[New drugs for myeloma]

Thalidomide, administered orally, bortezomib (Velcade) intravenously and lenalidomide (Revlimid), also orally, are three agents that act on myeloma relapse. Thalidomide acts by a variety of mechanisms and is toxic to the peripheral nervous system as well as teratogenic. It acts in synergy with dexamethasone. Recent results prove that its use as first-line treatment combined with oral conventional "MP" chemotherapy improves survival in patients older than 65 years. Its use as first-line treatment with this chemotherapy appears likely. Bortezomib is the first drug in the proteasome inhibitor class. It too is toxic to the peripheral nervous system and synergistic with dexamethasone. Several studies show its efficacy as first-line 'induction treatment' with dexamethasone, in patients to receive a subsequent autologous stem cell transplantation. The combination of bortezomib and "MP" is also promising. Lenalidomide, a structural analog of thalidomide, is effective in relapsing patients. Its toxicity is essentially hematologic. It is also synergistic with dexamethasone and promising as first-line treatment. These different drugs can be used successively at relapse, making myeloma a chronic disease. They can also be used together for greater effectiveness. These combinations will replace conventional chemotherapies in the future.

Lenalidomide and dexamethasone in the treatment of AL amyloidosis: results of a phase 2 trial

In immunoglobulin light chain (AL) amyloidosis, amyloid fibril deposits derived from immunoglobulin light chains produced by a clonal plasma cell dyscrasia accumulate in tissues and damage vital organs. Treatment regimens used in multiple myeloma can be effective in AL amyloidosis; however, patients with this disease often tolerate these regimens poorly because of multisystem organ dysfunction. Thalidomide and lenalidomide have both been shown to be effective in myeloma. In this report, we describe results of a phase 2 trial of the use of lenalidomide, as a single agent and in combination with dexamethasone, for the treatment of AL amyloidosis. Thirty-four patients with AL amyloidosis, most with prior therapies, were enrolled in the trial. The initial dose of lenalidomide used (25 mg/d) was poorly tolerated; however, a reduced dose of 15 mg/d was generally well tolerated. Of 24 evaluable patients, 7 (29%) achieved a hematologic complete response and 9 (38%) achieved a partial hematologic response, for an overall hematologic response rate of 67%. Hematologic responses were also associated with clinical responses. Fatigue and myelosuppression were the most common treatment-related adverse events (35%), while thromboembolic complications (9%) were the most serious. Findings from this trial indicate that lenalidomide can be effective in treating AL amyloidosis.

Pharmacy benefit spending on oral chemotherapy drugs

BACKGROUND

Pharmacy benefits have historically excluded injectable drugs, resulting in coverage of injectable drugs under the medical benefit. High-cost biologics and other new drug therapies are often injectables and therefore have not presented cost threats to pharmacy benefits. The U.S. Food and Drug Administration approval of capecitabine, an oral form of fluorouracil, in 1998, and imatinib mesylate in oral dose form for chronic myeloid leukemia, in 2001, signaled a new period in budget forecasting for pharmacy benefits, particularly for small, self-insured employers for whom a drug with a cost of 25,000 dollars per year of therapy for 1 patient could increase total pharmacy benefit costs by 10% or more.

OBJECTIVE

To quantify the actual relative costs of the oral chemotherapy drugs in pharmacy benefits in 2006 and identify the history of spending on oral chemotherapy drugs relative to total pharmacy benefit spending for small, self-insured employers over the 4.5 years through May 2006.

METHODS

Administrative pharmacy claims from the database of a pharmacy benefits manager (PBM) for approximately 500,000 members of small, self-insured employer plans were used to calculate the net plan cost of oral chemotherapy drugs relative to total drug benefit costs for the period January 1, 2002, through May 31, 2006. Current costs for oral chemotherapy drugs for small employers were compared with an insured health plan of approximately the same number of members for dates of service January 1, 2006, through May 31, 2006.

RESULTS

This descriptive analysis found that oral chemotherapy drugs represented 0.27% of total drug benefit costs, or approximately 0.08 dollars per member per month (PMPM) for small, self-insured employers in 2002, rising linearly to 0.73%, or approximately 0.24 dollars PMPM in the first 5 months of 2006. Members in pharmacy benefit plans sponsored by small employers paid an average 6.9% cost share for oral chemotherapy drugs in 2006, nearly identical to the average 8.5% paid by members of an insured health plan of similar size in total membership, versus 26.9% average cost share for all drugs. Imatinib mesylate accounted for 45% of total spending on oral chemotherapy agents in 2002 versus 40% in 2006.

