Efficacy and safety of thalidomide in patients with acute myeloid leukemia

New immunomodulatory anticancer quinazolinone-based thalidomide analogs: design, synthesis and biological evaluation

Aim: The current work is an extension to our previous work for the development of new thalidomide analogs.Materials & methods: Quinazolinone-based molecules carrying a glutarimide moiety have been designed, synthesized and biologically evaluated for immunomodulatory and anticancer activity.Results: Compounds 7d and 12 showed considerable immunomodulatory properties in comparison to thalidomide. 7d and 12 significantly reduced TNF-α levels in HepG-2 cells from 162.5 to 57.4 pg/ml and 49.2 pg/ml, respectively, compared with 53.1 pg/ml reported for thalidomide. Moreover, they caused 69.33 and 77.74% reduction in NF-κB P65, respectively, compared with 60.26% reduction for thalidomide. Similarly, they reduced VEGF from 432.5 to 161.3 pg/ml and 132.8 pg/ml, respectively, in comparison to 153.2 pg/ml reported for thalidomide. The two new derivatives, 7d and 12 also showed about eightfold increases in caspase-8 levels in cells treated with them. These results were slightly better than those of thalidomide. The obtained results revealed that Compound 12 had better immunomodulatory properties than thalidomide, with stronger effects on TNF-α, NF-κB P65, VEGF and caspase-8.Conclusion: This work indicates that compounds 7d and 12 have interesting biological properties that should be further evaluated and modified in order to develop clinically useful thalidomide analogs.

Design, synthesis, and biological evaluation of novel bioactive thalidomide analogs as anticancer immunomodulatory agents

Cancer is still a dangerous disease with a high mortality rate all over the world. In our attempt to develop potential anticancer candidates, new quinazoline and phthalazine based compounds were designed and synthesized. The new derivatives were built in line with the pharmacophoric features of thalidomide. The new derivatives as well as thalidomide were examined against three cancer cell lines, namely: hepatocellular carcinoma (HepG-2), breast cancer (MCF-7) and prostate cancer (PC3). Then the effects on the expression levels of caspase-8, VEGF, NF-κB P65, and TNF-α in HepG-2 cells were evaluated. The biological data revealed the high importance of phthalazine based compounds (24a-c), which were far better than thalidomide with regard to the antiproliferative activity. 24b showed IC₅₀ of 2.51, 5.80 and 4.11 μg mL^-1 compared to 11.26, 14.58, and 16.87 μg mL^-1 for thalidomide against the three cell lines respectively. 24b raised caspase-8 level by about 7 folds, compared to 8 folds reported for thalidomide. Also, VEGF level in HepG-2 cells treated with 24b was 185.3 pg mL^-1, compared to 432.5 pg mL^-1 in control cells. Furthermore, the immunomodulatory properties were proven to 24b, which reduced TNF-α level by approximately half. At the same time, NF-κB P65 level in HepG-2 cells treated with 24b was 76.5 pg mL^-1 compared to 278.1 and 110.5 pg mL^-1 measured for control cells and thalidomide treated HepG-2 cells respectively. Moreover, an in vitro viability study against Vero non-cancerous cell line was investigated and the results reflected a high safety profile of all tested compounds. This work suggests 24b as a promising lead compound for development of new immunomodulatory anticancer agents.

Reshaping the tumor microenvironment: The versatility of immunomodulatory drugs in B-cell neoplasms

Immunomodulatory drugs (IMiDs) such as thalidomide, lenalidomide and pomalidomide are antitumor compounds that have direct tumoricidal activity and indirect effects mediated by multiple types of immune cells in the tumor microenvironment (TME). IMiDs have shown remarkable therapeutic efficacy in a set of B-cell neoplasms including multiple myeloma, B-cell lymphomas and chronic lymphocytic leukemia. More recently, the advent of immunotherapy has revolutionized the treatment of these B-cell neoplasms. However, the success of immunotherapy is restrained by immunosuppressive signals and dysfunctional immune cells in the TME. Due to the pleiotropic immunobiological properties, IMiDs have shown to generate synergetic effects in preclinical models when combined with monoclonal antibodies, immune checkpoint inhibitors or CAR-T cell therapy, some of which were successfully translated to the clinic and lead to improved responses for both first-line and relapsed/refractory settings. Mechanistically, despite cereblon (CRBN), an E3 ubiquitin ligase, is considered as considered as the major molecular target responsible for the antineoplastic activities of IMiDs, the exact mechanisms of action for IMiDs-based TME re-education remain largely unknown. This review presents an overview of IMiDs in regulation of immune cell function and their utilization in potentiating efficacy of immunotherapies across multiple types of B-cell neoplasms.

Leukemia stem cell-bone marrow microenvironment interplay in acute myeloid leukemia development

Despite the advances in intensive chemotherapy regimens and targeted therapies, overall survival (OS) of acute myeloid leukemia (AML) remains unfavorable due to inevitable chemotherapy resistance and high relapse rate, which mainly caused by the persistence existence of leukemia stem cells (LSCs). Bone marrow microenvironment (BMM), the home of hematopoiesis, has been considered to play a crucial role in both hematopoiesis and leukemogenesis. When interrupted by the AML cells, a malignant BMM formed and thus provided a refuge for LSCs and protecting them from the cytotoxic effects of chemotherapy. In this review, we summarized the alterations in the bidirectional interplay between hematopoietic cells and BMM in the normal/AML hematopoietic environment, and pointed out the key role of these alterations in pathogenesis and chemotherapy resistance of AML. Finally, we focused on the current potential BMM-targeted strategies together with future prospects and challenges. Accordingly, while further research is necessary to elucidate the underlying mechanisms behind LSC–BMM interaction, targeting the interaction is perceived as a potential therapeutic strategy to eradicate LSCs and ultimately improve the outcome of AML.

Immunomodulatory Drugs in Acute Myeloid Leukemia Treatment

Immunomodulatory drugs (IMiDs) are analogs of thalidomide. They have immunomodulatory, antiangiogenic and proapoptotic properties and exert a role in regulating the tumor microenvironment. Recently IMiDs have been investigated for their pleiotropic properties and their therapeutic applications in both solid tumors (melanoma, prostate carcinoma and differentiated thyroid cancer) and hematological malignancies. Nowadays, they are applied in de novo and relapsed/refractory multiple myeloma, in myelodysplastic syndrome, in del5q syndrome with specific use of lenalidomide and B-cell lymphoma. Several studies have been conducted in the last few years to explore IMiDs possible use in acute myeloid leukemia treatment. Here we report the mechanisms of action of IMiDs in acute myeloid leukemia and their potential future therapeutic application in this disease.

