Phase II trial of carboplatin in the management of malignant mesothelioma

The role of interleukin-6 in malignant mesothelioma

Malignant mesothelioma (MM) still remains a dismal disease with a median overall survival between 9-12 months. During the past decade since the introduction of the multi-folate antagonist, pemetrexed, there have been no significant advances in its systemic treatment, particularly with novel therapeutics that have exhibited varying degrees of success in other solid tumours. In recent years, the pleiotropic proinflammatory cytokine, interleukin-6 (IL-6) has emerged as a mediator of pivotal processes such as cell proliferation and chemoresistance within the mesothelioma tumour microenvironment in addition to clinical symptoms commonly witnessed in this disease. This manuscript provides a brief summary on the pathophysiology and clinical management of MM, followed by the role of IL-6 in its tumourigenesis and the rationale for utilising anti-IL-6 therapeutics alongside standard chemotherapy and targeted agents in an attempt to prolong survival.

Combined chemotherapy with cytotoxic and targeted compounds for the management of human malignant pleural mesothelioma

Human malignant pleural mesothelioma (hMPM) is an aggressive asbestos-associated cancer, the incidence of which is increasing and which, despite progress in diagnosis and therapy, continues to have a poor prognosis. Asbestos fibers induce aberrant cell signaling, leading to proto-oncogene activation and chemoresistance. In this review, we discuss the evolution of pharmacological management of hMPM up to the most recent advances. Monotherapy with single cytotoxic drugs achieves modest objective response rates, seldom reaching 30%. However, combination regimens using novel drugs and standard molecules are showing gradually improving responses and clinical benefits. Phase II/III studies have identified pemetrexed, a multitarget folate pathway inhibitor in combination with platinum derivatives, and the cisplatin/gemcitabine association as front-line chemotherapy for hMPM. Detailed knowledge of molecular mechanisms of signal transduction and neoangiogenesis in hMPM should aid in the design and screening of other promising compounds such as more efficacious receptor tyrosine kinase inhibitors.

Hyperthermia combined with intra-thoracic chemotherapy and radiotherapy for malignant pleural mesothelioma

BACKGROUND

Prognosis for patients with malignant pleural mesothelioma (MPM) remains poor and such patients require intensive treatment. Few studies have examined hyperthermia for MPM. The present study investigated the feasibility of hyperthermia combined with weekly chemo-radiotherapy for patients with MPM and estimated the efficacy of this regimen.

METHODS

A total of 11 patients (median patient age was 67 and all had pleural effusion) with MPM were enrolled in this study. The treatment regimen comprised of weekly thermo-radiotherapy with intra-thoracic chemotherapy 2-5 times at initiation of treatment. Hyperthermia was performed once per week for approximately 60 min. Hemithorax external radiotherapy was administered once weekly on the same day as hyperthermia and just before thermochemotherapy. Median total radiation dose was 6 Gy (range, 2-10 Gy). Chemotherapy was administered into the thoracic cavity through a tube. Chemotherapeutic agents administered were CDDP for seven patients, carboplatinum (CBDCA) for three patients and both CDDP and CBDCA for one patient. Dose of CDDP was 50 mg/body and dose of CBDCA was 200-300 mg m-2. Response rate and median survival time (MST) and palliative effect were investigated.

RESULTS

Complete response was not achieved in any of the 11 patients. Partial response was achieved in three of 11 patients (27.3%), SD in six patients (54.5%) and PD in two patients (18.2%). There was no correlational relationship between thermal parameters and response. MST was 27.1 months. Pleural fluid decreased in all patients after therapy, while all patients displayed improved performance status and could be discharged from hospital. Patients with partial response had a relatively longer survival time than SD or PD. All patients underwent the complete course of treatment and only one of 11 patients developed grade 4 thrombocytopenia.

CONCLUSION

It was therefore concluded that hyperthermia combined with intra-thoracic chemotherapy using cisplatinum or carboplatinum may be tolerable. This approach appears effective and more acceptable for patients with MPM with pleural effusion than other multi-modality therapy.

Malignant pleural mesothelioma: medical treatment update

Malignant pleural mesothelioma (MPM) is a disease usually unaffected by current therapeutic strategies, but for the majority of patients, the use of systemic chemotherapeutic drugs remains the only therapeutic option available. During the past 15-20 years, many phase II and a few phase III clinical trials have studied a large variety of drugs such as anthracyclines, alkylating agents, platinum compounds, taxanes, vinka alkaloids, and antifolates as single agents and in combination, with the aim to increase responses and survival. The combination of pemetrexed and cisplatin tested in the largest phase III randomized trial of malignant pleural mesothelioma ever conducted has become the current standard of care. New targeted therapeutic approaches with a variety of anti-growth factor drugs are currently undergoing investigation worldwide.

Treatment of malignant pleural mesothelioma with carboplatin, liposomized doxorubicin, and gemcitabine: a phase II study

BACKGROUND

Malignant pleural mesothelioma has a poor prognosis and there is limited effect of treatment. The Nordic Mesothelioma groups decided in the year 2000 to investigate a combination of liposomized doxorubicin, carboplatin, and gemcitabine for this disease in a phase II study.

METHODS

From January 2001, to December 2003, 173 evaluable patients with biopsy-verified malignant mesothelioma were included. Two patients were lost to follow-up, but all the others were followed for at least 4 years or until death.

RESULTS

Toxicity was fairly low. There were 56 responses (32.4%), of which 2 were complete; the median time to progression was 8.6 months, and the median overall survival was 13 months. Some patients had their responses 4 to 6 months after last treatment. For 116 patients with epitheloid subtype, median survival was 17 months. A subgroup of these patients with good performance status, early stage, and age 70 years or less, showed a median survival of 22 months.

