The Toxicity Profile of Pemetrexed in Non-Small Cell Lung Cancer Patients With Moderate Renal Impairment: A Retrospective Cohort Study

PURPOSE

Pemetrexed is a key drug in the immunochemotherapy of non-small cell lung cancer (NSCLC). However, its use is contraindicated in patients with renal impairment due to severe toxicity risks. As renal impairment is common in lung cancer patients, healthcare professionals face a dilemma between withholding effective treatment and risking toxicity. Real-world data on pemetrexed toxicity may aid in this decision. The primary objective of this study was to describe the toxicity profile of pemetrexed treatment in NSCLC patients with renal impairment.

PATIENTS AND METHODS

This multicenter, descriptive, retrospective study was conducted across 9 hospitals in the Netherlands between 2015 and 2024. Patients included had a diagnosis of NSCLC, received ≥ 1 cycle of standard dose pemetrexed, and had a baseline creatinine clearance (CrCL)<45 mL/min. Data were collected on patient and treatment characteristics, hematological and nonhematological toxicity incidences, treatment discontinuation, dose reduction, and treatment-related hospitalization.

RESULTS

Forty-four patients were included, with median CrCL 41.1 mL/min (interquartile range: 35.0-43.9). Thirty-one patients (70%) did not finish 4 cycles of pemetrexed treatment, with 14 patients (45%) discontinuing due to pemetrexed-associated toxicity. More than half of patients (n = 28; 64%) were hospitalized due to treatment-related toxicity. Seventeen patients (39%) developed grade 3-4 neutropenia and leukopenia. Gastro-intestinal toxicity grade 3 to 4 occurred in fifteen (34%) patients.

CONCLUSION

Pemetrexed treatment of NSCLC patients with moderate renal impairment was associated with high incidence of hematological toxicity, hospitalization, dose reduction, and treatment discontinuation. These results highlight the necessity of developing new treatment regimens to enable safe pemetrexed-based immunochemotherapy in NSCLC patients with renal impairment.

Evaluation of UCP1162, a potent propargyl-linked inhibitor of dihydrofolate reductase with potential application to cancer and autoimmune disease

Cellular resistance can limit the effectiveness of antifolate drugs for the treatment of cancer and autoimmune diseases. We examined the biochemical and cellular effects of a propargyl linked, non-classical antifolate UCP1162 that shows exceptional potency and resilience in the background of methotrexate resistance. UCP1162 inhibited the human DHFR enzyme with affinity and kinetics comparable to methotrexate (MTX). UCP1162 also inhibited cancer cell proliferation and bound cellular DHFR at low nanomolar concentrations. Leucovorin suppressed the cellular effects of UCP1162, consistent with UCP1162 working as an antifolate. Like other antifolates, UCP1162 reduced acute inflammation in mice and inhibited FLS cell growth and motility. Single cell RNA-seq showed that MTX and UCP1162 generated overlapping gene expression changes after a 48-hour exposure. However, while leukemia cells (CCRF-CEM) resistant to MTX could be readily selected, UCP1162-resistant cells could not be obtained. Long-term exposure to UCP1162 resulted in static culture expressing stem cell genes (CD34, ABCG2, ABCB1), adaptive genes (TCN2, CDKN1A), and genes that might serve as therapeutic targets (TPBG/5T4, TNFRSF10A, ACE). These findings suggest that UCP1162 is a unique tool for studying cellular responses to long-term antifolate treatment and holds promise as a lead compound capable of overcoming some forms of antifolate resistance.

Chemotherapy-induced acute kidney injury: epidemiology, pathophysiology, and therapeutic approaches

Despite significant advancements in oncology, conventional chemotherapy remains the primary treatment for diverse malignancies. Acute kidney injury (AKI) stands out as one of the most prevalent and severe adverse effects associated with these cytotoxic agents. While platinum compounds are well-known for their nephrotoxic potential, other drugs including antimetabolites, alkylating agents, and antitumor antibiotics are also associated. The onset of AKI poses substantial risks, including heightened morbidity and mortality rates, prolonged hospital stays, treatment interruptions, and the need for renal replacement therapy, all of which impede optimal patient care. Various proactive measures, such as aggressive hydration and diuresis, have been identified as potential strategies to mitigate AKI; however, preventing its occurrence during chemotherapy remains challenging. Additionally, several factors, including intravascular volume depletion, sepsis, exposure to other nephrotoxic agents, tumor lysis syndrome, and direct damage from cancer's pathophysiology, frequently contribute to or exacerbate kidney injury. This article aims to comprehensively review the epidemiology, mechanisms of injury, diagnosis, treatment options, and prevention strategies for AKI induced by conventional chemotherapy.

