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

Thalidomide combined with chemotherapy in treating elderly patients with advanced gastric cancer

AIM

The current systemic chemotherapy brings toxicity to human body, which elder patients suffer more than young people. The effective and well-tolerated treatment methods are of great importance for elderly advanced GC patients. This paper proposed an effective way of combining thalidomide with chemotherapy to treat elderly advanced GC patients, on the purpose of improving life quality and the treatment efficacy.

METHODS

In the control group, capecitabine was given with 2000 mg/m² daily in a manner of 2 weeks on and 1 week off for elderly advanced GC patients. In the study group, thalidomide was given with 100 mg per day concurrently with chemotherapy additionally administered.

RESULTS

No significant differences were observed in the major prognostic factors among 64 eligible patients between the study and control groups. The ORRs and DCRs of the treatment and control groups showed no significant difference (P > 0.05). PFS of the study and control groups were 5.3 months (95% CI 4.5-6.2) and 4.2 months (95% CI 3.4-5.1), respectively. PFS exhibited a significant difference between the two group (P = 0.03), while the overall survivals of the patients between the two groups (10.4 months vs. 9.7 months) resulted as statistically non-significant (P = 0.47). Adverse effects were minimal in the study group, only a few patients suffered the grade 3 toxicity. The rate of drowsiness, fatigue, constipation of the study group was higher than that of the control group, and the rate of anorexia was lower (P < 0.05).

CONCLUSIONS

Our results demonstrated that thalidomide combined with capecitabine was mildly effective and safe for treating elderly patients with advanced GC.

Initial cytoreductive treatment with thalidomide plus bolus vincristine/doxorubicin and reduced dexamethasone followed by autologous stem cell transplantation for multiple myeloma

BACKGROUND

High-dose chemotherapy supported by autologous stem cell transplantation (ASCT) after combined chemotherapy with infusional vincristine/doxorubicin plus dexamethasone is effective in multiple myeloma (MM). Outpatient treatment with bolus vincristine/doxorubicin infusion plus dexamethasone is convenient and has acceptable efficacy and toxicity for MM. Thalidomide has recently been shown to have significant antimyeloma activity. We assessed the efficacy and toxicity of the combination of bolus vincristine/doxorubicin and reduced dose dexamethasone with thalidomide (T-bVAd), administered on an outpatient basis, in untreated MM.

PATIENTS AND METHODS

Twenty-six patients prospectively received T-bVAd, consisting of intravenous (i.v.) vincristine 0.4 mg plus doxorubicin 9 mg/m(2), administered as a single bolus on days 1 to 4, dexamethasone 20 mg per os daily for 4 days, and thalidomide 200 mg/day at bedtime. Response assessment was conducted after each 4-week treatment cycle. Patients who achieved response were allowed to proceed to high-dose chemotherapy with ASCT.

RESULTS

On an intention-to-treat basis, 23 of the 26 patients (88%) responded to treatment, with 16 (61%) achieving complete response (CR), 2 (8%) very good partial response (VGPR) and 5 (19%) partial response. Only three patients (12%) were rated as non-responders. Grade 3 and 4 hematologic toxicities consisted of neutropenia (13%), febrile neutropenia (6%), and thrombocytopenia (4%), without significant nonhematologic events. Of the 23 patients who showed response, 7 proceeded to single ASCT and 9 to tandem ASCT. With median follow-up time of 15.3 months (range, 9-25 months), median event free survival (EFS) and overall survival (OS) have not been reached yet, and OS and EFS rates for patients who achieved complete response after T-bVAd regimen were significantly higher than patients not.

CONCLUSIONS

Induction therapy with T-bVAd, administered as an outpatient regimen, was efficient and relatively well tolerated in the treatment of MM.