CONCLUSION

The treatment yields good results with a high number of responses and long survival, and a low toxicity. The long survival of the epitheloid subgroup with good prognostic factors is as good as or even better than some studies on "radical" surgery or multimodal treatment, underlining the need of randomized studies to evaluate such treatment options.

Gemcitabine and vinorelbine in pemetrexed-pretreated patients with malignant pleural mesothelioma

BACKGROUND

Pemetrexed-cisplatin chemotherapy is the standard of care in the first-line treatment of unresectable malignant pleural mesothelioma (MPM). Second-line cytotoxic therapy is considered for a growing group of patients, but the optimal treatment has not been defined to date. Gemcitabine and vinorelbine have shown activity in the first-line setting. The objective of this study was to evaluate the activity and toxicity of the gemcitabine-vinorelbine combination in pemetrexed-pretreated patients with MPM.

METHODS

From January 2004 to September 2006, 30 consecutive patients who were pretreated with pemetrexed with or without a platinum-derivative were enrolled. Gemcitabine 1000 mg/m(2) and vinorelbine 25 mg/m(2) were administered intravenously on Days 1 and 8 every 3 weeks. Treatment was repeated for a maximum of 6 cycles or until progression or unacceptable toxicity.

RESULTS

A partial response was observed in 3 patients (10%; 95% confidence interval [CI], 2.1-26.5%), and 10 patients (33.3%; 95% CI, 17.3-52.8%) had stable disease after treatment. Overall, 13 patients (43.3%; 95% CI, 25.5-62.6%) achieved disease control. The median time to progression was 2.8 months (range, 0.6-12.1 months), and the median survival was 10.9 months (range, 0.8-25.3 months). Hematologic toxicity was acceptable, with grade 3 or 4 neutropenia occurring in 11% of patients and thrombocytopenia occurring in 4% of patients; no case of febrile neutropenia was observed. Nonhematologic toxicity generally was mild.

CONCLUSIONS

The gemcitabine and vinorelbine combination was moderately active and had an acceptable toxicity profile in pemetrexed-pretreated patients with MPM. The role of second-line treatment in MPM needs to be evaluated in prospective trials in large series of patients who are stratified according to previous treatment and prognostic factors.

Phase II study of pemetrexed plus carboplatin in malignant pleural mesothelioma

PURPOSE

This multicenter, phase II clinical study was conducted to evaluate the activity of the combination of pemetrexed and carboplatin in patients with malignant pleural mesothelioma (MPM).

PATIENTS AND METHODS

Chemotherapy-naive patients with measurable disease and adequate organ function, who were not eligible for curative surgery, received pemetrexed 500 mg/m2 and carboplatin area under the plasma concentration-time curve of 5 mg/mL/min, administered intravenously every 21 days. All patients received folic acid and vitamin B12 supplementation. Pemetrexed was provided within the Expanded Access Program.

RESULTS

A total of 102 patients were enrolled. An objective response was achieved in 19 patients (two complete and 17 partial responses), for a response rate of 18.6% (95% CI, 11.6% to 27.5%). Forty-eight patients (47.0%; 95% CI, 37.1% to 57.2%) had stable disease after treatment. Overall, 67 patients (65.7%) achieved disease control (95% CI, 55.6% to 74.8%). Median time to progression was 6.5 months; median overall survival time was 12.7 months. Compliance to treatment was excellent, with a relative dose-intensity of 97% for pemetrexed and 98% for carboplatin. Toxicity was mild, with grade 3 or 4 neutropenia occurring in 9.7% of total cycles and grade 3 or 4 anemia occurring in 3.5% of total cycles. Nonhematologic toxicity was negligible.

CONCLUSION

Treatment with pemetrexed and carboplatin was active and well tolerated in patients with MPM. Disease control rate, time to disease progression, and overall survival were similar to the results achieved with the standard regimen of pemetrexed and cisplatin, suggesting that the carboplatin combination could be an alternative option for these patients.

An overview of chemotherapy for mesothelioma

Mesothelioma is an extraordinarily challenging disease to treat. While numerous clinical trials testing various chemotherapeutic agents have been conducted over the last several decades, only recently have larger studies proven the efficacy of newer chemotherapy regimens. This article reviews the data regarding specific classes of chemotherapeutic agents. The role of treatment in various disease settings and the difficulty in assessing the benefit of that therapy is discussed. Finally, an update is provided on novel therapeutics being testing in mesothelioma.

Second-line (post-study) chemotherapy received by patients treated in the phase III trial of pemetrexed plus cisplatin versus cisplatin alone in malignant pleural mesothelioma

BACKGROUND

A phase III trial in patients with malignant pleural mesothelioma demonstrated a survival advantage for pemetrexed plus cisplatin compared with single-agent cisplatin. Because post-study chemotherapy (PSC) may have influenced the outcome of the trial, we examined its use and association with survival.

PATIENTS AND METHODS

Eighty-four patients from the pemetrexed plus cisplatin arm and 105 patients from the single-agent cisplatin arm received PSC. Kaplan-Meier survival estimates were compared by treatment groups, and by PSC and non-PSC subgroups.

RESULTS

The percentage of patients receiving PSC was imbalanced between the treatment arms. Fewer pemetrexed plus cisplatin treated patients received PSC (37.2% versus 47.3%). A multiple regression analysis performed in this trial showed that PSC had a statistically significant correlation with prolonged survival (P <0.01), adjusting for baseline prognostic factors and treatment intervention. The adjusted hazard ratio for PSC over non-PSC subgroups was 0.56 (confidence interval 0.44-0.72).

CONCLUSIONS

PSC in malignant pleural mesothelioma was significantly associated with prolonged survival. It is not known whether the reduced risk of death was associated with PSC or whether patients who had prolonged survival tended to receive more PSC. The pemetrexed plus cisplatin treatment group had a statistically significant survival advantage even though fewer patients from that arm of the trial received PSC. The potentially beneficial role of PSC should be assessed in prospective trials.

