Thalidomide: an antineoplastic agent

Death and Rebirth of the Thalidomide Molecule: A Case of Thalidomide-Induced Sensory Neuropathy

The thalidomide molecule is a remarkable molecule that exists in a racemic mixture of optical isomers. In the 1950s, due to its teratogenicity, the levorotatory isomer led to its dramatic downfall. However, the molecule with its panoramic mechanisms of action and its uncanny ability to intercalate within the geometry of deoxyribonucleic acid (DNA), led to its remarkable renaissance; thalidomide being United States Food and Drug Administration (FDA)-approved for at least 13 different indications ranging from multiple myeloma to leprosy to glioblastoma. Thalidomide-induced polyneuropathy is usually reversible and is the rate-limiting step in its long-term use. The development of a polyneuropathy is invariably associated with a cumulative dose exceeding 20 grams. However, the polyneuropathy is almost always a sensory neuropathy. Asymmetry, bona fide weakness such as difficulty standing on the heels, a poly-ganglioneuropathy pattern with widespread or patchy numbness and sensory ataxia should raise a red flag and an alternative diagnosis should be considered. We present a typical case of a thalidomide-induced sensory neuropathy in order to highlight the resurgence of thalidomide use in clinical practice. We review the literature and outline the molecular biology of the thalidomide molecule.

The enhancement of radiosensitivity in human esophageal carcinoma cells by thalidomide and its potential mechanism

To investigate the effects of thalidomide on the radiosensitivity of human esophageal cancer cells (TE1 cells) and the potential mechanism underlying these effects. The effects of thalidomide on proliferation of TE1 cells were determined by Methyl thiazolyl tetrazolium assay. The multitarget click model was used to delineate the survival curve using a colony-forming assay, and the radiosensitivity was determined after TE1 cells were treated by thalidomide and/or X-ray radiation. The cell cycle was detected using flow cytometry. Our results are as follows: thalidomide alone suppressed the proliferation of TE1 cells in a dose- and time-dependent manner. The suppressive effects were enhanced by prolonged duration or elevated concentration of thalidomide. However, thalidomide did not affect the cell cycle of TE1 cells. The expression of vascular endothelial growth factor (VEGF) mRNA and protein was suppressed after treatment with thalidomide alone in a dose-dependent manner. Synergistic suppressive effects on VEGF expression were observed after administration of thalidomide and X-ray exposure. In conclusion, thalidomide was able to enhance the radiosensitivity of TE1 cells in vitro, which could be closely related to its suppressive effects on the expression of VEGF in TE1 cells, but had no obvious effects on the cell cycle.

A phase I study of paclitaxel/doxorubicin/ thalidomide in patients with androgen- independent prostate cancer

PURPOSE

The antiangiogenic and immunomodulatory effects of thalidomide induce responses in patients with androgen-independent prostate cancer (AIPC). Paclitaxel and doxorubicin also have significant antitumor activity. A phase I dose-escalation study was conducted to evaluate the use of these agents in combination to enhance the chemotherapeutic effects of treatment for refractory cancer.

PATIENTS AND METHODS

Twelve men with AIPC (mean age, 64.5 years) and a median prostate-specific antigen (PSA) level of 30 ng/mL were enrolled. Patients received starting doses of weekly paclitaxel (100 mg/m(2)) as a 1-hour intravenous infusion, weekly doxorubicin (20 mg/m(2)) as a 24-hour intravenous infusion, and daily oral thalidomide at escalating dose levels of 200 mg (dose level 0), 300 mg (dose level +1), and 400 mg (dose level +2). Paclitaxel and doxorubicin were administered for 3 consecutive weeks of a 5-week cycle. Exposure to thalidomide was daily. Patients were evaluated weekly for dose-limiting toxicities to determine the maximum tolerated dose. In addition, PSA levels were measured before each cycle of treatment. Response to treatment was defined as a > or =50% decrease in baseline PSA levels associated with stable radiographic disease, improvement of bone scan results with plain radiograph correlation, or improvement in soft tissue disease.

