Multiple folate enzyme inhibition: mechanism of a novel pyrrolopyrimidine-based antifolate LY231514 (MTA)

Pilot Study of High-Dose Pemetrexed in Patients with Progressive Chordoma

PURPOSE

Chordomas are ultrarare tumors of the axial spine and skull-base without approved systemic therapy. Most chordomas have negative expression of thymidylate synthase (TS), suggesting a potential for responding to the antifolate agent pemetrexed, which inhibits TS and other enzymes involved in nucleotide biosynthesis. We evaluated the therapeutic activity and safety of high-dose pemetrexed in progressive chordoma.

PATIENTS AND METHODS

Adult patients with previously treated, progressive chordoma participated in an open-label, single-institution, single-arm, pilot clinical trial of intravenous pemetrexed 900 mg/m2 every 3 weeks and supportive medications of folic acid, vitamin B12, and dexamethasone. The primary endpoint was objective response rate according to RECIST v1.1. Secondary endpoints included adverse events, progression-free survival (PFS), tumor molecular profiles, and alterations in tissue and blood-based biomarkers.

RESULTS

Fifteen patients were enrolled and the median number of doses administered was 15 (range, 4-31). One patient discontinued treatment due to psychosocial issues after four cycles and one contracted COVID-19 after 13 cycles. Of the 14 response-evaluable patients, 2 (14%) achieved a partial response and 10 (71%) demonstrated stable disease. Median PFS was 10.5 months (95% confidence interval: 9 months-undetermined) and 6-month PFS was 67%. Adverse events were expected and relatively mild, with one grade 3 creatinine increased, and one each of grade 3 and 4 lymphopenia. No grade 5 adverse events, unexpected toxicities, or dose-limiting toxicities were observed. Several patients reported clinical improvement in disease-related symptoms.

CONCLUSIONS

High-dose pemetrexed appears tolerable and shows objective antitumor activity in patients with chordoma. Phase II studies of high-dose pemetrexed are warranted.

Activity of pemetrexed in pre-clinical chordoma models and humans

Chordomas are rare slow growing tumors, arising from embryonic remnants of notochord with a close predilection for the axial skeleton. Recurrence is common and no effective standard medical therapy exists. Thymidylate synthase (TS), an intracellular enzyme, is a key rate-limiting enzyme of DNA biosynthesis and repair which is primarily active in proliferating and metabolically active cells. Eighty-four percent of chordoma samples had loss of TS expression which may predict response to anti-folates. Pemetrexed suppresses tumor growth by inhibiting enzymes involved in folate metabolism, resulting in decreased availability of thymidine which is necessary for DNA synthesis. Pemetrexed inhibited growth in a preclinical mouse xenograft model of human chordoma. We report three cases of metastatic chordoma that had been heavily treated previously with a variety of standard therapies with poor response. In two cases, pemetrexed was added and objective responses were observed on imaging with one patient on continuous treatment for > 2 years with continued shrinkage. One case demonstrated tumor growth after treatment with pemetrexed. The two cases which had a favorable response had a loss of TS expression, whereas the one case with progressive disease had TS present. These results demonstrate the activity of pemetrexed in recurrent chordoma and warrant a prospective clinical trial which is ongoing (NCT03955042).

A network meta-analysis for efficacies and toxicities of different concurrent chemoradiotherapy regimens in the treatment of locally advanced non-small cell lung cancer

Background

Concurrent chemoradiotherapy (CCRT) has become the cornerstone of treatment for patients with locally advanced non-small cell lung cancer (LA-NSCLC). The aim of this study was to compare the efficacies and toxicities of different CCRT regimens in the treatment of LA-NSCLC by adopting a network meta-analysis (NMA).

Methods

An exhaustive search of PubMed, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) was conducted to identify relevant studies from inception to October 1, 2020. Direct and indirect evidence was combined to calculate the odds radios (ORs) and 95% confidence intervals (CIs), as well as to plot the surface under the cumulative ranking (SUCRA) curves. Cluster analyses were adopted to compare the efficacies and toxicities of different CCRT regimens according to the similarity of 2 variables. Publication bias was detected by comparison-adjusted funnel plots.

Results

Twenty-two studies were enrolled in this NMA, including 18 regimens: CCRT (cisplatin + etoposide), CCRT (carboplatin + paclitaxel), CCRT (pemetrexed + carboplatin), CCRT (pemetrexed + cisplatin), CCRT (docetaxel + cisplatin), CCRT (S-1 + cisplatin), CCRT (mitomycin + vindesine + cisplatin), CCRT (cisplatin + vinorelbine), CCRT (cisplatin), CCRT (etoposide + cisplatin + amifostine), RT, CCRT (5-FU), CCRT (paclitaxel + cisplatin), CCRT (irinotecan + carboplatin), CCRT (nedaplatin), CCRT (carboplatin + etoposide), CCRT (paclitaxel), and CCRT (carboplatin). The results indicated that the regimens with CCRT (cisplatin + etoposide), CCRT (carboplatin + paclitaxel), CCRT (pemetrexed + cisplatin), CCRT (S-1 + cisplatin), and CCRT (cisplatin + vinorelbine) had relatively better efficacies compared with other regimens. As for toxicities of different CCRT regimens, the CCRT (carboplatin + paclitaxel), CCRT (pemetrexed + cisplatin), and CCRT (docetaxel + cisplatin) were relatively lower.

Conclusions

Our study demonstrated that CCRT (pemetrexed + cisplatin) and CCRT (carboplatin + paclitaxel) might be the best options for the treatment of LA-NSCLC, and CCRT (pemetrexed + cisplatin) had the highest 3-year overall survival (OS) rate.

Pemetrexed plus cisplatin in patients with previously treated advanced sarcoma: a multicenter, single-arm, phase II trial

Background

Patients with advanced sarcomas have a poor prognosis and few treatment options that improve overall survival. We assessed the efficacy and tolerability of pemetrexed and cisplatin combination therapy in patients with refractory bone and soft tissue sarcoma (STS).

Patients and Methods

Patients were included in this multicenter, phase II study (ClinicalTrials.gov identifier NCT03809637) if they progressed after receiving one or more chemotherapy regimens containing an anthracycline and/or ifosfamide. Pemetrexed was first administered intravenously, followed by cisplatin, over a cycle of 21 days, for a maximum of six cycles. The primary endpoint was a progression-free rate (PFR) at 3 months (3-month PFR).

Results

From January 2017 to September 2019, we enrolled 37 patients; of these, 73% had previously undergone three or more rounds of chemotherapy. Five patients (13.5%) exhibited objective responses, including two patients (2/6, 33.3%) with malignant peripheral nerve sheath tumors, one patient (1/4, 25%) with synovial sarcoma, one patient (1/4, 25%) with undifferentiated pleomorphic sarcoma, and one patient (1/4, 25%) with angiosarcoma. The median progression-free survival was 2.6 months, and the 3-month PFR was 45.9% (n = 17). None of the four patients with osteosarcoma exhibited objective responses or were progression free at 3 months. The most frequent treatment-related grade 3-4 toxicities included neutropenia (16.2%), anemia (13.5%), thrombocytopenia (13.5%), and fatigue (8.1%). Among 26 patients (70.3%) available for immunohistochemical assessments, patients in the low-excision repair cross-complementation group 1 (ERCC1) and low-thymidylate synthase expression groups showed a tendency for longer overall survival.

Conclusions

Combination therapy with pemetrexed and cisplatin was associated with clinically meaningful and sustained responses among patients with advanced and refractory STS. The combination therapy met its predefined primary study endpoint.

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Pemetrexed and cisplatin show promising efficacy for advanced sarcoma treatment, particularly as a salvage therapy option.

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The combination therapy met its predefined primary endpoint, with a 3-month PFR of 45.9%.

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Pemetrexed and cisplatin showed acceptable toxicity in heavily treated sarcoma patients.

Thymidylate synthase inhibitor raltitrexed can induce high levels of DNA damage in MYCN-amplified neuroblastoma cells

MYCN gene amplification is consistently associated with poor prognosis in patients with neuroblastoma, a pediatric tumor arising from the sympathetic nervous system. Conventional anticancer drugs, such as alkylating agents and platinum compounds, have been used for the treatment of high-risk patients with MYCN-amplified neuroblastoma, whereas molecule-targeting drugs have not yet been approved. Therefore, the development of a safe and effective therapeutic approach is highly desired. Although thymidylate synthase inhibitors are widely used for colorectal and gastric cancers, their usefulness in neuroblastoma has not been well studied. Here, we investigated the efficacies of approved antifolates, methotrexate, pemetrexed, and raltitrexed (RTX), on MYCN-amplified and nonamplified neuroblastoma cell lines. Cell growth-inhibitory assay revealed that RTX showed a superior inhibitory activity against MYCN-amplified cell lines. We found no significant differences in the protein expression levels of the antifolate transporter or thymidylate synthase, a primary target of RTX, among the cell lines. Because thymidine supplementation could rescue the RTX-induced cell growth suppression, the effect of RTX was mainly due to the reduction in dTTP synthesis. Interestingly, RTX treatments induced single-stranded DNA damage response in MYCN-amplified cells to a greater extent than in the nonamplified cells. We propose that the high DNA replication stress and elevated levels of DNA damage, which are a result of deregulated expression of MYCN target genes, could be the cause of increased sensitivity to RTX.