Inhibitory Effects of Arsenic Trioxide and Thalidomide on Angiogenesis and Vascular Endothelial Growth Factor Expression in Leukemia Cells

Acute myeloid leukemia (AML) is a blood disorder characterized by uncontrolled proliferation of myeloid progenitors and decrease in the apoptosis rate. The vascular endothelial growth factor (VEGF) promotes blood vessel regeneration which might play important roles in development and progression of neoplasia. Our previous studies focused on cytotoxicity and anticancer effects of arsenic trioxide (ATO) and thalidomide (THAL) as an anti-VEGF compound in the AML cell model. ATO also affects regulatory genes involved in cell proliferation and apoptosis. The aim of present study was to examine the effects of ATO and THAL alone and in combination on U937 and KG-1 cells, with attention to mRNA expression for VEGF isoforms. Growth inhibitory effects was assessed by MTT assay and apoptosis induction was determined by Annexin/PI staining. mRNA expression levels were evaluated by real-time PCR. Our data indicated that ATO (1.618μM and 1μM in KG-1 and U937 cell lines respectively), THAL (80μM and 60μM) and their combination inhibited proliferation and induced apoptosis in our cell lines. mRNA expression of VEGF (A, B) decreased while C and D isoforms did not show any significant changes. Taken together, according to the obtained results, the VEGF autocrine loop could be a target as a therapeutic strategy for cases of AML.

Drug Repurposing for the Treatment of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease characterized by the accumulation of immature myeloid progenitor cells in the bone marrow, compromising of normal blood cell production and ultimately resulting in bone marrow failure. With a 20% overall survival rate at 5 years and 50% in the 18- to 65-year-old age group, new medicines are needed. It is proposed that development of repurposed drugs may be a part of the new therapy needed. AML is subdivided into recurrent molecular entities based on molecular genetics increasingly accessible for precision medicine. Novel therapy developments form a basis for novel multimodality therapy and include liposomal daunorubicin/cytarabine, broad or FLT3-specific tyrosine kinase inhibitors, Bcl-2 family inhibitors, selective inhibitors of nuclear export, metabolic inhibitors, and demethylating agents. The use of non-transplant immunotherapy is in early development in AML with the exceptional re-approval of a toxin-conjugated anti-CD33. However, the full potential of small molecule inhibitors and modalities like immunological checkpoint inhibitors, immunostimulatory small molecules, and CAR-T cell therapy is unknown. Some novel therapeutics will certainly benefit AML patient subgroups; however, due to high cost, more affordable alternatives are needed globally. Also the heterogeneity of AML will likely demand a broader repertoire of therapeutic molecules. Drug repurposing or repositioning represent a source for potential therapeutics with well-known toxicity profiles and reasonable prices. This implies that biomarkers of response need to accompany the development of antileukemic therapies for sharply defined patient subgroups. We will illustrate repurposing in AML with selected examples and discuss some experimental and regulatory limitations that may obstruct this development.

Anticancer Properties of a Novel Class of Tetrafluorinated Thalidomide Analogues

Thalidomide has demonstrated clinical activity in various malignancies affecting immunomodulatory and angiogenic pathways. The development of novel thalidomide analogs with improved efficacy and decreased toxicity is an ongoing research effort. We recently designed and synthesized a new class of compounds, consisting of both tetrafluorinated thalidomide analogues (Gu973 and Gu998) and tetrafluorobenzamides (Gu1029 and Gu992). In this study, we demonstrate the antiangiogenic properties of these newly synthesized compounds. We examined the specific antiangiogenic characteristics in vitro using rat aortic rings with carboxyamidotriazole as a positive control. In addition, further in vitro efficacy was evaluated using human umbilical vein endothelial cells (HUVEC) and PC3 cells treated with 5 and 10 μmol/L doses of each compound. All compounds were seen to reduce microvessel outgrowth in rat aortic rings as well as to inhibit HUVECs to a greater extent, at lower concentrations than previously tested thalidomide analogs. The antiangiogenic properties of the compounds were also examined in vivo in fli1:EGFP zebrafish embryos, where all compounds were seen to inhibit the extent of outgrowth of newly developing blood vessels. In addition, Gu1029 and Gu973 reduced the anti-inflammatory response in mpo:GFP zebrafish embryos, whereas Gu998 and Gu992 showed no difference. The compounds' antitumor effects were also explored in vivo using the human prostate cancer PC3 xenograft model. All four compounds were also screened in vivo in chicken embryos to investigate their teratogenic potential. This study establishes these novel thalidomide analogues as a promising immunomodulatory class with anticancer effects that warrant further development to characterize their mechanisms of action.

[Inhibitory effect of thalidomide combined with interferon on the proliferation of Kasumi-1 cells]

OBJECTIVE

To explore the inhibitory effect of thalidomide combined with interferon (IFN) on the human acute myeloid leukemia cell line Kasumi- 1 and its mechanism.

METHODS

The inhibitiory effect of Kasumi- 1 cells by thalidomide, interferon or combination was detected by CCK- 8 method, the apoptosis by flow cytometry, the expression of apoptosis related proteins by Western blot, vascular endothelial growth factor (VEGF) concentration in culture supernatant by ELISA.

RESULTS

Thalidomide inhibited the proliferation of Kasumi- 1 in a dose- dependent manner from 50 μg/ml to 500 μg/ml with an IC₅₀ of (451.13 ± 6.92）μg/ml at 24 h and (362.50 ± 14.52）μg/ml at 48 h. IFN also demonstrated the inhibitory capacity in a dose-dependent manner from 500 U/ml to 5 000 U/ml, with an IC₅₀ of (2 209 ± 127) U/ml at 24 h and (1 393±63) U/ml at 48 h. The apoptosis rates of Kasumi-1 cells treated with thalidomide 350 μg/ml or IFN 1 400 U/ml for 48 h were (14.68 ± 2.61) % and (21.71 ± 0.71)%, respectively, significantly higher than control group (P<0.01). In combination group the inhibition and the apoptosis rate were (88.50 ± 2.40) % and (41.95 ± 3.41)%, significantly higher than control and each single agent group (P<0.01). The VEGF concentrations of combination group [(94.61 ± 5.46) ng/L decreased significantly, as compared to thalidomide group [(141.11 ± 3.70) ng/L and IFN group [(119.90 ± 2.00) ng/L (P < 0.05). Western blot analysis showed Bcl-2 expression of Kasumi-1 cells decreased, while p-P38, Bax, cytochrome C, cleaved-Caspase-3, 8, 9 increased after treated with thalidomide 350 μg/ml or IFN 1 400 U/ml for 48 h. When treated with the combination agents, the expression of Bcl-2 further decreased and p-P38, Bax, cytochrome C, cleaved-Caspase-3, 8, 9 further increased as compared with each single agent (P < 0.05).

