Activity of thalidomide in AIDS-related Kaposi's sarcoma and correlation with HHV8 titre

Immunotherapy for KSHV-associated diseases

Kaposi sarcoma herpesvirus (KSHV)-associated diseases (Kaposi sarcoma, multicentric Castleman disease, primary effusion lymphoma, and KSHV inflammatory cytokine syndrome) are associated with immune suppression and dysregulation and loss of KSHV-specific immunity. These diseases are most frequent in people living with HIV as well as those with primary or iatrogenic immune deficiencies. KSHV itself can modulate the immune system via viral homologs of host cytokines or downregulation of immune-surface markers altering host immune surveillance. These factors make KSHV-associated diseases prime targets for immunotherapy approaches. Several agents have been studied or are under investigation in KSHV-associated diseases, including monoclonal antibodies, immunomodulatory agents, and therapeutic cytokines. Here, we review the role of immunotherapies in KSHV-associated diseases.

AMC-070: Lenalidomide Is Safe and Effective in HIV-Associated Kaposi Sarcoma

PURPOSE

Kaposi sarcoma (KS), an endothelial cell tumor associated with KS herpesvirus (KSHV), remains among the most common malignancies occurring with HIV infection (HIV-KS). As an oral anti-inflammatory, antiangiogenic, and immunomodulatory agent, lenalidomide is potentially an attractive alternative to standard chemotherapy for KS.

EXPERIMENTAL DESIGN

The primary objectives of this phase I/II trial were to determine the maximum tolerated dose (MTD) and response rates for lenalidomide in HIV-KS. Secondary objectives included correlating response with natural killer (NK) and T-cell subsets, plasma cytokines, viral copy number, and KSHV gene expression in biopsies. Four dose levels of oral lenalidomide taken 21 consecutive days of 28-day cycles were evaluated in adults with HIV-KS on antiretroviral therapy with controlled viremia.

RESULTS

Fifteen and 23 participants enrolled in phases I and II, respectively, 76% of whom had received prior KS therapy. The MTD was not reached, declaring 25 mg as the recommended phase II dose (RP2D). The most frequent adverse events were neutropenia, fatigue, leukopenia, and diarrhea. Of the 25 evaluable participants receiving RP2D, 60% responded. Correlative studies performed in a subset of participants demonstrated a significant increase in proportions of blood T cells with T-regulatory phenotype, and plasma cytokines trended toward a less inflammatory pattern. Clinical response was associated with loss of KSHV transcription.

CONCLUSIONS

Lenalidomide is active in HIV-KS. The most common adverse events were manageable. With 60% of participants receiving RP2D obtaining a partial response and <10% discontinuing due to adverse events, the response and tolerability to lenalidomide support its use in HIV-KS. See related commentary by Henry and Maki, p. 2485.

Oncologic Treatment of HIV-Associated Kaposi Sarcoma 40 Years on

The observation in 1981 of the emergence of Kaposi sarcoma (KS) among young men who had sex with men was one of the first harbingers of the HIV epidemic. With advances in HIV care, the incidence of HIV-associated KS (HIV⁺KS) has decreased over time in the United States. However, it remains a persistent malignancy among some HIV-infected populations and is one of the most common tumors in sub-Saharan Africa. Because of the relapsing and remitting nature of this cancer, patients with HIV⁺KS can experience significant, long-term, morbidity. Patients with severe HIV⁺KS may also have concurrent lymphoproliferative syndromes, malignancies, and/or infections that can contribute to mortality. Several chemotherapy agents were explored in clinical trials for HIV⁺KS during the early stage of the epidemic. As HIV⁺KS emerges with CD4 lymphopenia and immunodysregulation, T-cell-sparing options are important to consider. Here, we explore the pathogenesis of HIV⁺KS and the current evidence for immunotherapy and therapies that potentially target KS pathogenesis. This review provides the current landscape of therapies for HIV⁺KS and highlights management issues for patients with HIV and cancer.

Safety, activity, and long-term outcomes of pomalidomide in the treatment of Kaposi sarcoma among individuals with or without HIV infection

PURPOSE

Kaposi sarcoma (KS) is caused by Kaposi sarcoma herpesvirus ((KSHV), also known as human herpesvirus 8 (HHV-8)). KS, which develops most frequently among people with HIV, is generally treated with chemotherapy, but these drugs have acute and cumulative toxicities. We previously described initial results of a trial of pomalidomide, an oral immunomodulatory derivative of thalidomide, in patients with KS. Here, we present results on the full cohort and survival outcomes.

EXPERIMENTAL DESIGN

Participants with KS with or without HIV were treated with pomalidomide 5mg once daily for 21 days per 28-day cycle with aspirin 81mg daily for thromboprophylaxis. Participants with HIV received antiretroviral therapy. Response was defined by modified version of the AIDS Clinical Trial Group KS criteria. We evaluated tumor responses (including participants who had a second course), adverse events, progression-free survival (PFS), and long-term outcomes.

RESULTS

Twenty-eight participants were enrolled. Eighteen (64%) were HIV-positive, 21 (75%) had advanced (T1) disease. Overall response rate was 71%: 95% confidence interval (CI) 51-87%. Twelve of 18 HIV-positive (67%; 95% CI: 41-87%) and 8 of 10 HIV-negative participants (80%; 95% CI: 44-97%) had a response. Two of 4 participants who received a second course of pomalidomide had a partial response. The median PFS was 10.2 months (95% CI: 7.6-15.7 months). Grade 3 neutropenia was noted among 50% of participants. In the follow-up period, 3 participants with HIV had other KSHV-associated diseases.

CONCLUSIONS

Pomalidomide is a safe and active chemotherapy-sparing agent for the treatment of KS among individuals with or without HIV.

Oral disease-modifying antirheumatic drugs and immunosuppressants with antiviral potential, including SARS-CoV-2 infection: a review

There have been several episodes of viral infection evolving into epidemics in recent decades, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the latest example. Its high infectivity and moderate mortality have resulted in an urgent need to find an effective treatment modality. Although the category of immunosuppressive drugs usually poses a risk of infection due to interference of the immune system, some of them have been found to exert antiviral properties and are already used in daily practice. Recently, hydroxychloroquine and baricitinib have been proposed as potential drugs for SARS-CoV-2. In fact, there are other immunosuppressants known with antiviral activities, including cyclosporine A, hydroxyurea, minocycline, mycophenolic acid, mycophenolate mofetil, leflunomide, tofacitinib, and thalidomide. The inherent antiviral activity could be a treatment choice for patients with coexisting rheumatological disorders and infections. Clinical evidence, their possible mode of actions and spectrum of antiviral activities are included in this review article.