Chemotherapy options and new advances in malignant pleural mesothelioma

Malignant pleural mesothelioma continues to be a challenging clinical problem. While traditionally, chemotherapy has been thought to be of only modest benefit to patients with this disease, novel antineoplastic agents and combination regimens incorporating these agents are gradually changing this perception. Early attempts at treatment and palliation with single agents such as doxorubicin met with low response rates and little clinical benefit. However, the recently reported clinical benefits of pemetrexed and raltitrexed in combination with cisplatin are changing the perception about the ability of chemotherapy to affect the natural history of the disease. Other combinations, including cisplatin and gemcitabine, have also shown encouraging response rates and clinical activity. Single-agent therapy with vinorelbine may provide useful palliation with low toxicity. Targeted agents developed through increased understanding of the biology of the disease, used alone or as part of multimodal therapy, may provide major clinical gains in the next few years.

Chemotherapy for malignant pleural mesothelioma: past results and recent developments

This review summarises results of previously conducted clinical trials and subsequently presents data arising from all phase II-III studies on chemotherapy for malignant pleural mesothelioma (MPM) published since the last relevant overview. While response rates exceeding 30% have barely been achieved with established cytotoxic drugs in MPM therapy, novel chemotherapeutic agents and their combinations appear somewhat more promising. This applies especially to the antimetabolites, and in particular to pemetrexed which produced response rates of up to 45% in combination with platinum compounds. Raltitrexed combined with oxaliplatin has also been shown to be effective, and gemcitabine--applied as a single agent or in combination with cisplatin--as well as vinorelbine appear to improve quality of life in patients presenting with MPM. Data can now be more precisely analysed by increasingly implemented randomised studies, applying a standardised staging system, and distinguishing prognostic groups. While chemotherapy for MPM remains a challenging task, important steps have clearly been made in the past years to combat this aggressive disease. Publication of results from a phase III trial of pemetrexed with cisplatin in a peer reviewed journal may soon establish a standard of care.

Malignant Pleural Mesothelioma

The diagnosis and management of malignant pleural mesothelioma are major challenges that often frustrate both patient and clinician alike. Occupational asbestos exposure to crocidolite or amosite forms of the fiber is the most important known risk factor in North America and Western Europe. Other mineral fibers such as erionite, a naturally occurring fibrous zeolite crystal, are associated with mesothelioma in volcanic tuffs of the Cappadocia region of central Anatolia in Turkey. In addition, other possible factors such as the presence of simian virus 40 and genetic susceptibility have been associated recently with the development of mesothelioma in animal models. These latter findings are increasing our understanding of this disease. In addition, the discovery of elevated levels of various markers such as folic acid receptor alpha, cyclooxygenase 2, and multidrug resistance proteins 1 and 2 in mesothelioma tissue have opened up new areas of potential diagnostic and therapeutic importance. However, traditional treatment modalities--surgery, radiotherapy, and chemotherapy--have evolved slowly, and few gains in therapeutic efficacy have occurred. Recently, however, continuing research efforts have led to novel treatment strategies that are changing the way clinicians view a disease that has traditionally been managed with almost universal therapeutic nihilism. This review explores our current knowledge of this disease and presents current and novel therapeutic strategies.

Neoadjuvant Chemotherapy Followed by Extrapleural Pneumonectomy in Malignant Pleural Mesothelioma

Purpose

To investigate neoadjuvant chemotherapy with cisplatin and gemcitabine followed by extrapleural pneumonectomy with or without radiation therapy in patients with potentially resectable malignant pleural mesothelioma (MPM).

Patients and Methods

Eligible patients had MPM with clinical stage T1-3, N0-2, M0 disease considered to be completely resectable and a WHO performance status of 0 to 2. Neoadjuvant chemotherapy consisted of three cycles of cisplatin 80 mg/m2on day 1 and gemcitabine 1,000 mg/m2on days 1, 8, and 15, given every 28 days. Surgery had to consist of a complete extrapleural pneumonectomy, including resection of pericardium and diaphragm. Postoperative radiotherapy was to be considered for all patients.

Results

Nineteen patients with MPM were included in this pilot study. According to the European Organization for Research and Treatment of Cancer prognostic score, two patients were in the good prognosis group, and 17 patients were in the poor prognosis group. The response rate to neoadjuvant chemotherapy was 32%. The major toxicity was thrombocytopenia. Extrapleural pneumonectomy was performed in 16 patients with no perioperative mortality. Major surgical complications occurred in six patients, and all were treated successfully. Thirteen patients received postoperative radiotherapy. The median survival time was 23 months. Two patients remain alive and free of disease 41 and 38 months after initiation of therapy.

Conclusion

For patients with potentially operable MPM, the availability of active and well-tolerated chemotherapy regimens, the fact that extrapleural pneumonectomy can be safely performed after neoadjuvant chemotherapy in an experienced center, and the promising results regarding survival in our pilot study warrant further investigation of the role of neoadjuvant chemotherapy in a multimodality strategy.

Antisense oligonucleotides directed at the bcl-xl gene product augment chemotherapy response in mesothelioma

Objective: Malignant pleural mesothelioma (MPM) is resistant to both conventional chemotherapy and apoptosis. The bcl-2 family proteins are major determinants of apoptotic homeostasis. MPM lines and tumors routinely overexpress the anti-apoptotic protein BCL-XL. We have previously shown that antisense inhibition of BCL-XL in MPM cells leads to apoptosis. We sought to determine whether antisense oligonucleotides directed at the bcl-xl gene product would augment response to a conventional chemotherapeutic agent in human mesothelioma cell lines.