Targeting ROR1 in combination with pemetrexed in malignant mesothelioma cells

OBJECTIVE

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is overexpressed in a subset of malignant cells. However, it remains unknown whether ROR1 is targetable in malignant mesothelioma (MM). Therefore, in this study, we investigated the effects of ROR1 inhibition in mesothelioma cells.

MATERIALS AND METHODS

Growth inhibition, colony formation, apoptosis, and mRNA/protein levels using siRNA-transfected MM cells were evaluated. Cluster analysis using Gene Expression Omnibus repository of transcriptomic information was also performed.

RESULTS

Our results indicated that in three (H2052, H2452, and MESO-1) among four MM cell lines, ROR1 inhibition had anti-proliferative and apoptotic effects and suppressed the activation of AKT and STAT3. Although growth inhibition by siROR1 was minimal in another mesothelioma cell line (H28), colony formation was significantly suppressed. Microarray, quantitative polymerase chain reaction, and Western blot analyses showed that there were differences in the suppression of mRNA and proteins between H2452 and H28 cells transfected with siROR1 compared with those transfected with control siRNA. Cluster analysis further showed that MM tumors had relatively high ROR1 expression, although the cluster in them was different from that in MM cell lines. Thymidylate synthase, a target of pemetrexed, was downregulated in H2452 cells transfected with siROR1. Accordingly, a combination of pemetrexed with siROR1 was found to be effective in the three MM cell lines we studied.

CONCLUSION

Our findings may provide novel therapeutic insight into the treatment of advanced MM.

Using Radiolabeled 3'-Deoxy-3'-18F-Fluorothymidine with PET to Monitor the Effect of Dexamethasone on Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is a leading cause of cancer mortality in the United States, and pemetrexed-based therapies are regularly used to treat nonsquamous NSCLC. Despite widespread use, pemetrexed has a modest effect on progression-free survival, with varying efficacy between individuals. Recent work has indicated that dexamethasone, given to prevent pemetrexed toxicity, is able to protect a subset of NSCLC cells from pemetrexed cytotoxicity by temporarily suppressing the S phase of the cell cycle. Therefore, dexamethasone might block treatment efficacy in a subpopulation of patients and might be contributing to the variable response to pemetrexed. Methods: Differences in retention of the experimental PET tracer 3'-deoxy-3'-fluorothymidine (FLT) were used to monitor S-phase suppression by dexamethasone in NSCLC cell models, animals with tumor xenografts, and patients with advanced cancer. Results: Significant reductions in tracer uptake were observed after 24 h of dexamethasone treatment in NSCLC cell lines and xenograft models expressing high levels of glucocorticoid receptor α, coincident with pemetrexed resistance visualized by attenuation of the flare effect associated with pemetrexed activity. Two of 4 patients imaged in a pilot study with ¹⁸F-FLT PET after dexamethasone treatment demonstrated reductions in tracer uptake from baseline, with a variable response between individual tumor lesions. Conclusion: ¹⁸F-FLT PET represents a useful method for the noninvasive monitoring of dexamethasone-mediated S-phase suppression in NSCLC and might provide a way to individualize chemotherapy in patients receiving pemetrexed-based regimens.

High pemetrexed sensitivity of docetaxel-resistant A549 cells is mediated by TP53 status and downregulated thymidylate synthase

The chemoresistance of non-small cell lung cancer (NSCLC) that occurs in docetaxel (DOC) chemotherapy substantially decreases the survival of patients. To overcome DOC-induced chemoresistance, we established DOC-selected A549 lung cancer sublines (A549/D16 and A549/D32) and revealed that both sublines were cross-resistant to vincristine (VCR) and doxorubicin (DXR). Notably, both sublines were more sensitive to pemetrexed (PEM) than parental cells according to MTT and clonogenic assays. The expression levels of thymidylate synthase (TS) and γ-glutamyl hydrolase (GGH) were downregulated in DOC-resistant sublines. When exogenous TS was overexpressed in A549/D16 cells, PEM sensitivity was significantly decreased, however it was not decreased by overexpression of exogenous GGH. PEM treatment induced more apoptotic sub-G1 cells in both DOC-resistant sublines and in the in vivo PEM sensitivities of A549/D16 cells. These findings were further confirmed by a xenografted tumor model. To unmask the mediator of TS downregulation, we investigated human lung cancer cell lines that have various TP53 statuses using DOC treatment. The level of TS protein was significantly decreased in wild-type TP53-containing cells with DOC treatment; TS expression levels were not affected in mutant-TP53 and TP53-null cells under the same conditions. Furthermore, when the expression of TP53 was inhibited in A549 cells, the expression level of TS was increased. Our data indicated that DOC activated wild-type TP53 and suppressed TS expression under continuous DOC exposure. Therefore, the expression of TS remained at low levels in DOC-resistant A549 cancer cells. Our data revealed that for lung cancer with DOC resistance and wild-type TP53 status, the administration of PEM as a second-line agent to overcome DOC-resistance may benefit patients.

Greater efficacy of chemotherapy plus bevacizumab compared to chemo- and targeted therapy alone on non-small cell lung cancer patients with brain metastasis

Control of non-small-cell lung cancer (NSCLC) with brain metastasis is clinically challenging. This study retrospectively evaluated the efficacy of different adjuvant therapies for 776 cases of advanced NSCLCs with brain metastasis who treated with chemotherapy, chemotherapy plus bevacizumab, tyrosine kinase inhibitor (TKI) alone, or supportive care. The median progression-free survival (mPFS) and median overall survival (mOS) of patients treated with chemotherapy plus bevacizumab were 8.5 and 10.5 months, respectively, which were better than those of patients treated with other three therapies(P < 0.01). For patients with EGFR-mutated NSCLC, the efficacy of TKI treatment was not statistically better than that of chemotherapy plus bevacizumab but was significantly better than that of other therapies. Moreover, for patients with EGFR wild-type NSCLC, the mPFS and mOS after chemotherapy plus bevacizumab were greater than those with other two therapies (P < 0.01). The local response rate (RR)and disease control rate (DCR)with regimen including pemetrexed were greater than those with regimen including paclitaxel (P < 0.05). Chemotherapy plus bevacizumab was more effective for NSCLC patients with brain metastasis. Further studies will investigate the benefit of TKI alone for patients with EGFR-mutated. For patients with EGFR wild-type, chemotherapy plus bevacizumab did improve PFS and OS. Furthermore, regimens including pemetrexed led to a greater RR.

Pretreatment Red Blood Cell Total Folate Concentration Is Associated With Response to Pemetrexed in Stage IV Nonsquamous Non-Small-cell Lung Cancer

INTRODUCTION

Pemetrexed inhibits folate-dependent enzymes involved in pyrimidine and purine synthesis. Previous studies of genetic variation in these enzymes as predictors of pemetrexed efficacy have yielded inconsistent results. We investigated whether red blood cell (RBC) total folate, a phenotypic rather than genotypic, marker of cellular folate status was associated with the response to pemetrexed-based chemotherapy in advanced nonsquamous non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

We conducted a prospective cohort study of patients with stage IV nonsquamous NSCLC receiving first-line chemotherapy containing pemetrexed. The pretreatment RBC total folate level was quantified using liquid chromatography mass spectrometry. We then compared the objective response rate (ORR) between patients with RBC total folate concentrations greater than and less than an optimal cutoff value determined from the receiver operating characteristic curve. A logistic regression model was used to adjust for age, sex, and the use of bevacizumab.

RESULTS

The ORR was 62% (32 of 52 patients). Receiver operating characteristic analysis was used to establish that a RBC total folate cutoff value of 364.6 nM optimally discriminated between pemetrexed responders and nonresponders. Patients with RBC total folate < 364.5 nM had an ORR of 27% compared with 71% for patients with RBC total folate > 364.5 nM (P = .01). This difference persisted after adjusting for age, sex, and the use of bevacizumab (odds ratio, 0.07; 95% confidence interval, 0.01-0.57; P = .01).

CONCLUSION

A low pretreatment RBC total folate was associated with an inferior response to pemetrexed-based chemotherapy in stage IV nonsquamous NSCLC. Larger, multicenter studies are needed to validate RBC total folate as a predictive marker of pemetrexed response.

