Phase 1 Dose-Escalation Study of Pegylated Arginine Deiminase, Cisplatin, and Pemetrexed in Patients With Argininosuccinate Synthetase 1-Deficient Thoracic Cancers.

Purpose Pegylated arginine deiminase (ADI-PEG 20) depletes essential amino acid levels in argininosuccinate synthetase 1 (ASS1) -negative tumors by converting arginine to citrulline and ammonia. The main aim of this study was to determine the recommended dose, safety, and tolerability of ADI-PEG 20, cisplatin, and pemetrexed in patients with ASS1-deficient malignant pleural mesothelioma (MPM) or non-small-cell lung cancer (NSCLC). Patients and Methods Using a 3 + 3 + 3 dose-escalation study, nine chemotherapy-naïve patients (five MPM, four NSCLC) received weekly ADI-PEG 20 doses of 18 mg/m2, 27 mg/m2, or 36 mg/m2, together with pemetrexed 500 mg/m2 and cisplatin 75 mg/m2 which were given every three weeks (maximum of six cycles). Patients achieving stable disease or better could continue ADI-PEG 20 monotherapy until disease progression or withdrawal. Adverse events were assessed by Common Terminology Criteria for Adverse Events version 4.03, and pharmacodynamics and immunogenicity were also evaluated. Tumor response was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 for NSCLC and by modified RECIST criteria for MPM. Results No dose-limiting toxicities were reported; nine of 38 reported adverse events (all grade 1 or 2) were related to ADI-PEG 20. Circulating arginine concentrations declined rapidly, and citrulline levels increased; both changes persisted at 18 weeks. Partial responses were observed in seven of nine patients (78%), including three with either sarcomatoid or biphasic MPM. Conclusion Target engagement with depletion of arginine was maintained throughout treatment with no dose-limiting toxicities. In this biomarker-selected group of patients with ASS1-deficient cancers, clinical activity was observed in patients with poor-prognosis tumors. Therefore, we recommend a dose for future studies of weekly ADI-PEG 20 36 mg/m2 plus three-weekly cisplatin 75 mg/m2 and pemetrexed 500 mg/m2.

Arginine Deprivation With Pegylated Arginine Deiminase in Patients With Argininosuccinate Synthetase 1-Deficient Malignant Pleural Mesothelioma: A Randomized Clinical Trial.

IMPORTANCE: Preclinical studies show that arginine deprivation is synthetically lethal in argininosuccinate synthetase 1 (ASS1)-negative cancers, including mesothelioma. The role of the arginine-lowering agent pegylated arginine deiminase (ADI-PEG20) has not been evaluated in a randomized and biomarker-driven study among patients with cancer. OBJECTIVE: To assess the clinical impact of arginine depletion in patients with ASS1-deficient malignant pleural mesothelioma. DESIGN, SETTING, AND PARTICIPANTS: A multicenter phase 2 randomized clinical trial, the Arginine Deiminase and Mesothelioma (ADAM) study, was conducted between March 2, 2011, and May 21, 2013, at 8 academic cancer centers. Immunohistochemical screening of 201 patients (2011-2013) identified 68 with advanced ASS1-deficient malignant pleural mesothelioma. INTERVENTIONS: Randomization 2:1 to arginine deprivation (ADI-PEG20, 36.8 mg/m2, weekly intramuscular) plus best supportive care (BSC) or BSC alone. MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival (PFS) assessed by modified Response Evaluation Criteria in Solid Tumors (RECIST) (target hazard ratio, 0.60). Secondary end points were overall survival (OS), tumor response rate, safety, and quality of life, analyzed by intention to treat. We measured plasma arginine and citrulline levels, anti-ADI-PEG20 antibody titer, ASS1 methylation status, and metabolic response by 18F-fluorodeoxyglucose positron-emission tomography. RESULTS: Median (range) follow-up in 68 adults (median [range] age, 66 [48-83] years; 19% female) was 38 (2.5-39) months. The PFS hazard ratio was 0.56 (95% CI, 0.33-0.96), with a median of 3.2 months in the ADI-PEG20 group vs 2.0 months in the BSC group (P = .03) (absolute risk, 18% vs 0% at 6 months). Best response at 4 months (modified RECIST) was stable disease: 12 of 23 (52%) in the ADI-PEG20 group vs 2 of 9 (22%) in the BSC group (P = .23). The OS curves crossed, so life expectancy was used: 15.7 months in the ADI-PEG20 group vs 12.1 months in the BSC group (difference of 3.6 [95% CI, -1.0 to 8.1] months; P = .13). The incidence of symptomatic adverse events of grade at least 3 was 11 of 44 (25%) in the ADI-PEG20 group vs 4 of 24 (17%) in the BSC group (P = .43), the most common being immune related, nonfebrile neutropenia, gastrointestinal events, and fatigue. Differential ASS1 gene-body methylation correlated with ASS1 immunohistochemistry, and longer arginine deprivation correlated with improved PFS. CONCLUSIONS AND RELEVANCE: In this trial, arginine deprivation with ADI-PEG20 improved PFS in patients with ASS1-deficient mesothelioma. Targeting arginine is safe and warrants further clinical investigation in arginine-dependent cancers. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01279967.

