Development of neuropathy in patients with myeloma treated with thalidomide: patterns of occurrence and the role of electrophysiologic monitoring

Pomalidomide is active in the treatment of anemia associated with myelofibrosis

PURPOSE

Thalidomide and lenalidomide can alleviate anemia in myelofibrosis. However, their value is undermined by their respective potential to cause peripheral neuropathy and myelosuppression. We therefore evaluated the safety and therapeutic activity of another immunomodulatory drug, pomalidomide.

METHODS

In a phase II randomized, multicenter, double-blind, adaptive design study, four treatment arms were evaluated: pomalidomide (2 mg/d) plus placebo, pomalidomide (2 mg/d) plus prednisone, pomalidomide (0.5 mg/d) plus prednisone, and prednisone plus placebo. Pomalidomide was administered for up to 12 28-day treatment cycles. Prednisone (30 mg/d) was given in a tapering dose schedule during the first three cycles. Response was assessed by International Working Group criteria.

RESULTS

Eighty-four patients with myelofibrosis-associated anemia were randomly assigned to the aforementioned treatment arms: 22, 19, 22, and 21, respectively. Response in anemia was documented in 20 patients, including 15 who became transfusion independent. Response rates in the four treatment arms were 23% (95% CI, 5% to 41%), 16% (95% CI, 0% to 33%), 36% (95% CI, 16% to 56%), and 19% (95% CI, 2% to 36%). The corresponding figures for patients receiving > or = 3 cycles of treatment (n = 62) were 38%, 23%, 40%, and 25%. Response to pomalidomide with or without prednisone was durable (range, 3.2 to 16.9+ months) and significantly better in the absence of leukocytosis (37% v 8%; P = .01); JAK2V617F or cytogenetic status did not affect response. Grade > or = 3 toxicities were infrequent and included (in each treatment arm) neutropenia (9%; 16%; 5%; 5%), thrombocytopenia (14%; 16%; 9%; 5%), and thrombosis (9%; 5%; 0%; 0%).

CONCLUSION

Pomalidomide therapy at 0.5 or 2 mg/d with or without an abbreviated course of prednisone is well tolerated in patients with myelofibrosis and active in the treatment of anemia.

Multiple myeloma

Multiple myeloma is characterised by clonal proliferation of malignant plasma cells, and mounting evidence indicates that the bone marrow microenvironment of tumour cells has a pivotal role in myeloma pathogenesis. This knowledge has already expanded treatment options for patients with multiple myeloma. Prototypic drugs thalidomide, bortezomib, and lenalidomide have each been approved for the treatment of this disease by targeting both multiple myeloma cells and the bone marrow microenvironment. Although benefit was first shown in relapsed and refractory disease, improved overall response, duration of response, and progression-free and overall survival can be achieved when these drugs are part of first-line regimens. This treatment framework promises to improve outcome not only for patients with multiple myeloma, but also with other haematological malignancies and solid tumours.

Single-agent bortezomib in previously untreated multiple myeloma: efficacy, characterization of peripheral neuropathy, and molecular correlations with response and neuropathy

PURPOSE To assess efficacy and safety of single-agent bortezomib in previously untreated patients with multiple myeloma, investigate prevalence of baseline and treatment-emergent polyneuropathy, and identify molecular markers associated with response and neuropathy. PATIENTS AND METHODS Patients received bortezomib 1.3 mg/m(2) on days 1, 4, 8, and 11, for up to eight 21-day cycles. A subset of patients underwent neurophysiologic evaluation pre- and post-treatment. Bone marrow aspirates were performed at baseline for exploratory whole-genome analyses. Results Among 64 patients, 41% had partial response or better, including 9% complete/near-complete responses; median duration of response was 8.4 months. Response rates did not differ in the presence or absence of adverse cytogenetics. After median follow-up of 29 months, median time to progression was 17.3 months. Median overall survival had not been reached; estimated 1-year survival was 92%. Thirty-two patients successfully underwent optional stem-cell transplantation. Bortezomib treatment was generally well tolerated. At baseline, 20% of patients had sensory polyneuropathy. Sensory polyneuropathy developed during treatment in 64% of patients (grade 3 in 3%), but proved manageable and resolved in 85% within a median of 98 days. Neurologic examination, neurophysiologic testing, and measurements of epidermal nerve fiber densities in 35 patients confirmed pretreatment sensory neuropathy in 20% and new or worsening neuropathy in 63%. Pharmacogenomic analyses identified molecular markers of response and treatment-emergent neuropathy, which will require future study. CONCLUSION Single-agent bortezomib is effective in previously untreated myeloma. Baseline myeloma-associated neuropathy seems more common than previously reported, and bortezomib-associated neuropathy, although a common toxicity, is reversible in most patients.