Methods: The human MPM cell lines REN and I-45 were exposed to two bcl-xl antisense oligonucleotides (15999, 16009) and one sense oligonucleotide (113529) construct at varying doses, followed by IC50 cisplatin. Cellular viability was assessed by a calorimetric assay, and apoptosis was evaluated by Hoechst staining, Annexin V staining, and sub-G1 fluorescence-activated cell sorter analysis. Western blot analysis of BCL-2 family proteins was performed following single agent and combined treatment. Isobologram mathematical analysis was used to determine whether or not combination therapies were additive or synergistic.

Results: Cell viability was most affected with the 15999 antisense oligonucleotides plus IC50 cisplatin combination (70% of I-45 and 90% of REN cells killed), and apoptosis was markedly increased with this combination by all measures. Western blot demonstrated 15999 antisense oligonucleotides construct down-regulation of BCL-XL, but no further effect on expression of BCL-2 proteins with cisplatin. Isobologram analysis demonstrated 15999 + cisplatin synergistic effect.

Conclusions: Exposure of human MPM cells to bcl-xl antisense oligonucleotides sensitizes human mesothelioma cells to the conventional chemotherapeutic agent cisplatin. Similar approaches using a combination of molecular and conventional treatment may have clinical utility for this tumor.

Experimental therapy of malignant mesothelioma: new perspectives from anti-angiogenic treatments

We reviewed the published literature of clinical studies in malignant mesothelioma (MM), including phase II as well as older single-agent and combination chemotherapy trials with more than 15 patients. While response rates exceeding 30% have been achieved with established cytotoxic drugs in MM therapy, novel chemotherapeutic agents and their combinations appear more promising. This applies especially to the anti-metabolites (i.e. pemetrexed) that produced response rates of up to 45% in combination with platinum compounds. Moreover, agents targeting novel proliferative and survival pathways in MM are developed to improve treatment outcomes. Here, we focused on the role of several angiogenic growth factors in MM biology and the data of MM-oriented studies on angiostatic agents tested in a phase I-II trial. It seems likely that no single treatment modality will be effective by itself. Studies that use combinations of the newer agents, including angiostatic drugs, with chemotherapy, should be conducted.

Novel Combinations Using Pemetrexed in Malignant Mesothelioma

Malignant mesothelioma is an uncommon malignancy that is locally invasive and rapidly fatal. The majority of patients with mesothelioma are not candidates for curative surgical resection. Chemotherapy has yielded only modest results in these patients. Pemetrexed is a multitargeted antifolate that is being evaluated in many tumor types. Recent single-agent data and data in combination with cisplatin have suggested that pemetrexed has therapeutic benefits in patients with malignant mesothelioma. This article summarizes the data regarding pemetrexed in the treatment of malignant mesothelioma and the potential novel combinations involving the drug that may be used in the future for the treatment of the disease.

Carboplatin and gemcitabine chemotherapy for malignant pleural mesothelioma: a phase II study of the GSTPV

This study describes the therapeutic effect of carboplatin and gemcitabine in combination for malignant pleural mesothelioma (MPM). Twenty patients (14 males and 6 females) with a median age of 53 years entered the study. These patients had histologically proven MPM with no previous chemo- and/or radiotherapy and malignancies. A total of 91 cycles of treatment were administered to 20 patients with a median of 4 cycles per patient. A partial response was observed in 4 out of 20 patients (20%, 95% confidence interval: 6-43%). No complete responses were observed. Only 5 patients (25%) had progressive disease. The response duration ranged form 4+ and 21 months.

Chemotherapy for Malignant Pleural Mesothelioma

Malignant pleural mesothelioma is an aggressive malignancy with no known single curative modality. Most patients are candidates for chemotherapy at some point in their treatment, but no standard regimen has been established. Several phase II single-agent and combination chemotherapy studies have been performed over the past 2 decades. Although the true impact of chemotherapy in mesothelioma remains to be determined, agents with consistent antitumor activity include doxorubicin, platinum agents, and antimetabolites. Combination chemotherapy is associated with higher response rates, but not necessarily longer median survivals. Large randomized trials, which are currently ongoing or have been performed in the past few years, will yield important answers in regard to the role of chemotherapy and the efficacy of various single and combination chemotherapy agents. Furthermore, the biologic and genetic studies of mesothelioma have identified several receptor tyrosine kinases that are aberrantly expressed in these tumors. Orally available small molecule inhibitors of several receptor tyrosine kinases have been developed and are now being evaluated in clinical trials.

Gemcitabine combined with carboplatin in patients with malignant pleural mesothelioma: a multicentric phase II study

BACKGROUND

Malignant pleural mesothelioma (MPM) is increasing rapidly worldwide. Currently, pemetrexed plus cisplatin chemotherapy showed a survival advantage versus cisplatin alone. No impact on patient survival of surgery, radiotherapy, or their combination has been demonstrated.

METHODS

Eight centers in northeastern Italy participated in a Phase II multicenter study. Chemotherapy was comprised of carboplatin area under the concentration-time curve 5 on Day 1 and gemcitabine 1000 mg/m(2) on Days 1, 8, and 15. This cycle was repeated every 4 weeks.

RESULTS

Between July 1996 and September 2000, 50 patients were treated. Of the sample, 68% were males, 88% had a Eastern Cooperative Oncology Group performance status score of 0-1, 56% had Stage I-II disease, 68% had epithelioid histology, and 62% had no previous treatments. The delivered dose intensity of gemcitabine was 617 mg/m(2) per week, which was 82% of the planned dose (750 mg/m(2) per week). For carboplatin, the delivered dose intensity was 80 mg/m(2) per week. Overall, 44% of 15th day doses were omitted or reduced. Twenty-six percent of the patients had partial responses (95% confidence interval: 15-40%) and 24% had disease progression. None of the patients had complete responses. The median response duration was 55 weeks (range, 13-113 weeks). Patients had good clinical benefit. For example, 46% had improved dyspnea, 40% improved in weight, and 26% experienced pain reduction. Patients developed Grade 3-4 leukopenia during 18 cycles (11%) of chemotherapy. Grade 3-4 thrombocytopenia occurred more frequently, i.e., there were 24 episodes (15%) among 17 patients. Grade 3 anemia developed among patients during eight cycles (5%). None of the patients developed Grade 3-4 nonhematologic toxicity. The median survival of this sample of patients was 66 weeks with 53%, 30%, and 20% of patients alive at 1, 2, and 3 years, respectively. The median progression-free survival period was 40 weeks.