Pemetrexed-Induced Rash May Be Prevented by Supplementary Corticosteroids

Pemetrexed, a chemotherapeutic drug, is highly active in non-small cell lung cancer and malignant pleural mesothelioma. Unfortunately, rashes are more commonly associated with pemetrexed than other chemotherapies, and it is recommended that patients receive corticosteroids (8 mg/d of dexamethasone) for 3 d, including the day of pemetrexed administration (day 1). However, the efficacy of corticosteroids in this context has not been fully verified. In this retrospective study, we evaluated the medical records of 78 patients who received pemetrexed between April 2009 and March 2014, to confirm whether supplementary corticosteroids prevented rash development. The incidence of rash was lower in the 47 patients who received supplementary corticosteroids (after day 1) compared with the incidence among the 31 patients who did not receive supplementary corticosteroids (19.1% vs. 38.7%). The average cutoff dosage of supplementary corticosteroids on day 2 and day 3 was 1.5 mg/d of dexamethasone, as calculated using the receiver operating characteristic curve, and the odds ratio was 0.33 (95% confidence interval: 0.12-0.94). Administration of ≥1.5 mg of corticosteroids on day 2 and day 3 significantly reduced the severity of the rash compared to no supplementary treatment (grades 2/3, 13.3% vs. 33.3%, p<0.05). However, increasing the dose of corticosteroids had no additional effect on rash development. These results suggest that ≥1.5 mg of supplementary dexamethasone on day 2 and day 3 (in addition to day 1) may be necessary for preventing pemetrexed-induced rash, but high doses of dexamethasone (e.g., 8 mg/d) are unnecessary.

Reduced folate and serum vitamin metabolites in patients with rectal carcinoma: an open-label feasibility study of pemetrexed with folic acid and vitamin B12 supplementation

The objectives of this single-center, open-label, phase II study were to evaluate (a) the feasibility and safety of neoadjuvant administration of pemetrexed with oral folic acid and vitamin B₁₂ (FA/B₁₂) in newly diagnosed patients with resectable rectal cancer and (b) intracellular and systemic vitamin metabolism. Patients were treated with three cycles of pemetrexed (500 mg/m², every 3 weeks) and FA/B₁₂ before surgery. The reduced folates tetrahydrofolate, 5-methyltetrahydrofolate, and 5,10-methylenetetrahydrofolate were evaluated from biopsies in tumor tissue and in adjacent mucosa. Serum levels of homocysteine, cystathionine, and methylmalonic acid were also measured. All 37 patients received three cycles of pemetrexed; 89.2% completed their planned dosage within a 9-week feasibility time frame. Neither dose reductions nor study drug-related serious adverse events were reported. Reduced folate levels were significantly higher in tumor tissue compared with adjacent mucosa at baseline. After FA/B₁₂ administration, tissue levels of reduced folates increased significantly and remained high during treatment in both tumor and mucosa until surgery. Serum levels of cystathionine increased significantly compared with baseline after FA/B₁₂ administration, but then decreased, fluctuating cyclically during pemetrexed therapy. Homocysteine and methylmalonic acid levels decreased significantly after FA/B₁₂ administration, and remained below baseline levels during the study. These results indicate that administration of three neoadjuvant cycles of single-agent pemetrexed, every 3 weeks, with FA/B₁₂ in patients with resectable rectal cancer is feasible and tolerable. Tissue and serum vitamin metabolism results demonstrate the influence of pemetrexed and FA/B₁₂ on vitamin metabolism and warrant further study.

Chemotherapy in non-small cell lung cancer: opportunities for advancement

Locally advanced non-small cell lung cancer (NSCLC) continues to be a challenging disease to treat. With high rates of both local and distant failures, there is significant interest in finding more biologically active chemotherapy regimens that can contribute to reduce both failures. The phase III PROCLAIM trial, recently published in the Journal of Clinical Oncology entitled “PROCLAIM: randomized phase III trial of pemetrexed–cisplatin or etoposide–cisplatin plus thoracic radiation therapy followed by consolidation chemotherapy in locally advanced nonsquamous non-small-cell lung cancer”, compared two different chemotherapy regimens given concurrently with radiotherapy in patients with stage III non-squamous lung cancer: pemetrexed plus cisplatin versus cisplatin plus etoposide. Both groups received consolidation chemotherapy. After enrolling 598 of planned 600 patients, the study was stopped early due to futility as no difference was seen in the primary end-point of overall survival. Since PROCLAIM was designed as a superiority trial, these results suggest that pemetrexed regimens do not offer a clinical advantage over standard cisplatin plus etoposide. There are some subpopulations who might still benefit from pemetrexed, especially if clinicians are concerned about myelosuppression-related adverse events. Future trials are needed to investigate novel biologic agents and irradiation techniques that can result in more durable local and distant disease control in locally advanced NSCLC.

Safety profiles of first-line therapies for metastatic non-squamous non-small-cell lung cancer

INTRODUCTION

Lung cancer still represents the leading cause of death for cancer. About the 70% of diagnosis are in advanced-stage. Non-small-cell lung cancer (NSCLC) represents the 85% of all diagnosed lung cancers and non-squamous histology represents the 40% of all NSCLC. First-line therapies increase survival, control symptoms and improve quality of life, compared with best supportive care. It is crucial to choose a treatment with a low impact on patient's life considering the related toxicities.

AREAS COVERED

Adverse events (AEs) of first-line therapies for non-squamous NSCLC are here reviewed and discussed, from evidences in clinical trials conducting to drugs approval.

EXPERT OPINION

For advanced disease, palliation and preserving patients QoL are still the primary goal of treatment. Therefore, differing toxicity profiles are often a deciding factor in first-line and also maintenance setting for non-squamous NSCLC. Special attention is necessary to renal function and drugs' nephrotoxicity. Moreover, it is to consider the specific AEs of drugs classes: hypertension, bleeding, and proteinuria, for anti-VEGF therapy; skin toxicity, diarrhea, interstitial lung disease for TKIs; vision disorders, and hepatotoxicity for ALK-inhibitor. It is important to select patients for a treatment on the basis of their comorbidities and the presence of risk factors.

Pemetrexed clinical studies in performance status 2 patients with non-small cell lung cancer (Review)

Because poor performance status (PS) is an independent prognostic factor in non-small cell lung cancer (NSCLC), PS scores are widely used by oncologists to make treatment decisions. Advanced NSCLC patients with an Eastern Cooperative Oncology Group PS of 2 have poor prognoses and are frequently excluded from clinical trials. This article reviews the efficacy and safety of pemetrexed in this patient group. We identified English-language literature (through March 2015) involving completed and ongoing studies through searches of PubMed, meeting abstracts, ClinicalTrials.gov and the European Clinical Trials Register; search terms included 'pemetrexed,' 'NSCLC' and 'PS2'. Only studies reporting ≥1 subset analysis of PS2 patients receiving pemetrexed were chosen. Our search identified a total of ten pemetrexed studies in PS2 patients. Eight studies included only chemonaive patients, one study included both chemonaive patients and patients with one prior chemotherapy regimen and one study included only patients with one prior regimen. In subset analyses in these studies, PS2 patients had worse outcomes than PS0-1 patients regardless of treatment. In a phase 3 study, chemonaive advanced NSCLC patients with PS2 receiving pemetrexed‑carboplatin versus pemetrexed experienced improved overall survival [hazard ratio (HR)=0.62; P=0.001], progression-free survival (HR=0.46; P<0.001) and response (P=0.032). This review confirms the poorer outcomes in PS2 vs. PS0-1 patients. Although it is not an approved combination therapy, in clinical studies, PS2 patients treated with pemetrexed plus carboplatin as first-line therapy had improved response rates and survival. Additional research on PS2 patients is needed.