CONCLUSION

Thalidomide and IFN could synergistically inhibit the proliferation of Kasumi-1 cells probably through inducing apoptosis via the mitochondrial pathway, death receptor pathway and P38 MAPK pathway, as well as inhibiting VEGF secretion.

Effect of thalidomide in combination with gemcitabine on human pancreatic carcinoma SW-1990 cell lines in vitro and in vivo

Pancreatic cancer is one of the most frequently occurring malignancies worldwide and it is the fourth most common cause of cancer-associated mortality in Western countries. Thalidomide (THD) plays an important role in tumor therapy, as it is able to promote early stage apoptosis and inhibit the process of angiogenesis. The present study evaluated the ability of the combination of THD and gemcitabine (GEM) to inhibit the growth of the pancreatic cancer SW-1990 cell line in vitro and in vivo. Early apoptosis in the SW-1990 cells was detected by the Annexin V/propidium iodide double staining method, the level of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis. In addition, the expression of vascular endothelial growth factor in transplanted tumor tissue was measured by RT-PCR, immunohistochemistry and western blot analysis. Cluster of differentiation 34 positivity was considered to indicate the microvessel density. Subsequent to treatment with THD and GEM alone or in combination, it was found that the expression of Bax was upregulated, while the expression of Bcl-2 was downregulated, and the growth of SW-1990 cells and transplanted tumors in nude mice was evidently inhibited. The administration of THD in combination with GEM may demonstrate a potent antitumor effect that increases with increasing dose. The mechanism behind the antitumor effect may be associated with the inhibition of tumor angiogenesis and induction of the apoptosis pathway.

Angiogenesis as a treatment target in leukemia

SUMMARY The importance of angiogenesis in the growth and survival of leukemia has been well established and confirmed by several studies. In the last 20 years, several antiangiogenic agents have been used in preclinical and clinical studies of the treatment of leukemia. This review article summarizes the literature focusing on the relationship between angiogenesis and disease progression, and the advantages and limits of the antiangiogenic treatment of leukemia.

Role of VEGF/VEGFR in the pathogenesis of leukemias and as treatment targets (Review)

Angiogenesis plays an important role in solid tumor growth, progression and metastasis. Evidence suggests that the progression of hematolymphoid malignancies also depends on the induction of new blood vessel formation under the influence of acute leukemia, myelodysplastic syndromes, myeloproliferative neoplasms, multiple myeloma and lymphomas. The vascular endothelial growth factor (VEGF) is the most important proangiogenic agent that activates receptors on vascular endothelial cells and promotes blood vessel regeneration. It has been demonstrated that VEGF/VEGF receptor (VEGFR) expression is upregulated in several types of hematolymphoid tumor cells accompanied with angiogenesis. The levels of VEGF/VEGFR are correlated with the treatment, relapse and prognosis of hematolymphoid tumors. In order for VEGF family and their receptors as antiangiogenic targets to treat solid tumors, several antiangiogenic agents targeting VEGF-related pathways have been used for the treatment of hematolymphoid malignancies in clinical trials. The results demonstrate a promising therapeutic intervention in multiple types of hematolymphoid tumors. This review aims to summarize recent advances in understanding the role of VEGF and angiogenesis in leukemias, mainly focusing on their upstream transcriptors, downstream targets and the correlation of VEGF/VEGFR with the treatment, relapse or prognosis of leukemia. The progress of VEGF and its receptors as attractive targets for therapies are also discussed in clinical application.

Clinical trials with anti-angiogenic agents in hematological malignancies

New blood vessel formation (angiogenesis) is not only essential for the growth of solid tumors but there is also emerging evidence that progression of hematological malignancies like multiple myeloma, acute leukemias, and myeloproliferative neoplasms, also depends on new blood vessel formation. Anti-angiogenic strategies have become an important therapeutic modality for solid tumors. Several anti-angiogenic agents targeting angiogenesis-related pathways like monoclonal antibodies, receptor tyrosine kinase inhibitors, immunomodulatory drugs, and proteasome inhibitors have been entered clinical trials or have been already approved for the treatment of hematological malignancies as well and in some instances these pathways have emerged as promising therapeutic targets. This review summarizes recent advances in the basic understanding of the role of angiogenesis in hematological malignancies and clinical trials with novel therapeutic approaches targeting angiogenesis.

Vascular endothelial growth factor-related pathways in hemato-lymphoid malignancies

Angiogenesis is essential for malignant tumor growth. This has been documented for solid tumors, and there is an emerging evidence suggesting that tumor progression of hematolymphoid malignancies also depends on the induction of new blood vessel formation. The most important proangiogenic agent is vascular endothelial growth factor (VEGF), activating VEGF receptors 1 and 2. The available data on angiogenesis in hemato-lymphoid malignancies, such as acute leukemias, myelodysplastic syndromes, myeloproliferative neoplasms, multiple myeloma, and lymphomas, point towards the significance of autocrine and paracrine VEGF-mediated effects for proliferation and survival of leukemia/lymphoma cells in addition to tumor vascularization. Antiangiogenic strategies have become an important therapeutic modality for solid tumors. Several antiangiogenic agents targeting VEGF-related pathways are also being utilized in clinical trials for the treatment of hemato-lymphoid malignancies, and in some instances these pathways have emerged as promising therapeutic targets. This review summarizes recent advances in the basic understanding of the role of angiogenesis in hemato-lymphoid malignancies and the translation of such basic findings into clinical studies.

Thalidomide for the Treatment of Acute Myeloid Leukemia

In analogy to solid neoplasms, accumulating data suggest the requirement of angiogenesis also for the development and progression of hematopoietic malignancies including acute myeloid leukemia (AML). Inhibition of increased microvessel density in bone marrow (BM) might be a promising target for pharmacological interventions aimed at reducing disease activity. Among the putative inhibitors of angiogenesis, thalidomide has demonstrated a considerable efficacy in myelodysplastic syndromes (MDS) and AML with overall response rates up to 56% and 25%, respectively. Responders experienced hematologic improvements with increased hemoglobin and platelet counts resulting in temporary transfusion independence. In AML, partial responses--defined as reduction of the leukemic blast cell infiltration of at least 50% in BM--occurred in four of 20 patients after one month of thalidomide administration in a previous phase I/II study. Additionally, we observed a long-term response in one AML patient of more than 20 months, meanwhile fulfilling the criteria of complete remission. The decrease in leukemic blast infiltration in BM of responders was accompanied by a significant reduction of the microvessel density. Overall adverse events caused by the drug consisted mainly of fatigue, constipation, skin rash and polyneuropathy with a tolerable dose of 200-400 mg p.o. per day. In conclusion, thalidomide as a single agent has significant anti-leukemic activity with some evidence for anti-angiogenic effects in BM, although the precise mechanism of action remains to be elucidated.