The efficacy and safety of weekly vinorelbine in relapsed malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a rapidly progressive invariably lethal tumor. Treatment options remain limited and the outcome in relapsed disease is poor warranting new therapeutic options. Following our previous experience in the first-line setting, we conducted a phase 2 open-label non-comparative study to assess the safety and efficacy of weekly vinorelbine chemotherapy, each cycle consisting of 30 mg/m(2) for 6 weeks, in patients with previous exposure to chemotherapy. In 63 individuals with relapsed MPM who had not received previous vinorelbine, we observed an objective response rate of 16% and an overall survival of 9.6 months (95% confidence interval 7.3-11.8 months). The main grade III/IV toxicity observed was neutropenia and toxicity was similar to weekly vinorelbine when used in the first-line setting. Weekly vinorelbine appeared to have a reasonable response rate with an acceptable toxicity profile in the second-line treatment of MPM. Its use should be prospectively evaluated in a randomised trial in the first or second-line therapy of MPM.

Phase II trial of irinotecan, cisplatin and mitomycin for relapsed small cell lung cancer.

There is no standard therapy for relapsed small cell lung cancer (rSCLC). We evaluated the efficacy and toxicity of a new triplet consisting of irinotecan (100 mg/m(2) Days 1 and 15 q28), cisplatin (40 mg/m(2) Days 1 and 15 q28) and mitomycin (6 mg/m(2) d1 q28) administered to a maximum of 6 cycles in individuals with rSCLC that had relapsed following first line treatment. Partial remissions were observed in 35% and progression in 30% of patients. Progression free survival measured 4.5 months (95% CI 0.8-8.2) and overall survival was 7.8 months (95% CI 5.3-10.3). QoL showed improvement in activity symptoms and stabilization of physical symptoms. As IPM was a well-tolerated regimen with activity in rSCLC, a phase III trial comparing this triplet with other regimens in this setting is warranted.

Efficacy and safety of first- or second-line irinotecan, cisplatin, and mitomycin in mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rapidly progressive lethal tumor. Treatment options remain limited and the outcome in recurrent disease is poor. METHODS: A Phase II open-label noncomparative study was conducted to assess the safety and efficacy of the triplet combination irinotecan, cisplatin, and mitomycin-C (IPM) chemotherapy in untreated patients and in those with previous exposure to chemotherapy. RESULTS: In 62 patients an objective response rate of 25% was observed. In the first-line setting progression-free survival measured 6.4 months (95% confidence interval [CI]: 4.5-7.3) and overall survival was 10.8 months (95% CI: 7.9-13.7). In the second-line setting progression-free survival was 7.3 months (95% CI: 3.4-11.2) and overall survival was also 7.3 months (95% CI: 4.8-9.8). Psychosocial well-being improved during chemotherapy and the main toxicity observed was neutropenia (40%). CONCLUSIONS: IPM appeared to have a reasonable response rate with an acceptable toxicity profile in the first- and second-line treatment of MPM.