Feasibility of cisplatin/pemetrexed with 15 mg/kg bevacizumab for the treatment of patients with advanced non-squamous non-small cell lung cancer

The aim of the present study was to retrospectively evaluate the feasibility of cisplatin/pemetrexed/bevacizumab (CPB) therapy at a bevacizumab (BEV) dose of 15 mg/kg as a first-line chemotherapeutic strategy for patients with advanced non-squamous non-small cell lung cancer (NSCLC). A total of 31 consecutive patients with non-squamous NSCLC were treated with first-line chemotherapy of CPB at a BEV dose of 15 mg/kg at the National Kyushu Cancer Center (Fukuoka, Japan) between November 2009 and December 2011. Clinical characteristics, response rate (RR), progression-free survival (PFS) time, overall survival (OS) time and adverse events were retrospectively analyzed. The 31 patients exhibited a male:female ratio of 21:10 and a median age of 60 years (range, 38-76 years). In total, 5 patients were of clinical stage III and 26 patients were of stage IV, 15 had a performance status of 0 and 16 had a performance status of 1, and 29 patients were diagnosed with adenocarcinoma and 2 were diagnosed with adenosquamous carcinoma. The EGFR mutation status was positive (exon 19 deletion), wild-type and unknown in 3, 21 and 7 patients, respectively. A total of 28 patients (90.3%) received a minimum of four courses of CPB therapy. Hematological toxicities classified as grade III or higher included neutropenia (29.0%), anemia (3.2%) and thrombocytopenia (3.2%), however, no severe non-hematological toxicities were observed. Additionally, 22 patients (71.0%) exhibited a partial response and 9 (29.0%) exhibited stable disease, resulting in a RR of 71.0% [95% confidence interval (CI), 41-74]. The median PFS and OS times were 8.4 months (95% CI, 7.9-9.0) and 28.5 months (95% CI, 26.4-30.6), respectively. Therefore, CPB therapy at a BEV dose of 15 mg/kg appears to be a feasible treatment strategy for patients with advanced non-squamous NSCLC.

Potential role of pemetrexed in metastatic breast cancer patients pre-treated with anthracycline or taxane

Objectives

This article reviews pharmacology, pharmacokinetic properties, clinical efficacy, and safety in metastatic breast cancer patients, as well as the predictive biomarkers for outcome of treatment with pemetrexed-based regimens.

Methods

PubMed, Embase, OVID, and the Cochrane Library databases were searched from the beginning of each database without any limitations to the date of publication. Search terms were ‘‘pemetrexed’’ or ‘‘LY231514’’ or “Alimta”, “metastatic breast cancer”, and “advanced breast cancer”.

Results

There were 15 studies (n = 1002) meeting our criteria for evaluation. Eight single-agent trials (n = 551) and seven using combinations with other agents (n = 451) were identified that evaluated pemetrexed for use in patients with metastatic breast cancer. Response rates to pemetrexed as a single agent varied from 8% to 31%, and with combination therapy have been reported to be between 15.8% and 55.7%. With routine supplementation of patients with folic acid, dexamethasone, and vitamin B₁₂, the toxicity profile of these patients was mild, including dose-limiting neutropenia and thrombocytopenia, as well as lower grades of reversible hepatotoxicity and gastrointestinal toxicity. Expression of thymidylate synthase (TS) and other biomarkers are associated with the prognosis and sensitivity for pemetrexed in breast cancer.

Conclusion

Pemetrexed has shown remarkable activity with acceptable toxicities for treatment of metastatic breast cancer patients. Translational research on pemetrexed in breast cancer identified biomarkers as well as additional genes important to its clinical activity and toxicity. Further research is needed to clarify the role of pemetrexed in breast cancer treatment in order to guide oncologists.

Serum Protein Pattern Could Predict the Therapeutic Effect of First-Line Pemetrexed/Cisplatin Chemotherapy in Patients With Lung Adenocarcinoma

Background

In patients with advanced non-squamous non-small cell lung cancer (NSCLC), a pemetrexed/cisplatin (PP) regimen is considered as one of the preferred first-line treatments. However, only about half of the treated patients respond, and there is no clinically useful marker that can predict the response to the regimen.

Methods

We established a potential pattern for the prediction of efficacy of first-line PP chemotherapy in patients with lung adenocarcinoma, by using artificial neural networks (ANNs) analysis of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) in this preliminary study.

Results

The samples were randomly divided into training set and test set. From the test set, through cross-validation, the established protein pattern for PP separated the responders from the non-responders with a sensitivity of 95.8% and a specificity of 90.0%.

Conclusion

It could be helpful for oncologists to select patients who could benefit from PP chemotherapy.

[Pemetrexed nephrotoxicity]

Pemetrexed belongs to a new generation of multitargeted antifolate cytotoxic agents. It is increasingly used as first-line treatment in combination with cisplatin, and as second-line treatment or maintenance monotherapy mainly in metastatic non-small cell lung cancer and in malignant mesothelioma. It is increasingly used as first-line treatment in combination with cisplatin in lung adenocarcinoma, and as second-line treatment or maintenance monotherapy in patients mainly controlled by the first-line to progression or poor tolerance. In mesothelioma, pemetrexed is indicated only in first-line with a platinum salt. The main side effect of pemetrexed is myelosuppression, which may be prevented by folinic acid supplementation. This review focuses on the progressive and cumulative emerging renal toxicity of pemetrexed, affecting five to ten percent of "long-term" pemetrexed-treated patients.

Carboplatin-pemetrexed in treatment of patients with recurrent/metastatic cancers of the head and neck; superior outcomes in oropharyngeal primaries

Background: Platinum-based therapy in combination with 5-fluorouracil with cetuximab has shown the best survival in pts with recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). The purpose of this study is to evaluate the efficacy and tolerability of carboplatin, pemetrexed and to assess differential outcomes in patients with oropharyngeal primary and HPV related disease.

Patients and Methods: The charts of consecutive patients with R/M SCCHN were reviewed. All patients receiving at least one cycle of the two-drug regimen (pemetrexed 500 mg/m², carboplatin area under the curve of five intravenously), were included for assessment of response, safety, toxicity, and survival.

Results: A total of 86 patients received this regimen between January 2008 and December 2012, of which, 63 were included in this analysis. Forty-one percent (26) of the patients had cancers of the oropharynx, and of those, 50% had HPV-positive disease, 32% (20) had cancers of the larynx, and 24% (15) of the oral cavity. Median number of cycles administered was 4 (range 1–14 cycles) with 50% of the patients receiving four or more cycles. Half the patients achieved stable disease as their best response, 8% (5) attained a partial response, 24% progressed on therapy, and the remaining patients (12) could not have their response assessed. On the basis of Kaplan–Meier analysis, median progression-free survival (PFS) was 5.1 months (95% CI 3.2, 6.2) and median overall survival (OS) was 9.4 months (95% CI 4.3, 13.1). Among pts with oropharyngeal primary (n = 26), median PFS was 6.4 months (95% CI 2.8, 7.9) and median OS was 16.6 months (95% CI 9.6, 19.5). Among HPV+ pts (n = 13), median PFS was 7.0 months (95% CI 4.8, ne) and median OS was 17.1 months (95% CI 11.2, 21.7).

Conclusion: Combination carboplatin-pemetrexed is an effective and well-tolerated treatment, associated with a median PFS of 5.1 months and a clinical benefit in at least 57% of the patients treated.

Glucocorticoid receptor status is a principal determinant of variability in the sensitivity of non-small-cell lung cancer cells to pemetrexed

INTRODUCTION

Pemetrexed is an S-phase targeted drug in front-line or maintenance therapy of advanced nonsquamous non-small-cell lung cancer (NSCLC) but methods are needed for predicting the drug response. Dexamethasone is typically administered the day before, the day of, and the day after pemetrexed. As dexamethasone strongly regulates many genes including p53 through the glucocorticoid receptor (GR), we hypothesized that dexamethasone influences tumor response to pemetrexed.

METHODS

Eight nonsquamous NSCLC cell line models with varied p53 and GRα/GRβ status were used for gene expression and cell-cycle analyses and for loss- or gain-of-function experiments.

RESULTS

In three cell lines dexamethasone profoundly, but reversibly, suppressed the fraction of S-phase cells. Dexamethasone also reversibly repressed expression of thymidylate synthase and dihydrofolate reductase, which are primary targets of pemetrexed but are also quintessential S-phase enzymes as well as the S-phase-dependent expression of thymidine kinase 1. Dexamethasone also decreased expression of the major pemetrexed transporters, the reduced folate carrier and the proton coupled folate transporter. Only cells expressing relatively high GRα showed these dexamethasone effects, regardless of p53 status. In cells expressing low GRα, the dexamethasone response was rescued by ectopic GRα. Further, depletion of p53 did not attenuate the dexamethasone effects. The presence of dexamethasone during pemetrexed treatment protected against pemetrexed cytotoxicity in only the dexamethasone responsive cells.

CONCLUSIONS

The results predict that in nonsquamous NSCLC tumors, reversible S-phase suppression by dexamethasone, possibly combined with a reduction in the drug transporters, attenuates responsiveness to pemetrexed and that GR status is a principal determinant of tumor variability of this response.

An open-label, multicenter, randomized, phase II study of pazopanib in combination with pemetrexed in first-line treatment of patients with advanced-stage non-small-cell lung cancer

INTRODUCTION

This randomized open-label phase II study evaluated the efficacy, safety, and tolerability of pazopanib in combination with pemetrexed compared with the standard cisplatin/pemetrexed doublet in patients with previously untreated, advanced, nonsquamous non-small-cell lung cancer.