Compounds in clinical Phase III and beyond

Targeted therapies against cancer have become more and more important. In particular, the inhibition of tumor angiogenesis and vascular targeting have been the focus of new treatment strategies. Numerous new substances were developed as angiogenesis inhibitors and evaluated in clinical trials for safety, tolerance, and efficacy. With positive study results, some of these molecules have already been approved for clinical use. For example, this is true for the vascular endothelial growth factor neutralizing antibody bevacizumab (BEV) in metastatic colorectal cancer, nonsmall cell lung cancer, renal cancer, and breast cancer. The tyrosine kinase (TK) inhibitors sorafenib and sunitinib have been approved for metastatic renal cancer as well as for hepatocellular carcinoma, and sunitinib has also been approved for gastrointestinal stroma tumors. In this chapter we try to give an overview of the substances currently investigated in Phase III studies and beyond with regard to antiangiogenesis in cancer therapy.

Phase II study of topotecan and thalidomide in patients with high-risk myelodysplastic syndromes

This phase II trial investigated the safety and preliminary efficacy of a topotecan/thalidomide combination therapy in patients with myelodysplastic syndrome who had refractory anemia with excess blasts (RAEB), RAEB with transformation, or chronic myelomonocytic anemia. Patients received three 21-day cycles of topotecan 1.25 mg/m(2) on days 1-5, which was repeated for two additional cycles in patients whose bone marrow blast percentages did not decrease. Oral thalidomide was then started at 100 mg/day (with the dose escalated up to 300 mg/day if well tolerated) for up to 1 year. Patients were monitored throughout the trial for hematologic and clinical adverse events, and efficacy was assessed using International Working Group (IWG) criteria. Forty-five patients, mostly elderly (median age 68 years; range 52-79 years), were enrolled. Therapy was generally well tolerated compared to high-dose chemotherapy. Three patients died from disease progression/infections during topotecan therapy, and four patients discontinued topotecan because of high-grade neutropenia (two patients), syncope (one patient), or hip surgery (one patient). Of 24 patients who received thalidomide, three discontinued because of treatment-related toxicity. Thirty-eight patients were evaluable for response: nine (24%) had hematologic improvement and 13 (34%) had stable disease. Responses occurred in patients with all disease subtypes. Six patients achieved transfusion independence, and one patient had a trilineage response. Approximately one-third of the patients had decreases in bone marrow blasts of 50%. Therefore, a topotecan and thalidomide combination therapy is promising, although further studies are needed to determine the optimum doses and schedule.

Micro-vessel density and the expression of vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PdEGF) in classical Hodgkin lymphoma (HL)

There is little information to date regarding the role of angiogenesis in Hodgkin lymphoma (HL). The present study examines micro-vessel density and the expression of vascular endothelial growth factor (VEGF) and platelet-derived endothelial growth factor (PdEGF) in lymph node biopsies of patients with HL at presentation and relapse. Using immunohistochemistry, the degree of new blood vessel formation and the expression of VEGF and PdEGF was assessed in Hodgkin-rich tissue. The micro-vessel density (MVD) increased with disease progression in seven out of 11 cases. Expression of VEGF was observed in endothelial cells (EC) of some micro-vessels and also in follicular dendritic cells. The Hodgkin/Reed-Sternberg (H-RS) cells as well as the inflammatory lymphocytes were negative for VEGF. Cytoplasmic or cytoplasmic and nuclear expression of PdEGF by the H-RS cells was observed in five of the 11 presentation cases. The expression of PdEGF increased with disease progression in seven cases. In conclusion, Hodgkin tissue shows prominent vascularization. The increased MVD and PdEGF expression with disease progression merits further investigation.

Thalidomide in multiple myeloma--clinical trials and aspects of drug metabolism and toxicity

BACKGROUND

After the tragic events in the early 1960s, thalidomide has re-emerged as therapeutic for multiple myeloma (MM). It was first approved for the treatment of erythema nodosum leprosum, and is now under evaluation for hematologic and non-hematologic disorders. Its complex mechanism of action is not fully understood; however extensive preclinical studies in MM have revealed its antiangiogenic and immunomodulatory properties.

OBJECTIVE

In this review, we focus on the importance and toxicity of thalidomide in today's clinical use.

METHODS

Key preclinical and clinical trials available as well as data on the pharmacokinetics and pharmacodynamics of thalidomide in humans are summarized.

CONCLUSIONS

Thalidomide is widely used as first-line treatment and in relapsed/refractory MM. The most common side effects are fatigue, constipation and peripheral neuropathy, and careful monitoring is required to avoid fetal exposure.

Emerging treatment strategies for acute myeloid leukemia (AML) in the elderly

Acute myeloid leukemia (AML) is more prevalent in older adults, with an incidence in the United States of 17.6 per 100,000 for those 65 years of age, compared with an incidence of 1.8 per 100,000 for those <65 years of age. While there have been improvements in survival during the last decade for younger patients, prognosis in elderly patients is still poor; approximately 50% achieve complete responses, but many of them relapse. With increasing age, more patients are suboptimal candidates for standard induction chemotherapy due to poor performance status, pre-existing myelodysplasia, unfavorable cytogenetics, treatment-related AML, multidrug resistance protein expression, and CD34 positivity, which are often characteristic of this patient population. In addition, the presence of comorbid conditions make many treatment options less tolerable for elderly patients. Several investigators have described subgroups showing no benefit after intensive treatment approaches in recent years. However, several novel agents have been developed to treat elderly AML patients. These include new chemotherapeutic agents, such as nucleoside analogs, as well as targeted therapies like farnesyltransferase inhibitors, tyrosine kinase inhibitors, epigenetic drugs, and antibodies. On the other hand new insights into the biology of the disease lead to a better understanding of its heterogeneity. Thus, with a variety of novel substances at hand it is increasingly important to introduce a risk-adapted approach for the optimal management of patients. This review will identify subgroups not likely to benefit from intensive chemotherapy and highlight the efficacy and tolerability of new agents in the treatment of AML.