Emerging combination treatment strategies containing novel agents in newly diagnosed multiple myeloma

Treatment strategies for multiple myeloma have changed substantially over the past 10 years following the introduction of bortezomib and the immunomodulatory drugs thalidomide and lenalidomide. In the front-line setting, combination regimens incorporating these novel agents are demonstrating substantial activity, which is translating into improved outcomes compared with previous standards of care. Response rates and depth of response that were previously only seen with high-dose therapy plus stem-cell transplantation (HDT-SCT) can now be achieved with new induction regimens utilizing these novel agents. This has raised the need for trials that will determine the clinical benefit of early SCT in patients that have already achieved a high quality of response. Here, we review the improvements in response and outcome that are seen with these novel-agent regimens, both as induction therapy prior to HDT-SCT and in non-transplant patients, and highlight the latest data from key studies of various novel combinations, including regimens featuring bortezomib plus thalidomide or lenalidomide. We also review data on response and outcomes in patients with poor prognostic characteristics that indicate that the adverse impact typically seen with these factors may be overcome using novel-agent therapy.

Platinum neurotoxicity pharmacogenetics

Cisplatin, carboplatin, and oxaliplatin anticancer drugs are commonly used to treat lung, colorectal, ovarian, breast, head and neck, and genitourinary cancers. However, the efficacy of platinum-based drugs is often compromised because of the substantial risk for severe toxicities, including neurotoxicity. Neurotoxicity can result in both acute and chronic debilitation. Moreover, colorectal cancer patients treated with oxaliplatin discontinue therapy more often because of peripheral neuropathy than tumor progression, potentially compromising patient benefit. Numerous methods to prevent neurotoxicity have thus far proven unsuccessful. To circumvent this life-altering side effect while taking advantage of the antitumor activities of the platinum agents, efforts to identify mechanism-based biomarkers are under way. In this review, we detail findings from the current literature for genetic markers associated with neurotoxicity induced by single-agent and combination platinum chemotherapy. These data have the potential for broad clinical implications if mechanistic associations lead to the development of toxicity modulators to minimize the noxious sequelae of platinum chemotherapy.

Thalidomide in multiple myeloma--clinical trials and aspects of drug metabolism and toxicity

BACKGROUND

After the tragic events in the early 1960s, thalidomide has re-emerged as therapeutic for multiple myeloma (MM). It was first approved for the treatment of erythema nodosum leprosum, and is now under evaluation for hematologic and non-hematologic disorders. Its complex mechanism of action is not fully understood; however extensive preclinical studies in MM have revealed its antiangiogenic and immunomodulatory properties.

OBJECTIVE

In this review, we focus on the importance and toxicity of thalidomide in today's clinical use.

METHODS

Key preclinical and clinical trials available as well as data on the pharmacokinetics and pharmacodynamics of thalidomide in humans are summarized.

CONCLUSIONS

Thalidomide is widely used as first-line treatment and in relapsed/refractory MM. The most common side effects are fatigue, constipation and peripheral neuropathy, and careful monitoring is required to avoid fetal exposure.

Central and peripheral nervous system toxicity of common chemotherapeutic agents

Central and peripheral nervous system toxicity are frequent complications of most chemotherapy regimens, often leading to reduction of dosages or cessation of the responsible drugs. However, sometimes the afflicted toxicity may not be reversible, especially if it is not recognized early, further compromising the quality of life of the cancer patients. The most common chemotherapeutic agents that might cause CNS toxicity manifested as encephalopathy of various severities include methotrexate, vincristine, ifosfamide, cyclosporine, fludarabine, cytarabine, 5-fluorouracil, cisplatin and the interferons (alpha > beta). Involvement of the peripheral nervous system manifested as distal peripheral neuropathy results after therapy with cisplatin, vincristine, taxanes, suramin and thalidomide. Although several compounds have been proposed as neuroprotective agents, few have been shown to be active against the chemotherapy induced neurotoxicity.

