Thalidomide in the treatment of cancer

Overcoming cancer therapeutic bottleneck by drug repurposing

Ever present hurdles for the discovery of new drugs for cancer therapy have necessitated the development of the alternative strategy of drug repurposing, the development of old drugs for new therapeutic purposes. This strategy with a cost-effective way offers a rare opportunity for the treatment of human neoplastic disease, facilitating rapid clinical translation. With an increased understanding of the hallmarks of cancer and the development of various data-driven approaches, drug repurposing further promotes the holistic productivity of drug discovery and reasonably focuses on target-defined antineoplastic compounds. The "treasure trove" of non-oncology drugs should not be ignored since they could target not only known but also hitherto unknown vulnerabilities of cancer. Indeed, different from targeted drugs, these old generic drugs, usually used in a multi-target strategy may bring benefit to patients. In this review, aiming to demonstrate the full potential of drug repurposing, we present various promising repurposed non-oncology drugs for clinical cancer management and classify these candidates into their proposed administration for either mono- or drug combination therapy. We also summarize approaches used for drug repurposing and discuss the main barriers to its uptake.

Thalidomide Reduces Vascular Endothelial Growth Factor Immunostaining in Canine Splenic Hemangiosarcoma

Hemangiosarcomas (HSA) are common neoplasms of dogs that often metastasize and are typically fatal. Recently it was demonstrated that thalidomide extends the survival time of dogs with HSA, potentially due to thalidomide-induced inhibition of vascular endothelial growth factor (VEGF) production by the neoplastic cells. To investigate this, immunostaining was used to evaluate VEGF within HSA metastases that developed after thalidomide treatment. The immunostaining was then compared to VEGF immunostaining in primary tumors from the same dogs prior to treatment with thalidomide and in metastatic tumors from untreated dogs with splenic HSA. Immunostaining was scored from 1 to 4 for each sample. Immunostaining in the metastatic lesions that had been treated with thalidomide had a mean immunostaining score of 1.4 which was significantly lower than the mean score in the corresponding primary splenic HSA (3.8, p = 0.02) and in metastases from untreated dogs (3.5, p = 0.02). This supports the hypothesis that thalidomide prolongs survival time in dogs with HSA due to inhibition of VEGF production by the neoplastic cells. As VEGF remained visible within HSAs exposed to thalidomide, additional treatments to inhibit VEGF production may further prolong survival times of dogs with these common canine neoplasms.

Adjuvant Thalidomide and Metronomic Chemotherapy for the Treatment of Canine Malignant Mammary Gland Neoplasms

BACKGROUND/AIM

The aim of the present study was to evaluate a multimodal approach for the treatment of canine malignant mammary gland neoplasms, including surgery, chemotherapy, thalidomide, and metronomic chemotherapy (MC).

MATERIALS AND METHODS

Fifty-eight female dogs were submitted to four different treatments: surgery; surgery with chemotherapy; surgery with chemotherapy and thalidomide; and surgery with chemotherapy and metronomic chemotherapy and overall survival was evaluated.

RESULTS

No statistical difference was found in the proliferative index and microvessel density of primary neoplasms and distant metastases following thalidomide treatment. Diffuse intense inflammatory infiltrate was predominant in primary tumors and diffuse moderate inflammatory infiltrate in metastatic lesions. No statistically significant difference was observed in median survival time (MST) between treatment groups when including all clinical stages (p=0.3177). However, animals diagnosed with distant metastasis treated with surgery and chemotherapy associated with thalidomide or MC presented longer MST when compared to animals treated only with surgery or surgery and chemotherapy (p<0.0001).

CONCLUSION

The proposed multimodal therapy protocols including antiangiogenic and immunomodulatory therapies demonstrated a clinical benefit for patients in advanced clinical stages.

Thalidomide combined with transcatheter artierial chemoembolzation for primary hepatocellular carcinoma: a systematic review and meta-analysis

OBJECTIVE

Transcatheter arterial chemoembolization (TACE) and thalidomide have been used for treating primary hepatocellular carcinoma(HCC). This study aims to evaluate the clinical efficacy and safety of thalidomide and TACE in primary HCC.

