A randomized phase II study of pemetrexed or RAD001 as second-line treatment of advanced non-small-cell lung cancer in elderly patients: treatment rationale and protocol dynamics

Gemcitabine plus vinorelbine as the second-line treatment and beyond in elderly patients with platinum-pretreated advanced non-small cell lung cancer

BACKGROUND

The efficacy and tolerance of a gemcitabine and vinorelbine (GV) combination as salvage therapy have not been reported in elderly patients with advanced non-small cell lung cancer (NSCLC).

METHODS

We reviewed elderly patients with advanced NSCLC who had disease progression after one or more chemotherapy regimens, at least one including platinum, and then who were treated with GV as the salvage therapy.

RESULTS

In total 40 patients were analyzed. GV was at least the third-line chemotherapy in 24 patients (60.0%). Only 2 patients (5.0%) experienced grade 3 febrile neutropenia. Nonhematologic toxicities were generally mild and there was no treatment-related mortality. Among 29 patients evaluable for treatment response, 10 (34.5%) and 9 (31.0%) achieved a partial response and stable disease, respectively. The median overall survival was 10.3 months and the median progression-free survival was 3.1 months.

CONCLUSIONS

GV in combination is an effective and tolerable salvage regimen in elderly and heavily pretreated patients with advanced NSCLC.

Efficacy of combining targeted therapy with pemetrexed or docetaxel as second-line treatment in patients with advanced non-small-cell lung cancer: a meta-analysis of 14 randomized controlled trials

OBJECTIVES

To compare the effects of adding targeted agents to standard second-line chemotherapy with a single agent (pemetrexed or docetaxel) in patients with advanced NSCLC, a meta-analysis of all relevant randomized controlled trials was performed and overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR) were assessed.

PATIENTS AND METHODS

The PubMed and Embase databases, and the Cochrane Central Register of Controlled Trials were searched for relevant publications reporting randomized controlled trials between January 2000 and December 2013. Hazard ratios (HRs) with their 95% confidence intervals (CIs), or data for calculating HRs with 95% CIs were derived.

RESULTS

Fourteen trials with a total of 6922 patients were included in this meta-analysis. Compared with chemotherapy, combination therapy did not improve OS (HR = 0.95; 95% CI, 0.90-1.01; P = 0.081) but improved PFS (HR = 0.83; 95% CI, 0.78-0.87; P = 0.000). Survival outcomes did not differ significantly among trials. Combination therapy significantly increased ORR (RR = 1.83; 95% CI, 1.59-2.127; P = 0.000) and DCR (RR = 1.18; 95% CI, 1.13-1.23, P = 0.000). Sub-analysis indicated that adding targeted therapy to chemotherapy significantly prolonged OS in patients with non-squamous NSCLC (HR = 0.87; 95% CI, 0.87-0.97; P = 0.009). Patients treated with combination therapy had an increased incidence of grade 3 or greater diarrhea (RR = 1.96; 95% CI, 1.37-2.81; P = 0.000), neutropenia (RR = 1.27, 95% CI, 1.14-1.61; P = 0.000) and thrombocytopenia (RR = 4.21, 95% CI, 1.87-9.51; P = 0.001). This meta-analysis has the limitations of heterogeneity among the included trials and not using individual patient data.

CONCLUSIONS

In the second-line treatment of advanced NSCLC, the combination of targeted therapy and chemotherapy significantly increased response rates and progression-free survival, but did not improve overall survival and was more toxic.

Aberrant activation of the mTOR pathway and anti-tumour effect of everolimus on oesophageal squamous cell carcinoma

Background:

The mammalian target of rapamycin (mTOR) protein is important for cellular growth and homeostasis. The presence and prognostic significance of inappropriate mTOR activation have been reported for several cancers. Mammalian target of rapamycin inhibitors, such as everolimus (RAD001), are in development and show promise as anti-cancer drugs; however, the therapeutic effect of everolimus on oesophageal squamous cell carcinoma (OSCC) remains unknown.

Methods:

Phosphorylation of mTOR (p-mTOR) was evaluated in 167 resected OSCC tumours and 5 OSCC cell lines. The effects of everolimus on the OSCC cell lines TE4 and TE11 in vitro and alone or in combination with cisplatin on tumour growth in vivo were evaluated.

Results:

Mammalian target of rapamycin phosphorylation was detected in 116 tumours (69.5%) and all the 5 OSCC cell lines. Everolimus suppressed p-mTOR downstream pathways, inhibited proliferation and invasion, and induced apoptosis in both TE4 and TE11 cells. In a mouse xenograft model established with TE4 and TE11 cells, everolimus alone or in combination with cisplatin inhibited tumour growth.

Conclusion:

The mTOR pathway was aberrantly activated in most OSCC tumours. Everolimus had a therapeutic effect both as a single agent and in combination with cisplatin. Everolimus could be a useful anti-cancer drug for patients with OSCC.

PI3Ks-drug targets in inflammation and cancer

Phosphoinositide 3-kinases (PI3Ks) control cell growth, proliferation, cell survival, metabolic activity, vesicular trafficking, degranulation, and migration. Through these processes, PI3Ks modulate vital physiology. When over-activated in disease, PI3K promotes tumor growth, angiogenesis, metastasis or excessive immune cell activation in inflammation, allergy and autoimmunity. This chapter will introduce molecular activation and signaling of PI3Ks, and connections to target of rapamycin (TOR) and PI3K-related protein kinases (PIKKs). The focus will be on class I PI3Ks, and extend into current developments to exploit mechanistic knowledge for therapy.

