequilibrium test). Resting serum TNF-alpha levels were higher in TNF1/2 heterozygotes than in TNF1/1 homozygotes (P < 0.05). These data led us to hypothesize that an individual's genotype at the TNF locus may be associated with whether he or she develops asymptomatic or symptomatic disease after L. chagasi infection. The results preliminarily suggest that this may be the case, and follow-up with larger populations is needed for verification.

Effect of thalidomide in patients with chronic heart failure

BACKGROUND

Congestive heart failure (CHF) is characterized by enhanced immune activation, which possibly plays a pathogenic role in this disorder. We therefore examined whether immunomodulation with thalidomide could improve cardiac performance in patients with CHF.

METHODS

Nine patients with chronic symptomatic CHF and left ventricular ejection fraction (LVEF) <40%, who were receiving "optimal" conventional cardiovascular treatment, were given 200 mg thalidomide daily in an open design for a period of 6 weeks. Tumor necrosis factor (TNF)-alpha and LVEF were measured at baseline and on completion of the study.

RESULTS

Two patients withdrew because of side effects. Sedation was common and required dose reduction in 6 of 7 patients completing the study. Plasma levels of TNF-alpha were elevated at baseline compared with levels in healthy control patients, but decreased significantly from 33.9 +/- 10.1 pg/mL to 19.3 +/- 6.1 pg/mL during therapy (P <.05). LVEF increased in all patients from 26% +/- 9% to 34% +/- 10% at the end of the observation period (P <.05).

CONCLUSIONS

In this pilot study, therapy with thalidomide in patients with CHF resulted in decreased TNF-alpha levels and increased cardiac performance. Although few patients were included, our results suggest that thalidomide should be further investigated as an immunomodulating agent in CHF.

Preclinical and clinical assessment of the safety and potential efficacy of thalidomide in heart failure

BACKGROUND

Inflammatory mediators, especially tumor necrosis factor (TNF), have been implicated in heart failure (HF). Thalidomide has anti-inflammatory properties and selectively inhibits TNF. Thus far, thalidomide or thalidomide analogues have not been evaluated in patients with heart failure.

METHODS

Thalidomide was assessed in preclinical and clinical studies. First, isolated cardiac myocytes were pretreated with thalidomide or thalidomide analogues, and TNF production was assessed after lipopolysaccharide (LPS) provocation. Second, to determine the safety and potential efficacy of thalidomide, an open-label dose escalation safety study was conducted in seven patients with advanced heart failure.

RESULTS

Thalidomide and thalidomide analogues inhibited LPS-induced TNF biosynthesis in cardiac myocytes in a dose-dependent manner. Thalidomide analogues had a greater inhibitory effect on TNF production than did thalidomide. In patients with advanced HF, thalidomide was safe and potentially effective when used at lower doses. However, dose-limiting toxicity was observed in two patients. There was a significant increase in the 6-minute walk distance and a trend toward improvement in left ventricular ejection fraction and quality of life after 12 weeks of maintenance therapy with thalidomide.

CONCLUSIONS

Taken together these results suggest that thalidomide or its derivatives may be useful in selected patients with HF. This potential needs to be studied in larger clinical trials.