METHODS

Randomized controlled trials(RCTs) about efficacy and safety of thalidomide combined with TACE for primary HCC were identified from the Cochrane Library, Pubmed, Embase, CNKI, and Wan Fang until August, 2016. The retrieved trials were reviewed and the data were extracted by two reviewers, independently. Combined analyses of survival rates, overall response rate(ORR), disease control rate(DCR), changes of KPS, parameters of cellular immunity and vascular endothelial growth factor(VEGF), and adverse events were performed using RevMan 5.3 software.

RESULTS

A total of 23 RCTs involving 1836 patients were included. The results showed that thalidomide plus TACE was significantly superior in increasing 6-month survival rate(OR=1.79, 95% CI:1.02-3.15, P=0.04), 1-year survival rate(OR=1.76, 95% CI:1.38-2.24, P<0.0001), 1.5-year survival rate(OR=4.72, 95% CI:2.64-8.43, P<0.001), 2-year survival rate(OR=1.78, 95% CI:1.37-2.30, P<0.001), ORR(OR=1.89, 95% CI:1.48-2.42, P<0.0001), DCR(OR=2.62, 95% CI:1.90-3.63, P<0.001), improvement in cellular immunity(MD=0.63, 95% CI:0.45-0.80, P<0.0001), and reduction of VEGF(MD=-119.71, 95% CI:-135.75-103.68, P<0.0001), when compared with TACE group. The incidences of gastrointestinal reactions, myelosuppression, and liver dysfunction were similar between combination group and TACE group(P>0.05). However, compared to TACE, the combination of thalidomide and TACE had a higher incidence of drug rash(OR=6.35, 95% CI:2.75-14.68, P<0.0001).

CONCLUSION

Our findings suggest that thalidomide combined with TACE shows better clinical efficacy and tolerable adverse events in patients with primary HCC when compared with TACE alone.

Does thalidomide prolong survival in dogs with splenic haemangiosarcoma?

OBJECTIVES

To investigate thalidomide as an adjuvant treatment for canine haemangiosarcoma.

MATERIALS AND METHODS

Fifteen dogs with splenic haemangiosarcoma, initially treated by splenectomy, were included. Following recovery from surgery, all dogs received thalidomide continuously until their death. Tumour stage was established using CT scans of the chest and abdomen immediately before starting thalidomide treatment and again three months later. Cause of death was confirmed by post mortem examination.

RESULTS

The median survival time of dogs receiving thalidomide was 172 days (95% confidence interval: 93 to 250 days). Five dogs (33% of the population receiving thalidomide) survived more than 1 year (range 458 to 660 days) after surgery. Dogs with stage 2 disease that received thalidomide also had a longer survival time than dogs with stage 3 disease (median survival time 303 versus 40 days). Of 15 dogs, 13 died from metastatic haemangiosarcoma.

CLINICAL SIGNIFICANCE

Treatment using thalidomide may improve survival of dogs with splenic haemangiosarcoma and should be considered a possible adjuvant therapy.

The protective effect of thalidomide on left ventricular function in a rat model of diabetic cardiomyopathy

AIMS

To evaluate the protective effect of thalidomide, a potent anti-inflammatory drug, on the development of diabetic cardiomyopathy (DMCMP).