Metabolomic Approach to Identify Potential Biomarkers in KRAS-Mutant Pancreatic Cancer Cells

Pancreatic cancer is characterized by its high mortality rate and limited treatment options, often driven by oncogenic RAS mutations. In this study, we investigated the metabolomic profiles of pancreatic cancer cells based on their KRAS genetic status. Utilizing both KRAS-wildtype BxPC3 and KRAS-mutant PANC1 cell lines, we identified 195 metabolites differentially altered by KRAS status through untargeted metabolomics. Principal component analysis and hierarchical condition trees revealed distinct separation between KRAS-wildtype and KRAS-mutant cells. Metabolite set enrichment analysis highlighted significant pathways such as homocysteine degradation and taurine and hypotaurine metabolism. Additionally, lipid enrichment analysis identified pathways including fatty acyl glycosides and sphingoid bases. Mapping of identified metabolites to KEGG pathways identified nine significant metabolic pathways associated with KRAS status, indicating diverse metabolic alterations in pancreatic cancer cells. Furthermore, we explored the impact of TRPML1 inhibition on the metabolomic profile of KRAS-mutant pancreatic cancer cells. TRPML1 inhibition using ML-SI1 significantly altered the metabolomic profile, leading to distinct separation between vehicle-treated and ML-SI1-treated PANC1 cells. Metabolite set enrichment analysis revealed enriched pathways such as arginine and proline metabolism, and mapping to KEGG pathways identified 17 significant metabolic pathways associated with TRPML1 inhibition. Interestingly, some metabolites identified in PANC1 compared to BxPC3 were oppositely regulated by TRPML1 inhibition, suggesting their potential as biomarkers for KRAS-mutant cancer cells. Overall, our findings shed light on the distinct metabolite changes induced by both KRAS status and TRPML1 inhibition in pancreatic cancer cells, providing insights into potential therapeutic targets and biomarkers for this deadly disease.

Pyrrole-based EGFR inhibitors for the treatment of NCSLC: Binding modes and SARs investigations

The treatment of advanced non-small cell lung cancer (NSCLC) has made substantial progress due to the rapid development of small molecule targeted therapy, with dramatically prolonged survival. As an effective drug for the treatment of NSCLC, epidermal growth factor receptor (EGFR) inhibitors are currently experiencing issues like severe adverse events and drug resistance. It is urgent to develop novel types of EGFR inhibitors to overcome the abovementioned limitations. Pyrrole always works well as a probe for the creation of novel medication candidates for hard-to-treat conditions like lung cancer. Although the design, synthesis, and biological assays of pyrrole derivatives have been reported, their inhibitory actions against the receptor tyrosine kinase (RTK) EGFR have not been in-depthly studied. This review highlights the small molecule EGFR inhibitors containing pyrrole heterocyclic pharmacophores in recent years, and the research on their mechanism, biological activity, and structure-activity relationship (SAR).

Predictive markers for efficiency of the amino-acid deprivation therapies in cancer

Amino acid deprivation therapy (AADT) is a promising strategy for developing novel anticancer treatments, based on variations in metabolism of healthy and malignant cells. L-asparaginase was the first amino acid-degrading enzyme that received FDA approval for the treatment of acute lymphoblastic leukemia (ALL). Arginase and arginine deiminase were effective in clinical trials for the treatment of metastatic melanomas and hepatocellular carcinomas. Essential dependence of certain cancer cells on methionine explains the anticancer efficacy of methionine-g-lyase. Along with significant progress in identification of metabolic vulnerabilities of cancer cells, new amino acid-cleaving enzymes appear as promising agents for cancer treatment: lysine oxidase, tyrosine phenol-lyase, cysteinase, and phenylalanine ammonia-lyase. However, sensitivity of specific cancer cell types to these enzymes differs. Hence, search for prognostic and predictive markers for AADT and introduction of the markers into clinical practice are of great importance for translational medicine. As specific metabolic pathways in cancer cells are determined by the enzyme expression, some of these enzymes may define the sensitivity to AADT. This review considers the known predictors for efficiency of AADT, emphasizing the importance of knowledge on cancer-specific amino acid significance for such predictions.