CONCLUSION

Spending on oral chemotherapy drugs as a proportion of total pharmacy benefit costs has more than doubled, from about 0.3% in 2002 to 0.7% in 2006. For small, self-insured employers, this represents a nearly 3-fold increase in spending, from about 0.08 dollars PMPM in 2002 to about 0.24 dollars PMPM in 2006.

Immunomodulatory drugs in myelodysplastic syndromes

This review summarises the mechanism of action of immunomodulatory analogues of thalidomide and their use in myelodysplastic syndromes. Thalidomide was found to have a response rate of approximately 20% in these patients. Lenalidomide--which is more potent and less toxic than thalidomide--has been used in three clinical trials and produced the best responses (60 - > 90%) in low- and intermediate-1-risk transfusion-dependent patients with del(5q). The responses are purely erythroid in nature, and are associated with major cytogenetic responses in > 50% of the del(5q) patients. Non-del(5q) low- and intermediate-1-risk transfusion-dependent patients also had a approximately 25% incidence of transfusion independence following therapy with lenalidomide. Median time to response is approximately 4 weeks and 90% of patients respond within 12 weeks. The precise mechanism of action remains unknown but anticytokine, antiangiogenic and immunomodulatory properties are thought to play a role.

Lenalidomide therapy in myelofibrosis with myeloid metaplasia

We present results of 2 similarly designed but separate phase 2 studies involving single-agent lenalidomide (CC-5013, Revlimid) in a total of 68 patients with symptomatic myelofibrosis with myeloid metaplasia (MMM). Protocol treatment consisted of oral lenalidomide at 10 mg/d (5 mg/d if baseline platelet count < 100 × 109/L) for 3 to 4 months with a plan to continue treatment for either 3 or 24 additional months, in case of response. Overall response rates were 22% for anemia, 33% for splenomegaly, and 50% for thrombocytopenia. Response in anemia was deemed impressive in 8 patients whose hemoglobin level normalized from a baseline of either transfusion dependency or hemoglobin level lower than 100 g/L. Additional treatment effects in these patients included resolution of leukoerythroblastosis (4 patients), a decrease in medullary fibrosis and angiogenesis (2 patients), and del(5)(q13q33) cytogenetic remission accompanied by a reduction in JAK2V617F mutation burden (1 patient). Grade 3 or 4 adverse events included neutropenia (31%) and thrombocytopenia (19%). We conclude that lenalidomide engenders an intriguing treatment activity in a subset of patients with MMM that includes an unprecedented effect on peripheral blood and bone marrow abnormalities.

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.

A randomized phase 2 study of lenalidomide therapy for patients with relapsed or relapsed and refractory multiple myeloma

This multicenter, open-label, randomized phase 2 study evaluated 2 dose regimens of lenalidomide for relapsed, refractory myeloma. Seventy patients were randomized to receive either 30 mg once-daily or 15 mg twice-daily oral lenalidomide for 21 days of every 28-day cycle. Patients with progressive or stable disease after 2 cycles received dexamethasone. Analysis of the first 70 patients showed increased grade 3/4 myelo-suppression in patients receiving 15 mg twice daily (41% versus 13%, P = .03). An additional 32 patients received 30 mg once daily. Responses were evaluated according to European Group for Blood and Marrow Transplantation (EBMT) criteria. Overall response rate (complete, partial, or minor) to lenalidomide alone was 25% (24% for once-daily and 29% for twice-daily lenalidomide). Median overall survival in 30-mg once-daily and twice-daily groups was 28 and 27 months, respectively. Median progression-free survival was 7.7 months on once-daily versus 3.9 months on twice-daily lenalidomide (P = .2). Dexamethasone was added in 68 patients and 29% responded. Time to first occurrence of clinically significant grade 3/4 myelosuppression was shorter in the twice-daily group (1.8 vs 5.5 months, P = .05). Significant peripheral neuropathy and deep vein thrombosis each occurred in only 3%. Lenalidomide is active and well tolerated in relapsed, refractory myeloma, with the 30-mg once-daily regimen providing the basis for future studies as monotherapy and with dexamethasone.