Thalidomide and lenalidomide: Mechanism-based potential drug combinations

Thalidomide and its analogue lenalidomide are potent anti-inflammatory, anti-angiogenic and immunomodulatory drugs, successfully used for the treatment of hematological cancers, in particular multiple myeloma (MM). Both drugs reveal a dual mechanism of action: they target tumour cells by direct cytotoxicity and, indirectly, by interfering with several components of the bone marrow microenvironment. Lenalidomide and thalidomide are versatile drugs with a broad range of activities that potentiate the anti-MM effects of conventional and novel agents. Here, we review the mechanism of action of these drugs, providing a rationale for combination studies in order to improve patient outcome and reduce side effects.

Neuropathies in the context of malignancies

PURPOSE OF REVIEW

To conduct a critical review of recent data pertaining to the clinical and therapeutic aspects of peripheral neuropathies in the setting of malignancies, with the exception of paraproteinemic neuropathies. Our search extended to the past 2 years, using a PubMed search strategy.

RECENT FINDINGS

In the field of neuropathies linked with the development of the cancer, recent works have focused on lymphoma and cancer-associated vasculitides. In paraneoplastic syndromes, the major fact of the past 2 years is the issue of guidelines for diagnosis and treatment of these disorders, under the aegis of the paraneoplastic syndromes Euronetwork and of the European Federation of Neurological Sciences. When considering chemotherapy, neurotoxicity is becoming increasingly better known. Finally, the spectrum of late-delayed complications of irradiation further increases with a better clinical characterization of radiotherapy-induced dropped head syndrome.

SUMMARY

This article successively reviews the results of the recent studies in these various fields. In the field of chemotherapy, we will particularly focus on some new data concerning oxaliplatin, bortezomib, the albumin-bound form of paclitaxel and lenalidomide.

New drugs in multiple myeloma

PURPOSE OF REVIEW

Advances in the understanding of multiple myeloma pathogenesis have led to the development of innovative targeted therapies and improved management of this aggressive hematological neoplasia. This review will focus on the clinical trials that have reinforced the use of these new agents. Also, we will briefly take a look at the newer drugs making their way out of the laboratory and into early phase studies.

RECENT FINDINGS

During the past decade new multiple myeloma therapies featuring bortezomib and lenalidomide have come to light, whereas known agents such as thalidomide and arsenic trioxide have been reintroduced as key factors in multiple myeloma management. These new agents and their combinations have shown increased response rates and have added more options for patients with multiple myeloma whose disease has become resistant to conventional therapy. With these drug therapies has come a more targeted approach to treatment enabling not only improved antimyeloma efficacy but also the use of decreased dosing enhancing the safety and tolerability of these regimens. Newer agents including the histone deacetylase, hsp90, mammalian target of rapamycin and Akt inhibitors are showing promise preclinically and are now being assessed in phase I/II trials.

SUMMARY

This new antimultiple myeloma arsenal has shown its worth in both the relapsed/refractory and frontline setting and provides valuable options for patients with this debilitating disease.

Peripheral neuropathy associated with novel therapies in patients with multiple myeloma: consensus statement of the IMF Nurse Leadership Board

The novel therapies thalidomide and bortezomib can cause peripheral neuropathy, a challenging adverse event that can affect quality of life and compromise optimal treatment for patients with multiple myeloma. At baseline, patients should be evaluated for signs and symptoms of peripheral neuropathy with a neurotoxicity assessment tool and educated about the symptoms and the importance of reporting them. Signs, symptoms, and the ability to perform activities of daily living should be evaluated regularly so that appropriate interventions can be employed if necessary. Specific management strategies for peripheral neuropathy are based on the grade of severity and on signs and symptoms; strategies include dose and schedule modifications, pharmacologic interventions, nonpharmacologic approaches, and patient education.

Bortezomib-induced peripheral neuropathy in multiple myeloma: a comprehensive review of the literature

Bortezomib has demonstrated significant activity in clinical trials, mainly against recurrent or newly diagnosed multiple myeloma (MM). Peripheral neuropathy is a significant toxicity of bortezomib, requiring dose modification and potential changes in the treatment plan when it occurs. The mechanism underlying bortezomib-induced peripheral neuropathy (BIPN) is unknown. Metabolic changes resulting from the accumulation of bortezomib in the dorsal root ganglia cells, mitochondrial-mediated disregulation of Ca(++) homeostasis, and disregulation of neurotrophins may contribute to the pathogenesis of BIPN. It is increasingly recognized that BIPN may be a proteasome inhibitor class effect, producing primarily a small fiber and painful, axonal, sensory distal neuropathy. Incidence of BIPN is mainly related to various risk factors, including cumulative dose and evidence of preexisting neuropathy. Assessment of BIPN is based primarily on neurologic clinical examination and neurophysiologic methods. To date, apart from the use of dose reduction and schedule change algorithm, there is no effective treatment with neuroprotective agents for BIPN. Analgesics, tricyclic antidepressants, anticonvulsants, and vitamin supplements have been used as symptomatic treatment against bortezomib-associated neuropathic pain with some success. This review looks critically at the pathogenesis, incidence, risk factors, diagnosis, characteristics, and management of BIPN, and highlights areas for future research.