LAY SUMMARY

Immunosuppressants often raise the concern of infection risks, especially for patients with underlying immune disorders. However, some disease-modifying antirheumatic drugs (DMARDs) with inherent antiviral activity would be a reasonable choice in the situation of concomitant viral infections and flare up of autoimmune diseases. This review covers DMARDs of treatment potential for SARS-CoV-2 in part I, and antiviral mechanisms plus trial evidence for viruses other than SARS-CoV-2 in part II.

AIDS-Related Kaposi Sarcoma, Version 2.2019, NCCN Clinical Practice Guidelines in Oncology

As treatment of HIV has improved, people living with HIV (PLWH) have experienced a decreased risk of AIDS and AIDS-defining cancers (non-Hodgkin's lymphoma, Kaposi sarcoma, and cervical cancer), but the risk of Kaposi sarcoma in PLWH is still elevated about 500-fold compared with the general population in the United States. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for AIDS-Related Kaposi Sarcoma provide diagnosis, treatment, and surveillance recommendations for PLWH who develop limited cutaneous Kaposi sarcoma and for those with advanced cutaneous, oral, visceral, or nodal disease.

Phase II Trial of Lenalidomide in HIV-Infected Patients with Previously Treated Kaposi's Sarcoma: Results of the ANRS 154 Lenakap Trial

Lenalidomide, an oral immunomodulating agent, has shown promising activity in HIV-infected individuals with Kaposi's sarcoma (KS). This single-arm, multicenter, open-label, Gehan's two-stage phase II trial evaluated the efficacy and safety of lenalidomide in HIV-infected patients with progressive KS despite previous chemotherapy (NCT01282047, ANRS 154 Lenakap trial). The primary endpoint was the rate of partial response (PR) or complete response (CR) at week 24, evaluated by both the study investigators and the patients using the Physical Global Assessment (PGA). AIDS Clinical Trials Group (ACTG) criteria for KS treatment evaluation were used as a secondary endpoint. The data and safety monitoring board recommended that enrollments be halted on April 24, 2013, because of lack of responses. We enrolled 12 antiretroviral-treated HIV-infected men with progressive KS despite previous chemotherapy. Their HIV plasma viral load was <50 copies/ml and their median CD4 cell count 444/mm³. One patient stopped taking lenalidomide because of hives at week 1 and a second patient died at week 7. The remaining 10 patients were assessable at week 24, when none had PGA-defined CR or PR and one had ACTG-defined PR. There were no additional PGA responses at week 48, but an additional three patients had ACTG responses, for a total of four patients with ACTG PR at week 48 (40%; 95% confidence interval: 12.2-73.8). Fourteen grade 3-4 adverse events were considered at least possibly related to lenalidomide during a total of 101 cycles. Lenalidomide was well tolerated in antiretroviral experienced patients with progressive KS previously treated with chemotherapy. The ACTG-defined response rate at week 48 was 40%, while it was 0% using PGA criteria.

Thalidomide in dermatology: revisited

The use of thalidomide in relation to dermatology is well- known and enough data is available in the literature about various aspects of thalidomide. Despite being an interesting and useful drug for many dermatoses, it is associated with many health hazards including the birth defects, phocomelia. We hereby present a comprehensive review about thalidomide and its application in dermatology.

Kaposi sarcoma-associated herpesvirus-associated malignancies: epidemiology, pathogenesis, and advances in treatment

Kaposi sarcoma associated herpesvirus (KSHV), a γ2-herpesvirus, also known as human herpesvirus-8, is the etiologic agent of three virally associated tumors: Kaposi sarcoma, a plasmablastic form of multicentric Castleman disease (KSHV-MCD), and primary effusion lymphoma. These malignancies are predominantly seen in people with acquired immunodeficiencies, including acquired immunodeficiency syndrome and iatrogenic immunosuppression in the setting of organ transplantation, but can also develop in the elderly. Kaposi sarcoma (KS) is most frequent in regions with high KSHV seroprevalence, such as sub-Saharan Africa and some Mediterranean countries. In the era of combination antiviral therapy, inflammatory manifestations associated with KSHV-infection, including KSHV-MCD, a recently described KSHV-associated inflammatory cytokine syndrome and KS immune reconstitution syndrome also are increasingly appreciated. Our understanding of viral and immune mechanisms of oncogenesis continues to expand and lead to improved molecular diagnostics, as well as novel therapeutic strategies that employ immune modulatory agents, manipulations of the tumor microenvironment, virus-activated cytotoxic therapy, or agents that target interactions between specific virus-host cell signaling pathways. This review focuses on the epidemiology and advances in molecular and clinical research that reflects the current understanding of viral oncogenesis, clinical manifestations, and therapeutics for KSHV-associated tumors.

The management of children with Kaposi sarcoma in resource limited settings

Kaposi sarcoma (KS) is common where HIV infection is endemic. Antiretroviral therapy (ART) has reduced the incidence in well-resourced settings but in some parts of the world access to ART is delayed. These recommendations are for use where only minimal requirements for treatment are available. Consensus was sought for the management of childhood HIV-associated KS in this setting. There are no randomised controlled studies of chemotherapy for KS in children and these recommendations have drawn on consensus of a group of experts and published reports from studies in adults.

The horizon for treating cutaneous vascular lesions

Dermatologists encounter a wide range of cutaneous vascular lesions, including infantile hemangiomas, port-wine stain birthmarks, arteriovenous malformations, venous malformations, Kaposi sarcomas, angiosarcomas, and angiofibromas. Current treatment modalities to reduce these lesions include topical and/or intralesional steroids, laser therapy, surgical resection, and endovascular therapy. However, each method has limitations owing to recurrence, comorbidities, toxicity, or lesion location. Photodynamic therapy, antiangiogenic therapy, and evolving methods of sclerotherapy are promising areas of development that may mitigate limitations of current treatments and offer exciting options for patients and their physicians.

Thalidomide: an old drug with new action

Thalidomide is a drug that, since its development, has made history in the world of medicine--having been withdrawn and now has returned with a boom as an anticancer and immunomodulatory drug. However, its mode of action in various diseases (i.e. different types of hematologic malignancies, solid tumors) as well as in various infections (i.e. pneumonia, tuberculosis, HIV infection etc.) and related inflammatory conditions is not well understood. As the immune system plays an important role in the pathogenesis of both infection-related as well as noninfectious (i.e. cancer) inflammatory diseases, much research has been done in the past few years to discover and design better immunomodulatory agents. Such immunomodulatory agents should be able to target the immune system in such a way that host suffers minimum damage and normal function of the immune system remains intact. In the present review an attempt is made to highlight the immunomodulatory action of thalidomide in various pathologic conditions.