The emerging role of arsenic trioxide as an immunomodulatory agent in the management of multiple myeloma

Multiple myeloma is a clonal disorder of plasma cells which is considered incurable with currently available therapies. Substantial advances have been achieved in the past decade with the identification of cellular mechanisms that confer drug resistance. This has resulted in newer agents such as arsenic trioxide (Trisenoxt), lenalidomide (Revlimid) and bortezomib (Velcade) with promising activity in this disease. In this review article we will outline the history, mechanisms of action, pharmacology, and clinical trials of arsenic trioxide in multiple myeloma.

Side effects of anti-cancer molecular-targeted therapies (not monoclonal antibodies)

PURPOSE OF REVIEW

Major advances have been achieved in the field of biologically based therapies for cancer in the last few years, and some of the recently approved 'molecular-targeted therapies' are now being used in daily clinical practice. We aim to review some aspects of the toxicity and safety of small-molecule anti-cancer molecular-targeted therapies, with some insights into the physiopathology and predictive factors of toxicity, its correlation with response, and how to prevent and overcome it.

RECENT FINDINGS

As a whole, small-molecule molecular-targeted therapies are well tolerated. Their toxic profile is favorable, but during the drug development process some severe (sometimes lethal) toxicities have been observed, such as interstitial lung disease in patients treated with drugs targeting the epidermal growth factor receptor. Pharmacogenomic studies can help us to identify those patients with well characterized polymorphisms, and to define the best-tolerated and most effective treatments.

SUMMARY

Molecular-targeted therapies have a good toxicity profile in general; however, some patients are exquisitely sensitive to developing particular and severe toxicities related to these drugs.

Lenalidomide inhibits proliferation of Namalwa CSN.70 cells and interferes with Gab1 phosphorylation and adaptor protein complex assembly

Lenalidomide (Revlimid, CC-5013) belongs to a line of compounds known as immunomodulatory drugs (IMiDs) that are under clinical investigation in hematopoietic and solid tumor cancers. Lenalidomide efficacy has been reported in clinical trials of multiple myeloma and myelodysplastic syndromes (MDS), particularly in MDS patients with a del 5q cytogenetic abnormality, with or without other cytogenetic abnormalities. Here we report that lenalidomide inhibits proliferation of chromosome 5 deleted hematopoietic tumor cell lines in vitro, whether from the B cell, T cell, or myeloid lineage. There was diversity in the responses of the various cell lines to lenalidomide, with one undergoing cell cycle arrest, and others undergoing apoptosis. In the most lenalidomide-sensitive chromosome 5 deleted cell line, Namalwa CSN.70, the compound induced G0/G1 cell cycle arrest, inhibited Akt and Gab1 phosphorylation, and inhibited the ability of Gab1 to associate with a receptor tyrosine kinase. Lenalidomide also enhanced AP-1 transcriptional activity in Namalwa, but not in the other cell lines tested. These studies provide evidence for the mechanism of action of lenalidomide in chromosome 5 deleted hematopoietic tumors in vitro, and may provide a better understanding of the drug's activity in clinical applications.

Clinical management of myelodysplastic syndromes with interstitial deletion of chromosome 5q

Deletions of the long (q) arm of chromosome 5 [del(5q)]occur in patients with myelodysplastic syndromes (MDS) including, but not limited to, those who meet the WHO definition of the 5q- syndrome. Del(5q) MDS patients frequently have symptomatic anemia, and its treatment has traditionally consisted of RBC transfusions and, for some, iron chelation therapy. Erythropoietin, darbepoetin, hypomethylating agents, and lenalidomide can enhance erythropoiesis in MDS patients with anemia, increasing hemoglobin levels and abrogating RBC transfusion requirements. Lenalidomide is particularly active in treating the anemia of del(5q) MDS, which is especially relevant given the low response rate to erythropoietin in this group of patients. In a recent study of 43 MDS patients, 10 of 12 patients (83%) with del(5q) MDS achieved sustained RBC transfusion independence (or a > 2 g/dL increase in hemoglobin), compared with 57% of those with a normal karyotype and 12% of those with other karyotypic abnormalities. Complete cytogenetic remissions were achieved in 75% (nine of 12) of the del(5q) MDS patients, suggesting that lenalidomide targets a fundamental pathogenetic feature of MDS that is more pronounced in the presence of chromosomal 5q deletions. This review highlights some issues about the classification and treatment of del(5q) MDS.