CONCLUSIONS

The gemcitabine/carboplatin combination is a valid option in the treatment of MPM due to its acceptable toxicity profile, the good response rate, and the clinical benefit to patients. Minor adjustments in schedule (3-week cycles instead of 4-week cycles) would permit a more optimal treatment administration.

Ifosfamide, carboplatin and etoposide combined with 41.8 degrees C whole body hyperthermia for malignant pleural mesothelioma

We performed a phase II study combining 41.8 degrees C whole body hyperthermia with ICE chemotherapy, i.e. ifosfamide (5 g/m(2)), carboplatin (300 mg/m(2)) and etoposide (150 mg/m(2) on days 2 and 3), administered every 4 weeks, for patients with malignant pleural mesothelioma. Of 27 chemonäive, non-metastatic patients enrolled, 25 patients were evaluable for response. Overall response rate was 20% (five partial remissions; 95% CI 8.9-39.1%). Median survival time from the start of treatment for all patients was 76.6 weeks (95% CI 65.4-87.8 weeks). Progression free survival for all patients measured 29.6 weeks (95% CI 24.4-34.7 weeks). One year overall survival was 68% and 2 year overall survival was 20%. Major treatment toxicities included grade 3/4 neutropenia and thrombocytopenia in 74 and 33% of treatment cycles, respectively. One patient died due to sepsis. These promising results are consistent with continued clinical investigation; a phase III clinical trial with whole body hyperthermia as the independent variable has been initiated.

Chemotherapy for malignant pleural mesothelioma

This paper covers the outcome of previously conducted clinical trials on chemotherapy for malignant pleural mesothelioma and presents data from recent phase II and phase III trials. In contrast to conventional cytotoxic drugs, which have barely produced response rates exceeding 30%, recently introduced chemotherapeutic agents and their combinations promise to be more effective. Especially pemetrexed has yielded response rates of up to 45% in combination with platinum compounds. Furthermore, raltitrexed-oxaliplatin has shown promising activity and gemcitabine was found to improve quality of life in patients with malignant pleural mesothelioma when applied as a single agent or in combination with cisplatin. Based on robust phase III study results, pemetrexed-cisplatin may soon be considered with chemotherapy for this aggressive disease.

Chemotherapy for malignant pleural mesothelioma: past results and recent developments

This review summarises the results of previously conducted clinical trials, and subsequently presents data arising from all phase II-III studies on chemotherapy of malignant pleural mesothelioma (MPM) published since the last relevant overview. While response rates exceeding 30% have barely been achieved with established cytotoxic drugs in MPM therapy, novel chemotherapeutic agents and their combinations appear more promising. This applies especially to the antimetabolites, and in particular to pemetrexed that produced response rates of up to 45% in combination with platinum compounds. Raltitrexed combined with oxaliplatin has also been shown to be effective, and gemcitabine-applied as a single agent or in combination with cisplatin-as well as vinorelbine appear to improve the quality of life in patients presenting with MPM. Data can now be more precisely analysed by increasingly implemented randomised studies, applying a standardised staging system, and distinguishing prognostic groups. While chemotherapy for MPM remains a challenging task, important steps have clearly been made in the past years to combat this aggressive disease. The publication of pemetrexed with cisplatin phase III results in a peer-reviewed journal may soon establish a standard of care.

Activity of chemotherapy and immunotherapy on malignant mesothelioma: a systematic review of the literature with meta-analysis

The role of chemotherapy for unresectable malignant mesothelioma is unclear. The aims of the present study were to evaluate the methodological quality of published papers relative to chemotherapy or immunotherapy in malignant mesothelioma and to aggregate, for trials having a similar methodology, the response rates in order to identify the most active chemotherapeutic drugs and regimens. The literature relative to this topic, published between 1965 and June 2001 was reviewed. A methodological qualitative evaluation was performed according to the European Lung Cancer Working Party scale, specifically designed for phase II trials. A study was considered as potentially positive if the upper limit of the 95% confidence interval (CI) of the response rate was greater than 20% and positive if the lower limit of the 95% CI was > 20%. Eighty-three studies (88 treatment arms) were eligible for the systematic review. Fifty-three arms were considered as positive or potentially positive. No statistically significant difference in the methodological quality was observed between negative and positive studies. Studies were aggregated in four groups according to the presence of cisplatin and/or doxorubicin in the treatment regimen. The combination of cisplatin and doxorubicin had the highest response rate (28.5%; P < 0.001). Cisplatin was the most active single-agent regimen. Our systematic qualitative and quantitative overview of the literature suggests that the most active chemotherapeutic regimen, in term of objective response rate, is the combination of cisplatin and doxorubicin and the best single-agent is cisplatin. The combination of these two drugs can be recommended as control arm for future randomised phase III trials.

Phase I clinical and pharmacokinetic study of pemetrexed and carboplatin in patients with malignant pleural mesothelioma

PURPOSE

To determine the maximum tolerated dose (MTD) of pemetrexed and carboplatin given in combination, to derive a recommended dose for phase II studies, and to explore its efficacy. We assessed toxicities and explored the activity of the drug combination exclusively in patients with malignant pleural mesothelioma (MPM). The pharmacokinetics of both agents was investigated.

