Pharmacokinetic evaluation of pemetrexed

Double-dose osimertinib combined with intrathecal injection of pemetrexed improves the efficacy of EGFR-mutant non-small cell lung cancer and leptomeningeal metastasis: case report and literature review

Leptomeningeal metastasis (LM) is a complication of non-small cell lung cancer (NSCLC) characterized by poor prognosis and short survival. A variety of therapeutic approaches have been sought to improve the efficacy of LM. Here we present a clinical case and conduct a literature review to investigate the effectiveness and safety of double-dose osimertinib combined with a pemetrexed intrathecal injection. This is an older man who underwent thoracoscopic pneumonectomy and was diagnosed with stage IIA lung adenocarcinoma with EGFR21 L858R mutation. He experienced thoracic vertebral metastases 33 months postoperatively and received first-line treatment with gefitinib combined with radiotherapy for vertebral metastases. However, the patient developed a grade 3 rash with unacceptable toxicity and his CEA levels were significantly increased 22 months later, leading to a targeted treatment adjustment to 80 mg of osimertinib orally once daily. Four months later, the patient developed LM and osimertinib dosage was increased to 160 mg once daily; however, neurological symptoms did not improve, and cerebrospinal fluid (CSF) tumor cells remained detected. Accordingly, the patient received an intrathecal injection of pemetrexed (dose 30 mg) every 2-3 months, 2-3 times per course (4-6 days each time), and continued to receive a double dose of osimertinib. After three courses of intrathecal chemotherapy, CSF tumor cells were eliminated, and neurological symptoms significantly improved. During the treatment, he experienced a one-degree rash, leukopenia, thrombocytopenia, and fatigue. This patient has been alive and well with disease control for 28 months since the diagnosis of meningeal metastases. Combining double-dose osimertinib and an intrathecal injection of pemetrexed demonstrated therapeutic efficacy and manageable adverse effects in this patient with advanced NSCLC with EGFR-mutant and LM.

Detecting TYMS Tandem Repeat Polymorphism by the PSSD Method Based on Next-generation Sequencing

Background:

Thymidylate Synthase (TS) is an important target for folic acid inhibitors such as pemetrexed, which has considerable effects on the first-line treatment, second-line treatment and maintenance therapy for patients with late-stage Non-Small Cell Lung Cancer (NSCLC). Therefore, detecting mutations in the TYMS gene encoding TS is critical in clinical applications. With the development of Next-Generation Sequencing (NGS) technology, the accuracy of TYMS mutation detection is getting higher and higher. However, traditional methods suffer from false positives and false-negatives caused by factors like limited sequencing read length and sequencing errors.

Objective:

A method was needed to overcome the short sequencing read length and sequencing errors of NGS to make the detection of TYMS more accurate.

Methods:

In this study, we developed a novel method based on "Paired Seed Sequence Distance” (PSSD) to detect the Variable Number of Tandem Repeat (VNTR) mutation for TYMS.

Results:

With the 121 samples validated by sanger, the consistency rate of PSSD method was 85.95% (104/121), higher than the strict matching method (78.51% (95/121)). The consistency rate of the two methods was 89.26% (108/121). We also found that the PSSD method was significantly better than the strict matching method, especially in the 4R typing.

Conclusion:

Our method not only improves the detection rate and accuracy of TYMS VNTR mutations but also avoids problems caused by sequencing errors and limited sequencing length. This method provides a new solution for similar polymorphism analyses and other sequencing analyses.

Haematological toxicity of pemetrexed in patients with metastatic non-squamous non-small cell carcinoma of lung with third-space fluid

BACKGROUND

Pemetrexed was approved by United States Food and Drug Administration (US FDA) in combination with platinum for the treatment of advanced non-squamous non-small cell lung carcinoma (NSCLC) and malignant mesothelioma. Due to the structural similarity with methotrexate, there has been concern about the accumulation of pemetrexed in third space fluid that may result in increased toxicity. Previous small-scale studies have yet to conclusively prove this association.

METHODS

This was a retrospective single-center cohort study conducted in Queen Mary Hospital in Hong Kong. The study included 329 patients with advanced stage non-squamous NSCLC that received first line pemetrexed and platinum. Patients who had non-evacuated third-space fluid, evacuated third-space fluid and without third-space fluid were compared. The primary endpoint was the occurrence of hematological toxicity.