Alternate day pomalidomide retains anti-myeloma effect with reduced adverse events and evidence of in vivo immunomodulation

We previously reported that daily dose pomalidomide (CC-4047), a thalidomide analogue, has excellent anti-myeloma activity but is associated with myelosuppression and deep vein thrombosis. We report here a phase 1 study to determine the maximum tolerated dose (MTD) of pomalidomide at 1 mg, 2 mg, 5 mg and 10 mg on alternate days (ad). Twenty patients with relapsed myeloma were treated. Grade 4 neutropenia occurred in all patients receiving 10 mg and the MTD was defined as 5 mg ad. No thrombotic events were observed. Pomalidomide was continued following the 4-week MTD study in 17/20 patients for a median of 14 months. 10% of patients had a complete response and >50% reduction in paraprotein was achieved in 50% of subjects. Progression-free survival was 10.5 months and median overall survival was 33 months. A significant rise was observed in the proportion of CD8(+) cells. Alternate day pomalidomide was associated with a marked reduction in the incidence of thrombosis whilst maintaining excellent anti-myeloma activity. This trial provides further in vivo evidence that pomalidomide modulates the immune system in myeloma patients. Phase 2 studies to further assess the optimal schedule of administration and anti-myeloma activity of this agent are planned.

Chemotherapy-induced neuropathy

Neurotoxic side effects of cancer therapy are second in frequency to hematological toxicity. Unlike hematological side effects that can be treated with hematopoietic growth factors, neuropathies cannot be treated and protective treatment strategies have not been effective. For the neurologist, the diagnosis of a toxic neuropathy is primarily based on the case history, the clinical and electrophysiological findings, and knowledge of the pattern of neuropathy associated with specific agents. In most cases, toxic neuropathies are length-dependent, sensory, or sensorimotor neuropathies often associated with pain. The platinum compounds are unique in producing a sensory ganglionopathy. Neurotoxicity is usually dependent on cumulative dose. Severity of neuropathy increases with duration of treatment and progression stops once drug treatment is completed. The platinum compounds are an exception where sensory loss may progress for several months after cessation of treatment ("coasting"). As more effective multiple drug combinations are used, patients will be treated with several neurotoxic drugs. Synergistic neurotoxicity has not been extensively investigated. Pre-existent neuropathy may influence the development of a toxic neuropathy. Underlying inherited or inflammatory neuropathies may predispose patients to developing very severe toxic neuropathies. Other factors such as focal radiotherapy or intrathecal administration may enhance neurotoxicity. The neurologist managing the cancer patient who develops neuropathy must answer a series of important questions as follows: (1) Are the symptoms due to peripheral neuropathy? (2) Is the neuropathy due to the underlying disease or the treatment? (3) Should treatment be modified or stopped because of the neuropathy? (4) What is the best supportive care in terms of pain management or physical therapy for each patient? Prevention of toxic neuropathies is most important. In patients with neuropathy, restorative approaches have not been well established. Symptomatic and other management are necessary to maintain and improve quality of life.

Single-institute phase 2 study of thalidomide treatment for refractory or relapsed multiple myeloma: prognostic factors and unique toxicity profile

We previously reported a pilot study of thalidomide monotherapy for Japanese patients with refractory or relapsed multiple myeloma. In the present work, we have extended this clinical trial to a single-institute phase 2 study with a larger number of patients and longer follow-up time. New information on the optimal dose and prognostic factors as well as the correlation of toxicities with treatment schedule was obtained. Fifteen of 56 (27%) patients achieved a partial response, including three cases with near-complete remission. Most patients suffered toxicities at a dose of 400 mg per day, but there was no clear dose-response relationship. Thus, a lower dose such as 200 mg per day or less is considered optimal. Multivariate analyses identified only lack of response to therapy as an adverse prognostic factor for progression-free survival. Chromosomal abnormality, C-reactive protein >10 mg/L, and more than six previous courses of chemotherapy were significantly associated with shorter overall survival. Grade 3 or 4 neutropenia and thrombocytopenia were observed in 23 and 11% of patients, respectively. Grade 4 interstitial pneumonia and grade 5 pulmonary hypertension were observed; however, no patient suffered deep vein thrombosis, which has frequently been observed in other studies. Duration of therapy was closely related to the development of peripheral neuropathy. The efficacy and prognostic factors of this treatment were confirmed in long-term observation. However, special attention should be paid to toxicities such as hematological and pulmonary complications as well as peripheral neuropathy in long-term users.