PATIENTS AND METHODS

Twenty-seven patients (23 male, four female) with MPM were treated on five escalating dose levels. Doses ranged from pemetrexed 400 mg/m(2) (as a 10-minute intravenous infusion), followed by carboplatin area under the plasma concentration-time curve (AUC) 4 mg/mL.min (as a 30-minute intravenous infusion) to pemetrexed 500 mg/m(2), carboplatin AUC 6 mg/mL.min. All patients had a World Health Organization performance status of 1. A total of 163 courses of treatment were administered (median, six; range, one to 10).

RESULTS

The main toxicity was hematologic, particularly neutropenia, although this was characteristically short-lived and caused few clinical problems. The MTD was pemetrexed 500 mg/m(2), carboplatin AUC 6, because three of the five patients treated at this dose level experienced a dose-limiting toxicity. Eight partial responses (in 25 assessable patients) were observed for a response rate of 32%. Seventy percent of patients noticed an improvement in symptoms, usually (84%) after only two courses. Median time to progression was 305 days, and median survival time was 451 days.

CONCLUSION

The MTD was pemetrexed 500 mg/m(2) and carboplatin AUC 6 mg/mL.min. The recommended phase II dose of the combination is pemetrexed 500 mg/m(2) and carboplatin AUC 5 mg/mL.min. The combination is both active and well tolerated in MPM and deserves further exploration.

Malignant mesothelioma: options for management

In the past, there has been a tendency to think of diffuse malignant pleural mesothelioma as one disease in therapeutic terms, regardless of histological type and tumor stage. This does not happen with other tumors, yet it is equally illogical and inappropriate in mesothelioma. As with other tumors, early diagnosis-while the disease is still in stage I, or even at an in situ stage-must be the goal so that therapy can be maximized, particularly if immunotherapy or gene therapy is to be used. Patients with pure epithelial mesothelioma have a better prognosis and respond better to trimodality therapy. Stage I patients who meet fitness criteria should be offered the option of radical surgery in combination with chemotherapy and radiotherapy. Further research is required to determine the optimum neoadjuvant and adjuvant modalities, particularly the timing of individual drugs, use of hyperthermia, and route of administration. The place of immunotherapy and gene therapy as adjunctive treatments also remains to be defined. For example, it may be possible to reduce tumor bulk and perhaps downstage the disease with immunotherapy before radical surgery, if treatment is started early enough. Gene therapy may have a role either preoperatively or in destroying the microscopic disease that remains after radical surgery. These and other combinations of treatment need to be tested in well-designed clinical trials, probably on a multicenter basis (to enroll a sufficient number of patients). Finding the means to improve treatment for sarcomatous and mixed histology mesothelioma remains a challenge. At present, radical surgery does not seem worthwhile for these patients when combined with currently employed chemotherapy and radiotherapy; however, chemotherapy combinations used for treating other sarcomas need to be evaluated as adjunctive therapy before radical surgery is abandoned altogether as a mode of treatment. A collaborative approach involving thoracic surgeons, basic scientists and oncologists, and physicians with experience in treating mesothelioma is essential. Despite its increasing frequency, mesothelioma is still a relatively rare tumor, so treatment should be concentrated in relatively few supraregional centers to maximize expertise and allow innovative treatment combinations to be implemented with the greatest chance of success. Evaluation of new therapeutic approaches will be achieved more rapidly if these supraregional centers collaborate in multicenter trials. The nihilistic approach of simply waiting until the mesothelioma epidemic eventually begins to decline spontaneously in 20 or 30 years is untenable in view of the hundreds of thousands of deaths that will result if no effective treatment is found.

Chemotherapy for malignant mesothelioma: from doxorubicin to vinorelbine

It has been a challenge to find effective chemotherapeutic treatments for malignant mesothelioma. Over the last several decades numerous single-drug and combination regimens have been examined, but no standard treatment with chemotherapy alone has emerged. Possible explanations for this lack of success are the heterogeneity between the different subclasses of mesothelioma and the difficulties experienced in determining responses on computed tomographic (CT) scan. This review will present the results of most chemotherapy trials. An attempt is also been made to overcome the problem of identifying the overall response rate by presenting the median survival time. Other types of response evaluation and guidelines for patient selection are warranted to properly compare chemotherapeutic treatments.

Malignant pleural mesothelioma

Malignant pleural mesothelioma remains a difficult tumor to treat, much less cure. Currently, the best chance for long-term survival lies with early diagnosis and aggressive surgical extirpation, but given the typically long delay between the onset of symptoms and diagnosis, this is only possible with a high index of suspicion and an aggressive diagnosis workup. Early referral to a tertiary center experienced in the treatment of MPM may be important for several reasons: (1) decreased risk of tumor spread along multiple thoracenesis/biopsy tracts, (2) the availability of specialized pathologic assays for definitive diagnosis, (3) the availability of critical staging modalities (aggressive mediastinoscopy +/- thoracoscopy, MRI scans performed according to specific mesothelioma protocols, and perhaps PET scans), (4) surgical experience with pleurectomy/decortication and/or extrapleural pneumonectomy, that may decrease morbidity and mortality, and (5) the availability of novel adjuvant protocols. Single-modality therapy is unlikely to result in long-term survival. Aggressive surgery is required for optimal debulking, and extrapleural pneumonectomy may offer better local control compared with pleurectomy/ecortication. Delivery of optimal radiation schedules, which may involve large fractions as well as large total doses, is limited by the presence of nearby dose-limiting structures. Current chemotherapy is severely lacking in producing objective responses and improved survival although gemcitabine and IL-2 may be active agents to be combined with radiation and/or other agents. Hyperthermia, photodynamic therapy, intracavitary therapy, and gene therapy are all relatively new techniques under active investigation that should be supported by enrollment in on-going protocols. Predictably, many of these techniques provide greater benefit when used in the setting of adjuvant protocols or minimal residual disease, emphasizing the importance of multimodality therapy.