RESULTS

Four patients were treated on dose level 0, 5 were treated on dose level +1, and 3 were treated on dose level +2. The thalidomide 400-mg dose level resulted in 3 of 3 patients experiencing grade 3 leukopenia. The maximum tolerated dose was 300 mg of thalidomide in combination with paclitaxel/doxorubicin. Nine of the 12 patients were evaluable for PSA response, with 88% exhibiting partial responses or stable disease. One patient (11%) had a significant response, with PSA levels decreasing > 90% from baseline values. Overall, PSA-level decreases ranged from 0.5 ng/mL to 39.5 ng/mL among the 9 evaluable patients. A maximum of 7 cycles of therapy were administered. Twelve patients were evaluable for toxicity: neutropenia (grade 3, 27%; grade 4, 54%), leukopenia (grade 3, 63%), constipation (grade 3, 27%), fatigue (grade 3, 27%), nausea (grade 3, 9%), and deep vein thrombosis (grade 3, 9%) were reported.

CONCLUSION

The combined dosing of paclitaxel (100 mg/m(2) weekly), doxorubicin (20 mg/m(2) weekly), and thalidomide (300 mg daily) is tolerated by men with AIPC and merits continued phase II study.

Phase II trial of interferon and thalidomide in metastatic renal cell carcinoma

OBJECTIVES

To evaluate the toxicity and efficacy of interferon and thalidomide combination in a phase II clinical trial.

PATIENTS AND METHODS

Eligibility included metastatic renal cancer with a maximum of two prior regimens, performance status of 0-2 and adequate renal, hepatic and bone marrow function.

RESULTS

Twenty patients were enrolled on this phase II trial. Median age was 60.5 years (Range: 39-75 years). 17 patients had visceral metastases (lung/liver/both) and 3 patients had lymph node only metastases. A total of 26 cycles of 4 weeks each were administered; median of 1 cycle and range from 0-9 cycles. The therapy was poorly tolerated with grade 3 adverse events noted in 12 (60%) of the 20 patients. No objective responses were noted. Of the 14 response evaluable patients, one had an unconfirmed response (38% decrease in size) and one had prolonged disease stabilization for 10 months. The median time to progression was 1.0 month and median survival was 2.8 months. Pre and post therapy PET scans were performed nine weeks apart on one patient. The mean standardized uptake values (SUV) declined from 1.45 (SUV min-max 0.89-1.76) to 1.12 (SUV min-max 0.55-1.47), denoting anti vascular effect. The patient did not have an objective response but had a disease stabilization sustained for 10 months.

CONCLUSION

The combination of interferon and thalidomide has minimal efficacy and considerable toxicity which makes this combination unworthy of future investigation in metastatic renal cancer.

Targeted Anti-Cancer Therapies for Renal Cancer

In the past several years, significant advances in the underlying biological mechanisms of renal cell cancer, particularly the role of tumour angiogenesis, have permitted the design of molecularly targeted therapeutics. For this review, single-agent therapies inhibiting the following different targets were identified in the published literature: epithelial growth factor receptor, vascular endothelial growth factor receptor, basic fibroblast growth factor receptor, platelet-derived growth factor, nuclear factor-kappabeta, the mammalian target of rapamycin (mTOR) pathway, raf kinase pathway and tyrosine kinase pathway. Distinct fields of clinical research have emerged--monoclonal antibodies, small molecules, nanopeptides and immunomodulators. All therapies demonstrated acceptable toxicity profiles. Clinical benefit was assessed on the basis of the reported criteria for each study, and antitumour response (regression or delay in progression-free survival) ranged from 5% to 71%. On the basis of the limited studies to date, targeted therapies offer the greatest clinical benefit in the management of this malignancy, although additional basic research is still warranted to further improve clinical outcome.

Phase I/II study of thalidomide in combination with interleukin-2 in patients with metastatic renal cell carcinoma

BACKGROUND

The purpose of the study was to determine, in a Phase I/II study, the efficacy and safety profile of thalidomide with interleukin-2 (IL-2) in patients with metastatic renal cell carcinoma (MRCC).

METHODS

Fifteen patients (8 of whom were previously treated) enrolled in Phase I were treated with escalating doses of oral thalidomide (200-600 mg) and a fixed dose of IL-2 (7 mIU/m(2)) by subcutaneous injection. A course was 6 weeks, with the exception of Course 1, which was 7 weeks. Thirty-seven Phase II patients who had not received prior chemotherapy or immunotherapy for renal cell carcinoma (RCC) received an initial thalidomide dose of 200 mg at Week 0, which was escalated to 400 mg after 48 hours. Subcutaneous IL-2 was administered at the same fixed daily dose used in Phase I.