In vivo loss of expression of argininosuccinate synthetase in malignant pleural mesothelioma is a biomarker for susceptibility to arginine depletion.

PURPOSE: Malignant pleural mesothelioma (MPM) is an increasing health burden on many societies worldwide and, being generally resistant to conventional treatment, has a poor prognosis with a median survival of <1 year. Novel therapies based on the biology of this tumor seek to activate a proapoptotic cellular pathway. In this study, we investigated the expression and biological significance of argininosuccinate synthetase (AS), a rate-limiting enzyme in arginine production. EXPERIMENTAL DESIGN: Initially, we documented down-regulation of AS mRNA in three of seven MPM cell lines and absence of AS protein in four of seven MPM cell lines. We confirmed that the 9q34 locus, the site of the AS gene, was intact using a 1-Mb comparative genomic hybridization array; however, there was aberrant promoter CpG methylation in cell lines lacking AS expression, consistent with epigenetic regulation of transcription. To investigate the use of AS negativity as a therapeutic target, arginine was removed from the culture medium of the MPM cell lines. RESULTS: In keeping with the cell line data, 63% (52 of 82) of patients had tumors displaying reduced or absent AS protein, as assessed using a tissue microarray. Cell viability declined markedly in the AS-negative cell lines 2591 and MSTO but not in the AS-positive cell line, 28. This response was apparent by day 4 and maintained by day 9 in vitro. Arginine depletion induced BAX conformation change and mitochondrial inner membrane depolarization selectively in AS-negative MPM cells. CONCLUSIONS: In summary, we have identified AS negativity as a frequent event in MPM in vivo, leading to susceptibility to cytotoxicity following restriction of arginine. A phase II clinical trial is planned to evaluate the role of arginine depletion in patients with AS-negative MPM.

Prognostic factors for mesothelioma.

Our understanding of malignant mesothelioma has increased rapidly in the last 5 years. The prognosis remains poor for most patients, however. Radical surgery is inappropriate for most, and palliative chemotherapy can be toxic if used without care. Patient selection is crucial, and prognostic factors allow us to predict which patients are likely to benefit from intensive treatment. Longer survival is associated with epithelioid histology, earlier stage, female gender, left-sided primary, nonexposure to asbestos, no history of smoking, and a lack of symptoms at presentation. Numerous genes of significance are identified and many have been shown to correlate with clinical outcome. Molecular data will provide prognostication of exceptional accuracy, biologic insights, and targets for improved treatment.

Prognostic factors in mesothelioma.

Prognostic factors can help clinicians and patients when deciding a treatment plan. Patients in the best prognostic groups can be considered for more intensive or experimental therapy. Alternatively, patients in the best prognostic groups might prefer a period of observation prior to commencement of therapy. For patients with mesothelioma prognostic factors are potentially especially important because of the lack of a widely applicable anatomical staging system. Both the International Mesothelioma Interest Group (IMIG) and Brigham staging systems are of limited relevance to patients not undergoing radical debulking surgery. Radiological prediction of IMIG or Brigham stage is of little value. Review of the best-known prognostic scoring systems from the EORTC and CALGB has shown that the most important predictors of poor prognosis are: poor performance status; non-epithelioid histology; male gender; low hemoglobin; high platelet count; high white blood cell count; and high lactate dehydrogenase (LDH). The EORTC model was validated at St Bartholomew's Hospital in a group of 145 patients treated in sequential phase II chemotherapy trials. For 70 patients treated with vinorelbine, those having the best EORTC prognosis had a median survival of 19.2 months [95% C.I.=14.7-23.7] compared to 9.9 months [95% C.I.=8.5-11.3] for those in the worst group. The suggestion is that all clinical and biological factors relevant to prognosis should be recorded prospectively in mesothelioma patients selected for clinical trials.