Methionine synthase is essential for cancer cell proliferation in physiological folate environments

Folate metabolism can be an effective target for cancer treatment. However, standard cell culture conditions utilize folic acid, a non-physiological folate source for most tissues. We find that the enzyme that couples folate and methionine metabolic cycles, methionine synthase, is required for cancer cell proliferation and tumour growth when 5-methyl tetrahydrofolate (THF), the major folate found in circulation, is the extracellular folate source. In such physiological conditions, methionine synthase incorporates 5-methyl THF into the folate cycle to maintain intracellular levels of the folates needed for nucleotide production. 5-methyl THF can sustain intracellular folate metabolism in the absence of folic acid. Therefore, cells exposed to 5-methyl THF are more resistant to methotrexate, an antifolate drug that specifically blocks folic acid incorporation into the folate cycle. Together, these data argue that the environmental folate source has a profound effect on folate metabolism, determining how both folate cycle enzymes and antifolate drugs impact proliferation.

Identification of proteins related with pemetrexed resistance by iTRAQ and PRM-based comparative proteomic analysis and exploration of IGF2BP2 and FOLR1 functions in non-small cell lung cancer cells

Pemetrexed (PEM), a multi-target folate antagonist, has been extensively used for the treatment of non-small cell lung cancer (NSCLC). However, the therapeutic efficacy of PEM is limited by tumor resistance. In this project, iTRAQ and parallel reaction monitoring (PRM)-based LC-MS/MS comparative proteomic analysis was performed to identify protein determinants of PEM resistance in A549/PEM cells versus A549 parental cells. A total of 567 differentially expressed proteins (DEPs) were identified by iTRAQ analysis. The function and classification of DEPs were analyzed through GO and KEGG Pathway databases. Moreover, PRM analysis further validated the expression changes of 14 DEPs identified by iTRAQ analysis. Moreover, insulin-like growth factor (IGF) 2 mRNA-binding protein 2 (IGF2BP2) or folate receptor alpha (FOLR1) knockdown weakened PEM resistance, reduced cell viability and promoted cell apoptosis in A549/PEM cells. IGF2BP2 depletion inhibited cell migration, invasion and epithelial-mesenchymal transition (EMT), while FOLR1 loss had no much effect on cell migration, invasion and EMT in A549/PEM cells. Our study can provide a deep insight into molecular mechanisms of PEM resistance in NSCLC and contribute to the development of more effective therapeutic schedules. SIGNIFICANCE: Our study can provide deeper insight into molecular mechanisms of PEM resistance in NSCLC and contribute to the development of more effective therapeutic schedules.

Cumulative pemetrexed dose increases the risk of nephrotoxicity

INTRODUCTION

Pemetrexed is a pharmacotherapeutic cornerstone in the treatment of non-small cell lung cancer. As it is primarily eliminated by renal excretion, adequate renal function is essential to prevent toxic exposure. There is growing evidence for the nephrotoxic potential of pemetrexed, which even becomes a greater issue now combined immuno-chemotherapy prolongs survival. Therefore, the aim of this study was to describe the incidence of nephrotoxicity and related treatment consequences during pemetrexed-based treatment.

METHODS

A retrospective cohort study was conducted in the Jeroen Bosch Hospital, Den Bosch, the Netherlands. All patients that received at least 1 cycle of pemetrexed based therapy were included in the dataset. The primary outcome was defined as a ≥25 % reduction in eGFR. Additionally, the treatment consequences of decreased renal function were assessed. Logistic regression was used to identify risk factors for nephrotoxicity during treatment with pemetrexed.

RESULTS

Of the 359 patients included in this analysis, 21 % patients had a clinically relevant decline in renal function after treatment and 8.1 % of patients discontinued treatment due to nephrotoxicity. Cumulative dose (≥10 cycles of pemetrexed based therapy) was identified as a risk factor for the primary outcome measure (adjusted OR 5.66 (CI 1.73-18.54)).

CONCLUSION

This study shows that patients on pemetrexed-based treatment are at risk of developing renal impairment. Risk significantly increases with prolonged treatment. Renal impairment is expected to become an even greater issue now that pemetrexed-based immuno-chemotherapy results in longer survival and thus longer treatment duration.