METHODS AND RESULTS

We induced type 1 diabetes using streptozocin in 8-week-old Sprague-Dawley rats, divided them into two groups-a thalidomide treatment group (DM-T, n = 15) and a non-treatment group (DM-N, n = 15)-and compared them with a normal control (n = 10). Ten weeks after diabetes induction, heart and lung mass indices were higher in the DM-N group compared with the control group. In the DM-T group, increases in heart and lung mass indices were attenuated compared with the DM-N group. On echocardiographic examination, systolic and diastolic mitral annulus velocities were impaired in the DM-N group, but they remained normal in the DM-T group. On haemodynamic analyses, left ventricular (LV) systolic function, represented by end-systolic elastance (0.35 ± 0.14 vs. 0.18 ± 0.07 mmHg/μl, P < 0.001) and preload-recruitable stroke work (90.5 ± 24.3 vs. 51.8 ± 22.0 mmHg, P < 0.001), was preserved in the DM-T group compared with the DM-N group. Likewise, deterioration of LV diastolic function was attenuated in the DM-T group. Increases in serum levels of TNF-α were attenuated in the DM-T group compared with the DM-N group. On histological analysis, thalidomide treatment lowered total myocardial collagen content and the expression of TNF-α, IL-1β, ICAM-1, and VCAM-1.

CONCLUSION

In an animal model of DMCMP, deterioration of LV systolic and diastolic function was partially prevented by thalidomide treatment.

Successful treatment of idiopathic febrile panniculitis (Weber-Christian disease) with thalidomide in a patient having failed multiple other medical therapies

The authors describe a case of idiopathic nodular panniculitis (Weber-Christian disease) with recurrent febrile episodes resistant to glucocorticosteroids and methotrexate (MTX) in various combinations with hydroxychloroquine, azathioprine, cyclosporine, colchicine, and doxycycline. Thalidomide at 100 mg/day has induced a remission for 3 years.

Thalidomide for treating metastatic hepatocellular carcinoma: a pilot study

BACKGROUND

Thalidomide has been reported to have antitumor activity for treating metastatic hepatocellular carcinoma (HCC). We evaluated the safety and efficacy of using thalidomide for treating selected patients with unresectable or metastatic HCC, and their disease was refractory to systemic chemotherapy.

METHODS

Eight patients with measurable and metastatic HCC that had progressed with prior systemic chemotherapy and who desired further active therapy were enrolled in this study. Thalidomide was given orally at bedtime and it was started at 200 mg/day with no further dose escalation. The response was measured at 2-month intervals.

RESULTS

The median age was 44 years (range: 34-52 years) and all the patients had received doxorubicin-based systemic chemotherapy prior to their enrollment. Each patient received thalidomide for a median of 152 days (range: 5-422 days). One partial response was observed (12.5%, 95% CI; 0-42%) along with 4 cases of stable diseases. The most commonly encountered toxicity was somnolence; grade 3 somnolence was noted for one patient, which led to treatment discontinuation. Skin rash was observed in one responding patient.

CONCLUSIONS

The results indicate that thalidomide may feasibly offer disease stabilization to metastatic HCC patients. Further dose escalation of thalidomide, or its combination with other chemotherapeutic agents, may be of interest and this should be investigated for treating patients with metastatic HCC.

Effects of Thalidomide Treatment in Heart Failure Patients

BACKGROUND

Several studies have reported a direct association between elevated plasma levels of inflammatory cytokines and worse functional class (New York Heart Association [NYHA]) and cardiac function, measured as left ventricular ejection fraction (LVEF). Thalidomide has recently shown to improve LVEF in chronic heart failure patients, accompanied by a marked decrease in plasma levels of tumor necrosis factor alpha (TNF-alpha).

METHODS

In a randomized prospective open label study of men and women with heart failure (HF) due to ischemic and non-ischemic cardiomyopathy who had systolic dysfunction (LVEF <40%) and NHYA classification, functional classes II and III were assigned to control (without thalidomide, 60 patients) or thalidomide group (20 patients). The initial dose of thalidomide was 100 mg once a day, and it was increased to 100 mg twice a day after a period of 10 days, if the prior dosage was well-tolerated. Demographic characteristics, etiology of HF, prior myocardial infarction, co-morbidities associated were registered and laboratory routine test, TNF-alpha serum levels, and echocardiogram were obtained at the beginning and after 6 months of follow-up.

RESULTS

Clinical status (NYHA) at the end of the follow-up period, improved moderately in both groups. TNF-alpha levels were initially of 5.88 +/- 0.9 and 6.49 +/- 1.82 vs. 6.32 +/- 1.6 and 7.94 +/- 3.8 pg/ml during follow-up, for thalidomide and control groups, respectively. There were non-significant differences in echocardiography variables.