Phase II trial of vinorelbine and oxaliplatin as first-line therapy in malignant pleural mesothelioma.

UNLABELLED: The incidence of malignant pleural mesothelioma (MPM) is increasing. Treatment options are limited, although recently published data have offered cause for optimism. We reported a response rate of 24% with low toxicity for single agent vinorelbine. Here we report a phase II trial of vinorelbine with oxaliplatin (VO) in patients with untreated MPM. Chemotherapy consisted of vinorelbine 30 mg/m(2), days 1 and 8 of a 21-day-cycle, and oxaliplatin 130 mg/m(2), day 1. Treatment continued up to six cycles. The primary endpoint was objective response. Secondary endpoints were toxicity, progression-free and overall survival. Responses were assessed by modified RECIST criteria. Twenty-six patients were enrolled. There were six partial remissions, 17 patients with stable disease, and three patients with PD. Response rate was 23% (95% confidence interval 9-44%). Median number of cycles delivered was four. Progression-free survival from first treatment was 4.7 months, and overall survival was 8.8 months. One-year-survival was 27%. Toxicity (% of patients with at least one episode of grade 3 or 4 toxicity): neutropenia 18%, phlebitis 12%, malaise 12%, anorexia 12%, nausea and vomiting 12%, constipation 6%. Quality of life assessed by Rotterdam symptom checklist was associated with stabilization or improvement of psychological well-being and lung symptoms in the majority of patients, but deterioration in physical symptoms. CONCLUSION: VO has activity in MPM with most patients responding or having stable disease, although this doublet is associated with significant toxicity.

Low-dose continuous chemotherapy for metastatic melanoma: a phase II trial.

The prognosis of patients with metastatic melanoma remains poor and there is a need to develop new regimens with low toxicity. We investigated a novel outpatient regimen combining oral and intravenous chemotherapy with daily subcutaneous bleomycin. Twenty-nine chemotherapy-naive patients with metastatic melanoma were treated with a novel regimen consisting of low dose lomustine, daily subcutaneous bleomycin, chlorambucil, methotrexate and vinblastine with tamoxifen for an 8 week cycle (LBCMVT-56). A median of two cycles were given until disease progression or grade 3/4 toxicity. Five out of 29 (17%) patients had an objective response, of whom two (7%) had a complete response and remain progression-free after 2 years of follow-up. The median overall survival was 7.3 months. A symptomatic response was seen in 11 out of 29 patients (38%). Toxicity was acceptable, with grade 3/4 haematological toxicity seen in 25% of cycles, infection requiring intravenous antibiotics in 11% of cycles, and pulmonary toxicity seen in 4% of cycles. Hospitalization was required in 21% of the patients at some point during the treatment, most commonly for neutropenic sepsis. LBCMVT-56 chemotherapy is a novel outpatient regimen producing occasional durable complete responses in a patient group with a poor prognosis. The median survival is similar to that obtained with dacarbazine, though the toxicity is greater.

Prognostic factors in mesothelioma.

Prognostic factors in oncology may help physicians give their patients a prognosis for their disease and thus allow them to make plans for the future. These factors also assist in the selection of patients more likely to benefit from intensive treatments, especially in the context of clinical trials. Recently it has become clear that prognostic factors may have an additional benefit: they may provide insight into the biology of the cancer being studied and lead to improved understanding of the molecular pathogenesis. For malignant mesothelioma, the prognostic scoring systems of the Cancer and Leukemia Group B (CALGB) and European Organization for Research and Treatment of Cancer (EORTC) are the most useful of those currently available. These systems rate performance status, age, histological subtype, weight loss, and hematological parameters as the best prognostic factors for malignant mesothelioma. In the future, biological markers may provide additional information on mesothelioma and will help in prognostication.