KSHV activation of VEGF secretion and invasion for endothelial cells is mediated through viral upregulation of emmprin-induced signal transduction

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS)-one of the most common tumors arising in the setting of immune suppression. Hallmarks of KS lesions include KSHV-infected cells of endothelial lineage and neoangiogenesis. Promigratory factors secreted in the tumor microenvironment by KSHV-infected cells promote endothelial cell (EC) migration and angiogenesis but existing therapies targeting these pathways are not widely utilized. This underscores the need for additional characterization of KSHV-host interactions relevant to EC pathogenesis to identify new therapeutic targets. We recently demonstrated that de novo infection by KSHV promotes EC invasion through upregulation of extracellular matrix metalloproteinase inducer (emmprin)-a multifunctional glycoprotein previously shown to induce tumor cell invasion and regional angiogenesis through upregulation of signal transduction and promotion of tumor-stroma interactions. This study was undertaken to determine whether EC invasion for KSHV-infected cells is induced through activation of specific signal transduction pathways and proangiogenic factors by emmprin. We found that KSHV activation of emmprin induces PI3K/Akt- and mitogen-activated protein kinase (MAPK)-dependent secretion of vascular endothelial growth factor (VEGF). Functionally, EC invasion following de novo infection is induced by emmprin-dependent PI3K/Akt and MAPK activation of VEGF. These findings support the potential utility of targeting emmprin for reducing VEGF secretion and EC migration in the KS microenvironment.

Innovative uses of thalidomide

Thalidomide is approved for treating erythema nodosum leprosum and multiple myeloma, but it has also emerged as a useful treatment option for many refractory dermatologic disorders. Some of the innovative but off-label uses of thalidomide include aphthous stomatitis, Behçet's disease, lupus erythematosus, prurigo nodularis, sarcoidosis, actinic prurigo, graft-versus-host disease, Langerhans cell histiocytosis, erythema multiforme, lichen planus, Kaposi sarcoma, Jessner lymphocytic infiltrate, uremic pruritus, pyoderma gangrenosum, scleroderma, scleromyxedema, and necrobiosis lipoidica. This article reviews the background, pharmacology, and innovative uses of thalidomide in dermatology.

Thalidomide in the treatment of Kaposi's sarcoma

BACKGROUND

Kaposi's sarcoma (KS) is a lymphangioproliferative tumour. Therapy of KS depends on the characteristics of the disease, especially area and growth rate of lesions, and patient condition. Currently symptomatic resectable lesions are excised, whereas more advanced disease and unresectable lesions are treated with radiotherapy. If a large area or internal organs are affected or other treatments fail, chemotherapy is used. Recently some authors have reported their encouraging experience in the use of thalidomide in patients with AIDS-related KS.

OBJECTIVE

To evaluate the efficacy of thalidomide in 3 patients with non-AIDS-related KS.

METHODS

Two patients with classic widespread cutaneous and 1 with iatrogenic cutaneous and visceral KS were treated with thalidomide (100 mg/day) for 12 months.

RESULTS

In all 3 patients partial remission was evident after 4 months of thalidomide therapy; in 2 out of 3 complete remission was achieved after 12 months of treatment.

CONCLUSIONS

Our results seem to confirm the utility of thalidomide in the treatment of non-AIDS-related KS.

A Retrospective Analysis of Thalidomide Therapy in Non-HIV-Related Kaposi’s Sarcoma

BACKGROUND

Thalidomide has antiangiogenic and immunomodulatory properties and has recently been used in the management of human malignancies. Several studies have suggested its interest for treating AIDS-related Kaposi's sarcoma.

OBJECTIVES

This study aimed to assess the efficacy and toxicity of thalidomide, an antiangiogenic agent, for the treatment of non-HIV-related Kaposi's sarcoma.

METHODS

Eleven patients were included in this retrospective study conducted in the Department of Dermatology of Saint Louis, Paris, between 2000 and 2003. Among them, 2 were immunosuppressed (1 renal transplant recipient and 1 patient with microscopic polyangiitis treated by oral steroids) with stable immunosuppressive regimens during the past 6 months. The median daily thalidomide dosage was 100 mg and the median duration of drug treatment was 16 weeks.

RESULTS

Three patients achieved a partial response and 4 had a stable disease. Although no grade 3 or 4 was observed, 3 (27%) out of 11 patients prematurely discontinued thalidomide because of grade 1 sensory neuropathy (paresthesia) and vertigo.

CONCLUSIONS

Our results show a true although modest interest of thalidomide in non-HIV-related Kaposi's sarcoma and prompt us to evaluate less toxic thalidomide analogues for this indication.

Phase III Double-Blind, Placebo-Controlled Study of Thalidomide in Extensive-Disease Small-Cell Lung Cancer After Response to Chemotherapy: An Intergroup Study FNCLCC cleo04–IFCT 00-01

Purpose

This randomized, double-blind, placebo-controlled phase III study aimed to determine whether thalidomide prolongs survival of patients with extensive-disease small-cell lung cancer (SCLC).

Patients and Methods

One hundred nineteen patients received two courses of etoposide, cisplatin, cyclophosphamide, and 4′-epidoxorubicin (PCDE). Responder patients who had recovered from chemotherapy toxicity were randomly assigned to receive four additional PCDE cycles plus thalidomide (400 mg daily) or placebo.

Results

After the first two PCDE cycles, objective response rate was 81.5%, and 92 patients were randomly assigned to placebo (n = 43) or thalidomide (n = 49). Median exposure duration to placebo was 4.5 months, and median exposure to thalidomide was 4.9 months. Patients treated with thalidomide had a longer survival compared with patients who received placebo, although the difference was not statistically significant (minimal follow-up, 3 years; median survival time, 11.7 v 8.7 months, respectively; log-rank test: hazard ratio [HR] = 0.74; 95% CI, 0.49 to 1.12; P = .16). Patients with a performance status (PS) of 1 or 2 who received thalidomide had a significantly longer survival (HR = 0.59; 95% CI, 0.37 to 0.92; P = .02). The disease also progressed slower in patients with PS of 1 or 2 receiving thalidomide (HR = 0.54; 95% CI, 0.36 to 0.87; P = .02), whereas the difference did not reach statistical significance for the whole population (HR = 0.74; 95% CI, 0.49 to 1.12; P = .15). Neuropathy occurred more frequently in the thalidomide group compared with the placebo group (33% v 12%, respectively).