An Overview of Chemotherapy-Induced Peripheral Neuropathy

Peripheral neuropathy remains a major limitation of chemotherapeutic agents used in cancer treatment. This neurologic complication from chemotherapy occurs frequently and can be debilitating. Although difficult to predict, both chemotherapeutic and patient-specific risk factors may contribute to this adverse event. Symptoms of peripheral neuropathy may appear acutely after treatment or persist chronically upon drug discontinuation. The taxanes, vinca alkaloids, and immunomodulatory drugs commonly cause peripheral nervous system toxicity. Prompt recognition and evaluation of this neurological adverse event by those who provide care to patients with cancer can prove to have a positive impact on the quality of life of those patients.

Thalidomide in the treatment of multiple myeloma

Thalidomide--either alone or in combination with dexamethasone or chemotherapy--has shown significant activity in relapsed/refractory disease. When used in the induction regimens in untreated patients, it significantly increases the response rates as well progression-free survival. Moreover, thalidomide as a maintenance therapy has become a very attractive option. However, the toxicity profile of the drug, mainly neurotoxicity and thrombotic events, mandate careful monitoring of patients treated with thalidomide, whether as the first line, in the relapsed setting, or as maintenance. In this chapter we will review the pharmacology, mechanisms of action, and toxicity of the drug, and will focus on available data from clinical experience and randomized trials of thalidomide in the different settings of multiple myeloma: refractory/relapsed disease, upfront treatment in patients who are eligible for high-dose therapy as well as those who are not, and finally the use of thalidomide as a maintenance treatment.

An update on drug combinations for treatment of myeloma

Multiple myeloma is the second most common haematological malignancy. It is becoming increasingly manageable with conventional and high-dose chemotherapy but there remains a critical need to develop both new drugs and combinations to improve long-term outcomes. Novel biological therapies that specifically target myeloma cells and/or their microenvironmental interactions are being developed that are highly effective, both as single agents and as combinations. Chief among these new agents are the proteasome inhibitor, bortezomib, and the immunomodulatory agents, thalidomide and lenalidomide. These drugs show improved single agent activity that is enhanced in combination. However, many drugs that are being developed in this setting may only have limited single agent activity, but combination use with these and other agents represents a very exciting way of targeting important pathogenic pathways crucial in myeloma development. This represents a challenge for both drug development and clinical trial evaluation, which has the potential to revolutionise the clinical management of myeloma and a paradigm for drug development in other diseases.

Thalidomide for treatment of multiple myeloma: 10 years later

Thalidomide, bortezomib, and lenalidomide have recently changed the treatment paradigm of myeloma. In young, newly diagnosed patients, the combination of thalidomide and dexamethasone has been widely used as induction treatment before autologous stem cell transplantation (ASCT). In 2 randomized studies, consolidation or maintenance with low-dose thalidomide has extended both progression-free and overall survival in patients who underwent ASCT at diagnosis. In elderly, newly diagnosed patients, 3 independent randomized studies have reported that the oral combination of melphalan and prednisone plus thalidomide (MPT) is better than the standard melphalan and prednisone (MP). These studies have shown better progression-free survival, and 2 have shown improved overall survival for patients assigned to MPT. In refractory-relapsed disease, combinations including thalidomide with dexamethasone, melphalan, doxorubicin, or cyclophosphamide have been extensively investigated. The risks of side effects are greater when thalidomide is used in combination with other drugs. Thromboembolism and peripheral neuropathy are the major concern. The introduction of anticoagulant prophylaxis has reduced the rate of thromboembolism to less than 10%. Immediate thalidomide dose reduction or discontinuation when paresthesia is complicated by pain or motor deficit has decreased the severity of neuropathy. Future studies will define the most effective or the best sequence of combinations which could improve life expectancy.

Neurologic complications of chemotherapy agents

PURPOSE OF REVIEW

To review neurologic complications of common and recently developed chemotherapeutic agents, as well as recent research regarding 'chemobrain'.