A limited sampling schedule to estimate individual pharmacokinetics of pemetrexed in patients with varying renal functions

Purpose

Pemetrexed is a widely used cytostatic agent with an established exposure–response relationship. Although dosing is based on body surface area (BSA), large interindividual variability in pemetrexed plasma concentrations is observed. Therapeutic drug monitoring (TDM) can be a feasible strategy to reduce variability in specific cases leading to potentially optimized pemetrexed treatment. The aim of this study was to develop a limited sampling schedule (LSS) for the assessment of pemetrexed pharmacokinetics.

Methods

Based on two real-life datasets, several limited sampling designs were evaluated on predicting clearance, using NONMEM, based on mean prediction error (MPE %) and normalized root mean squared error (NRMSE %). The predefined criteria for an acceptable LSS were: a maximum of four sampling time points within 8 h with an MPE and NRMSE ≤ 20%.

Results

For an accurate estimation of clearance, only four samples in a convenient window of 8 h were required for accurate and precise prediction (MPE and NRMSE of 3.6% and 5.7% for dataset 1 and of 15.5% and 16.5% for dataset 2). A single sample at t = 24 h performed also within the criteria with MPE and NRMSE of 5.8% and 8.7% for dataset 1 and of 11.5% and 16.4% for dataset 2. Bias increased when patients had lower creatinine clearance.

Conclusions

We presented two limited sampling designs for estimation of pemetrexed pharmacokinetics. Either one can be used based on preference and feasibility.

Afatinib Overcomes Pemetrexed-Acquired Resistance in Non-Small Cell Lung Cancer Cells Harboring an EML4-ALK Rearrangement

Background: The aim of this study is to elucidate the mechanisms of acquired resistance to pemetrexed in echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) rearranged non-small cell lung cancer. Methods: We analyzed the sensitivity to pemetrexed and the expression patterns of various proteins after pemetrexed treatment in the cell lines, A549, NCI-H460, NCI-H2228 harboring EML4-ALK variant 3, and NCI-H3122 harboring EML4-ALK variant 1. Pemetrexed-resistant cell lines were also generated through long-term exposure to pemetrexed. Results: The EML4-ALK variant 1 rearranged NCI-H3122 was found to be more sensitive than the other cell lines. Cell cycle analysis after pemetrexed treatment showed that the fraction of cells in the S phase increased in A549, NCI-H460, and NCI-H2228, whereas the fraction in the apoptotic sub-G₁ phase increased in NCI-H3122. The pemetrexed-resistant NCI-H3122 cell line showed increased expression of EGFR and HER2 compared to the parent cell line, whereas A549 and NCI-H460 did not show this change. The pan-HER inhibitor afatinib inhibited this alternative signaling pathway, resulting in a superior cytotoxic effect in pemetrexed-resistant NCI-H3122 cell lines compared to that in the parental cells line. Conclusion: The activation of EGFR-HER2 contributes to the acquisition of resistance to pemetrexed in EML4-ALK rearranged non-small cell lung cancer. However, the inhibition of this alternative survival signaling pathway with RNAi against EGFR-HER2 and with afatinib overcomes this resistance.

Simple and Rapid Quantification of the Multi-Enzyme Targeting Antifolate Pemetrexed in Human Plasma

BACKGROUND

Pemetrexed is an antifolate cytostatic drug that targets multiple enzymes involved in folate biosynthesis and is indicated for treatment of non-small-cell lung cancer and malignant pleural mesothelioma. As evidence for an exposure-response/toxicity relationship is accumulating, dose individualization using therapeutic drug monitoring may be a feasible strategy to optimize treatment. The purpose of this study was to develop a simple, sensitive, high-performance liquid chromatography method with UV detection for quantification of pemetrexed levels in human plasma.

METHOD

The method involves a simple protein precipitation, followed by ultra-performance liquid chromatography with ultraviolet detection at a wavelength of 254 nm. Pemetrexed was separated using a mobile phase with a linear gradient and a run time of only 7 minutes.

RESULTS

The assay has been validated over the concentration range 0.25-500 mg/L of pemetrexed. Accuracy for this assay ranged from -4.50% to 1.78%, and the within- and between-run coefficients of variation were <3.57%. Pemetrexed in plasma was proven to be stable for 8 months at -40°C.