Conclusion

Treatment with thalidomide was not associated with a significant improvement in survival of SCLC patients. There was pronounced heterogeneity in survival outcomes between groups of patients. Some benefit was observed among patients with a PS of 1 or 2 (exploratory analyses), deserving further studies targeting angiogenesis in this disease.

Anterior Segment and External Ocular Disorders Associated with Human Immunodeficiency Virus Disease

The eye is a common site for complications of human immunodeficiency virus (HIV) infection. Although cytomegalovirus retinitis remains the most prevalent of the blinding ocular disorders that can occur in individuals with the acquired immunodeficiency syndrome (AIDS), several important HIV-associated disorders may involve the anterior segment, ocular surface, and adnexae. Some of these entities, such as Kaposi sarcoma, were well described, but uncommon, before the HIV epidemic. Others, like microsporidial keratoconjunctivitis, have presentations that differ between affected individuals with HIV disease and those from the general population who are immunocompetent. The treatment of many of these diseases is challenging because of host immunodeficiency. Survival after the diagnosis of AIDS has increased among individuals with HIV disease because of more effective antiretroviral therapies and improved prophylaxis against, and treatment of, opportunistic infections. This longer survival may lead to an increased prevalence of anterior segment and external ocular disorders. In addition, the evaluation and management of disorders such as blepharitis and dry eye, which were previously overshadowed by more severe, blinding disorders, may demand increased attention, as the general health of this population improves. Not all individuals infected with HIV receive potent antiretroviral therapy, however, because of socioeconomic or other factors, and others will be intolerant of these drugs or experience drug failure. Ophthalmologists must, therefore, still be aware of the ocular findings that develop in the setting of severe immunosuppression. This article reviews the spectrum of HIV-associated anterior segment and external ocular disorders, with recommendations for their evaluation and management.

Phase II study of thalidomide in patients with metastatic carcinoid and islet cell tumors

PURPOSE

Carcinoid and islet cell tumors are known to be highly vascular. There is no effective systemic therapy currently available for metastatic disease. We conducted a phase II trial to evaluate the efficacy of the anti-antiangiogenic agent thalidomide in metastatic neuroendocrine tumors.

PATIENTS AND METHODS

Eighteen patients with measurable, histologically proven metastatic carcinoid neuroendocrine carcinomas (well-differentiated, n = 13; moderately-differentiated, n = 5) were enrolled on this study. The majority of the patients had gastrointestinal primaries (small bowel, 8; pancreas, 5; colon, 1). All but one patient had hepatic metastases, and 12 patients (67%) had carcinoid syndrome. All patients had Eastern Cooperative Oncology Group performance status of zero or one. Eight patients (44%) had received previous hepatic artery chemoembolization and 11 (61%) had undergone surgical resection. Patients were started on oral thalidomide at a daily dose of 200 mg that was escalated to the target dose of 400 mg daily after 2 weeks. Tumor response was assessed at 12-week intervals using RECIST criteria. Planned treatment duration was 24 weeks unless unacceptable toxicity or disease progression was observed.

RESULTS

No patient achieved a partial remission or a complete remission. Best response was stable disease (SD) in 11 of 16 response-evaluable patients (69%). Serum pancreastatin results did not correlate with clinical response. Grade 3 toxicities included dizziness with orthostatic hypotension (n = 5), sensory neuropathy (n = 2), fatigue (n = 2), hemorrhagic cystitis (n = 1), and deep venous thrombosis (n = 1). Frequent Grade 1-2 toxicities were: fatigue (n = 13), constipation (n = 13), dry mouth (n = 12), somnolence (n = 12), dizziness/syncope (n = 10), weight gain (n = 5), and peripheral neuropathy (n = 5).

CONCLUSIONS

Thalidomide was fairly well tolerated in patients with metastatic carcinoid/islet cell tumors, but failed to reveal any objective responses. The single stage design of the trial makes it difficult to determine whether observed SD in a subset of patients was attributable to the indolent nature of these tumors, or to beneficial effect of thalidomide.

Kaposi sarcoma as a model of oncogenesis and cancer treatment

Kaposi sarcoma is the most common cancer among HIV-infected individuals and one of the most common cancers in sub-Saharan Africa. Kaposi sarcoma lesions are highly vascularized, and comprised of spindle-shaped tumor cells. Kaposi sarcoma herpesvirus is etiologically linked to Kaposi sarcoma development and encodes genes that contribute to cellular transformation, evasion of apoptosis, aberrant angiogenesis and an inflammatory tumor microenvironment. The study of Kaposi sarcoma herpesvirus-driven malignancies has provided a model of oncogenesis and identified some of the key steps and, therefore, therapeutic targets of Kaposi sarcoma development. However, current Kaposi sarcoma treatments are not specific and rely on reconstitution of the immune system and systemic administration of cytotoxic agents. Recent studies have demonstrated that mechanism-based therapeutics, such as vascular endothelial growth factor A or mammalian target of rapamycin inhibitors, are promising therapeutic approaches bridging basic research with clinical practice.

Targeting angiogenesis for the treatment of sarcoma

PURPOSE OF REVIEW

More therapeutic options are needed for bone and soft tissue sarcomas, especially for patients with metastatic disease. Recent randomized clinical trials conducted in colon, breast and lung cancer have shown the anti-vascular endothelial growth factor agent, bevacizumab, alone or in combination with chemotherapy, improves response and survival. Preclinical studies have demonstrated the anti-tumor effects of varied anti-angiogenic agents in sarcoma cell lines and tumor models.

RECENT FINDINGS

Preclinical studies in sarcomas have evaluated the role of targeted agents including platelet-derived growth factor, matrix metalloproteinases, urokinase receptor and varied small-molecule tyrosine kinase inhibitors. Novel angiogenesis inhibitors are being studied in the treatment of sarcoma, including monoclonal antibodies against vascular endothelial growth factor, cis- and trans-retinoic acids, thalidomide, and tyrosine kinase inhibitors. Phase I, II and III clinical trials continue to evaluate these agents alone, in combinations together and combined with standard chemotherapy. We review herein the preclinical rationale and clinical trial results of anti-angiogenesis therapy in the treatment of soft tissue and bone sarcoma.