CONCLUSION

In conclusion, although there is a large amount of information supporting a direct relationship between TNF-alpha and worsening of symptoms and prognosis in patients with HF and recently, the beneficial effect on thalidomide treatment has been suggested, these preliminary observations should be confirmed in a larger prospective study, specially trying to clarify the action mechanisms.

Second-line strategies for metastatic renal cell carcinoma: classics and novel approaches

OBJECTIVES

Renal cell carcinoma is an aggressive malignancy with a high propensity for both early and metachronous regional and distant metastasis. While surgical resection is the mainstay of therapy for patients with localized disease, the prognosis for patients with distant metastasis is poor with a 5-year survival rate of less than 10%. Response rates to first-line immunotherapy or immunochemotherapy range from 10-35%; responses achieved are predominantly partial remissions of short duration. Until today, there is no standard therapeutic procedure for the growing number of patients who relapse following first-line therapy and desire further active treatment.

MATERIALS AND METHODS

This article reviews classic and recent publications about second- and third-line approaches, their potential efficacy and toxicity.

RESULTS

Several novel approaches have raised well-founded hope. Especially the application of monoclonal antibodies targeting VEGF signalling as well as different receptor tyrosine kinase inhibitors have the potential to change the face of second-line treatment of patients with metastatic RCC. Both groups of agents are focused in current phase III trials, either as mono- and/or combination therapy.

CONCLUSIONS

Until today, second-line treatment of patients with metastatic RCC progressing under therapy with biological response modifiers remains an unresolved issue. The results of ongoing clinical trials evaluating novel targeted approaches can be expected with suspense.

Effect of thalidomide on cardiac remodeling in chronic heart failure: results of a double-blind, placebo-controlled study

BACKGROUND

Inflammation and matrix degradation may play a pathogenic role in chronic heart failure (CHF), and therefore, we examined whether thalidomide, a drug with potential immunomodulating and matrix-stabilizing properties, could improve left ventricular (LV) function in patients with CHF secondary to idiopathic dilated cardiomyopathy (IDCM) or coronary artery disease (CAD).

METHODS AND RESULTS

Fifty-six patients with CHF and an LV ejection fraction (LVEF) <40% who were already on optimal conventional cardiovascular treatment were randomized to thalidomide (25 mg QD increasing to 200 mg QD) or placebo and followed up for 12 weeks. Our main findings were as follows: (1) During thalidomide treatment but not during placebo, there was a marked increase in LVEF (&7 EF units) along with a significant decrease in LV end-diastolic volume and heart rate. (2) This improvement in LVEF was accompanied by a decrease in matrix metalloproteinase-2 without any changes in its endogenous tissue inhibitor, suggesting a matrix-stabilizing net effect. (3) Thalidomide also induced a decrease in total neutrophil count and an increase in plasma levels of tumor necrosis factor-alpha, suggesting both proinflammatory and antiinflammatory effects. (4) The effect of thalidomide on LVEF was more marked in IDCM than in CAD, possibly partly reflecting that the former group was able to tolerate a higher thalidomide dosage.

CONCLUSIONS

Although our results must be confirmed in larger studies that also examine the effects on morbidity and mortality, our findings suggest a role for thalidomide in the management of CHF in addition to traditional cardiovascular medications.