RESULTS

Fifty-one of 52 Phase I/II patients were evaluable. Twenty-seven patients (52%) experienced disease control, including 4 (8%) complete responses, 15 (29%) partial responses, and 8 (15%) cases of stable disease. Disease progression was observed in 24 patients (47%). Survival in the 2 phases ranged from 4 weeks to 45.2+ months. At the time of last follow-up, 2 of 51 patients (4%) remained on maintenance thalidomide therapy and continue to be followed. Three of the 51 patients with CRs (6%) ceased thalidomide therapy at 23-25 months and have maintained their responses to date. One complete responder was lost to follow-up. As of January 2005, 14 of 51 patients (27%) remained alive. Toxicities were mild to moderate, including Grade 1 to 2 somnolence, constipation, neuropathy, rash, flu-like symptoms, fluid retention, hypotension, and hypothyroidism (according to version 2.0 of National Cancer Institute Common Toxicity Criteria). In addition, two patients experienced deep venous thrombosis.

CONCLUSIONS

Thalidomide in combination with IL-2 is tolerable and can produce durable, active responses in patients with MRCC. To evaluate the merits of thalidomide as a valuable agent against MRCC and to more fully determine the efficacy of thalidomide/IL-2 combination therapy, the scrutiny of Phase III testing is required. Further development of thalidomide/IL-2 combination therapy will be the focus of this group.

Recurrent and metastatic clivus chordoma: systemic palliative therapy retards disease progression

We report on a male patient with progressive and metastatic clivus chordoma treated over a period of 9 years by a multidisciplinary approach. Within the first 4 years, the patient underwent surgery four times. Thereafter, he received radiotherapy and subsequent chemotherapy. Stabilization of disease was achieved repeatedly for variable periods under local radiotherapy, systemic chemotherapy, immunomodulatory and anti-angiogenic therapy with isotretinoin and interferon-alpha, followed by thalidomide. Due to the occurrence of brain and lung metastases 8 years after initial diagnosis, liposomal doxorubicin was added to thalidomide. At the last follow-up control the patient had stable disease, with no progression of the intracranial tumor and regression of pulmonary metastases. He is in a good physical, psychological and neurological condition with a Karnofsky score of 80. Our observations show that multimodal therapy including a systemic palliative approach is associated with long quiescent intervals in recurrent chordoma and with regression of its metastases. Use of substances with high efficacy on tumor tissue and low toxicity, allowing long-term administration, seems promising in similar situations.

Thalidomide in the Management of Recurrent Aphthous Ulcerations in Patients Who fire HIV-Positive: A Review and Case Reporst

Recurrent Aphthous Ulceration (RAU) is an inflammatory ulcerative disease of unknown etiology. Although RAU are common in the general population, people with HIV disease may have ulcers that are large and painful and take a long time to heal. Local and systemic steroid therapy has been the traditional method of treatment for recurrent lesions. Recent studies have shown that systemic thalidomide therapy has the best efficacy in the treatment of major RAU in HIV-seropositive patients. Two case histories of complete resolution of the RAU are presented. We have included recommended guidelines for prescribing thalidomide according to the System for Thalidomide Education and Prescribing Safety (STEPS) Program.

Thalidomide enhances the anti-tumor activity of standard chemotherapy in a human melanoma xenotransplatation model

It has been demonstrated that thalidomide's anti-angiogenic properties result in clear anti-tumor activity in a number of human malignancies. We studied thalidomide in a human melanoma severe combined immunodeficiency mouse xenotransplantation model. Thalidomide as a single agent showed a significant tumor reduction of 46% compared with the control group. Thalidomide combined with dacarbazine treatment markedly enhanced the anti-tumor effect of chemotherapy and showed a significant tumor reduction relative to the dacarbazine-only group (61%) and even more tumor reduction (74%) compared with the control group. We also measured clearly reduced levels of tumor necrosis factor-alpha in the thalidomide-treated group. A significantly lower microvessel density was encountered in the thalidomide treatment groups (thalidomide alone or combined with DTIC), underscoring the anti-angiogenic effect of thalidomide as a single agent as well as in combination with chemotherapy in this model. In line with these results, we observed a nearly 3-fold increase of apoptosis for the combination of thalidomide and DTIC compared with the rate of apoptotic cells in DTIC-only-treated melanoma xenotransplants. These data underline the rationale for combining dacarbazine--a cytotoxic agent--and thalidomide--an anti-angiogenic cytostatic agent--as a promising strategy for the treatment of melanoma.