SUMMARY

Preclinical mechanistic study and clinical trials are continuing in order to evaluate the therapeutic role and ultimately validate the efficacy of the varied anti-angiogenesis agents in soft tissue and bone sarcoma.

Molecular biology of KSHV in relation to AIDS-associated oncogenesis

KSHV has been established as the causative agent of KS, PEL, and MCD, malignancies occurring more frequently in AIDS patients. The aggressive nature of KSHV in the context of HIV infection suggests that interactions between the two viruses enhance pathogenesis. KSHV latent infection and lytic reactivation are characterized by distinct gene expression profiles, and both latency and lytic reactivation seem to be required for malignant progression. As a sophisticated oncogenic virus, KSHV has evolved to possess a formidable repertoire of potent mechanisms that enable it to target and manipulate host cell pathways, leading to increased cell proliferation, increased cell survival, dysregulated angiogenesis, evasion of immunity, and malignant progression in the immunocompromised host. Worldwide, approximately 40.3 million people are currently living with HIV infection. Of these, a significant number are coinfected with KSHV. The complex interplay between the two viruses dramatically elevates the risk for development of KSHV-induced malignancies, KS, PEL, and MCD. Although HAART significantly reduces HIV viral load, the entire T-cell repertoire and immune function may not be completely restored. In fact, clinically significant immune deficiency is not necessary for the induction of KSHV-related malignancy. Because of variables such as lack of access to therapy noncompliance with prescribed treatment, failure to respond to treatment and the development of drug-resistant strains of HIV, KSHV-induced malignancies will continue to present as major health concerns.

Toxicity profile of the immunomodulatory thalidomide analogue, lenalidomide: phase I clinical trial of three dosing schedules in patients with solid malignancies

Thalidomide is an anti-angiogenic agent currently used to treat patients with malignant cachexia or multiple myeloma. Lenalidomide (CC-5013) is an immunomodulatory thalidomide analogue licensed in the United States of America (USA) for the treatment of a subtype of myelodysplastic syndrome. This two-centre, open-label phase I study evaluated dose-limiting toxicities in 55 patients with malignant solid tumours refractory to standard chemotherapies. Lenalidomide capsules were consumed once daily for 12 weeks according to one of the following three schedules: (I) 25 mg daily for the first 7 d, the daily dose increased by 25 mg each week up to a maximum daily dose of 150 mg; (II) 25mg daily for 21 d followed by a 7-d rest period, the 4-week cycle repeated for 3 cycles; (III) 10 mg daily continuously. Twenty-six patients completed the study period. Two patients experienced a grade 3 hypersensitivity rash. Four patients in cohort I and 4 patients in cohort II suffered grade 3 or 4 neutropaenia. In 2 patients with predisposing medical factors, grade 3 cardiac dysrhythmia was recorded. Grade 1 neurotoxicity was detected in 6 patients. One complete and two partial radiological responses were measured by computed tomography scanning; 8 patients had stable disease after 12 weeks of treatment. Fifteen patients remained on treatment as named patients; 1 with metastatic melanoma remains in clinical remission 3.5 years from trial entry. This study indicates the tolerability and potential clinical efficacy of lenalidomide in patients with advanced solid tumours who have previously received multi-modality treatment. Depending on the extent of myelosuppressive pre-treatment, dose schedules (II) or (III) are advocated for large-scale trials of long-term administration.

Randomized Phase II Study Comparing Thalidomide With Medroxyprogesterone Acetate in Patients With Metastatic Renal Cell Carcinoma

Purpose

To investigate escalating doses of thalidomide compared with medroxyprogesterone in patients with metastatic renal cell carcinoma (RCC), who had either progressed after first-line immunotherapy or who were not suitable for immunotherapy.

Patients and Methods

Thalidomide was started at 100 mg/d orally (PO) and escalated by 100 mg/d every 2 weeks to the maximum dose of 400 mg/d. Medroxyprogesterone was given at a fixed dose of 300 mg PO daily.

Results

Sixty patients were entered (thalidomide:medroxyprogesterone = 29:31; median age, 59 [thalidomide], 60 [medroxyprogesterone]; No. of patients assessable for response, 22 [thalidomide], 26 [medroxyprogesterone]). In the thalidomide arm, there was no objective response seen. The best response was SD in three patients lasting 5+, 6+, and 12 months, respectively. All patients in the medroxyprogesterone arm progressed. There was no difference in overall survival between the two arms; median survival in the thalidomide arm was 8.2 months compared with 4.8 months in the medroxyprogesterone arm (P = .62). Hazard ratio was 0.88 (95% CI, 0.67 to 1.94). Median duration of treatment was 73 days (range, 14 to 364 days) in the thalidomide arm, and 84 days (range, 7 to 175 days) in the medroxyprogesterone arm. The high incidence of toxicity in the thalidomide arm, mainly somnolence, constipation, fatigue and paraesthesia, meant that only 30.8% of patients were able to tolerate the maximum dose of 400 mg/d of treatment.

Conclusion

Thalidomide is not superior to medroxyprogesterone acetate in patients with metastatic RCC. Its risk/benefit ratio does not favor its use in this patient population.

Thalidomide: dermatological indications, mechanisms of action and side-effects

Thalidomide was first introduced in the 1950s as a sedative but was quickly removed from the market after it was linked to cases of severe birth defects. However, it has since made a remarkable comeback for the U.S. Food and Drug Administration-approved use in the treatment of erythema nodosum leprosum. Further, it has shown its effectiveness in unresponsive dermatological conditions such as actinic prurigo, adult Langerhans cell histiocytosis, aphthous stomatitis, Behçet's syndrome, graft-versus-host disease, cutaneous sarcoidosis, erythema multiforme, Jessner-Kanof lymphocytic infiltration of the skin, Kaposi sarcoma, lichen planus, lupus erythematosus, melanoma, prurigo nodularis, pyoderma gangrenosum and uraemic pruritus. This article reviews the history, pharmacology, mechanism of action, clinical uses and adverse effects of thalidomide.