METHODS

Patients were randomized (2:1 ratio) to receive pemetrexed 500 mg/m(2) intravenously once every 3 weeks plus either oral pazopanib 800 mg daily or cisplatin 75 mg/m(2) intravenously once every 3 weeks up to six cycles. All patients received folic acid, vitamin B12, and steroid prophylaxis. The primary endpoint was progression-free survival (PFS).

RESULTS

The study was terminated after 106 of 150 patients were randomized due to a higher incidence of adverse events leading to withdrawal from the study and severe and fatal adverse events in the pazopanib/pemetrexed arm than in the cisplatin/pemetrexed arm. At the time enrolment was discontinued, there were three fatal adverse events in the pazopanib/pemetrexed arm, including ileus, tumor embolism, and bronchopneumonia/sepsis. Treatment with pazopanib/pemetrexed was discontinued resulting in more PFS data censored for patients in the pazopanib/pemetrexed arm than those in the cisplatin/pemetrexed arm. There was no statistically significant difference between the pazopanib/pemetrexed and cisplatin/pemetrexed arms for PFS (median PFS, 25.0 versus 22.9 weeks, respectively; hazard ratio = 0.75; 95% confidence interval, 0.43%-1.28%; p = 0.26) or objective response rate (23% versus 34%, respectively; 95% confidence interval, -30.6% to 7.2%; p = 0.21).

CONCLUSION

The combination of pazopanib/pemetrexed in first-line treatment of non-small-cell lung cancer showed some antitumor activity but had unacceptable levels of toxicity.

Pemetrexed for previously treated patients with metastatic gastric cancer: a prospective phase II study

Background:

Gastric cancer is one of the leading causes of cancer-related death worldwide. There were debates on the value of the second-line and beyond chemotherapy by the time we designed this trial. So we designed this phase II trial to assess the efficacy and safety of pemetrexed in patients with pretreated metastatic gastric cancer.

Methods:

Thirty-four patients with pretreated metastatic gastric cancer were enroled in the study. Patients received pemetrexed 500 mg m⁻² every 21 days until the presence of progressive disease (PD) or unacceptable toxicity.

Results:

A total of 34 patients were enroled in the study; 34 were eligible for toxicity and 30 for response. The response rate was 13.3%, 13.3% patients achieved a partial response, 50.0% achieved stable disease and 36.7% had a PD as the best response. The median overall survival time and median progression-free survival time was 6.4 months (95% confidence interval (CI) 5.8–9.5 months) and 2.2 months (95% CI 2.0–5.5 months), respectively. Most haematologic and non-haematologic toxicity were grade 1/2. Grade 3/4 toxicity included fatigue, neutropenia, thrombocytopenia, weight loss, anorexia and transaminase elevation.

Conclusions:

The monochemotherapy of pemetrexed is active and well tolerated when used in previously treated patients with metastatic gastric cancer.

Phase II study of pemetrexed in combination with cisplatin in patients with advanced urothelial cancer: the PECULIAR study (KCSG 10-17)

Background:

Pemetrexed has shown a favourable response rate of about 30% with minimal toxicity when used as a single agent for treatment of advanced urothelial carcinoma. This phase II study evaluated the efficacy and safety of pemetrexed plus cisplatin in advanced urothelial carcinoma.

Methods:

This multicentre, single-arm, open-label, phase II clinical trial enrolled patients who had advanced urothelial carcinoma, ECOG PS 0–2, and measurable disease. Pemetrexed 500 mg m⁻² with cisplatin 70 mg m⁻² on day 1 were administered every 3 weeks. The primary endpoint was the objective response rate (ORR). Secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity.

Results:

A total of 42 patients were enrolled (median age, 66 years; ECOG 0–1, 100% visceral metastasis, 54.8% recurrent disease, 57.1%). Twenty-seven partial responses for an ORR of 64.3% (95% CI, 49.2%–77.0%) were documented. Seven patients had stable disease. Median PFS and OS were 6.9 (95% CI, 6.2–7.6) and 14.4 (95% CI, 10.4–18.4) months, respectively. Grade 3 or 4 neutropenia was observed in 28.6% of patients. No patients experienced febrile neutropenia.

Conclusion:

The combination of pemetrexed and cisplatin is active, and well tolerated in patients with advanced urothelial cancer as a first-line treatment.

Comparison of pemetrexed plus cisplatin with gemcitabine plus docetaxel in refractory/metastatic osteosarcoma: Clinical outcomes from a retrospective database monitored in a single institute

The prognosis for patients with relapsed/metastatic osteosarcoma is poor and the optimal treatment strategy remains to be refined. Whilst gemcitabine plus docetaxel combination treatment has already been demonstrated to have certain promising results in the treatment of osteosarcoma, the use of pemetrexed, a multi-targeted antifolate, remains controversial. In the present study, a retrospective investigation was conducted to evaluate the toxicity and efficacy of the pemetrexed plus cisplatin combination in relapsed/metastatic osteosarcoma. Comparison of this treatment with that of the gemcitabine plus docetaxel combination was also conducted. Clinical data from 39 patients suffering from refractory/metastatic osteosarcoma between January 2005 and May 2011 were reviewed retrospectively. Of these patients, 21 were administered the gemcitabine plus docetaxel combination, and 18 were provided the pemetrexed plus cisplatin combination. Treatment was continued until the occurrence of disease progression or unacceptable toxicity. In the gemcitabine plus docetaxel group, the overall response rate and disease control rate were found to be 9.5 and 28.5% respectively, compared with 5.5 and 33.3% respectively in the pemetrexed plus cisplatin group. The median progression-free survival (PFS) time was found to be 1.8 months for both the gemcitabine plus docetaxel and pemetrexed plus cisplatin groups. The median overall survival (OS) time was 6 months in the gemcitabine plus docetaxel group and 7 months in the pemetrexed plus cisplatin group. No statistically significant differences were recognized between the overall response rates, disease control rates, PFS times and OS times in the two groups. The two combinations appeared to be well tolerated. However, the incidence of grade 3/4 thrombocytopenia and leucopenia was higher in the gemcitabine plus docetaxel group than in the pemetrexed plus cisplatin group. The present study clearly demonstrated that both chemo-combinations were well-tolerated and exerted antitumor activity in patients with refractory/metastatic osteosarcoma. However, with regard to grade 3/4 toxicity, the pemetrexed plus cisplatin chemotherapy appears to be better tolerated.

Characteristics of pemetrexed transport by renal basolateral organic anion transporter hOAT3

PURPOSE

Pemetrexed transport by human organic anion transporters, hOAT1 (SLC22A6) and hOAT3 (SLC22A8), were characterized in comparison with methotrexate.

METHODS

Accumulation of pemetrexed and methotrexate in hOAT1- and hOAT3-expressing cells were evaluated. Pemetrexed and methotrexate were determined by HPLC. Kinetic parameters were calculated by Eadie-Hofstee plot.

RESULTS

When HEK-hOAT3 and -hOAT1 cells were incubated with 100 µM pemetrexed for 30 min, pemetrexed was accumulated at 14- and 1.7-fold greater than that in control cells, respectively. Pemetrexed and methotrexate transport by hOAT3 was saturated at high concentrations with apparent Km values 28.2 µM and 76.6 µM, respectively. In addition, intrinsic activity (Vmax/Km) of pemetrexed and methotrexate transport by hOAT3 was 4.82 and 0.42 µl/min/mg protein, respectively, suggesting 11-fold higher transport of pemetrexed than methotrexate by hOAT3. Furthermore, loxoprofen, ibuprofen, pravastatin, and cefazolin, transport substrates of hOAT3, inhibited pemetrexed transport by hOAT3 with IC50 values, 34.2, 27.9, 76.3 and 650 µM, respectively.

CONCLUSIONS

Pemetrexed is a superior substrate to methotrexate for hOAT3. Loxoprofen, ibuprofen, and cefazolin could cause drug-drug interactions when attaining high blood concentrations.

Effect of folic acid and vitamin B12 on pemetrexed antifolate chemotherapy in nutrient lung cancer cells

Pemetrexed (MTA) is a multitargeted antifolate drug approved for lung cancer therapy. Clinically, supplementation with high doses of folic acid (FA) and vitamin B₁₂ (VB12) lowers MTA cytotoxicities. An antagonistic effect of FA/VB12 on MTA efficacy has been proposed. However, patients who receive FA/VB12 show better tolerance to MTA with improved survival. The aims of this study are to investigate the modulation of FA and VB12 on MTA drug efficacy in human nonsmall cell lung cancer (NSCLC) cell lines. The sensitivities of cells, apoptosis, and MTA-regulated proteins were characterized to determine the possible effects of high doses of FA and VB12 on MTA efficacy. MTA has the lowest efficacy under 10% serum conditions. However, supplementation with FA and VB12 individually and additively reversed the insensitivity of NSCLC cells to MTA treatment with 10% serum. The enhanced sensitivities of cells following FA/VB12 treatment were correlated with increasing apoptosis and were specific to MTA but not to 5-fluorouracil (5-FU). Enhanced sensitivity was also associated with p21^WAF1/Cip1 expression level. Our results revealed no antagonistic effect of high doses of FA/VB12 on MTA efficacy in cancer cells grown in nutrient medium. Furthermore, these data may partially explain why supplementation of FA and VB12 resulted in better survival in MTA-treated patients.