Malignant pleural mesothelioma

Despite innumerable trials of surgery, radiotherapy, and countless chemotherapeutic drugs, it is unclear whether any intervention has had a significant impact on more than a few highly selected patients with malignant pleural mesothelioma. Because most patients die of respiratory failure from extensive disease progression in the thorax, treatment usually includes attempts at local control. Unfortunately, radiotherapy is associated with significant complications in pleural mesothelioma, and surgery is feasible in only a small percentage of patients. Although there have been several single-institution reports of combined-modality therapy with extrapleural pneumonectomy, postoperative radiation, and chemotherapy in which prolonged survival has been observed, most patients with malignant pleural mesothelioma have locally advanced disease, advanced age, or comorbid medical illnesses that preclude aggressive surgery. Therefore, the use of a systemic anticancer agent is the only treatment option for most patients with malignant pleural mesothelioma. Evaluation of effective chemotherapy regimens for this disease has been hampered by many factors. Because mesothelioma is an uncommon malignancy, most studies have enrolled small numbers of patients, and few trials have been randomized. The disease is heterogeneous, yet until recently there was no single staging system that could reliably predict survival, nor is there a universally accepted set of prognostic criteria for selecting a uniform group of patients. Response assessment has been limited by the inherent difficulties of reproducibly measuring pleural-based disease. The real impact of systemic chemotherapy on the natural history of malignant mesothelioma is still uncertain because phase III trials comparing chemotherapy with best supportive care have not yet been completed. Although nearly every class of cytotoxic agent has been evaluated in mesothelioma, response rates of greater than 20% have not been consistently demonstrated for any drug. The most active drug classes are the antifolates, the anthracyclines, and the platinums. Doxorubicin has historically been considered the gold-standard chemotherapy, although its true response rate is likely only 15%. The most active commercially available drug for mesothelioma so far appears to be gemcitabine. Although gemcitabine has a limited role as a single agent, it is quite active in combination with a platinating agent. The impressive 48% response rate reported for the combination of gemcitabine with cisplatin in a single phase II study has made this regimen the new standard of care for off-protocol treatment of this disease, although this trial still requires validation. With the recent introduction of several new agents with definite activity in this disease, the therapeutic nihilism previously associated with malignant pleural mesothelioma is gradually being replaced by a cautious optimism. Early trials of angiogenesis inhibitors, gene therapy, and vaccines offer additional avenues for treatment. As we begin to incorporate these active new drugs with each other and in adjuvant and neoadjuvant treatment regimens, there is reason to believe that superior results for patients with malignant pleural mesothelioma can be achieved in the near future.

Randomised phase II study of cisplatin-etoposide versus infusional carboplatin in advanced non-small-cell lung cancer and mesothelioma

BACKGROUND

A randomised phase II study was performed to compare standard combination chemotherapy containing cisplatin and etoposide with infusional carboplatin.

PATIENTS AND METHODS

One hundred twenty patients with locally advanced/metastatic non-small-cell lung cancer or mesothelioma were enrolled. All were chemotherapy-naïve and had a Karnofsky performance status of > or = 50. Patients were randomised to either four cycles of bolus therapy of cisplatin 80 mg/m2 day 1, etoposide 120 mg/m2 day 1-3, or continuous infusion of carboplatin 100/mg/m2/week for six weeks.

RESULTS

No patients on infusional therapy incurred grade 3-4 toxicity while in the bolus arm, grade 3 and grade 4 leucopenia occurred in 17% and 35% of patients, respectively. Grade 4 thrombocytopenia occurred in 8% of patients and there were two instances of grade 3 renal toxicity. No responses occurred in the pump arm. Eight of forty-six patients with non-small-cell lung cancer responded to treatment (response rate 17.3%) with two complete responses and six partial responses. Only one patient with mesothelioma responded to bolus therapy. There was no difference in survival for the subset of NSCLC patients. Survival for mesothelioma patients in the pump arm was superior but this was likely to be a result of early deaths in the bolus arm.

CONCLUSIONS

The pump arm was well-tolerated but not active, whilst combination platinum-based therapy demonstrated activity but significantly more toxicity than the pump arm. Further studies of infusional carboplatin with this schedule are not warranted.

Advances in the treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma is a neoplasm that is commonly fatal and for which there are no widely accepted curative approaches. Mesothelioma is unresponsive to most chemotherapy and radiotherapy regimens, and it typically recurs even after the most aggressive attempts at surgical resection. Multimodality approaches have been of some benefit in prolonging survival of very highly selected subgroups of patients, but they have had a relatively small impact on the majority of the patients diagnosed with this disease. As the incidence of pleural mesothelioma peaks in the United States and Europe over the next 10 to 20 years, new therapeutic measures will be necessary. This review will discuss the roles of chemotherapy, radiotherapy, surgery, and combined modality approaches in the treatment of pleural mesothelioma, as well as scientific advances made in the past decade that have led to the development of experimental techniques, such as photodynamic therapy, immunotherapy, and gene therapy, that are currently undergoing human clinical trials. These promising new avenues may modify the therapeutic nihilism that is rampant among clinicians dealing with mesothelioma.