RESULTS

The presence of non-evacuated third-space fluid was shown to be associated with significantly more hematological toxicities, namely grade 3 or above hematological toxicities [Odd ratio (OR) = 2.450, p = 0.002], postponement of chemotherapy (OR = 3.837, p = 0.000) and need for dose adjustment (OR = 2.436, p = 0.022) when compared with those without third-space fluid. For patients with evacuated third-space fluid, these adverse effects were nullified.

CONCLUSIONS

Presence of non-evacuated third-space fluid in patients with advanced non-squamous NSCLC predispose patients to significant hematological toxicity when pemetrexed and platinum chemotherapy is used. Evacuation of third-space fluid should be considered before starting pemetrexed and platinum doublet.

A Pilot Phase 1 Study of Intrathecal Pemetrexed for Refractory Leptomeningeal Metastases From Non-small-cell Lung Cancer

Objectives: We aim to determine the feasibility, safety, maximally tolerated dose (MTD), recommended dose and potential anti-tumor activity of intrathecal pemetrexed (IP).

Materials and Methods: Lung adenocarcinoma patients with recurrent or progressive leptomeningeal metastases (LM) after intrathecal chemotherapy were recruited. IP dose was escalated from 10 mg. A minimum of three patients and a maximum of six were enrolled in each cohort. Schedule protocol was IP twice per week for 2 weeks in induction therapy, followed by once per week for 4 weeks in consolidation therapy. Serial samples of plasma and cerebrospinal fluid (CSF) were obtained for pharmacokinetic studies.

Results: Thirteen patients were enrolled between March 2017 and July 2018. EGFR driver oncogene was identified in most of the patients. Severe adverse events (AEs) were encountered in 31% (4/13) of the cases, including myelosuppression, radiculitis, and elevation of hepatic aminotransferases (EHA). Study protocol was revised due to lethal myelosuppression. Following protocol revision, vitamin B12 and folic acid supplementation was given at the beginning of treatment, and myelosuppression was well-controlled. Dose-limiting toxicities (DLT) were myelosuppression, radiculitis, and EHA. Two patients (2/2) developed dose-limiting myelosuppression at 15 mg level. One patient (1/6) experienced dose-limiting radiculitis and EHA at 10 mg level. MTD was 10 mg. Response rate was 31% (4/13) and disease control rate was 54% (7/13). The drug concentration showed a decreasing trend in serial CSF samples following each IP. After IP, the peak plasma concentration was reached at 4 h in two cases, 6 h in two cases, 9 h in one case, and 12 h in one case, respectively.

Conclusion: Pemetrexed was appropriate for intrathecal administration. IP at 10 mg dose in combination with vitamin supplementation on the schedule of 1–2 times per week showed controllable toxicity and good efficacy. This regimen paves the way for subsequent clinical trial.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier NCT03101579.

The evolving role of pemetrexed disodium for the treatment of non-small cell lung cancer

INTRODUCTION

Non-small cell lung cancer (NSCLC) remains one of the big cancer killers, despite the introduction of a number of approved therapeutics in recent times. Pemetrexed is a multi-target folate inhibitor, which is currently available to patients affected by advanced non-squamous NSCLC in combination with a platinum derivate in first-line therapy and as a single agent in second-line therapy. Areas covered: This review covers presents the use pemetrexed in the management of NSCLC by exploring the data available from clinical trials and meta-analyses. Data from a phase III trial confirmed its role in the first-line setting in combination with immune checkpoint inhibitors (ICIs). Furthermore, data suggested a role for pemetrexed in local and advanced NSCLC. Expert opinion: To date, in spite of the introduction of novel anti-neoplastic agents, pemetrexed still represents a cornerstone in the management of non-squamous NSCLC. Furthermore, recently published data support its role in innovative combinations including together with chemotherapy and immunotherapy.

Evaluation of changes in renal function in PARAMOUNT: a phase III study of maintenance pemetrexed plus best supportive care versus placebo plus best supportive care after induction treatment with pemetrexed plus cisplatin for advanced nonsquamous non-small-cell lung cancer

OBJECTIVES

To assess the effect of long-term pemetrexed maintenance therapy on patients' renal function.

METHODS

In the PARAMOUNT phase III trial (NCT 00789373), pemetrexed was compared with placebo as maintenance treatment in advanced nonsquamous non-small-cell lung cancer patients who completed 4 cycles of pemetrexed plus cisplatin induction therapy. To evaluate changes in renal function during pemetrexed continuation maintenance treatment, we retrospectively analyzed changes in serum creatinine (sCr), treatment-emergent adverse events, dose delays and treatment discontinuations associated with impaired renal function.