Comparative study analyzing survival and safety of bevacizumab/carboplatin/paclitaxel and cisplatin/pemetrexed in chemotherapy-naïve patients with advanced non-squamous bronchogenic carcinoma not harboring EGFR mutation

Purpose

The majority of Egyptian patients with lung cancer present at a late stage of the disease. Bevacizumab/carboplatin/paclitaxel, as well as cisplatin plus pemetrexed, are both standard regimens for advanced non-squamous bronchogenic cancer. This study compares both regimens, in terms of efficacy and toxicity profile, in Egyptian patients.

Patients and methods

This is a randomized Phase II study comparing toxicity profile and survival in 41 chemotherapy-naïve patients with stage IIIB or IV non-squamous NSCLC, with an ECOG performance status of 0 to 2. The epidermal growth factor receptor (EGFR) mutation detection was performed prior to treatment of all patients. Patients in the first group received: bevacizumab 7.5 mg/m² on Day 1 and Day 15; carboplatin area under the curve-5 on Day 1; and paclitaxel 60 mg/m² on Day 1, Day 8, and Day 15 every 4 weeks. In the second group, patients received cisplatin 75 mg/m² and pemetrexed 500 mg/m² every 3 weeks.

Results

The combination of bevacizumab/carboplatin/paclitaxel demonstrated higher Grade III–IV toxicity than cisplatin/pemetrexed regarding sensory/motor neuropathy (P = 0.06), DVT (P = 0.23), proteinuria (P = 0.23), and hypertension (P = 0.11), as well as Grade II alopecia (P = 0.001); however, no significant difference in toxicities between both arms was recorded regarding nausea and vomiting (P = 0.66), hematological toxicity, febrile neutropenia (P = 1) and fatigue (P = 0.66). Progression-free survival was similar for both treatment arms with a median of 6 months (P = 0.978). Overall median survival was comparable in both arms, 16.07 months versus 16.01 months (P = 0.89).

Conclusion

Bevacizumab/carboplatin/paclitaxel and cisplatin/pemetrexed provided meaningful and comparable efficacy in advanced non-squamous bronchogenic carcinoma not harboring EGFR mutation. No significant difference in toxicity was observed between both treatment arms, apart from bevacizumab/carboplatin/paclitaxel-related risks as DVT, hypertension, proteinuria, sensory/motor neuropathy, and alopecia.

Pemetrexed as the first-line therapy for Chinese patients with advanced non-squamous non-small-cell lung cancer

Non-small cell lung cancer (NSCLC) represents the most common cause of cancer mortality worldwide and counts for the greatest number of deaths from lung cancer in both men and women over age 60. Pemetrexed is a multi-targeted anti-metabolite and has shown comparable activity for Caucasian patients with advanced NSCLC. In this single-center retrospective study, we analyzed the outcome in 75 Chinese non-squamous NSCLC patients treated with pemetrexed as first-line therapy and assessed its efficacy and tolerability. The overall response rate was 9.3% (7/75) with 7 partial response s and no complete response. There were 44 (58.7%) stable diseases and 24 progressive diseases (32.0%). The median progression-free survival (PFS) was 6.79 months (95% CI 5.69-7.90 months), and the median overall survival (OS) was 11.67 months (95% CI 9.98-13.36 months). Good performance status and negative smoke history predicted better PFS and OS. Most side effects were generally mild and well tolerated. Taken together, pemetrexed was safe and effective in Chinese patients with non-squamous NSCLC. Pemetrexed alone or in combination with other efficacious drugs may serve as first-line therapy for this disease.

Pemetrexed in combination with cisplatin versus cisplatin monotherapy in East Asian patients with recurrent or metastatic head and neck cancer: Results of an exploratory subgroup analysis of a phase III trial

AIM

An exploratory subgroup analysis of East Asian (EA) patients in a phase III trial was conducted to assess efficacy and safety trends based on ethnicity.

METHODS

The 795 patients with recurrent or metastatic squamous cell carcinoma of the head and neck included 111 EA patients randomized to pemetrexed-cisplatin (n = 55) and placebo-cisplatin (n = 56) and 684 non- EA patients randomized to pemetrexed-cisplatin (n = 343) and placebo-cisplatin (n = 341). Treatment differences in median overall survival and progression-free survival were compared using a stratified log-rank test. Survival was estimated using the Kaplan-Meier method.

RESULTS

The median overall survival in the pemetrexed-cisplatin and placebo-cisplatin arms of the EA group (6.8 and 5.7 months, respectively [P = 0.275]) was similar to that in the global population (7.3 and 6.3 months, respectively [P = 0.082]); the median progression-free survival in the pemetrexed-cisplatin and placebo-cisplatin arms in the EA group (2.8 and 1.9 months, respectively [P = 0.748]) was similar to that in the global population (3.6 and 2.8 months, respectively [P = 0.166]). Compared to the findings in the global population, overall survival for the EA group receiving prior platinum-based therapy was longer (P = 0.042 vs P = 0.065). There was no significant interaction between treatment arms and ethnicity.

CONCLUSION

Consistent with findings in the global population, pemetrexed-cisplatin did not improve survival compared with placebo-cisplatin for the EA group. However, in a subgroup analysis, pemetrexed-cisplatin showed an overall survival advantage in EA patients receiving prior platinum-based therapy.

Phase 2 trial of pemetrexed in children and adolescents with refractory solid tumors: a Children's Oncology Group study

BACKGROUND

Pemetrexed is a multi-targeted antifolate that inhibits key enzymes involved in nucleotide biosynthesis. We performed a phase 2 trial of pemetrexed in children with refractory or recurrent solid tumors, including CNS tumors, to estimate the response rate and further define its toxicity profile.

PROCEDURE

Pemetrexed, at a dose of 1910 mg/m(2) , was administered as a 10-minute intravenous infusion every 21 days. Patients also received vitamin B(12) , daily multivitamin supplementation, and dexamethasone. A two-stage design (10 + 10) was employed in each of the following disease strata: osteosarcoma, Ewing sarcoma/peripheral primitive neuroectodermal tumor (PNET), rhabdomyosarcoma, neuroblastoma, ependymoma, medulloblastoma/supratentorial PNET, and non-brainstem high-grade glioma.

RESULTS

Seventy-two eligible subjects (39 males) were enrolled. Median age was 11 years (range 3-23). Sixty-eight were evaluable for response. The median number of cycles administered was 2 (range 1-13). No complete or partial responses were observed. Stable disease, for a median of 5 (range 4-13) cycles, was observed in five patients (ependymoma, Ewing sarcoma, medulloblastoma, neuroblastoma, osteosarcoma; n = 1 each). Neutropenia (44%), anemia (35%), and elevated alanine transaminase (35%) attributable to pemetrexed were the most commonly recurring toxicities observed in patients receiving multiple cycles. Other toxicities attributed to pemetrexed occurring in ≥10% of cycles included thrombocytopenia (30%), fatigue (18%), nausea (14), hyperglycemia (13%), rash (11%), vomiting (13%), and hypophosphatemia (11%).

CONCLUSIONS

Pemetrexed, administered as an intravenous infusion every 21 days, was tolerable in children and adolescents with refractory solid tumors, including CNS tumors, but did not show evidence of objective anti-tumor activity in the childhood tumors studied.

Genotoxicity of pemetrexed in human peripheral blood lymphocytes

Pemetrexed (PMX) is an antineoplastic antifolate used in the treatment of non-small cell lung cancer, mesothelioma and several types of neoplasms. Its toxicity in tumor cells has been linked with the potent inhibition of thymidylate synthase, dihydrofolate reductase and glycinamide ribonucleotide formyl transferase, and subsequent depletion of both purine and pyrimidine nucleotides. However, cytogenetic toxicity of PMX in non-diseased cells has not been adequately studied; despite the increasing data on the DNA-damaging potential of antineoplastic agents on normal cells. In the present study, the genotoxic potential of PMX was evaluated in peripheral blood lymphocytes obtained from healthy human subjects using chromosome aberration (CA), sister chromatid exchange (SCE) and micronucleus (MN) assays as the cytogenetic damage markers. Human peripheral blood lymphocytes were exposed to four different concentrations (25, 50, 75 and 100 μg/mL) of PMX for 24- and 48-h treatment periods. PMX significantly increased the formation of CA in 24-h treatment, but not in 48-h treatment. PMX did not increase the mean SCE frequency in 24- and 48-h treatment periods; however, there was a striking increase (although not statistically significant, p > 0.05) in the number of SCEs at 25 μg/mL (24- and 48-h treatment) and 50 μg/mL (24-h treatment) due to an increase of SCE at the single-cell level. Interestingly, PMX did not induce MN formation in either 24- or 48-h treatment periods. PMX strongly decreased the mitotic index (MI), proliferation index (PI) and nuclear division index (NDI) in 24- and 48-h treatment periods. Our results suggest that PMX has a potent cytotoxic effect against human peripheral blood lymphocytes at concentrations which are reached in vivo in the blood plasma.