RECENT FINDINGS

Bortezomib, a new anticancer agent, has a propensity toward causing a largely sensory and reversible peripheral neuropathy. Infusion of magnesium and calcium pre and post-oxaliplatin infusion reduces neuropathy but may interfere with clinical response to oxaliplatin. No other measures currently reduce the incidence or severity of neuropathy related to platinum compounds, taxanes, or thalidomide. Chemobrain, cognitive decline attributed to chemotherapy, has garnered research interest. Prevalence and epidemiology of chemobrain are poorly understood. Potential underlying mechanisms are under investigation in animal models and include effects on long-term potentiation and cerebral blood flow. Blood-brain barrier permeability, efficiency of cellular efflux pumps, DNA damage, telomere shortening, alteration of cytokine regulation, defects in neural repair, and oxidative stress may play roles in the effects of chemotherapy on central nervous system function.

SUMMARY

Data on prevention and treatment of chemotherapy-induced peripheral neuropathy are limited. Calcium and magnesium infusions for oxaliplatin administration have the most scientific support and are widely used in practice but may interfere with the clinical efficacy of oxaliplatin. Some novel agents, particularly bortezomib, have significant risk of chemotherapy-induced peripheral neuropathy. Animal models are beginning to reveal the mechanisms underlying the impact of individual chemotherapeutic drugs on cognition.

Novel therapies in myeloma

PURPOSE OF REVIEW

Several novel therapies have been licensed for the treatment of myeloma in recent years. We summarize some of the trials leading to their approval and the current evidence for their clinical use. A number of promising agents undergoing phase I/II trial evaluation are also discussed.

RECENT FINDINGS

The immunomodulatory drugs, thalidomide and lenalidomide, and the proteasome inhibitor, bortezomib, have been shown to be effective agents, both alone and as part of combination regimens, for the treatment of myeloma. Studies are now focusing on the optimal sequencing of these drugs throughout the disease course, with a view to maximizing antitumor efficacy and minimizing overlapping toxicities. New protocols are increasingly based on preclinical evidence of synergy. The incorporation of these agents into transplant-based treatment protocols has improved outcomes. Other examples of novel agents undergoing assessment at present include arsenic trioxide, hsp90 inhibitors and histone deacetylase inhibitors. Future developments are likely to include individualized treatment plans based on patient-specific parameters including cytogenetic analysis and gene expression profiling.

SUMMARY

Thalidomide, lenalidomide and bortezomib can now be considered as standard options both as first-line agents and beyond for the treatment of myeloma, with respective combinations also emerging as valid choices for all stages of the disease.

Neurotoxicity of bortezomib therapy in multiple myeloma: a single-center experience and review of the literature

BACKGROUND

Bortezomib is active in heavily pretreated multiple myeloma patients; the dose-limiting toxicity is peripheral neuropathy (PN).

METHODS

The authors retrospectively reviewed the incidence, severity, and risk factors for PN in 78 patients who received bortezomib. The median age was 57 years (range, 33-80 years), 62% of patients were men, and 37% of patients were African Americans. Seventeen patients (22%) had diabetes mellitus (DM), and 66 patients (85%) had received thalidomide. Before bortezomib treatment, 37% of the patients reported subjective, grade 1 or 2 PN. Patients received bortezomib alone (n = 10 patients) plus dexamethasone (n = 36 patients) and thalidomide (n = 20 patients) or chemotherapy (n = 12 patients). PN affected 52% of patients, including grade 3 and 4 PN in 15% and 7%, respectively.

RESULTS

Twelve patients stopped bortezomib because of side effects that included PN (n = 9 patients), diarrhea (n = 2 patients) and cytomegalovirus pneumonia (n = 1 patient); 11 patients had dose reductions because of PN. Grade 4 PN affected 6 patients (sensory, n = 4 patients; motor/sensory, n = 2 patients). The onset of grade 4 PN was sudden rather than cumulative. Factors that were predictive of PN grade were baseline PN (P = .002), prior thalidomide use (P = .03), and the presence of DM (P = .03). Multiple myeloma responses included complete, near complete, and partial responses in 5% of patients, 10% of patients, and 27% of patients, respectively. Responses were independent of PN and of whether bortezomib was combined with chemotherapy or thalidomide. Patients remained on therapy longer for a median of 5 cycles (range, 2-36 cycles) when they received bortezomib plus thalidomide versus 3 cycles (range, 1-19 cycles) for the other combinations. PN therapy was mostly supportive. It was noteworthy that 6 of 9 patients with PN who received lenalidomide as salvage therapy after bortezomib had significant improvement in their symptoms.