RESULTS

Creatinine clearance ≥45 mL/min was required before the start of any cycle. Patients on pemetrexed maintenance had a significantly higher percentage maximum increase in sCr over baseline versus placebo for the range of ≥10% to ≥90% increase (p < .05). The risk of experiencing renal events leading to dose delays and discontinuations was higher with higher increases in sCr but reversible in most patients. sCr increases of ≥30% and ≥40% were associated with gender (female), age (<70 years) and longer exposure to pemetrexed compared with placebo. Sixteen (4%) pemetrexed patients and 1 (1%) placebo patient discontinued treatment due to drug-related renal events; 13/16 (81%) of those pemetrexed patients had sCr increases ≥30% and 7/13 (54%) had pre-existing conditions and/or were receiving nephrotoxic drugs.

CONCLUSIONS

The appearance of renal events leading to dose delays and/or treatment discontinuations was associated with sCr increase of at least 30%. However, it was difficult to identify patients at a higher risk of treatment discontinuation due to a drug-related renal event based only on changes in pre-maintenance laboratory values.

Comparison of open and closed abdomen techniques for the delivery of intraperitoneal pemetrexed using a murine model

BACKGROUND AND OBJECTIVES

Pemetrexed is an appealing agent to use for cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). However, the optimal method of pemetrexed delivery still remains undefined. Using a murine model, we compared the use of open and closed abdomen techniques on the absorption of intraperitoneal (IP) pemetrexed in different compartments.

METHODS

Eleven Sprague-Dawley rats were submitted to a fixed dose of IP pemetrexed (1000 mg/m² ) at a perfusion temperature of 40°C during 25 min according to two techniques: open and closed. At the end of perfusion, samples in different compartments were harvested and the concentrations of pemetrexed were measured by high performance liquid chromatography.

RESULTS

Absorption of IP pemetrexed in portal and systemic blood was significantly higher using the open compared to the closed abdomen technique (93.17 vs 52.50 µg/mL, P < 0.001) and (76.26 vs 51.65 µg/mL, P < 0.001), respectively. No difference was found between the two techniques on the peritoneal tissue concentration of pemetrexed (18.07 vs 19.17 µg/g, P = 0.51).

CONCLUSION

Peritoneal absorption of pemetrexed is not modified by the use of either technique. However, systemic concentrations of pemetrexed increased using the open technique, suggesting it could increase systemic toxicity.

Development and characterization of cationic solid lipid nanoparticles for co-delivery of pemetrexed and miR-21 antisense oligonucleotide to glioblastoma cells

The practical use of solid lipid nanoparticles (SLNs) in research has been highlighted in the literature, but few reports have combined SLNs with miRNA-based therapy and chemotherapy. We aimed to prepare cationic SLNs (cSLNs) to load anti-miR-21 oligonucleotide and pemetrexed for glioblastoma therapy in vitro. cSLNs were employed to encapsulate both pemetrexed and anti-miR-21 by a high-pressure homogenization method, and then the properties of cSLNs were characterized. We studied cellular uptake and cytotoxicity properties of cSLNs in U87MG cells. cSLNs were 124.9 ± 1.6 nm in size and 27.3 ± 1.6 mV in zeta potential with spherical morphology in the TEM image. cSLNs uptake by U87MG cells was increased significantly higher and more effective than free pemetrexed. These findings suggest that cSLNs represent a potential new approach for carrying both pemetrexed and anti-miR-21 for glioblastoma therapy.

Co-delivery of pemetrexed and miR-21 antisense oligonucleotide by lipid-polymer hybrid nanoparticles and effects on glioblastoma cells

Combination therapy using anticancer drugs and nucleic acid is a more promising strategy to overcome multidrug resistance in cancer and to enhance apoptosis. In this study, lipid-polymer hybrid nanoparticles (LPNs), which contain both pemetrexed and miR-21 antisense oligonucleotide (anti-miR-21), have been developed for treatment of glioblastoma, the most aggressive type of brain tumor. Prepared LPNs have been well characterized by particle size distribution and zeta potential measurements, determination of encapsulation efficiency, and in vitro release experiments. Morphology of LPNs was determined by transmission electron microscopy. LPNs had a hydrodynamic size below 100 nm and exhibited sustained release of pemetrexed up to 10 h. Encapsulation of pemetrexed in LPNs increased cellular uptake from 6% to 78%. Results of confocal microscopy analysis have shown that co-delivery of anti-miR-21 significantly improved accumulation of LPNs in the nucleus of U87MG cells. Nevertheless, more effective cytotoxicity results could not be obtained due to low concentration of anti-miR-21, loaded in LPNs. We expect that the effective drug delivery systems can be obtained with higher concentration of anti-miR-21 for the treatment of glioblastoma.