CONCLUSIONS

The bioanalytical method we developed proved to be simple, accurate, precise, and fast. This analytical method is successfully in use for therapeutic drug monitoring and will be used for pharmacokinetic studies.

Interplay of non-coding RNAs and approved antimetabolites such as gemcitabine and pemetrexed in mesothelioma

Gemcitabine and pemetrexed are clinically approved antimetabolites for the therapy of mesothelioma diseases. These drugs are often applied in combination with platinum complexes and other drugs. The activity of antimetabolites depended on the expression levels of certain non-coding RNAs, in particular, of small microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). The development of tumor resistance towards antimetabolites was regulated by non-coding RNAs. An overview of the interplay between gemcitabine/pemetrexed antimetabolites and non-coding RNAs in mesothelioma is provided. Further to this, various non-coding RNA-modulating agents are discussed which displayed positive effects on gemcitabine or pemetrexed treatment of mesothelioma diseases. A detailed knowledge of the connections of non-coding RNAs with antimetabolites will be constructive for the design of improved therapies in future.

Efficacy and safety of pemetrexed and nedaplatin followed by pemetrexed maintenance therapy in advanced lung adenocarcinoma

Objective

To evaluate the efficacy and safety of pemetrexed and nedaplatin followed by pemetrexed maintenance therapy in advanced lung adenocarcinoma.

Methods

A total of 53 advanced lung adenocarcinoma patients hospitalized between July 2013 and June 2016 with a performance status ≤2 were enrolled in this study. All patients received 4-6 cycles of combination chemotherapy comprising pemetrexed (500 mg/m² dL) and nedaplatin (80 mg/m² dL). Each chemotherapy cycle consisted of 21 days. After the efficacy of the combination chemotherapy was assessed, patients with stable disease, partial remission, or complete remission received pemetrexed maintenance therapy (500 mg/m² dL) until disease progression or intolerable side effects occurred. Each pemetrexed maintenance therapy cycle was 28 days.

Results

After completion of the pemetrexed and nedaplatin combination chemotherapy, 26 (49.1%), 15 (28.3%), and 12 (22.6%) patients exhibited partial remission, stable disease, and progressive disease, respectively. Complete remission was not achieved in any patient. Therefore, the response and disease control percentages were 49.1% and 77.4%, respectively. A total of 38 patients were further administered pemetrexed maintenance chemotherapy for an average of 9.8 cycles. The median progression-free survival and overall survival of the 38 patients receiving the pemetrexed maintenance therapy were 9.3 (95% confidence interval: 8.6-10) months and 16.3 (95% confidence interval: 14.5-18.2) months, respectively. The major adverse effects included bone marrow suppression and gastrointestinal reactions, which were well tolerated.

Conclusions

Combination chemotherapy based on pemetrexed and nedaplatin is effective for the treatment of advanced lung adenocarcinoma with a high tolerance by patients. In addition, pemetrexed maintenance therapy of advanced lung adenocarcinoma is safe and effective for the treatment of advanced lung adenocarcinoma following pemetrexed and nedaplatin combination chemotherapy.

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.

Best Practices in Treatment Selection for Patients With Advanced NSCLC

Worldwide, lung cancer is the most prevalent form of cancer, and its non-small-cell subtype constitutes up to 85% of cases. Overall, lung cancer is the most common cause of cancer-related death in the United States for both sexes, and its 5-year survival rate is 17%. It is a heterogeneous disease characterized by a variety of biomarkers and differing histologies. Non-small-cell lung cancer may be squamous or nonsquamous in nature and fueled by a number of oncodrivers. Obtaining sufficient tissue during biopsy to perform thorough biomarker testing is a challenge but essential for the modern, targeted therapeutic environment. Although platinum-based doublets still play a major role in first-line treatment, novel therapeutic agent targeting BRAF, EGFR, ALK, and ROS1, as well as agents targeting the T790M mutation, may offer options for patients whose disease fails to respond to initial therapy or relapses following an initial response. The emergence of immunotherapy as second-line standard therapy has changed the treatment paradigm. Some patients will have more favorable outcomes in the first-line setting with immunotherapy. However, managing lung cancer has become more complex than it was 15 years ago when the challenge of treatment was seen as being only binary, ie, small-cell vs non-small-cell disease.