Agents targeting inflammation in heart failure

Evidence from both experimental and clinical trials indicates that inflammatory mediators are important in the pathogenesis of chronic heart failure (HF), contributing to cardiac remodelling and peripheral vascular disturbances. Several studies have shown raised levels of inflammatory cytokines such as TNF-alpha, IL-1beta and -6 in HF patients in plasma, circulating leukocytes, atherosclerotic lesions, and in the failing myocardium itself. Importantly, this rise in inflammatory mediators does not seem to be accompanied by a corresponding increase in anti-inflammatory cytokines such as IL-10 and transforming growth factor-beta; thus resulting in an inflammatory imbalance in the cytokine network. Traditional cardiovascular drugs have little influence on the cytokine network in HF patients. Results from randomised, placebo-controlled anti-TNF studies suggest lack of effect of such therapy. Although somewhat disappointing, these negative results do not necessarily argue against the 'cytokine hypothesis'; these studies just underscore the challenges in understanding the complex cytokine network in order to develop effective treatment modalities in HF patients. More general immunmodulating treatments, such as pentoxyfylline, intravenous immunoglobulin, thalidomide and statins, have shown promising results in smaller studies, which need to be confirmed in larger studies with hospitalisations and death as the end points. In addition, further research in this area will have to be more precise in identifying the most important 'actors' in the immunopathogenesis of chronic HF.

Inflammatory and anti-inflammatory cytokines in chronic heart failure: potential therapeutic implications

Persistent inflammation, involving increased levels of inflammatory cytokines, seems to play a pathogenic role in chronic heart failure (HF) by influencing heart contractility, inducing hypertrophy and promoting apoptosis, contributing to myocardial remodeling. While several stimuli may be operating such as heat shock proteins, microbial antigens and oxidative stress, it seems that the inflammatory response to these stimuli may represent a common final pathogenic pathway in HF regardless of the initial event. Traditional cardiovascular drugs appear to have little influence on the cytokine network, and immunomodulatory therapy has emerged as a possible new treatment modality in HF. Several animal studies and also some clinical studies have suggested that downregulation of inflammation may improve cardiac performance. However, the results from the placebo-controlled anti-tumor necrosis factor studies suggest no improvement or even adverse effects of such therapy. Although somewhat disappointing, these negative results do not necessarily argue against the 'cytokine hypothesis'. These studies just underscore the challenges in developing treatment modalities that can modulate the cytokine network in HF patients resulting in beneficial net effects. Further research will have to identify more precisely the most important actors in the immunopathogenesis of chronic HF in order to develop more specific immunomodulating agents for this disorder.

Therapeutic potential of anticytokine therapy in congestive heart failure

Accumulating evidence indicates that inflammatory cytokines play a pathogenic role in congestive heart failure (CHF) by influencing heart contractility, inducing hypertrophy, and promoting apoptosis or fibrosis, contributing to the continuous myocardial remodeling process. While several stimuli may be operating such as heat-shock protein, microbial antigen, bacterial lipopolysaccharide, shear and oxidative stress, hypoxia and oxidized low-density lipoprotein (LDL), it seems that the inflammatory response to these stimuli may represent a common final pathogenic pathway in CHF regardless of the initial event. Traditional cardiovascular drugs seem to have little influence on the overall cytokine network, and immunomudulatory therapy has emerged as a possible new treatment modality in CHF. Several animal studies, and some clinical pilot studies, have suggested that down-regulation of inflammatory cytokines may improve cardiac performance. On the other hand, preliminary results from the placebo-controlled studies suggest no effect, or even adverse effect, of antitumor necrosis factor (TNF) therapy on mortality and hospitalization. Although somewhat disappointing, these negative results do not necessarily argue against the 'cytokine hypothesis'. These studies just underscore the difficulties and the challenges in developing treatment modalities that can modulate the cytokine network in CHF patients resulting in anti-inflammatory and beneficial net effects. Further research in this area will have to more precisely identify the most important actors in the immunopathogenesis of CHF in order to develop more specific immunomodulating agents for this disorder. However, at present the beneficial role of anticytokine therapy in patients with CHF remains unproven.