The adverse prognostic impact of advanced age in multiple myeloma

The adverse prognostic impact of advanced age in multiple myeloma is multi-factorial. In this review we explore the various contributory factors to this phenomenon. These include general biological and psychosocial factors, which impact on cancer in the elderly population such as the presence of multiple co morbidities and poor performance status at diagnosis and variation in patient's expectations of treatment. Factors specific to myeloma include the ability to deliver optimum therapy in older patients and the impact of this on disease response, possible biological differences of myeloma in older patients, and how these various factors impact on the efficacy of conventional-dose, high-dose (HDT) and newer disease modifying therapies. Selected elderly patients can gain equal benefit to younger patients from effective therapies such as HDT. However, the use of specific assessment tools for the elderly, apart from chronological age, should be used to select elderly patients who will benefit. Future testing of newer therapies in patients with myeloma must include older patients, who will make up an increasing proportion of the myeloma population in the future and should incorporate assessment of effect of these therapies on quality of life.

Effect of CKBM on prostate cancer cell growth in vitro and in vivo

Prostate carcinoma and metastasis are common among male subjects worldwide. CKBM is a drug product targeting prostate cancer in multiple ways. Prostate cancer cell lines PC3 and DU145 were treated with CKBM. The effect of CKBM on the cell's viability, cell cycle, adhesive and invasive properties and its growth in an animal model were assessed. Results indicated that CKBM inhibited PC3 and DU145 cell growth in vitro at IC(50 )values 3.923 and 4.697% respectively, and it brought about cell cycle arrest at G2/M phase. CKBM also attenuated DU145 cells to invade and adhere to extracellular matrices including Matrigel, laminin, fibronectin and collagen IV. Moreover, PC3 tumor xenograft growth was inhibited by over 60% after 28-day of 0.2, 0.4 or 0.8 ml/day CKBM treatment. The present study indicates that CKBM is effective against prostate cancer cell growth in vitro and in vivo. Further studies are required to elucidate its mechanism of action.

Treatment Strategies in Elderly Patients with Multiple Myeloma

Multiple myeloma (MM), a plasma cell malignancy, is a disorder of the elderly with an increasing prevalence as the average life expectancy increases. Survival remains unacceptably low in elderly patients with MM, in whom the gold standard of treatment has been, until recently, oral melphalan and prednisolone, which induces a response rate of approximately 50% and overall survival of <3 years. In the last 15 years, traditional treatment paradigms for elderly patients with MM have been challenged not only as a result of the change in what we define as 'elderly' but also as a result of the reduced morbidity and treatment-related mortality associated with high-dose chemoradiotherapy (HDT) and autologous stem cell transplantation (ASCT), and the emergence of novel therapies including thalidomide, its immunomodulator drug derivative lenalidomide and the first-in-class proteasome inhibitor, bortezomib. In this review, we examine currently available data regarding the treatment of MM in the elderly population. Recent years have seen a paradigm shift in the standard of care of elderly patients with MM from oral melphalan and prednisolone to approaches including HDT with ASCT using intermediate-dose melphalan in selected elderly patients, and the evaluation of and incorporation of drugs such as thalidomide, bortezomib and lenalidomide. Importantly, we now have been able to change the traditional goal of palliation in the elderly group of patients to a more ambitious objective of achieving a complete response or a near complete response, in the hope that this will translate into improved progression-free survival, overall survival and quality of life.

Drug bioactivation, covalent binding to target proteins and toxicity relevance

A number of therapeutic drugs with different structures and mechanisms of action have been reported to undergo metabolic activation by Phase I or Phase II drug-metabolizing enzymes. The bioactivation gives rise to reactive metabolites/intermediates, which readily confer covalent binding to various target proteins by nucleophilic substitution and/or Schiff's base mechanism. These drugs include analgesics (e.g., acetaminophen), antibacterial agents (e.g., sulfonamides and macrolide antibiotics), anticancer drugs (e.g., irinotecan), antiepileptic drugs (e.g., carbamazepine), anti-HIV agents (e.g., ritonavir), antipsychotics (e.g., clozapine), cardiovascular drugs (e.g., procainamide and hydralazine), immunosupressants (e.g., cyclosporine A), inhalational anesthetics (e.g., halothane), nonsteroidal anti-inflammatory drugs (NSAIDSs) (e.g., diclofenac), and steroids and their receptor modulators (e.g., estrogens and tamoxifen). Some herbal and dietary constituents are also bioactivated to reactive metabolites capable of binding covalently and inactivating cytochrome P450s (CYPs). A number of important target proteins of drugs have been identified by mass spectrometric techniques and proteomic approaches. The covalent binding and formation of drug-protein adducts are generally considered to be related to drug toxicity, and selective protein covalent binding by drug metabolites may lead to selective organ toxicity. However, the mechanisms involved in the protein adduct-induced toxicity are largely undefined, although it has been suggested that drug-protein adducts may cause toxicity either through impairing physiological functions of the modified proteins or through immune-mediated mechanisms. In addition, mechanism-based inhibition of CYPs may result in toxic drug-drug interactions. The clinical consequences of drug bioactivation and covalent binding to proteins are unpredictable, depending on many factors that are associated with the administered drugs and patients. Further studies using proteomic and genomic approaches with high throughput capacity are needed to identify the protein targets of reactive drug metabolites, and to elucidate the structure-activity relationships of drug's covalent binding to proteins and their clinical outcomes.