Thalidomide Is Inactive in Heavily Pretreated Patients with Metastatic Breast Cancer

Experimental studies have demonstrated that thalidomide has anti-tumor activity mediated by blockage of angiogenesis, with clinical efficacy in multiple myeloma, glioblastoma multiforme, and renal cell cancer. We investigated the therapeutic activity and toxicity of thalidomide in patients with progressive metastatic breast cancer pretreated with chemotherapy. Inclusion criteria were metastatic breast cancer in progression of disease after at least two lines of chemotherapy, age > or = 18 years, performance status < or = 2, and adequate hematologic, renal, and hepatic functions. Twelve patients entered the study, eight of whom were pretreated with three or more lines of chemotherapy (66.7%). Thalidomide was well tolerated: the most common side effects were constipation and somnolence (58.3% of patients). No objective response or durable stable disease was observed. Median time to progression and median overall survival were 8 weeks (range, 4-10 weeks) and 16 weeks (range, 8-54 weeks), respectively. In conclusion, thalidomide is an ineffective treatment in patients with progressive metastatic breast cancer heavily pretreated with chemotherapy.

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.

Use of liposomal anthracyclines in Kaposi’s sarcoma

Conventional chemotherapy regimens for the treatment of advanced Kaposi's sarcoma (KS) show limited efficacy and considerable toxicity. Liposomal anthracyclines with potential utility in KS include pegylated liposomal doxorubicin (Doxil/Caelyx [PLD]), daunorubicin citrate liposome (DaunoXome [DNX]), and nonpegylated liposomal doxorubicin (Myocet [NPLD]). Preclinical data showed that pegylated liposomes accumulate preferentially in highly vascularized KS lesions. In randomized clinical trials, PLD induced higher response rates than did the conventional combination chemotherapy regimens, bleomycin + vincristine (BV) and BV + conventional doxorubicin (ABV); DNX produced a response rate comparable to that of ABV. NPLD has not been compared with conventional chemotherapy for KS. PLD and DNX were associated with less toxicity compared with BV or ABV, including less alopecia and fewer gastrointestinal and neurologic side effects. Grade 3/4 myelosuppression was common with both PLD and DNX; stomatitis and infusion reactions occurred with PLD treatment, but hand-foot syndrome was relatively infrequent in the dose schedules used for KS. Health-related quality of life was improved in several domains in patients treated with PLD or DNX compared with ABV.

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.

Thalidomide: Current Role in the Treatment of Non-Plasma Cell Malignancies

Thalidomide, initially introduced as a sedative, was withdrawn from the market in the early 1960s after it was found to be a teratogen. However, it later found use as an investigational agent in the treatment of erythema nodosum leprosum, oral ulcers, graft versus host disease, and wasting associated with the human immunodeficiency syndrome. Its antiangiogenic properties were recognized in the early 1990s during a period where the importance of angiogenesis became increasingly apparent as a critical step in the in the proliferation and spread of malignant neoplasms. This led to the evaluation of thalidomide as an antiangiogenic agent in the treatment of several cancers. Thalidomide has already become part of standard therapy for the treatment of patients with relapsed and refractory multiple myeloma. It has also been found to have varying degree of benefit in various other malignancies. Although more clinical trials are needed, Kaposi's sarcoma and myelofibrosis represent other malignancies in which thalidomide has already demonstrated promising activity. The mechanism of action of thalidomide in cancer is still unclear, but do appear to be mediated by several other mechanisms in addition to its anti-angiogenic properties. This article reviews the current status of thalidomide for the treatment of non-plasma-cell malignancies.

Thalidomide

Despite its history as a human teratogen, thalidomide is emerging as a treatment for cancer and inflammatory diseases. Although the evolution of its clinical application could not have been predicted from the tragedy associated with its misuse in the past, its history serves as a lesson in drug development that underscores the need to understand the molecular pharmacology of a compound's activity, including associated toxicities. Here, we summarise the applications for thalidomide with an emphasis on clinical trials published over the past 10 years, and consider our knowledge of the molecular pharmacology of the drug in the context of clinical trial data, attempting to provide a mechanism-guided understanding of its activity.

Phase I study to determine the safety, tolerability and immunostimulatory activity of thalidomide analogue CC-5013 in patients with metastatic malignant melanoma and other advanced cancers

We assessed the safety, tolerability and efficacy of the immunomodulatory drug, CC-5013 (REVIMID™), in the treatment of patients with metastatic malignant melanoma and other advanced cancers. A total of 20 heavily pretreated patients received a dose-escalating regimen of oral CC-5013. Maximal tolerated dose, toxicity and clinical responses were evaluated and analysis of peripheral T-cell surface markers and serum for cytokines and proangiogenic factors were performed. CC-5013 was well tolerated. In all, 87% of adverse effects were classified as grade 1 or grade 2 according to Common Toxicity Criteria and there were no serious adverse events attributable to CC-5013 treatment. Six patients failed to complete the study, three because of disease progression, two withdrew consent and one was entered inappropriately and withdrawn from the study. The remaining 14 patients completed treatment without dose reduction, with one patient achieving partial remission. Evidence of T-cell activation was indicated by significantly increased serum levels of sIL-2 receptor, granulocyte–macrophage colony-stimulating factor, interleukin-12 (IL-12), tumour necrosis factor-α and IL-8 in nine patients from whom serum was available. However, levels of proangiogenic factors vascular endothelial growth factor and basic foetal growth factor were not consistently affected. This study demonstrates the safety, tolerability and suggests the clinical activity of CC-5013 in the treatment of refractory malignant melanoma. Furthermore, this is the first report demonstrating T-cell stimulatory activity of this class of compound in patients with advanced cancer.

Angiosarcoma of the small intestine: a possible role for thalidomide?

An 85-yr-old male presented with complaints of a 40-lb weight loss and a dull left upper quadrant abdominal pain. He also complained of decreased appetite, generalized weakness, generally not feeling well, and a dull left upper quadrant abdominal pain that was not relieved by food. He had a ventral and a left-sided inguinal hernia. Laboratory investigations revealed iron deficiency anemia, the cause of which was not apparent despite extensive investigation including computerized tomographic scans, esophagogastroduodenoscopy, and small-bowel follow-through examination. Surgical exploration for possible angiodysplasia, malignancy, and/or mesenteric ischemia revealed an incarcerated hernia, and the histopathological examination of the surgical specimen revealed high-grade angiosarcoma. The tumor showed strong positivity for vimentin and CD31 and a focal positivity for Factor VIII and CD34. At that time he was found to have hepatic metastases. He was started on thalidomide as an experimental measure with no change in the performance status and increasing evidence of necrosis in the metastatic lesion.

Dermatologic and nondermatologic uses of thalidomide

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION AND DATA EXTRACTION

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

DATA SYNTHESIS

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

CONCLUSIONS

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

Thalidomide: a new anticancer drug?