A phase II trial of interferon alpha-2a and carboplatin in patients with advanced malignant mesothelioma

We defined the antitumor activity, toxicity, and tolerability of a combined chemoimmunotherapy approach in patients with advanced malignant mesothelioma using daily low-dose interferon alpha-2a and carboplatin given every 4 weeks. This was a phase II study of 15 patients with surgically unresectable or metastatic malignant mesothelioma. All patients had measurable or assessable disease. No prior chemotherapy or immunotherapy was allowable. Carboplatin was given at 150 mg/m2 daily on days 1-3 and interferon alpha-2a at 3 million units subcutaneously daily throughout the study. Treatment was recycled every 28 days. Therapy was continued until disease progression. Fifteen patients were assessable for toxicity and 14 for response. One partial response (7%, 95% CI, 0-20%), with a response duration of 40 weeks, was seen. Most patients had early progression of disease. Toxicity was tolerable, and grade III/IV toxicity was uncommon. The median time to progression was 14 weeks (range, 1-52 weeks). The median survival was 25 weeks (range, 8-66 weeks). The combination of low-dose interferon alpha-2a and carboplatin did not result in greater antitumor activity than that reported for single-agent carboplatin in advanced malignant mesothelioma. Although toxicity was mild, carboplatin and low-dose interferon, given at this dose and schedule, cannot be recommended for this patient group.

A review of chemotherapy trials for malignant mesothelioma

Treatment of malignant pleural mesothelioma continues to be frustrating regardless of the modality employed. Numerous trials of chemotherapeutic agents have been performed, but until recently, these studies were small and subject to inaccuracies of disease measurement. To our knowledge, no chemotherapeutic regimen has emerged as a standard of care. A review of the literature reveals that small activity against this disease has been shown by the anthracyclines, platinum compounds, and alkylating agents, whereas higher activity has been reported with the antimetabolites. The plant alkaloids have not demonstrated any activity against mesothelioma. Dose-escalated chemotherapeutic regimens may offer an advantage, whereas combination chemotherapy has not shown any benefit over single-agent therapy. Favorable responses have been reported with the administration of intrapleural biological response modifiers. Further trials and the investigation of new agents in the treatment of this disease are necessary.

Dihydro-5-azacytidine in malignant mesothelioma. A phase II trial demonstrating activity accompanied by cardiac toxicity. Cancer and Leukemia Group B

BACKGROUND

Malignant mesothelioma is a disease that is refractory to chemotherapy. Therefore, the objective of this multi-institutional, cooperative group Phase II trial was to determine the efficacy of dihydro-5-azacytidine (DHAC), a pyrimidine analogue, in the treatment of malignant mesothelioma.

METHODS

Forty-one patients with histologically confirmed malignant mesothelioma received 120-hour continuous infusions of DHAC (1,500 mg/m2/day every 21 days) until maximal response, intolerable toxicity, or disease progression.

RESULTS

One patient had a complete response, two had objective partial responses, and four had regression of evaluable disease. The overall response rate was 17%. The one complete responder remains without disease progression at 6 years. Chest pain and nausea were the most common toxicities. Supraventricular tachycardia and pericardial effusion occurred in 20% and 15% of patients, respectively. In most patients, gastrointestinal effects were manageable. There was no significant hematologic toxicity.

CONCLUSIONS

In malignant mesothelioma, a disease that is refractory to chemotherapy, dihydro-5-azacytidine has definite antitumor activity. Its modest hematologic toxicity profile favors its use in combination with other agents. Caution regarding cardiac arrhythmias and pericardial effusion is necessary.

Prospective study of combination chemotherapy with cyclophosphamide, doxorubicin, and cisplatin for unresectable or metastatic malignant pleural mesothelioma

BACKGROUND

This study was designed to determine the efficacy and side effects of a combination of cyclophosphamide (C), doxorubicin (D), and cisplatin (P) in patients with inoperable, unresectable, or metastatic malignant pleural mesothelioma.

METHODS

Twenty-three patients with unresectable or metastatic malignant pleural mesothelioma were entered onto the study. The median age was 62 years (range, 42-74 years); there were 20 males and 3 females; the median performance status was 1 (Zubrod's scale). The histologic types included epithelial (14 patients), sarcomatoid (4 patients), unclassified (4 patients), and mixed type (1 patient). Twenty patients were known to have been exposed to asbestos and 3 were not. All patients were treated with the following starting dose of chemotherapy: a cycle comprised of C, 500 mg/m2 intravenously, day 1; D, 50 mg/m2 intravenously, day 1; and P, 80 mg/m2 intravenously, day 1 every 3 weeks. The cisplatin dose was reduced to 50 mg/m2 for the subsequent courses. For the assessment of tumor response, all patients had computed tomography scans of the chest after each three cycles of chemotherapy.

RESULTS

Overall, 7 of 23 patients (30%) had partial responses (durations of responses [weeks]: 158+, 91+, 70+, 41+, 40, 39, 25), three had minor responses, and 14 had stable or progressive disease. One partial responder later underwent surgical resection and no viable tumors cells were found in the pathologic specimen. All patients have stopped treatment, and eight are still alive. The most common side effect was granulocytopenia (grade 4, 52%; grade 3, 17%). Other hematologic side effects were modest. Nonhematologic side effects included mild to moderate nausea and vomiting, neutropenic fever (three patients), peripheral neuropathy (one patient), and congestive heart failure (one patient). The overall median duration of survival was 60 weeks.

CONCLUSION

Combination chemotherapy with CDP was well tolerated and had significant activity against unresectable or metastatic malignant pleural mesothelioma. The median duration of responses was 60 weeks; however, the survival rate was far from satisfactory. Continued development of new approaches including the biologic understanding of tumor development and testing new agents is warranted.

Clinical features and current treatment of diffuse malignant pleural mesothelioma

Malignant pleural mesothelioma is an uncommon cancer for which the major risk factor is prior asbestos exposure. During the past decade, there has been progress in the diagnosis, staging and biology of mesothelioma. Treatment remains controversial and ranges from supportive care alone to aggressive multimodality therapy. Prospective clinical trials in carefully staged patients are needed to determine what approaches to treatment may confer a survival benefit.