[Thromboembolic risk associated with use of angiogenesis inhibitors used for the treatment of cancers]

Among antiangiogenic agents, thalidomide is not the most potent nor the most specific even so when venous thromboembolic events have been reported with the prescription of thalidomide in multiple myeloma. This side effect has been related to the antiangiogenic effect of this immunomodulator. In keeping with this observation venous thromboembolic events have been reported in other indications of thalidomide and with thalidomide analogues (Lenalidomide and Actimid). The thrombotic side effects are mostly venous but arterial thrombotic events are also observed with the use of these molecules. With the other and more specific antiagiogenic agents an increase in thrombotic events are also observed. This increase was not immediately evident since the situation in which they are prescribed (metastatic cancers) are already characterized by a high rate of thrombotic events. The prothrombotic effect of antiangiogenic agents are probably linked to an effect on endothelium (decrease of antithrombotic activities and stimulation of a prothrombotuic state). The other sides effects of antiangiogenic agents (hemorrhages, hypertension, proteinuria, microangiotpahia, delay in scaring) are also probably related to endothelial effects. The prothrombotic effect of antoangiogenic agents appears as potentiating the prothrombotic conditions of the disease (myeloma, cancer) and the prothombotic effects of the associated treatments (chemotherapy, high dose corticosteroids, erythropoietin). The increased thrombotic risk linked to prescription of antiangiogenic agents and specially of thalidomide and analogues for multiple myeloma is such that it is recommended to associate a preventive antithrombotic treatment. Some efficacy has been reported with the use of aspirin, oral anticoagulant or low molecular weight heparin. No head to head comparative trial do not allow to prefer one strategy. From published data full dose oral anticoagulants appear to confer the highest hemorrhagic risk and perhaps low molecular weight heparin the best benefit-risk ratio.

Antiangiogenic activity of thalidomide in combination with fludarabine, carboplatin, and topotecan for high-risk acute myelogenous leukemia

Forty-two patients with poor prognosis AML were enrolled in a phase II study combining fludarabine, carboplatin, and topotecan (FCT) with thalidomide. Laboratory correlates included serum vascular endothelial growth factor levels (VEGF) and bone marrow microvascular density (MVD). Ten of 42 (24%) patients achieved a complete remission (CR or CRp). Serious thrombotic adverse events were observed in 5 patients suggesting that the combination of cytotoxic chemotherapy and thalidomide may be thrombogenic despite significant thrombocytopenia. VEGF did not correlate with response to therapy, while a trend towards decreased MVD was noted in patients who achieved CR. The addition of thalidomide did not significantly influence angiogenic markers. It is not clear that thalidomide adds any efficacy to the FCT regimen.

Downregulation of neuropilin-1 in patients with acute myeloid leukemia treated with thalidomide

OBJECTIVE

Neuropilin-1 (NRP-1), a non-tyrosine kinase receptor functioning as a mediator of angiogenesis and neuronal guidance, was recently found to be significantly overexpressed in newly diagnosed acute myeloid leukemia (AML) patients with significant correlation to survival. The role of NRP-1 in refractory or relapsed AML patients and its regulation during anti-angiogenic treatment remain to be elucidated.

METHODS

Bone marrow biopsies of 10 patients with refractory or relapsed AML were evaluated for NRP-1 expression by immunohistochemical analysis, and NRP-1 expression level was determined before and after start of thalidomide therapy and correlated to response and growth factor expression.

RESULTS

NRP-1 expression was significantly increased in AML patients [median 7 arbitrary units (AU)] when compared with controls (n = 38, median 2.75 AU). Under thalidomide treatment, a marked difference in the course of NRP-1 expression between responders and non-responders was observed, however, without a statistical significance (P = 0.071) being reached. Additionally, a significant correlation of the NRP-1 expression level to microvessel density could be detected under treatment with thalidomide (P = 0.018).

CONCLUSION

Our data provide evidence of increased NRP-1 expression in relapsed or refractory AML. Additionally, our results suggest that thalidomide-induced antileukemic properties might at least in part be mediated by NRP-1 downregulation.

Ex vivo activity of thalidomide in childhood acute leukemia

Thalidomide is a drug with anti-angiogenic, anti-inflammatory, immunomodulatory and anti-cancer properties that were found to inhibit the production of TNF-alpha in vitro, stimulate reactive oxygen species production, and inhibit VEGFR in acute leukemias. Ex vivo activity of thalidomide as a single agent and in combination with prednisolone or cytarabine in childhood acute leukemias was analyzed. Forty samples of childhood acute lymphoblastic leukemia (ALL) and 13 acute myeloid leukemia (AML) were tested for cytotoxicity by the MTT assay and cell cycle phases by flow cytometry. Control studies were performed on 9 samples of normal lymphocytes and 4 cell lines. A weak anti-leukemic activity of thalidomide against childhood leukemic samples was observed. However, in the presence of thalidomide, cytotoxicity of prednisolone or cytarabine, increased 3.3-fold and 2.7-fold, respectively, in childhood ALL but was not changed in AML. Thalidomide increased apoptosis in lymphoblasts, and modulated cell cycle arrest caused by prednisolone but not cytarabine in childhood acute lymphoblastic leukemia samples. Thalidomide potentiated ex vivo sensitivity of childhood ALL cells to prednisolone and cytarabine, while no sensitization effect was observed in AML cells.

Cancer chemotherapy I: hepatocellular injury

Although hepatotoxicity is a frequent concern with all medications, chemotherapeutic agents are more often implicated in causing liver damage than most other drug classes. In many instances, these reactions are considered dose related because cytotoxic therapy directed at rapidly growing cancer cells may readily impact hepatocytes even though they are dividing more slowly. Because the stakes (remission of cancer) are high, so are the risks that the oncologist and the patient are willing to assume. The dose of many chemotherapeutic agents is limited by the toxic effects on the lungs, bone marrow, kidneys, and gastrointestinal system, including the liver. An awareness of the toxic potential of each chemotherapeutic agent is necessary before initiation of new oncologic treatments.

Autocrine VEGF loops, signaling pathways, and acute leukemia regulation

Data obtained from animal models, and partially confirmed in pre-clinical studies, have provided clear evidence of the importance of angiogenesis for the growth of solid tumors. Similarly, in hematological cancers such as leukemias and lymphomas, the role of angiogenesis has been under intense scrutiny. However, the molecular singularities of leukemia, namely its cellular origin, have suggested a putative role for angiogenesis in these tumors may have distinct features. We and others have shown acute leukemia cells use angiogenic growth factor signaling pathways, namely those activated by vascular endothelial growth factor (VEGF) in autocrine and paracrine fashion. Autocrine and paracrine VEGF stimulation of subsets of leukemias results in cell proliferation, increased survival and migration. This review discusses recent advances in the field of leukemia angiogenesis, focusing on the role of VEGF and its receptors, acting in a paracrine or autocrine manner. We also briefly describe some of the novel anti-angiogenic compounds, namely VEGF blockers, and suggest their use to treat subsets of hematological malignancies may have clinical benefit.