Experimental studies have demonstrated that thalidomide (Thal), a drug developed as a sedative, has antitumoural properties. The possible antitumour mechanisms of action involve: inhibition of angiogenesis, cytokine-mediated pathways, modulation of adhesion molecules, inhibition of cyclooxygenase-2 and stimulation of immuno response. Therefore, Thal is under clinical evaluation in oncology. This paper provides an overview of the data currently available in literature regarding, in terms of activity and toxicity, the use of Thal in cancer patients. Multiple myeloma is so far the most responsive malignancy. A moderate activity has been documented in certain solid tumours: glioblastoma multiforme, renal cell carcinoma and malignant melanoma. Tolerability is generally satisfactory with peripheral neuropathy being the most relevant dose-dependent toxicity. The more frequent, but moderate side effects are: somnolence, constipation, dizziness and fatigue. More studies are needed to properly evaluate the anticancer activity of Thal alone or in combination with other anticancer treatments. Preliminary studies suggest promising results of Thal in combinations with corticosteroids and cytotoxic drugs as front-line therapy of multiple myeloma. Regarding therapy of solid tumours in the adult, combination with chemotherapy, radiation therapy and molecular-targeting compounds are under investigation.

Therapy of AIDS-associated Kaposi's sarcoma: targeting pathogenetic mechanisms

Only a small number of the many agents with the potential to inhibit factors known to stimulate KS growth have been tested clinically, and many were investigated at a time when treatment options for HIV infection were relatively ineffective. The failure of some of these agents to induce KS regression may not signify failure to achieve a relevant biologic effect in all cases, but may simply mean that in a neoplasm that expresses a broad array of growth factors, inhibition of a single factor may be insufficient to achieve tumor regression. Moreover, agents that inhibit angiogenesis may be expected to stabilize tumors rather then eradicate them, but tumor stabilization is a difficult endpoint to quantify. In fact, given the redundancy of growth factors believed to be involved in KS development, it is perhaps remarkable that members of several classes of agents (eg, a synthetic retinoid, an MMPI, thalidomide, IL-12) have induced KS regression in a substantial minority of patients. It is likely, however, that drug combinations that target several pathogenetic mechanisms will be more effective than will single drugs in suppressing KS growth. A particular need. especially in the early evaluation of therapies aimed at specific pathogenic targets, is the development of assays to measure specific biologic effects (eg, changes in the activity of signal transduction pathways within tumor biopsy specimens) related to the agent's putative mechanism of action. Greater availability and clinical application of these types of markers of biologic efficacy may speed the identification of potentially active agents that could then be "fast tracked" into larger efficacy trials and combination studies.

Thalidomide: current therapeutic uses and management of its toxicities

Thalidomide currently is used to treat relapsed and refractory multiple myeloma. The drug also is being actively investigated in patients newly diagnosed with multiple myeloma. The therapeutic applications of thalidomide are expected to grow as clinical trials document its activity in treating other neoplastic disorders and diseases. Healthcare providers need to be well informed of its toxicities and able to identify their signs and symptoms immediately. They must have adequate knowledge about thalidomide administration and provide comprehensive patient education regarding thalidomide and its toxicities to ensure patient safety and compliance.

Thalidomide: a review of approved and investigational uses

BACKGROUND

Thalidomide is best known as a major teratogen that caused birth defects in up to 12,000 children in the 1960s. More recently, this agent has been approved by the US Food and Drug Administration for the treatment of erythema nodosum leprosum (ENL) through a restricted-use program. Its immunomodulatory, anti-inflammatory, and antiangiogenic properties are currently under study in a number of clinical conditions.

OBJECTIVE

This article reviews the pharmacology of thalidomide; its approved and off-label uses in dermatologic, oncologic, and gastrointestinal conditions; and adverse events associated with its use.

METHODS

Relevant articles were identified through searches of MEDLINE (1966-June 2002), International Pharmaceutical Abstracts (1970-June 2002), and EMBASE (1990-June 2002). Search terms included but were not limited to thalidomide, pharmacokinetics, pharmacology, therapeutic use, and teratogenicity, as well as terms for specific disease states and adverse events. Further publications were identified from the reference lists of the reviewed articles. Abstracts of recent symposia were obtained from the American Society of Clinical Oncology Web site.

RESULTS

Thalidomide is thought to exert its therapeutic effect through the modulation of cytokines, particularly tumor necrosis factor-alpha. In addition to its approved indication for ENL, thalidomide has been studied in various other conditions, including graft-versus-host disease, discoid lupus erythematosus, sarcoidosis, relapsed/refractory multiple myeloma, Waldenstrom's macroglobulinemia, myelodysplastic syndromes, acute myeloid leukemia, myelofibrosis with myeloid metaplasia, renal cell carcinoma, malignant gliomas, prostate cancer, Kaposi's sarcoma, colorectal carcinoma, oral aphthous ulcers, Behçet's disease, Crohn's disease, and HIV/AIDS-associated wasting. Adverse events most frequently associated with its use include somnolence, constipation, rash, peripheral neuropathy, and thromboembolism.

CONCLUSIONS

Use of thalidomide is limited by toxicity, limited efficacy data, and restricted access. Evidence of its efficacy in conditions other than ENL awaits the results of controlled clinical trials.

Treatment of Kaposi's sarcoma--an update

Kaposi's sarcoma (KS) is an angioproliferative disease of multifactorial origin arising in different clinic-epidemiologic forms, which show the same histopathological features. It generally starts as a hyperplastic reactive-inflammatory and angiogenic process, which may evolve into monomorphic nodules of KS cells that can be clonal (late-stage lesions) and resemble a true sarcoma. Infection with the human herpesvirus 8, cytokine- and angiogenic factor-induced growth together with an immuno-dysregulated state represent fundamental conditions for the development of this tumor. Several local therapies are used to eradicate early and confined skin lesions, whereas widely disseminated, progressive or symptomatic disease requires a more aggressive treatment. Although different chemotherapeutic agents have been used to treat aggressive KS, the growing understanding of the pathogenetic factors participating in KS development has provided a strong rationale for using less- or non-cytotoxic agents that block the mechanisms involved in KS pathogenesis. The angiogenic nature of KS makes it particularly suitable for using therapies based on anti-angiogenic agents. Of note on this goal, recent studies indicate that the highly active anti-retroviral therapy, including at least one human immunodeficiency virus (HIV) protease inhibitor (PI), is associated with a dramatic decrease in the incidence of AIDS-KS and with a regression of KS in treated individuals. Consistent with this, results from preclinical studies indicate that PIs have potent and direct anti-angiogenic and anti-KS activities, suggesting that they should be further investigated, alone or combined with other therapies, as a novel treatment for KS in both HIV seropositive or seronegative individuals.