Thalidomide inhibits the growth and progression of hepatic epithelioid hemangioendothelioma

Hepatic epithelioid hemangioendothelioma (HEH) is a rare vascular tumor of the liver with an unpredictable malignant potential. Its growth can lead to hepatic failure, extrahepatic metastasis and death. Surgical resection or liver transplantation is the treatment of choice if metastasis is not identified. Several antineoplastic agents have been proposed for cases of nonresectable HEH. We report the case of a 52-year-old patient with HEH metastatic to the lungs who was successfully treated with oral thalidomide therapy.

Renal cell carcinoma: review of novel single-agent therapeutics and combination regimens

A search of the Medline database and ASCO 2003 conference proceedings was conducted to identify clinical trials currently underway using single-agent therapy for renal cell carcinoma (RCC). Combination trials were identified using the ASCO 2003 conference proceedings. Fourteen single-agent therapies employing different mechanisms of action were identified in the published literature: imatinib mesylate (Gleevec); bevacizumab (Avastin); thalidomide (Thalomid); gefitinib (ZD1839) (Iressa); cetuximab (IMC-C225) (Erbitux); bortezomib (PS-341) (Velcade); HSPPC-96 (Oncophage); BAY 59-8862; ABT-510; G250; CCI-779; SU5416; PTK/ZK; and ABX-EGF. Six distinct fields of clinical research have emerged: monoclonal antibodies, small molecules, vaccines, second-generation taxanes, nonapeptides and immunomodulators. Five combination regimens, primarily biological response modifiers (interleukin-2 or interferon-alpha), chemotherapy- or thalidomide-based, were identified. All therapies demonstrated acceptable toxicity profiles. Clinical benefit was assessed based on each study's reported criteria: antitumor response (regression or stability) ranged from 5% to 71%. In the past several years, significant advances in the underlying biological mechanisms of RCC, particularly the role of tumor angiogenesis, have permitted the design of molecularly targeted therapeutics. Based on preliminary and limited studies, combination therapies offer the greatest clinical benefit in the management of this malignancy, although additional basic research is still warranted.

Thalidomide and analogues: current proposed mechanisms and therapeutic usage

Microvessel density is a prognostic factor for many cancers, including prostate. For this reason, several studies and therapeutic approaches that target the tumor microvasculature have been attempted. Thalidomide has long been recognized as an antiangiogenic molecule. Recently, this drug has regained favor as an anticancer agent and is in clinical trial for multiple myeloma and prostate cancer, among others. This article will briefly review the proposed mechanisms of action for thalidomide, discuss why these activities are of therapeutic value in diseases currently undergoing clinical trials, and summarize the current status of clinical trials for prostate cancer. The focus will be predominantly on the relationship of thalidomide to angiogenesis, as well as on the future and potential value of thalidomide-inspired structural derivatives.

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.

Human herpesvirus 8, Kaposi's sarcoma, and associated conditions

HHV-8 is a recently identified human herpes virus that can produce tumors, most often in immune compromised hosts. The virus is most closely associated with Kaposi's sarcoma, but is also clearly associated with primary effusion lymphomas and multicentric Castleman's disease. The prevalence of HHV-8 infection varies considerably, but is highest among men who have sex with men and others with histories of sexually transmitted diseases and high numbers of lifetime sexual partners. HHV-8 is shed in saliva, and less commonly in genital secretions. Treatment of HHV-8 associated diseases includes reversal of immune compromise either via discontinuation of immunosuppressives or immune reconstitution via antiretroviral regimens. Specific antiviral drug inhibit HHV-8 replication, and can result in responses in certain HHV-8-associated conditions.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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