Hapten-enhanced therapeutic effect in advanced stages of lung cancer by ultra-minimum incision personalized intratumoral chemoimmunotherapy therapy

Aim

The objective of the study reported here was to evaluate the therapeutic effects of hapten-enhanced chemoimmunotherapy in the treatment of advanced lung cancer by ultra-minimum incision personalized intratumoral chemoimmunotherapy (UMIPIC) and to analyze the effect of this immune booster.

Materials and methods

A total of 97 patients with advanced lung cancer were treated with UMIPIC or intratumoral chemotherapy (ITCT). UMIPIC was delivered intratumorally in combination with a proprietary therapeutic regimen composed of three components – an oxidant, a cytotoxic drug, and hapten. ITCT applied using the same procedures and regimen, only without hapten. All data from the two groups were reviewed and analyzed. A total of 55 patients were treated with UMIPIC and 42 with ITCT. Patient responses were assessed with computed tomography scan 4–6 weeks after treatment, and all of the patients were followed until their deaths.

Results

Median overall survival was 11.23 months in the UMIPIC (test) group and 5.62 months in the ITCT (control) group (P<0.01). The 6-month and 1-year survival rates of the UMIPIC and ITCT groups were 76.36% versus 45.23% (P<0.01) and 45.45% versus 23.81% (P<0.05), respectively. Two cycles of UMIPIC treatment (n=19) conferred a significant survival benefit compared with two cycles of ITCT (n=29); significant benefits in survival time were also found with UMIPIC (n=20) compared with ITCT (n=13) when both were utilized without adjuvant treatment.

Conclusion

The hapten-enhanced clinical effect of UMIPIC conferred a superior survival time in patients with advanced lung cancer compared with ITCT. The addition of the hapten in UMIPIC demonstrates a significant advantage in terms of prolonged survival time.

Effectiveness and safety of pemetrexed versus docetaxel as a treatment for advanced non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Our aim was to conduct a meta-analysis to compare the efficacy and safety of pemetrexed and docetaxel for non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

We systematically searched the Cochrane Library, PubMed, Embase, China Biology Medicine Database for randomized controlled trials (RCTs) comparing the efficacy and toxicities of pemetrexed versus docetaxel as a treatment for advanced NSCLC. We limited the languages to English and Chinese. Two reviewers independently screened articles to identify eligible trials according to the inclusion and exclusion criteria and assessed the methodological quality of included trials, and then extracted data. The meta-analysis was performed using STATA12.0.

RESULTS

Six RCTs involving 1,414 patients were identified. We found that there was no statistically significant differences in overall response rate, survival time, progression-free survival, disease control rate, and 1-2 yr survival rate (p>0.050) but it is worthy of mention that patients in the pemetrexed arms had significantly higher 3-yr survival rate (P=0.002). With regard to the grade 3 or 4 hematological toxicity, compared with docetaxel, pemetrexed led to lower rate of grade 3-4 febrile neutropenia, neutropenia, and leukocyts toxicity (p<0.001). There was no significant difference in anemia between the two arms (p=0.08). In addition, pemetrexed led to higher rate of grade 3-4 thrombocytopenia toxicity (p=0.03). As for the non-hematological toxicities, compared with docetaxel, pemetrexed group had lower rate of grade 3-4 diarrhea and alopecia.

CONCLUSIONS

Pemetrexed was almost as effective as docetaxel in patients with advanced NSCLC. At the same time, pemetrexed might increase the 3-yr survival rate. As for safety, pemetrexed led to lower rate of grade 3-4 febrile neutropenia, neutropenia, leukocytes, diarrhea and alopecia toxicity. However, it was associated with a higher rate of grade 3-4 thrombocytopenia.

Critical appraisal of pemetrexed in the treatment of NSCLC and metastatic pulmonary nodules

Pemetrexed, a new multitarget antifolate antineoplastic agent, has significantly improved the overall survival in nonsquamous non-small-cell lung cancer patients. Presently, pemetrexed is recommended for first line treatment in combination with platinum derivatives, for second line treatment as a single agent and, more recently, as maintenance treatment after first line chemotherapy. In this article we critically appraise the status of pemetrexed including pharmacodynamics, pharmacokinetics, toxicity, and the cost effectiveness of pemetrexed, as well as the predictive biomarkers for pemetrexed based chemotherapy.