Autologous bone marrow transplantation for children with AML in first remission

In Children's cancer group (CCG) 2891, newly diagnosed patients with AML were randomized between standard and intensive timing induction therapies. Patients in first remission who lacked an HLA matched family donor were randomized between an autologous bone marrow transplantation (ABMT) where marrow was purged with 4 hydroperoxycyclophosphamide and consolidation chemotherapy. One hundred and thirty seven patients received an ABMT. Myeloid and platelet engraftment occurred at a median of 44 and 42 days, respectively. Disease-free survival (DFS), relapse-free survival and overall survival at 8 years post induction were 47% (95% confidence interval (CI): 38-55), 50% (CI: 42-59) and 55% (CI: 46-63), respectively. Multivariate analysis of DFS showed WBC <50 000/microl and having received intensively timed induction therapy were associated with improved DFS. Recipients who received intensive timed induction therapy and whose WBC was less than 50 000/microl had a DFS at 8 years of 62% (CI: 49-73). Conversely, recipients who received intensive timed induction therapy patients whose WBC was > or =50 000/microl had a DFS of 33% (CI: 17-50), P=0.003. The results confirm previous studies that ABMT is effective post remission therapy for pediatric patients with AML in first remission.

New molecular therapy targets in acute myeloid leukemia

Despite improvements to acute myelogenous leukemia (AML) therapy during the last 25 years, the majority of patients still succumb to the disease. Thus, there remains an urgent need for further improvements in this field. The present chapter focuses on exciting areas of research in the field of AML therapy, including promising results with regards to recent improvements in our understanding of angiogenesis, tyrosine kinase signaling, farnesylation, cell cycling, modulation of gene expression, protein degradation, modulation of intracellular proteins, apoptosis, metabolism, and the possible retargeting of oncogenic proteins.

JTE-607, a multiple cytokine production inhibitor, ameliorates disease in a SCID mouse xenograft acute myeloid leukemia model

OBJECTIVE

Accumulating findings suggest that in acute myeloid leukemia (AML) patients, proinflammatory cytokines and growth factors play important roles in the proliferation and survival of AML cells in an autocrine and paracrine manner, leading to deterioration of AML. JTE-607 is a multiple cytokine inhibitor that potently suppresses production of proinflammatory cytokines. In the present study, we investigated the potency of JTE-607 as an antileukemic agent by exploiting a SCID mouse acute leukemia model.

METHODS

SCID mice injected with anti-asialo-GM1 antibody were exposed to sublethal total-body irradiation at a dose of 3 Gy and then inoculated intravenously with AML cells. JTE-607 was administered using osmotic minipumps. The effects of JTE-607 on mouse survival time, human interleukin (IL)-8 levels in mouse plasma, and proportion of human CD45(+) cells in the bone marrow were studied.

RESULTS

The survival time of the mice was strictly dependent on the number of U-937 cells proliferating in vivo. Administration of JTE-607 during the initial 7 days significantly prolonged survival of the mice, suggesting killing activity of JTE-607 against AML cells in vivo. Delayed administration of JTE-607 also prolonged the survival of mice bearing established leukemia with an effect comparable to the maximum tolerable dose of cytarabine. Flow cytometer analysis of bone marrow cells revealed decreased number of human CD45(+) cells. Human IL-8 level was also reduced by JTE-607.

CONCLUSION

Our results indicate that JTE-607 has potential to be a new class of antileukemic drug that exerts inhibitory activities against both the proliferation and proinflammatory cytokine production of AML cells.

Phase I and pharmacokinetic study of oral thalidomide in patients with advanced hepatocellular carcinoma

PURPOSE

To evaluate the dose-limiting toxicities (DLT), maximum tolerated dose (MTD), and pharmacokinetics of thalidomide in patients with advanced hepatocellular carcinoma (HCC).

METHODS

Patients with advanced HCC who were not feasible for definitive local therapy were eligible. Patients were enrolled in a cohort of three to receive thalidomide twice daily for 1 week to determine the MTD. Intra-patient dose escalation was permitted. Pharmacokinetic studies were performed at the first dose level and repeated at the second dose level of each patient.

RESULTS

Fifteen patients were accrued at four dose levels with the starting dose range 100-400 mg/day. Two patients at 400 mg/day experienced DLT (grade 3 angioedema and dyspnea, respectively). The MTD of twice-daily schedule was determined as 300 mg/day. The mean steady-state maximal blood concentration and mean steady-state area under the curve had a trend toward positive correlation, but non-linear proportionate, to the daily dose of thalidomide. Pharmacokinetic parameters are comparable for patients of Child-Pugh's A and B. Apparent mild, transient drug-induced transaminitis was early onset, self-limited, which occurred in 30.7% of patients. Serum hepatitis B or C viral titers was largely not affected.

CONCLUSION

The absorption and elimination of thalidomide are not significantly different in HCC patients with compensated or decompensated hepatic dysfunction.

Etodolac induces apoptosis and inhibits cell adhesion to bone marrow stromal cells in human myeloma cells

OBJECTIVES

Cyclooxygenase-2 (COX-2) is reported to regulate apoptosis and to be an important cellular target for therapy.

METHODS

We examined whether etodolac, meloxicam, and thalidomide inhibited proliferation and induced apoptosis in myeloma cell lines (RPMI 8226 and MC/CAR cells).

RESULTS

Etodolac induced apoptosis more strongly compared with thalidomide or meloxicam. Etodolac induced down-regulation of Bcl-2 protein and mRNA, activation of Caspase-9, -7 and -3, cIAP-1 and Survivin, and loss of mitochondrial membrane potential in a dose-dependent manner. In addition, when myeloma cells were coincubated with 50 microM etodolac on bone marrow stromal cells (BMSCs), myeloma cell adhesion to BMSCs was significantly inhibited compared with thalidomide or meloxicam coincubation, and the adhesion molecules VLA-4, LFA-1 (CD11a), CXCX4, and CD44 were suppressed on myeloma cells treated with etodolac. Moreover, 50-100 microM racemate of etodolac significantly inhibited the proliferation of myeloma cells compared to 100 microM R-etodolac or S-etodolac.

CONCLUSIONS

Etodolac induced loss of mitochondrial membrane potential and apoptosis via a COX-2-independent pathway, suppressed the expression of adhesion molecules, and inhibited myeloma cell adhesion to BMSCs compared with thalidomide or meloxicam. The activities of etodolac potentially extend to the treatment of patients with myeloma resistant to standard chemotherapy, including thalidomide.