CONCLUSIONS

The risk of bortezomib-related PN was greater in patients who had PN and DM at baseline. The authors concluded that an unexpected, symptomatic improvement of PN on lenalidomide is worth further investigation.

New drugs for myeloma

Although multiple myeloma remains incurable with conventional treatments, management of the disease has recently been transformed with the introduction of three novel agents, bortezomib, thalidomide, and lenalidomide. The proteasome inhibitor bortezomib is approved for the treatment of patients who have received one prior therapy; there is a growing body of clinical evidence showing its effectiveness alone and in combination in the frontline setting, with high response rates and consistently high rates of complete response. Thalidomide plus dexamethasone is approved as frontline treatment of multiple myeloma. Other combination regimens including thalidomide have demonstrated substantial activity in both relapsed and frontline settings. Recently, the thalidomide analogue lenalidomide has been approved, in combination with dexamethasone, for the treatment of patients who have received one prior therapy; this regimen has shown promising results in the frontline setting. These agents represent a new generation of treatments for multiple myeloma that affect both specific intracellular signaling pathways and the tumor microenvironment. Other novel, targeted therapies are also being evaluated in preclinical and clinical studies. Regimens incorporating bortezomib, thalidomide, lenalidomide, and other novel agents, together with commonly used conventional drugs, represent a promising future direction in myeloma treatment. At present, further investigation is required to assess the safety and activity of combinations integrating these other novel agents. However, bortezomib, thalidomide, and lenalidomide are now in widespread clinical use. This review therefore focuses on the extensive clinical data available from studies of these drugs in the treatment of newly diagnosed and advanced multiple myeloma.

Single autologous stem-cell transplantation followed by maintenance therapy with thalidomide is superior to double autologous transplantation in multiple myeloma: results of a multicenter randomized clinical trial

From April 2003 to December 2006, 195 patients with de novo symptomatic myeloma and younger than 60 years of age were randomly assigned to receive either tandem transplantation up front (arm A, n = 97) or one autologous stem-cell transplantation followed by a maintenance therapy with thalidomide (day + 90, 100 mg per day during 6 months) (arm B, n = 98). Patients included in arm B received a second transplant at disease progression. In both arms, autologous stem-cell transplantation was preceded by first-line therapy with thalidomide-dexamethasone and subsequent collection of peripheral blood stem cells with high-dose cyclophosphamide (4 g/m(2)) and granulocyte colony stimulating factor. Data were analyzed on an intent-to-treat basis. With a median follow-up of 33 months (range, 6-46 months), the 3-year overall survival was 65% in arm A and 85% in arm B (P = .04). The 3-year progression-free survival was 57% in arm A and 85% in arm B (P = .02). Up-front single autologous transplantation followed by 6 months of maintenance therapy with thalidomide (with second transplant in reserve for relapse or progression) is an effective therapeutic strategy to treat multiple myeloma patients and appears superior to tandem transplant in this setting. This study was registered at www.ClinicalTrials.gov as (NCT 00207805).

New therapies in multiple myeloma

The melphalan-prednisone regimen has been considered as standard therapy for patients with multiple myeloma (MM) for many years. Recently, high-dose chemotherapy with stem-cell support has extended progression-free survival and increased overall survival, and it is now considered conventional therapy in younger patients. However, most patients relapse and the salvage treatment is not very effective. New active drugs, including immunomodulatory agents, thalidomide (Thal) and lenalidomide, and the proteasome inhibitor bortezomib, have shown promising anti-myeloma activity. These novel treatments are aimed at overcoming resistance of tumour cells to conventional chemotherapy, acting both directly on myeloma cells and indirectly by blocking the interactions of myeloma cells with their local microenvironment and suppressing growth and survival signals induced by autocrine and paracrine loops in the bone marrow. Thal has been widely studied, mostly in combination regimens in patients with relapsed MM and, more recently, in front-line therapy, showing efficacy in terms of response rate and event-free survival. Bortezomib has been found to possess remarkable activity, especially in combination with other chemotherapeutic agents, in relapsed/refractory and newly diagnosed MM, as well as in patients presenting adverse prognostic factors. Lenalidomide, in combination with dexamethasone, is showing high overall response rates in relapsed and refractory MM and promising results also in first-line therapy. In this paper, the results of the most significant trials with Thal, bortezomib and lenalidomide are reported. Several ongoing clinical studies will hopefully allow the identification of the most active combinations capable of improving survival in patients with MM.