Ethnic differences in non-small-cell lung cancer treatment: the Asian perspective

SUMMARYLung cancer is the leading cause of cancer death worldwide, including Asia. With advances in technology and in understanding the molecular biology of lung cancer, discoveries of genomic abnormalities and druggable targets in non-small-cell lung cancer are rapidly progressing, leading to the development of new targeted agents. Accordingly, the cumulative epidemiologic evidence demonstrates a high possibility of ethnic difference between Asian and Caucasian lung cancer. Additionally, compelling evidence pointing to ethnic and pathologic differences in lung cancer is indicative of differences in treatment and subsequent clinical outcomes. However, given that no data are available for a direct comparison between Asian and Caucasian lung cancer patients in many clinical trials, and only subgroup or post hoc analyses have been performed, we recommend multinational clinical trials in the future with appropriate ethnic stratification in order to improve the representation and enrollment of Asian patients to have adequate statistical power for subgroup analyses.

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.

A randomized, phase 2 study comparing pemetrexed plus best supportive care versus best supportive care as maintenance therapy after first-line treatment with pemetrexed and cisplatin for advanced, non-squamous, non-small cell lung cancer

BACKGROUND

Maintenance therapy for non-small cell lung cancer (NSCLC) aims to extend disease control after first-line chemotherapy with active and well-tolerated agents. The utility of continuation maintenance therapy requires further research.

METHODS

This multicenter, randomized, phase 2 study compared continuation maintenance therapy with pemetrexed (500 mg/m2 every 21 days) and best supportive care (BSC) versus BSC alone in patients with advanced, non-squamous NSCLC who had not progressed after 4 cycles of induction chemotherapy with pemetrexed (500 mg/m2) and cisplatin (75 mg/m2). The primary endpoint was progression-free survival (PFS) from randomization, was analyzed using a Cox model, stratified for the tumor response at the end of induction therapy, at a one-sided alpha of 0.2. Secondary endpoints: response and disease control rates, overall survival (OS), one year survival rates, and treatment-emergent adverse events (TEAEs).

RESULTS

A total of 106 patients commenced induction therapy, of whom 55 patients were randomized to maintenance pemetrexed/BSC (n = 28) or BSC (n = 27). Although the median PFS time for maintenance phase for both arms was 3.2 months, the one-sided p-value for the PFS HR comparison was less than the prespecified limit of 0.2 (HR = 0.76, two-sided 95% confidence interval [CI]: 0.42 to 1.37; one-sided p-value = 0.1815), indicating that PFS was sufficiently long in the pemetrexed/BSC arm to warrant further investigation. Similar PFS results were observed for the overall study period (induction plus maintenance) and when the PFS analysis was adjusted for sex, baseline disease stage, and the ECOG PS prior to randomization. The median OS for the maintenance phase was 12.2 months (95%CI: 5.6 to 20.6) for the pemetrexed/BSC arm and 11.8 months (95% CI: 6.3 to 25.6) for BSC arm. The one-year survival probabilities were similar for both arms for the maintenance phase and the overall study period. Both the induction and continuation maintenance therapies were generally well-tolerated, and similar proportion of patients in each arm experienced at least 1 grade 3/4 TEAE (pemetrexed/BSC, 17.9%; BSC, 18.5%).

CONCLUSIONS

Continuation pemetrexed maintenance therapy resulted in promising PFS with an acceptable safety profile in a Middle Eastern population with advanced non-squamous NSCLC and is worthy of further investigation.

TRIAL REGISTRATION

NCT00606021.

High-resolution structures of Trypanosoma brucei pteridine reductase ligand complexes inform on the placement of new molecular entities in the active site of a potential drug target

Pteridine reductase (PTR1) is a potential target for drug development against parasitic Trypanosoma and Leishmania species. These protozoa cause serious diseases for which current therapies are inadequate. High-resolution structures have been determined, using data between 1.6 and 1.1 Å resolution, of T. brucei PTR1 in complex with pemetrexed, trimetrexate, cyromazine and a 2,4-diaminopyrimidine derivative. The structures provide insight into the interactions formed by new molecular entities in the enzyme active site with ligands that represent lead compounds for structure-based inhibitor development and to support early-stage drug discovery.