Molecularly targeted therapies in myelodysplastic syndromes and acute myeloid leukemias

Although there has been significant progress in acute myeloid leukemia (AML) treatment in younger adults during the last decade, standard induction therapy still fails to induce remission in up to 40% of AML patients. Additionally, relapses are common in 50-70% of patients who achieve a complete remission, and only 20-30% of patients enjoy long-term disease-free survival. The natural history of myelodysplastic syndrome (MDS) is variable, with about half of the patients dying from cytopenic complications, and an additional 20-30% transforming to AML. The advanced age of the majority of MDS patients limits the therapeutic strategies often to supportive care. To address these shortcomings, much effort has been directed toward the development of novel treatment strategies that target the evolution and proliferation of malignant clones. Presented here is an overview of molecularly targeted therapies currently being tested in AML and MDS patients, with a focus on FMS-like tyrosine kinase 3 inhibitors, farnesyltransferase inhibitors, antiangiogenesis agents, DNA hypomethylation agents, and histone deacetylase inhibitors.

Chemotherapy-induced thrombosis

Venous thromboembolism (VTE) is a frequent and potentially life-threatening complication associated with hematological and solid tumor malignancies. In patients with cancer, VTE portends a poor prognosis; in fact, only 12% of those who suffer an event will survive beyond one year. There are several different risk factors for the development of VTE in cancer patients that are well-described in the literature. One that has become increasingly recognized over the past two decades is the independent risk factor of chemotherapy. The annual incidence of VTE in patients receiving chemotherapy is estimated at 11%. This risk can climb to 20% or higher depending on the type of drug(s) being administered. In addition to chemotherapy, there are many other anti-neoplastic and supportive therapies that are also associated with an increased risk for the development of VTE. At present, several original basic science studies and clinical trials are underway in an effort to enhance our understanding of the mechanisms by which different chemotherapeutic agents can generate a prothrombotic state. The purpose of this article is to review the pertinent literature related to VTE in malignancy, and more specifically, chemotherapy and other cancer-related treatments associated with VTE.

Immunomodulatory drug CC-5013 or CC-4047 and rituximab enhance antitumor activity in a severe combined immunodeficient mouse lymphoma model

New thalidomide derivatives CC-5013 and CC-4047 (immunomodulatory drugs, IMiD) are up to 10,000 times more potent than Thalidomide. The biological effects of IMiDs are presumed to be mediated by (a) activation of some components of the innate [natural killer (NK) cells] or adoptive immune system (T cells), (b) modification of cytokine microenvironment in the tumor bed, or by (c) inhibition of angiogenesis. In this article, we tested an innovative combination strategy involving rituximab and IMiDs in aggressive lymphoma cell lines and human lymphoma xenografts. Treatment of non-Hodgkin's lymphoma cells with CC-5013 resulted in a 40% to 70% growth inhibition when compared with controls (P < 0.05). Exposure of lymphoma cells to CC-4047 resulted in a lesser degree of growth inhibition. Induction of apoptosis was shown in 10% to 26% of lymphoma cells 24 hours following exposure to either IMiD. In vivo studies in severe combined immunodeficient mice showed synergistic activity between CC-4047 (and to a lesser degree, CC-5013) plus rituximab. Animals treated with the CC-4047/rituximab combination had a median survival of 74 days (P = 0.0012) compared with 58 days (P = 0.167) in CC-5013/rituximab-treated animals compared with 45 days in rituximab monotherapy-treated animals. The synergistic effect between IMiDs and rituximab in our mouse model was attributed to NK cell expansion. The enhancement of rituximab activity by IMiDs was abrogated by in vivo depletion of NK cells. Augmenting NK cell function by CC-4047 or CC-5013 exposure may increase the antitumor effects of rituximab against B-cell lymphomas and warrants further exploration in the context of a clinical trial.

Therapeutic renaissance of thalidomide in the treatment of haematological malignancies

Very few drugs had a history similar to that of thalidomide (alpha-N-[phthalimido] gluramide). First introduced in the late 1950s in Germany, in 1961 thalidomide was withdrawn due to its teratogenic effects. More than three decades after, it is attracting growing interest because of its reported immunomodulatory and anti-inflammatory properties. The discovery that thalidomide inhibits angiogenesis led to preclinical and clinical trials as an anticancer agent in the treatment of solid tumours and haematological malignancies, as summarized in this review article. More recently, structural analogues of thalidomide have been synthesized in order to explore potential molecular targets of thalidomide, as well as to identify new agents with improved therapeutic efficacy.

Talidomida no tratamento do eritema nodoso hansênico: revisão sistemática dos ensaios clínicos e perspectivas de novas investigações

FUNDAMENTOS: A hanseníase persiste como problema de saúde pública, e episódios de ENH são eventos agudos que ocorrem antes, durante e após PQT. Na última década, o uso da talidomida como agente imunomodulador foi expandido a outras doenças. OBJETIVOS: realizar revisão sistemática dos ensaios clínicos publicados sobre a eficácia e efeitos colaterais da talidomida no ENH. Descrever metodologia e resultados da triagem para recrutamento de ensaio clínico visando avaliar dose-resposta da talidomida seguida de desmame no ENH moderado e grave, realizado no Brasil. MÉTODOS: Analisaram-se ensaios publicados sobre talidomida no ENH. Foi delineado um ensaio clínico duplo-cego randomizado para avaliar dose de 100 thalid 300mg/dia de talidomida durante fase aguda de ENH, seguida de desmame da talidomida, thalid placebo. Para este ensaio clínico descreve-se metodologia e dados de recrutamento de pacientes, com ênfase na gravidade dos episódios de ENH. RESULTADOS: Os seis ensaios clínicos publicados nas décadas de 1960 e 1970 apontam para o benefício da talidomida no ENH, embora diferenças metodológicas dificultem a comparação. Na fase de recrutamento do ensaio brasileiro, dos 143 pacientes de ENH triados, 65% eram potencialmente elegíveis. A associação com neurite em 56,4% dos ENH moderados e graves exigiu co-intervenção com corticosteróide. CONCLUSÃO: O padrão de recrutamento dos pacientes evidenciou alta freqüência de neurite nos episódios de ENH. O esquema de talidomida isolada no ENH foi avaliado como infreqüente na prática clínica brasileira. O desafio atual é acumular evidências sobre a eficácia e efeitos colaterais da talidomida em associação com corticosteróides.

Thalidomide treatment reduces apoptosis levels in bone marrow cells from patients with myelodysplastic syndromes

We treated with thalidomide seven patients with primary MDS and observed reduction of the transfusion requirement in three cases and reduction of bone marrow blasts in one case. The apoptotic rate of bone marrow cells diminished significantly from a mean of 43.8% to a mean of 17.5%, whereas the proliferative activity did not change. Plasma TNF-alpha, bFGF, IL-1beta levels decreased variably, whereas VEGF levels tended to increase. Matrix metalloproteinases 2 and 9 expression decreased in bone marrow cells of responders. A reduction of CD4 cells and an increase of NK cells was observed in the peripheral blood. Thus, thalidomide may produce a fairly good hematological improvement in erythroid series in MDS, with complex biological mechanisms.