Peripheral Neuropathy Related to Chemotherapy

OBJECTIVES

To review the evidence base for prevention and intervention of chemotherapy-induced peripheral neuropathy (PN).

DATA SOURCES

Medical and nursing literature.

CONCLUSION

Many small studies that reported positive findings have either not been validated in large prospective, randomized controlled trials (RCT), or have not been further studied. Prevention strategies based on RCTs include the use of xaliproden to reduce the incidence of grade 3 PN in patients receiving oxaliplatin-based regimens, and dose reduction or interruption until recovery. There are gaps in the literature of nurse-sensitive outcome studies for nursing assessment and intervention

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to be knowledgeable about the evidence, or lack of it, on strategies to prevent and manage chemotherapy-induced PN. Nurses also need to measure the effectiveness of interventions for PN, such as exercise, patient teaching about self-care strategies, and develop and/or participate in well-designed intervention studies regarding the prevention and management of PN.

VAD-doxil versus VAD-doxil plus thalidomide as initial treatment for multiple myeloma: results of a multicenter randomized trial of the Greek myeloma study group

BACKGROUND

We have previously demonstrated that vincristine, liposomal doxorubicin and dexamethasone (VAD-doxil) is equally effective with VAD-bolus yielding objective response rates of 61% as first-line treatment in multiple myeloma (MM). In a phase II study, the addition of thalidomide to VAD-doxil (TVAD-doxil) proved feasible and increased response rate to 74%. The aim of the present multicenter prospective randomized clinical trial was to compare the efficacy and toxicity of VAD-doxil and TVAD-doxil in previously untreated MM patients.

PATIENTS AND METHODS

We enrolled 232 newly diagnosed MM patients aged <75 years, 115 randomized to VAD-doxil (arm A) and 117 to TVAD-doxil (arm B). Patients in arm A received vincristine 2 mg i.v. and liposomal doxorubicin 40 mg/m(2) i.v., on day 1 and dexamethasone 40 mg p.o. daily on days 1-4, 9-12 and 17-20 for the first cycle and on days 1-4 for the next three cycles. Patients in arm B received additionally thalidomide 200 mg p.o. daily, at bedtime. Treatment was administered every 28 days.

RESULTS

On an intention-to-treat basis, at least partial response was observed, in 62.6% and in 81.2% of patients randomized to arms A and B, respectively (P = 0.003). Progression-free survival (PFS) at 2 years was 44.8% in arm A and 58.9% in arm B (P = 0.013). Overall survival (OS) at 2 years was 64.6% and 77%, in arms A and B, respectively (P = 0.037). Considering overall toxicity, constipation, peripheral neuropathy, dizziness/somnolence, skin rash and edema were significantly higher in arm B compared with arm A (P < 0.01), but grade 3-4 toxicities were low and similar in both arms.

CONCLUSIONS

The addition of thalidomide to VAD-doxil increases response and PFS rates and probably OS in previously untreated myeloma patients. The superiority of efficacy counterbalances the higher overall toxicity of TVAD-doxil.

An analysis of clinical trials assessing the efficacy and safety of single-agent thalidomide in patients with relapsed or refractory multiple myeloma

Given that the efficacy/safety of thalidomide for relapsed or refractory multiple myeloma have not been well characterized in a randomized, controlled setting, an analysis of larger, single-agent trials was conducted. Nine trials met the following inclusion criteria: primary population of multiple myeloma; all patients relapsed or refractory; single-agent thalidomide; and sample size > or =50. At median doses of 200 - 800 mg per day, the pooled overall response rate (ORR) was 28.2% (95% CI: 22.6 - 33.7%), including a complete response (CR) rate of 1.6% (95% CI: 0.3 - 2.9%) and partial response rate of 26.0% (95% CI: 20.1 - 32.0%). Response was typically based on M-protein reduction alone. Peripheral neuropathy (PN) incidence varied from 12 - 44%, possibly impacted by the short median follow-up (9 - 29 months). Pooled venous thromboembolism (VTE) incidence was 2.7% (95% CI: 1.1 - 4.3%) and discontinuation due to intolerance (DDI) rate was 14.9% (95% CI: 12.0 - 17.7%). Overall survival (OS), progression-free survival (PFS) and PN incidence were not pooled due to lack of reporting and trial heterogeneity. Prognostic factors identified included B2M (PFS) and advanced age (PFS and OS). Overall, thalidomide demonstrated an ORR approaching 30%, with low CR rate of 1.6% and VTE and DDI incidences of 3% and 15%, respectively.

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.