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.

Activity of pemetrexed-based regimen as first-line chemotherapy for advanced non-small cell lung cancer with asymptomatic inoperable brain metastasis: a retrospective study

This retrospective study was conducted to assess the efficacy of combination of pemetrexed and cisplatin/carboplatin as first-line treatment in inoperable and asymptomatic brain metastasis (BM) from non-small cell lung cancer (NSCLC). A total of 30 patients with adenocarcinoma were included. Nine patients had solitary, and 21 patients had multiple BM. At evaluation after two cycles, the complete response (CR) rate, partial response (PR) rate, and stable disease (SD) for brain lesions was 0, 33.3, and 46.7%, respectively. The overall CR, PR, and SD were 0, 23.3, and 46.7%, respectively. The median time to tumour progression of BM (TTP-BM) was 6.0 months (95% CI 4.068-7.932). The median progression-free survival (PFS) and overall survival (OS) were 5.0 months (95% CI 4.197-5.803) and 11.0 months (95% CI 7.398-14.602), respectively. Pemetrexed has comparable activity on brain lesions as on extracranial tumours in advanced lung adenocarcinoma patients with inoperable and asymptomatic BM.

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.

Thymidylate synthase protein expression levels remain stable during paclitaxel and carboplatin treatment in non-small cell lung cancer

BACKGROUND

Thymidylate synthase (TS) is a potential predictive marker for efficacy of treatment with pemetrexed. The current study aimed at investigating whether TS expression changes during non-pemetrexed chemotherapy of non-small cell lung cancer (NSCLC), thus making rebiopsy necessary for deciding on pemetrexed second-line treatment.

MATERIALS AND METHODS

TS immunohistochemístry was performed on biopsies and available resection specimens from 65 NSCLC patients stage T1-3N0-2 treated with preoperative carboplatin and paclitaxel [neoadjuvant chemotherapy (NAC)-group] and from 53 NSCLC patients stage T1-4N0-1 treated with surgery without preceding chemotherapy [operation (OP)-group] that served as controls. The diagnostic biopsies and subsequent resection samples were compared in order to evaluate for change in TS expression in groups treated with and without preoperative chemotherapy.

RESULTS

No statistically significant change in TS expression was observed between diagnostic biopsies and subsequent surgical resections of primary tumors in either the OP-group (p = 0.186) or the NAC-group (p = 0.542). Primary tumors were discordant between diagnostic biopsies and resection specimens when TS expression was dichotomized into high (H score ≥ 150) and low (H score < 150), in 45 and 33% in the OP-group and NAC-group, respectively (p = 0.288). The fraction of tumors which increased (19 vs. 20%; p = 0.900) and decreased (42 vs. 23%; p = 0.095) in TS expression was equal between the OP- and the NAC-group.

CONCLUSION

The discordance observed between paired serial samples likely reflects intratumoral heterogeneity of TS expression and highlights the need of sufficient representative material for TS expression analysis if this biomarker is to be used for treatment selection. TS expression in primary tumors remained unchanged, and new biopsies for deciding on second-line pemetrexed does not seem warranted based on the current results.

Pemetrexed for the treatment of non-small cell lung cancer

INTRODUCTION

Non-small cell lung cancer (NSCLC) is a major cause of cancer-related death worldwide. Although advanced NSCLC is still incurable, various anti-neoplastic agents have become available for the treatment of this disease. Pemetrexed , a multi-target folate antagonist, has improved the survival of non-squamous NSCLC patients. Currently, pemetrexed is approved for first-line treatment in combination with a platinum derivate, for second-line treatment as a single agent and, more recently, as maintenance treatment after first-line chemotherapy.

AREAS COVERED

The authors analyzed the state of the art of pemetrexed through a review of the literature. Clinical trials and meta-analyses involving pemetrexed in NSCLC were evaluated. Pemetrexed improved survival of non-squamous NSCLC in first-line, maintenance, and second-line treatments; this benefit is limited to non-squamous histology. Because pemetrexed has become part of the standard of care, current clinical trials are designed to compare it to other investigational combinations. Limited data on resectable disease are available, and additional clinical trials are being conducted.

EXPERT OPINION

Pemetrexed has shown effectiveness and a favorable toxicity profile. Histology-driven indications and the relationship of pemetrexed with thymidylate synthase expression suggest that a more precise definition of predictive biomarkers could be further investigated.