Thalidomide in dermatology

Thalidomide is an effective agent to treat over 25 seemingly unrelated dermatological conditions that have an inflammatory or autoimmune basis. The main side-effects of teratogenesis and peripheral neuropathy limit its use. Currently, in Australia no assurance is given as to the quality, safety and efficacy of thalidomide. The use of thalidomide for toxic epidermal necrolysis can lead to an increase in mortality, and its use as a prophylactic agent for the prevention of chronic graft-versus-host disease following bone marrow transplantation has raised more speculations as to the safety of this notorious drug. A review of the therapeutic indications for thalidomide in dermatology as well as the mechanisms of action and side-effects of this drug are presented. The current suggested guidelines for its use in clinical practice in Australia are discussed.

Virology, pathogenetic mechanisms, and associated diseases of Kaposi sarcoma-associated herpesvirus (human herpesvirus 8)

Kaposi sarcoma-associated herpesvirus (KSHV) is a recently discovered and characterized member of the herpesvirus family. It is one of a few viruses proved to be associated with tumorigenesis in humans. Its causal association with 4 clinical and epidemiologic variants of Kaposi sarcoma (classic, endemic, iatrogenic, and acquired immunodeficiency virus-associated) as well as with several lymphoproliferative disorders (notably primary effusion lymphoma and multicentric Castleman disease) is reviewed critically. Issues related to the epidemiology, transmission, and molecular and serologic diagnosis are discussed. Several intriguing oncogenic mechanisms of KSHV infection have been identified. These are often dependent on the interaction of KSHV with other viruses, such as human immunodeficiency virus, Epstein-Barr virus, or both. However, important problems remain and once resolved will substantially enhance our understanding of oncogenesis in general and viral-induced oncogenesis in particular. This may also translate into improved treatment and perhaps prevention of this common and intriguing viral infection.

Thalidomide: a role in oral oncology?

Thalidomide is having increasing application in the management of a wide spectrum of immunologically-mediated and infectious disorders. It is also suggested that this agent may also have be of importance in the treatment of solid and non-solid malignancies. The present article reviews the role of thalidomide in the management of malignancy and outlines its possible potential in the treatment of malignancy of the mouth.

Thalidomide in cancer treatment: a potential role in the elderly?

There is increased interest in the treatment of cancer with thalidomide because of its antiangiogenic, immunomodulating and sedative effects. In animal models, the antitumour activity of thalidomide is dependent on the species, route of administration and coadministration of other drugs. For example, thalidomide has shown antitumour effects as a single agent in rabbits, but not in mice. In addition, the antitumour effects of the conventional cytotoxic drug cyclophosphamide and the tumour necrosis factor inducer 5,6-dimethylxanthenone-4-acetic acid (DMXAA) were found to be potentiated by thalidomide in mice bearing colon 38 adenocarcinoma tumours. Further studies have revealed that thalidomide upregulates intratumoral production of tumour necrosis factor-alpha 10-fold over that induced by DMXAA alone. Coadministration of thalidomide also significantly reduced the plasma clearance of DMXAA and cyclophosphamide. All these effects of thalidomide may contribute to the enhanced antitumour activity. Recent clinical trials of thalidomide have indicated that it has minimal anticancer activity for most patients with solid tumours when used as a single agent, although it was well tolerated. However, improved responses have been reported in patients with multiple myeloma. Palliative effects of thalidomide on cancer-related symptoms have also been observed, especially for geriatric patients with prostate cancer. Thalidomide also eliminates the dose-limiting gastrointestinal toxic effects of irinotecan. There is preliminary evidence indicating that the clearance of thalidomide may be reduced in the elderly. The exact role of thalidomide in the treatment of cancer and cancer cachexia in the elderly remains to be elucidated. However, it may have some value as part of a multimodality anticancer therapy, rather than as a single agent.

Update on Kaposi's sarcoma and other HHV8 associated diseases. Part 1: epidemiology, environmental predispositions, clinical manifestations, and therapy

Kaposi's sarcoma (KS) is a mesenchymal tumour involving blood and lymphatic vessels. Only recently has the pathogenesis of this extraordinary neoplasm been elucidated. Viral oncogenesis and cytokine-induced growth together with some state of immunocompromise represent important conditions for this tumour to develop. In 1994, a novel virus was discovered and termed human herpesvirus 8 (HHV8), also known as Kaposi's sarcoma-associated herpes virus, which can be found in all types of KS, whether related to HIV or not. In the era of highly active antiretroviral therapy (HAART), the incidence of AIDS-KS has considerably declined, probably due to enhanced immune reconstitution and anti-HHV8-specific immune responses. If HAART is able to prevent spreading of KS, local therapy of KS may become an essential component of patient management. Part 1 of the review covers the epidemiology, environmental predispositions, clinical manifestations, and therapy of KS. Newer treatments such as pegylated liposomal anthracyclines and experimental strategies are discussed. We also present rationales and graduated treatment algorithms for local and systemic therapy in patients with KS to appropriately meet the challenges of this extraordinary neoplasm. Part 2, to be published next month, will summarise recent insights in the pathogenesis of KS and will discuss other HHV8-related diseases such as Castleman's disease and primary effusion lymphoma.

Antiproliferative effect of thalidomide alone and combined with carmustine against C6 rat glioma

Thalidomide could have therapeutic applications in neoplasms and in other diseases, particularly those of autoimmune origin. The objective of this study was to investigate the effect of various doses of thalidomide on the growth of C6 glioma in rats, and to determine its effects on parameters of cell proliferation and angiogenesis. Additionally, we investigated a potential enhancement of the antitumoral action of thalidomide when combined with a low dose of the antineoplastic carmustine. C6 glioma cells were implanted subcutaneously in Wistar rats. A highly malignant glioma developed in 80% of animals. When the tumour reached 2.0 cm diameter thalidomide was administered at doses of 100, 200 or 400 mg/kg/day. When given at a dose of 400 mg/kg/day thalidomide significantly reduced the tumour volume, the mitotic index and cell proliferation but not the vascular density. The combination of thalidomide plus carmustine increased the inhibitory effect on tumoral growth. Our results indicate that thalidomide is effective against malignant glioma; apparently by an antiproliferative effect, rather than by inhibition of angiogenesis; when combined with carmustine it could increase the response of glioma to antineoplastic treatment.