A wholly nutritional 'multifocal angiostatic therapy' for control of disseminated cancer

A great deal of effort is now being devoted to the development of new drugs that hopefully will control the spread of inoperable cancer by safely inhibiting tumor-evoked angiogenesis. However, there is growing evidence that certain practical nutritional measures have the potential to slow tumor angiogenesis, and it is reasonable to anticipate that, by combining several measures that work in distinct but complementary ways to impede the angiogenic process, a clinically useful 'multifocal angiostatic therapy' (MAT) might be devised. Several measures which might reasonably be included in such a protocol are discussed below, and include: a low-fat, low-glycemic index vegan diet, which may down-regulate the systemic IGF-I activity that supports angiogenesis; supplemental omega-3-rich fish oil, which has been shown to inhibit endothelial expression of Flk-1, a functionally crucial receptor for VEGF, and also can suppress tumor production of pro-angiogenic eicosanoids; high-dose selenium, which has recently been shown to inhibit tumor production of VEGF; green tea polyphenols, which can suppress endothelial responsiveness to both VEGF and fibroblast growth factor; and high-dose glycine, whose recently reported angiostatic activity may reflect inhibition of endothelial cell mitosis, possibly mediated by activation of glycine-gated chloride channels. In light of evidence that tumor-evoked angiogenesis has a high requirement for copper, copper depletion may have exceptional potential as an angiostatic measure, and is most efficiently achieved with the copper-chelating drug tetrathiomolybdate. If logistical difficulties make it difficult to acquire this experimental drug, high-dose zinc supplementation can achieve a slower depletion of the body's copper pool, and in any case can be used as maintenance therapy to maintain an adequate level of copper depletion. A provisional protocol is offered for a nutritionally based MAT entailing a vegan diet and supplemental intakes of fish oil, selenium, green tea polyphenols, glycine, and zinc. Inasmuch as cox-2 is overexpressed in many cancers, and cAMP can boost tumor production of various angiogenic factors as well as autogenous growth factors, adjunctive use of cox-2-specific NSAIDS may be warranted in some cases.

Advances in molecular therapies in patients with brain tumors

BACKGROUND

We are witnessing the development of new treatment modalities for primary brain tumors. An area under intense investigation is the use of small molecules targeting intracellular signaling pathways that interfere with growth, invasion, and metastasis of high-grade gliomas.

METHODS

We review clinical trials of small molecules in adults with brain tumors. This search included electronic databases, specialty journals, textbooks, proceedings, and Web sites of the National Cancer Institute and other cooperative brain tumor groups in Europe and the United States.

RESULTS

Several drugs with the ability to down-regulate the growth and invasion of malignant gliomas are at various stages of testing. Most of these focus on interfering with oncogenic and tumor survival pathways. Examples include inhibitors of tyrosine kinases, farnesyltransferases, and matrix metalloproteinases. These molecules are at different stages of testing, and a conclusive picture of which drug is most effective, either alone or in combination, needs better definition. The metalloproteinase inhibitor marimastat with temozolomide has given the best results to date in phase II trials, increasing the rate of 6-month progression-free survival for recurrent glioblastoma multiforme and anaplastic gliomas.

CONCLUSIONS

As our understanding of the biology of gliomas increases and new drugs targeting specific molecular pathways enter well-designed cooperative trials, the control and prognosis of these tumors should improve.

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.

Clinical impact of novel treatment strategies

Following two decades of research on the biology of cancer and in particular of lung cancer, we have now a large number of molecular targets that can be utilized to create specific medicines against these cancers. Non-small cell lung cancer represents numerically the most important solid tumor in Western world, and is poorly affected by current therapies, where surgery represents almost the only curative therapy for about 25% of patients who are resectable at diagnosis. An abundant number of targeted therapies are being investigated in NSCLC. Among them are the metalloproteinase inhibitors, several tyrosine kinase inhibitors and several attempts of gene replacement have also been made. Promising results have so far been obtained with some of these approaches, and the outcome of large randomized studies is awaited. Small cell lung cancer (SCLC) represents about 20% of lung carcinomas, and several of the novel approaches that are being attempted for NSCLC, are also being investigated for SCLC. All these novel therapies open a new era of anticancer treatment that will likely complement the currently available therapies in the near future.