Second-line pemetrexed versus docetaxel in Chinese patients with locally advanced or metastatic non-small cell lung cancer: a randomized, open-label study

INTRODUCTION

This randomized, open-label study compared pemetrexed versus docetaxel as second-line therapy for Chinese patients with locally advanced or metastatic non-small cell lung cancer (NSCLC). The primary endpoint tested non-inferiority of overall survival (OS) on the combined data from these patients and those in the global registration trial. Data from patients in the current study only (Chinese patients) were the basis for the study's secondary objectives.

METHODS

Patients with stage IIIB/IV disease were randomized (1:1) to receive pemetrexed (500 mg/m(2); 107 randomized; 106 treated) or docetaxel (75 mg/m(2); 104 randomized; 102 treated) on Day 1 of each 21-day cycle. Treatment continued until progressive disease, unacceptable toxicity or patient/investigator decision. All efficacy and safety data were analyzed at the pre-specified study completion; supplementary OS analyses were performed later, after additional events had been recorded.

RESULTS

The primary endpoint of OS noninferiority of pemetrexed to docetaxel was not met, the lower CL was <50% and P>0.025 (efficacy retained=97.9% [95% CLs: 47.1, 141.9]; P=0.0276), in the combined population (pemetrexed: n=390, docetaxel: n=392). Supplementary values were 101.3% (95% CLs: 57.9, 148.8), P=0.0186. For the secondary objectives, assessed in the population from the current study (pemetrexed: n=107, docetaxel: n=104), median OS was 11.7 and 12.2 months for the pemetrexed and docetaxel arms, respectively (HR [95% CLs]: 1.14 [0.78, 1.68], P=0.492). Supplementary values were 11.4 and 11.5 months, respectively (HR [95% CLs]: 1.02 [0.74, 1.40], P=0.926). Median PFS values were 2.8 and 3.1 months (HR [95% CLs]: 1.05 [0.75, 1.46], P=0.770) and ORR values were 9.6% and 4.1% (odds ratio [95% CLs]: 2.50 [0.76, 8.25], P=0.133) for pemetrexed and docetaxel, respectively. Pemetrexed-treated patients had significantly fewer drug-related grade 3-4 adverse events (pemetrexed: 20.8%, docetaxel: 40.2%; P=0.003). Few drug-related serious adverse events were reported (pemetrexed: 5 patients, docetaxel: 8 patients).

CONCLUSION

The comparable efficacy and superior tolerability of pemetrexed compared with docetaxel in this study supports the use of single-agent, second-line pemetrexed for advanced non-squamous NSCLC in Chinese patients. ClinicalTrials.gov: NCT00391274.

High expression of folate receptor alpha in lung cancer correlates with adenocarcinoma histology and EGFR [corrected] mutation

INTRODUCTION

Folate receptor alpha (FRα) and reduced folate carrier-1 (RFC1) regulate uptake of folate molecules inside the cell. FRα is a potential biomarker of tumors response to antifolate chemotherapy, and a target for therapies using humanized monocloncal antibody. Information on the protein expression of these receptors in non-small-cell lung carcinoma (NSCLC) is limited.

MATERIAL AND METHODS

Expressions of FRα and RFC1 were examined by immunohistochemistry (IHC) in 320 surgically resected NSCLC (202 adenocarcinomas and 118 squamous cell carcinomas) tissue specimens and correlated with patients' clinico-pathologic characteristics. Folate receptor α gene (FOLR1) mRNA expression was examined using publicly available microarray datasets. FRα expression was correlated with thymidylate synthase and p53 expression in NSCLCs, and with epidermal growth factor receptor (EGFR) and V-Ki-ras2 Kirsten rat sarcoma viral (KRAS) gene mutations in adenocarcinomas.

RESULTS

NSCLC overexpressed FRα and RFC1. In a multivariate analysis, lung adenocarcinomas were more likely to express FRα in the cytoplasm (OR = 4.39; p < 0.0001) and membrane (OR = 5.34; p < 0.0001) of malignant cells than squamous cell carcinomas. Tumors from never-smokers were more likely to express cytoplasmic (OR = 3.35; p<0.03) and membrane (OR = 3.60; p=0.0005) FRα than those from smokers. In adenocarcinoma, EGFR mutations correlated with higher expression of membrane FRα and FOLR1 gene expressions. High levels of FRα expression was detected in 42 NSCLC advanced metastatic tumor tissues.

CONCLUSIONS

FRα and RFC1 proteins are overexpressed in NSCLC tumor tissues. The high levels of FRα in lung adenocarcinomas may be associated to these tumors' better responses to antifolate chemotherapy and represents a potential novel target for this tumor type.

Pemetrexed plus platinum as the first-line treatment option for advanced non-small cell lung cancer: a meta-analysis of randomized controlled trials

To compare the efficacy and toxicities of pemetrexed plus platinum with other platinum regimens in patients with previously untreated advanced non-small cell lung cancer (NSCLC). Methods: A meta-analysis was performed using trials identified through PubMed, EMBASE, and Cochrane databases. Two investigators independently assessed the quality of the trials and extracted data. The outcomes included overall survival (OS), progression-free survival (PFS), response rate (RR), and different types of toxicity. Hazard ratios (HRs), odds ratios (ORs) and their 95% confidence intervals (CIs) were pooled using RevMan software. Results: Four trials involving 2,518 patients with previously untreated advanced NSCLC met the inclusion criteria. Pemetrexed plus platinum chemotherapy (PPC) improved survival compared with other platinum-based regimens (PBR) in patients with advanced NSCLC (HR = 0.91, 95% CI: 0.83–1.00, p = 0.04), especially in those with non-squamous histology (HR = 0.87, 95% CI: 0.77–0.98, p = 0.02). No statistically significant improvement in either PFS or RR was found in PPC group as compared with PBR group (HR = 1.03, 95% CI: 0.94–1.13, p = 0.57; OR = 1.15, 95% CI: 0.95–1.39, p = 0.15, respectively). Compared with PBR, PPC led to less grade 3–4 neutropenia and leukopenia but more grade 3–4 nausea. However, hematological toxicity analysis revealed significant heterogeneities. Conclusion: Our results suggest that PPC in the first-line setting leads to a significant survival advantage with acceptable toxicities for advanced NSCLC patients, especially those with non-squamous histology, as compared with other PRB. PPC could be considered as the first-line treatment option for advanced NSCLC patients, especially those with non-squamous histology.

Inhibition of dUTPase induces synthetic lethality with thymidylate synthase-targeted therapies in non-small cell lung cancer

Chemotherapies that target thymidylate synthase (TS) continue to see considerable clinical expansion in non-small cell lung cancer (NSCLC). One drawback to TS-targeted therapies is drug resistance and subsequent treatment failure. Novel therapeutic and biomarker-driven strategies are urgently needed. The enzyme deoxyuridine triphosphate nucleotidohydrolase (dUTPase) is reported to protect tumor cells from aberrant misincorporation of uracil during TS inhibition. The goal of this study was to investigate the expression and significance of dUTPase in mediating response to TS-targeted agents in NSCLC. The expression of dUTPase in NSCLC cell lines and clinical specimens was measured by quantitative real-time reverse transcriptase PCR and immunohistochemistry. Using a validated RNA interference approach, dUTPase was effectively silenced in a panel of NSCLC cell lines and response to the fluoropyrimidine fluorodeoxyuridine (FUdR) and the antifolate pemetrexed was analyzed using growth inhibition and clonogenic assays. Apoptosis was analyzed by flow cytometry. Significant variation in the quantity and cellular expression of dUTPase was observed, including clear evidence of overexpression in NSCLC cell line models and tumor specimens at the mRNA and protein level. RNA interference-mediated silencing of dUTPase significantly sensitized NSCLC cells to growth inhibition induced by FUdR and pemetrexed. This sensitization was accompanied by a significant expansion of intracellular dUTP pools and significant decreases in NSCLC cell viability evaluated by clonogenicity and apoptotic analyses. Together, these results strongly suggest that uracil misincorporation is a potent determinant of cytotoxicity to TS inhibition in NSCLC and that inhibition of dUTPase is a mechanism-based therapeutic approach to significantly enhance the efficacy of TS-targeted chemotherapeutic agents.