New treatment strategies for multiple myeloma

Multiple myeloma remains an incurable disease despite aggressive, high-dose therapy and intensive supportive care. Newer therapies with good safety profiles are needed for patients with multiple myeloma to improve the quality of responses and prolong survival. Novel treatment strategies for multiple myeloma include replacing conventional doxorubicin with pegylated liposomal doxorubicin and reducing the dexamethasone dose (DVd) in the widely accepted VAD (vincristine, conventional doxorubicin, dexamethasone) regimen to improve the safety profile. Because of its antiangiogenic and immunomodulatory effects, thalidomide has also been explored for use in the treatment of multiple myeloma and has demonstrated increased response rates when used in combination with dexamethasone. These findings subsequently led to the evaluation of the role of thalidomide in combination with pegylated liposomal doxorubicin, vincristine, and reduced-dose dexamethasone (the DVd-T regimen). This regimen was associated with response rates greater than 80% in patients with both newly diagnosed and relapsed/refractory multiple myeloma. Future applications of this and similar regimens for the treatment of multiple myeloma are currently being explored.

Modifications to Therapy for Multiple Myeloma: Pegylated Liposomal Doxorubicin in Combination With Vincristine, Reduced‐Dose Dexamethasone, and Thalidomide

The combination of vincristine, doxorubicin, and dexamethasone is an effective treatment for multiple myeloma that produces a more rapid response than other regimens, probably a function of the high-dose, intense steroid schedule. However, vincristine/doxorubicin/dexamethasone administration requires a 96-hour continuous infusion delivered via a central venous catheter, which necessitates hospitalization in a large number of patients and may increase the risk for infection. Moreover, the high dosages of corticosteroids required with this regimen can cause substantial toxicity. Therefore, a number of modifications to the regimen have been evaluated in an effort to improve its tolerability and efficacy. These include replacing doxorubicin with pegylated liposomal doxorubicin and using a reduced frequency of dexamethasone, and, later, the addition of thalidomide. The results of an ongoing study demonstrated that this latest regimen (including thalidomide) is associated with an improved response rate and a higher quality of response compared with previous regimens in patients with relapsed/refractory multiple myeloma. This modified regimen is well tolerated when prophylactic and supportive measures are incorporated. Although additional follow-up is required to determine the effect on survival, this modified regimen has significant potential in the management of advanced myeloma.

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.

Thalidomide and immunomodulatory drugs as cancer therapy

The demonstration of increased angiogenesis in cancer pathogenesis prompted the use of thalidomide in both solid tumors and hematologic malignancies. Its broad spectrum of actions besides its antiangiogenic potential, specifically, its immunomodulatory properties, antiinflammatory actions, and direct effect on tumor cells and their microenvironment, provides an alternative strategy in the armamentarium against cancer. Thalidomide is being evaluated for treatment of hematologic cancers like multiple myeloma and myelodysplasia, and solid tumors like lung, breast, renal, and colon cancer. Thalidomide analogues, the immunomodulatory drugs have increased potency and have demonstrated efficacy and reduced toxicity in phase I and II clinical studies. This article reviews both laboratory-based and clinical studies with thalidomide and the immunomodulatory drugs and their application in different cancers.