Thalidomide and lenalidomide in the treatment of multiple myeloma

Although multiple myeloma (MM) is incurable with currently available treatments, the introduction of thalidomide and the development of safer and more active thalidomide analogues represent a major advance in the therapy of this disease. Thalidomide, initially introduced for treatment of MM because of its anti-angiogenic properties, has shown remarkable activity alone and in combination with other drugs in patients across all stages of the disease. Given the potential for teratogenicity with thalidomide and the non-haematologic toxicities of the drug, several analogues referred to as "immunomodulatory drugs" (IMiDs) were developed with the intent of enhancing the immunomodulatory effect while minimizing the teratogenic risk. Lenalidomide (CC-5013) and Actimid (CC-4047) are the first such analogues to undergo clinical testing. Lenalidomide has shown impressive activity in relapsed refractory myeloma as well as newly diagnosed disease. The precise mechanism of anti-MM activity of thalidomide and the IMiDs is not clear, but studies suggest that several other mechanisms besides anti-angiogenic effects may play a role. In this paper we review the development, pharmacology, mechanism of action, pre-clinical and clinical efficacy, and the current status of thalidomide and the IMiDs in the treatment of MM.

Immunomodulating drugs for chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is a malignant haematological disorder that remains mostly incurable; more than 95% of patients have disease of B-cell origin. Advances with targeted agents such as monoclonal antibodies, antisense therapy, or both these techniques combined with traditional chemotherapy have improved the frequency of remission. The clinical course of CLL is marked by frequent relapse, and there are limited therapeutic options for patients with relapsed or refractory disease. The morphologically mature CLL clone regulates the microenvironment through modulation of the cytokine milieu that aids its growth and survival, and has a role in immune escape. Targeting of the tumour-cell microenvironment has not been investigated as a treatment option for CLL. Immunomodulating agents are a new class of drugs that change expression of various cytokines and that costimulate immune effector cells.

[The plasma cell myeloma--molecular pathogenesis and target therapies]

The cells of the malignant clone of plasmacell myeloma have cytogenetic aberrations in a substantial number of cases. Many of these abnormal karyotypes are predictive for an unfavorable outcome. Gene mutations and abnormal gene expression, particularly of oncogenes and tumor suppressor genes, are often observed in myeloma cells. The cross talk between the myeloma cells and the bone marrow microenvironment plays an important role for growth and survival of the tumor cells. As a consequence of this cell-to-cell-interaction, several cytokines are secreted. The intracellular signaling, evoked by these cytokines, leads to continuous growth and proliferation and inhibition of apoptosis. Since these molecular pathways have been defined, many new targets for therapeutical interventions become obvious. Some molecules, directed against cytokines, are under early clinical investigation. Medicaments intervening in the cross talk between the myeloma cell and the bone marrow stroma as Thalidomide, Lenalidomide or Bortezomib are already available. Many of the myeloma patients suffer from bone disease. Some new drugs inhibiting the differentiation and activation of osteoclasts are evaluated in clinical trials. These molecules will be an important contribution against the painful bone disease of plasmacell myeloma.

Thalidomide and lenalidomide extend survival in a transgenic mouse model of amyotrophic lateral sclerosis

Accumulating evidence suggests that inflammation plays a major role in the pathogenesis of motor neuron death in amyotrophic lateral sclerosis (ALS). Important mediators of inflammation such as the cytokine tumor necrosis factor-alpha (TNF-alpha) and its superfamily member fibroblast-associated cell-surface ligand (FasL) have been implicated in apoptosis. We found increased TNF-alpha and FasL immunoreactivity in lumbar spinal cord sections of ALS patients and G93A transgenic mice. Both increased TNF-alpha and FasL immunostaining in the lumbar spinal cord of the G93A SOD1 transgenic mice occurred at 40-60 d, well before the onset of symptoms and loss of motor neurons. We tested the neuroprotective effect of thalidomide and its analog lenalidomide, pharmacological agents that inhibit the expression of TNF-alpha and other cytokines by destabilizing their mRNA. Treatment with either thalidomide or lenalidomide attenuated weight loss, enhanced motor performance, decreased motor neuron cell death, and significantly increased the life span in G93A transgenic mice. Treated G93A mice showed a reduction in TNF-alpha and FasL immunoreactivity as well as their mRNA in the lumbar spinal cord. Both compounds also reduced interleukin (IL)-12p40, IL-1alpha, and IL-1beta and increased IL-RA and TGF-beta1 mRNA. Therefore, both thalidomide and lenalidomide bear promise as therapeutic interventions for the treatment of ALS.