Preclinical evaluation of pemetrexed in pediatric solid tumors

Renewed interest in antifols for the treatment of childhood cancers has resulted from identification of novel antifols with broad spectrums of anti-cancer activity. We evaluated the in vitro cytotoxicity of methotrexate and pemetrexed in a panel of 12 pediatric solid tumor cell lines using the sulforhodamine-B assay. The Ewing sarcoma (ES) cell lines demonstrated the greatest sensitivity to both methotrexate and pemetrexed. Expression of folate pathway genes (DHFR, TS, GARFT, GGH) did not correlate with in vitro drug sensitivity. Further evaluation of pemetrexed for the treatment of ES is warranted.

Customizing systemic therapy in patients with advanced non-small cell lung cancer

Lung cancer is the leading cause of cancer deaths worldwide. Standard chemotherapy has been shown to improve quality of life and has a modest influence on overall survival. This modest improvement in survival is partly due to the choice of chemotherapy regimens that have been based on prognostic factors such as age, performance status and comorbidities of the patient. This underlines the importance of developing a more personalized therapy for patients with non-small cell lung cancer. Such an approach may reduce the variation in how individual patients respond to medications by tailoring therapies to their genetic profile. In this review we focus on several aspects of customized therapy, looking not only at patient characteristics but also to tumor histology and specific tumor biomarkers.

Revisiting cutaneous adverse reactions to pemetrexed

Pemetrexed (Alimta®) is a multitargeted antifolate drug approved as a single agent or in combination with cisplatin for the treatment of a small number of malignancies including advanced and metastatic non-squamous non-small cell lung cancer (NSCLC), and malignant pleural mesothelioma. This review reports the recent peer-reviewed publications and original findings regarding cutaneous adverse reactions (CARs) to pemetrexed. Pemetrexed-related CARs are frequently reported under the unspecific term 'skin rash'. However, more specific diseases were tentatively identified as alopecias, urticarial vasculitis, acute generalized exanthematous pustulosis, toxic epidermal necrolysis, radiation recall dermatitis and pityriasis lichenoides. Most of the skin reactions occur shortly after pemetrexed administration. As with methotrexate-related CARs, the cell cycle arrest in the S phase may be regarded as a direct and major cause of the cytotoxic pathobiology. An adverse immune reaction is unlikely. In conclusion, pemetrexed is responsible for CARs exhibiting a variety of clinical presentations. Their origin is likely attributed to direct cytotoxicity following the cell cycle arrest in the S phase and cell necrosis.

Emerging treatment options in the management of non-small cell lung cancer

Lung cancer (LC) has become the leading cancer-related cause of death in the US and in developed European countries in the last decade. Its incidence is still growing in females and in smokers. Surgery remains the treatment of choice whenever feasible, but unfortunately, many patients have an advanced LC at presentation and one-third of potentially operable patients do not receive a tumor resection because of their low compliance for intervention due to their compromised cardiopulmonary functions and other comorbidities. For these patients the alternative therapeutic options are stereotactic radiotherapy or percutaneous radiofrequency. When surgery is planned, an anatomical resection (segmentectomy, lobectomy, bilobectomy, pneumonectomy, sleeve lobectomy) is usually performed; wedge resection (considered as a nonanatomical one) is generally the accepted option for unfit patients. The recent increase in discovering small and peripheral LCs and/or ground-glass opacities with screening programs has dramatically increased surgeons' interest in limited resections. The role of these resections is discussed. Also, recent improvements in molecular biology techniques have increased the chemotherapic options for neoadjuvant LC treatment. The role and the importance of targeted chemotherapy is also discussed.

ABCC11/MRP8 confers pemetrexed resistance in lung cancer

We have previously shown that overexpression of thymidylate synthetase (TS) resulted in pemetrexed (MTA) resistance. To investigate another mechanism of MTA resistance, we investigated the expression of ATP-binding cassette (ABC)-transporters in MTA-resistant lung cancer cell lines and found that the gene and protein expression of ABCC11/MRP8 (ABCC11) was higher in MTA-resistant cells than in the parental cells. The MTA resistant cells showed cross-resistance to methotrexate (MTX), which is a substrate for ABCC11, and intracellular MTX accumulation in MTA-resistant cells was lower than in the parental cells. We then tested the effect of decreasing the expression of ABCC11 by siRNA and found that decreased expression of ABCC11 enhanced MTA cytotoxicity and increased intracellular MTX accumulation in MTA-resistant cells. These findings suggested that ABCC11 directly confers resistance to MTA by enhancing efflux of the intracellular anti-cancer drug. Next, we analyzed the relationship between ABCC11 gene expression and MTA sensitivity of 13 adenocarcinoma cells, but there was no correlation. The ABCC11 gene has been shown to have a functional single-nucleotide polymorphism (SNP), 538G>A. We then classified 13 lung adenocarcinoma cell lines into three groups based on the genotype of this ABCC11 SNP: G/G, G/A and A/A. The A/A group showed a significant reduction in the IC(50) of MTA compared with the combined G/G and G/A groups, indicating that the SNP (538G>A) in the ABCC11 gene is an important determinant of MTA sensitivity. These results showed that ABCC11 may be one of the biomarkers for MTA treatment in adenocarcinomas.

New therapies in soft tissue sarcoma

IMPORTANCE OF THE FIELD

Soft tissue sarcomas are rare mesenchymal tumors accounting for < 1% of all adult neoplasia. In the last decade, locally advanced and metastatic soft tissue sarcoma have been managed only through surgery, radiotherapy and standard chemotherapy (mainly based on anthracycline and ifosfamide). Despite the efforts, overall 5-year survival rate in patients with soft tissue sarcomas of all stages remains only 50 - 60%.

AREAS COVERED IN THIS REVIEW

In the present article, all the main new molecules under clinical evaluation for the treatment of soft tissue sarcoma are revised by describing the mechanism of action, the biological rationale of their use in sarcoma and by reporting the available data about safety and efficacy, up to 2009.

WHAT THE READER WILL GAIN

A brief summary of the standard treatments available at the moment and a complete analysis of the state of art about the development of new target therapies in the management of soft tissue sarcoma.

TAKE HOME MESSAGE

The identification of new biological therapies that target soft tissue sarcoma tumorigenesis key points seems to offer a real opportunity of improving the prognosis of this often aggressive disease. In this sense, the best management for soft tissue sarcoma patients is in a clinical trial and participation in clinical trials should be encouraged.

Carboplatin/pemetrexed/bevacizumab in the treatment of patients with advanced non-small-cell lung cancer: a single-institution experience

PURPOSE

The purpose of this study was to determine the efficacy and tolerability of carboplatin, pemetrexed, and bevacizumab in patients with advanced, nonsquamous non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

The charts of consecutive patients with stage IIIB/IV nonsquamous NSCLC were reviewed. All patients receiving at least 1 cycle of the 3-drug regimen (pemetrexed 500 mg/m2, carboplatin area under the curve of 5-6, bevacizumab 15 mg/kg intravenously), were included for assessment of response, safety, and toxicity.

RESULTS

A total of 27 patients received this regimen between February 2008 and July 2009; 63% were women. Median follow-up was 6.3 months (range, 1.6-21.1 months). Median number of cycles was 6 (range, 1-6 cycles); 67% completed 6 cycles; 83% went on to receive maintenance bevacizumab/pemetrexed. Among those who received maintenance, the median number of cycles administered was 4.5 (range, 1-18 cycles). Response rate was 52%; stable disease was observed in another 40%. On the basis of Kaplan-Meier analysis, actuarial overall survival was 83% at 12 months; actuarial progression-free survival was 83% and 63% at 6 and 12 months, respectively. Clinical improvement was noted in 41% of the patients, with clinical stability in another 48%. Grade 2 and 3 toxicities from the regimen included anemia (11% and 15%), fatigue (37% and 7.4%), febrile neutropenia (7.4%; grade 3 only), thrombocytopenia (7.4% and 0), and thromboembolic disorders (3.7% and 3.7%). Bevacizumab-induced side effects (any grade) included headaches (22.2%), epistaxis (30%), hemoptysis (3.7%), and hypertension (11%). No grade 4 or 5 toxicities were seen.

CONCLUSION

Combination carboplatin/pemetrexed and bevacizumab followed by maintenance therapy with pemetrexed/bevacizumab is effective, with response rates > 50%, acceptable toxicity, and promising early survival in patients with advanced nonsquamous NSCLC.