Thalidomide and immunomodulatory drugs in the treatment of cancer

Thalidomide has antiangiogenic and immunomodulatory properties and has recently been used in the management of human malignancies. Multiple studies have confirmed its activity in multiple myeloma, alone or combined with dexamethasone and/or chemotherapy as first- or second-line treatment. In addition, it may reduce the need for transfusions in patients with myelofibrosis or myelodysplastic syndromes. The activity of thalidomide in solid tumours is less prominent. The most promising results have been reported in Kaposi's sarcoma, malignant melanoma and prostate cancer, especially when it is combined with chemotherapy. Recently, thalidomide analogues (immunomodulatory drugs), with higher immunomodulatory activity and different toxicity profile, have been developed. They have already shown promising activity in multiple myeloma and are currently being evaluated in clinical studies.

Thalidomide-derived immunomodulatory drugs as therapeutic agents

Thalidomide, a drug originally used to treat morning sickness, was removed from the market place in the early 1960s after it was found to cause serious congenital birth defects. However, thalidomide has recently been investigated in a new light following its activity in a number of chronic diseases. Moreover, like thalidomide itself, its second-generation immunomodulatory drug (IMiD) analogues have been shown to act as powerful anticancer agents and are clearly active in the treatment of patients with relapsed multiple myeloma. These new drugs, in particular the second-generation IMiDs, lenalidomide (CC-5013, REVLIMID; Celgene Corp., NJ, USA) and CC-4047 (ACTIMID; Celgene Corp.), offer improvements over thalidomide (a first-generation IMiD) in terms of efficacy and safety in human studies. The key to the therapeutic potential of IMiDs lies in the fact that the drugs have multiple mechanisms of action, which may produce both anti-inflammatory and antitumour effects. These effects are probably contextual, depending both on the cell type and the stimulus involved. Mechanisms associated with IMiD activity include TNF-alpha-inhibitory, T cell costimulatory and antiangiogenic activities. Studies of the mechanisms of action of these drugs are ongoing and will facilitate the continued development of this class of compound in a number of diseases.

Thalidomide : mécanismes d'action et indications en hématologie

Purpose. - Thalidomide, a major teratogen drug, was rehabilitated mainly in malignant hemopathy. Current knowledge and key points. - Thalidomide-mechanisms of action are well known, multiple, they combine immunomodulatory, antiangiogenic properties, and the modulation of cytokines, particularly tumour necrosis factor-alpha. Multiple trials are ongoing, however, the main indication remain multiple myeloma with a response rate of 30% in relapsed patients. Future prospects and projects. - New structural analogues of the thalidomide which priviligiate some of the thalidomide-specific mechanisms of action, the selected cytokine inhibitory drugs (SelCIDS) and the immunomodulatory drugs (IMiDs) family are under evaluation. The IMiDs, which mechanism is based on stimulation of T lymphopoiesis rather than inhibition of tumour necrosis factor-alpha, are under clinical trials in multiple myeloma with interesting results.

Single-agent thalidomide induces response in T-cell lymphoma

T-cell lymphoma is an aggressive lymphoma that cannot be cured despite aggressive therapy, including autologous stem cell transplantation. Thalidomide is an immunomodulatory drug with numerous properties that has proven effective in relapsed multiple myeloma and, to a lesser extent, in other hematologic diseases. We report three cases of relapsed refractory T-cell lymphoma treated with thalidomide with a good tumor response.

Thalidomide in cancer medicine

Thalidomide, an oral agent with antiangiogenic and immunomodulatory properties, is being investigated extensively in the management of advanced cancer. Multiple studies with large numbers of patients have confirmed that this drug has significant activity in multiple myeloma. Some patients with myelofibrosis or myeodysplatic syndromes may reduce their need for transfusions after thalidomide treatment. The activity of thalidomide in solid tumors is less prominent. Studies in Kaposi's sarcoma, malignant melanoma, renal cell carcinoma and prostate cancer appear more promising especially when thalidomide is combined with biological agents or with chemotherapy. Limited activity was demonstrated in patients with glioma, while thalidomide appears to be inactive in patients with head and neck cancer, breast or ovarian cancer.

Adverse effects of thalidomide administration in patients with neoplastic diseases

Thalidomide, a glutamic acid derivative, was withdrawn from clinical use in 1962 due to its severe teratogenic effects. Its recent reinstitution in clinical practice was related to its benefits in leprosy and multiple myeloma. Moreover, the antiangiogenic and immunomodulatory properties of thalidomide have led to its evaluation in several malignant diseases, including myelofibrosis, renal cell cancer, prostate cancer, and Kaposi sarcoma. However, thalidomide use is associated with several side effects: somnolence and constipation are the most common, while deep vein thrombosis and peripheral neuropathy are the most serious. A combination of thalidomide with steroids or chemotherapy is being evaluated in several phase 2 studies. While it is not yet clear whether these combinations will enhance efficacy, they appear to increase the toxicity of thalidomide, and thalidomide analogs are being developed to minimize this toxicity. Ongoing studies will clarify the potential advantages of these agents in the treatment of neoplastic diseases.

Hematopoietic Cancer and Angiogenesis

The growth of solid tumors is certainly angiogenesis dependent. However, the role of angiogenesis in the growth and survival of leukemias and other hematological malignancies has only been rendered evident since 1994 in a series of demonstrations showing that the progression of several forms is clearly related to their degree of angiogenesis. Here, we present an overview of the literature concerning the relationship between angiogenesis and disease progression in several hematological malignancies and the recent advances in antiangiogenesis in these diseases and we describe the most important active substances, preclinical and clinical data, and future perspectives.

The therapy of relapsed acute leukaemia in adults

Although the cure of acute leukaemia has improved significantly, many patients will still relapse and die. The unraveling of the molecular pathogenesis of acute leukaemia has lead to the identification of new prognostic factors and improved the detection of minimal residual disease. The treatment of relapsed acute leukaemia with chemotherapy remains unsatisfactory. Allogeneic or autologous blood and marrow transplant (BMT) can cure a subset of patients with relapsed acute leukaemia. The identification of the graft-vs-leukaemia (GVL) effect has lead to the development of donor lymphocyte infusions to re-induce remission in patients with relapsed leukaemia after allogeneic BMT and also stimulated the development of the less toxic nonmyeloablative allogeneic transplant approach. The identification of molecular targets of therapy and the development of monoclonal antibody-directed therapy has generated optimism. It is possible that combinations of chemotherapy, molecularly directed therapy, and immunotherapy may be combined to cure an increasing proportion of patients with acute leukaemia.