Mechanisms and future directions for angiogenesis-based cancer therapies

Targeting angiogenesis represents a new strategy for the development of anticancer therapies. New targets derived from proliferating endothelial cells may be useful in developing anticancer drugs that prolong or stabilize the progression of tumors with minimal systemic toxicities. These drugs may also be used as novel imaging and radiommunotherapeutic agents in cancer therapy. In this review, the mechanisms and control of angiogenesis are discussed. Genetic and proteomic approaches to defining new potential targets on tumor vasculature are then summarized, followed by discussion of possible antiangiogenic treatments that may be derived from these targets and current clinical trials. Such strategies involve the use of endogenous antiangiogenic agents, chemotherapy, gene therapy, antiangiogenic radioligands, immunotherapy, and endothelial cell-based therapies. The potential biologic end points, toxicities, and resistance mechanisms to antiangiogenic agents must be considered as these therapies enter clinical trials.

Effect of thalidomide in different tumors in rodents

This study investigated the effects of chronic administration of thalidomide on three different neoplasms of ectodermic origin in rodents: 1) chemically induced tumors of the nervous system of rats by transplacental exposure to ethylnitrosourea; 2) transplanted RPMI-1846 melanoma in hamsters and 3) transplanted C6 glioblastoma in rats. No effects were seen on thalidomide-treated rats on the frequency- and time of tumor development induced by ethylnitrosourea. In contrast, a reduction in tumoral growth and mitotic-index was obtained in animals treated with thalidomide in transplanted tumors, melanoma and glioblastoma, when compared with controls (P < 0.001 and 0.025, respectively). These results suggest that, although thalidomide is not a cytotoxic drug for neoplastic cells, it might partially inhibit the tumoral growth through any of its pharmacological actions; by blockage of cell-surface adhesion receptors induction of DNA oxidation, or inhibition of angiogenesis. Further investigations on the use of thalidomide perhaps associated to cytotoxic drugs, for treatment of ectodermic neoplasms seem guaranteed.

New drugs for the anorexia-cachexia syndrome

Anorexia and cachexia accompany advancing cancer to a greater extent than any other symptom. Cachexia alone causes 22% of cancer deaths. The pathophysiology of cachexia is distinctly different from that of starvation. Resting energy expenditures are elevated, and abnormal intermediary metabolism, proteolysis, and lipolysis occur independently of caloric intake. A facilatative interaction between catecholamines, prostaglandins, and inflammatory cytokines is responsible for cachexia. Successful treatment requires reduction of energy expenditures, reversal of anorexia, and correction of abnormal intermediary metabolism, lipolysis, and proteolysis. Multiple appetite stimulants can be used in combination. Several new potentially useful biologic agents have been tested in animal tumor models. Several of the anticachectic agents have demonstrated in vivo or in vitro antitumor activity. The biologic and clinical activity of each drug is reviewed herein, and potentially useful combinations are listed.

Structural development of biological response modifiers based on thalidomide

Thalidomide (N-alpha-phthalimidoglutarimide) is a teratogenic hypnotic/sedative agent which was used widely in the late 1950s and the early 1960s. In spite of its withdrawal from the market because of its severe teratogenicity, there has been a resurgence of interest in the drug in recent years due to its potential usefulness for the treatment of various diseases, including acquired immunodeficiency syndrome (AIDS) and various cancers. It has been revealed that thalidomide elicits pleiotropic effects and is a multi-target drug. Our structural development studies of thalidomide, focusing on tumor necrosis factor-alpha(TNF-alpha) production-regulating activity, anti-androgenic activity, puromycin-sensitive aminopeptidase-inhibiting activity, alpha-glucosidase-inhibiting activity, and inhibitory activities toward some other enzymes, are reviewed in relation to the pharmacological effects of thalidomide.

Thalidomide: dual benefits in palliative medicine and oncology

Thalidomide is an immunomodulator, anti-angiogenic agent, anti-cytokine, and anti-integrin. Alone or in combination with other drugs, thalidomide has also demonstrated anti-cachexin and anti-neoplastic properties. Anorexia and cachexia are common symptoms of advanced cancer. Since certain cytokines also promote tumor growth, we may have a class of agents with palliative and anti-tumor benefits in combination with anti-neoplastics and anti-cytokines, such as thalidomide.