Schedule-dependent inhibition of T-cell lymphoma cells by cotreatment with the mTOR inhibitor everolimus and anticancer drugs

OBJECTIVE

Everolimus (RAD001) is a novel mammalian target of rapamycin (mTOR) inhibitor, and anti-proliferative activity in various malignancies has been reported. This study evaluated the anti-tumor effects and schedule-dependent synergism of everolimus in combination with other chemotherapeutic agents in T-cell lymphoma cell lines.

MATERIALS AND METHODS

Human T-cell lymphoma cell lines Hut-78 and Jurkat were treated with increasing doses of everolimus, alone or in combination with doxorubicin, etoposide, vincristine, or bortezomib, using different dosing schedules. Anti-tumor effects were measured by assays for cell proliferation, apoptosis, and cell cycle distribution. Drug interactions were determined by median effect analysis.

RESULTS

Exposure to everolimus alone induced G1 phase cell cycle arrest without significant apoptosis. With certain dosing schedules, everolimus showed synergism with doxorubicin, etoposide, and bortezomib, but antagonism with vincristine. Cytotoxic synergism was observed following cotreatment with doxorubicin and everolimus, bortezomib and everolimus, doxorubicin followed by everolimus, and bortezomib followed by everolimus. By contrast, cell exposure to everolimus followed by doxorubicin or followed by bortezomib resulted in antagonistic effects. Sequential exposure to doxorubicin or bortezomib followed by everolimus effectively prevented potential negative interactions, and resulted in drug synergism. Drug combination synergisms or antagonisms were associated with variable effects on the cell cycle distribution.

CONCLUSIONS

Everolimus effectively inhibited the growth of T-cell lymphoma cells in vitro. Specific schedule-dependent combinations of everolimus with other anti-tumor agents which avoid potential drug antagonism and produce effective synergism may lead to clinically effective treatments for T-cell lymphoma.

Rapamycin selectively reduces the association of transcripts containing complex 5' UTRs with ribosomes in C4-2B prostate cancer cells

mTOR pathway inhibitors, specifically rapamycin and its derivatives, are promising therapeutics that targets downstream pathways including protein translation. We examined the effects of a series of inhibitors targeting various pathways on ribosomal polysome distribution, overall translation rates, and translation of specific mRNAs in the bone derived prostate cancer cell line, C4-2B. Treatment with either rapamycin, PD98059 or LY294002 failed to change the distribution of polysomes in sucrose gradients. Although no change in the accumulation of heavy polysomes was observed, there was an overall decrease in the rate of translation caused by treatment with rapamycin or LY294002. Inhibiting the MAPK pathway with PD98059 decreased overall translation by 20%, but had no effect on mRNAs containing a 5' terminal oligopyrimidine tract (TOP) sequences or those with complex 5' UTRs. In contrast, treatment with rapamycin for 24 h reduced overall translation by approximately 45% and affected the translation of mRNAs with complex 5' UTRs, specifically VEGF and HIF1alpha. After 24 h, LY294002 treatment alone decreased overall translation by 60%, more than was observed with rapamycin. Although LY294002 and similar inhibitors are effective at blocking prostate cancer cell growth, they act upstream of AKT and PTEN and cancer cells can find a way to bypass this inhibition. Thus, we propose that inhibiting downstream targets such as mTOR or targets of mTOR will provide rational approaches to developing new combination therapies focused on reducing growth of prostate cancer after arrival in the bone environment.

A landmark point analysis with cytotoxic agents for advanced NSCLC

INTRODUCTION

As a result of recent publications, we hypothesized that period of 8 weeks after initiation of treatment is a useful landmark point for cytotoxic agents for advanced non-small cell lung cancer (NSCLC). To test this hypothesis, we conducted landmark analyses with clinical trials employing cytotoxic agents. Our goal was to assess the proper design of clinical trials with cytotoxic agents for NSCLC for maximizing patients' benefit.

METHODS

We conducted landmark analyses of a phase II study of pemetrexed in locally advanced or metastatic NSCLC and a phase III study of Four-Arm Cooperative Study for advanced NSCLC. A total of 806 patients who received chemotherapy (pemetrexed, cisplatin and irinotecan, paclitaxel and carboplatin, cisplatin and gemcitabine, cisplatin and vinorelbine) were included in this assessment.

RESULTS

Tumor-shrinkage rate at 8 weeks was significantly associated with longer survival in the study with pemetrexed (p = 0.043), whereas tumor-shrinkage rate at 4 weeks did not correlated with survival (p = 0.139). Similarly, using the Four-Arm Cooperative Study data, the optimal landmark point was 8 weeks (p = 0.002), not 4 weeks (p = 0.190).

CONCLUSION

The landmark point for NSCLC was 8 weeks with all cytotoxic agents in our analysis when the therapy was given as a frontline or subsequent therapy. Our result suggests the concept of a disease-specific landmark point, which may lead to a change of phase II/III clinical study design to evaluate cytotoxic agents and clinical investigators, and their sponsors may consider an early look to assess the efficacy of cytotoxic agents for NSCLC.

Therapeutics by cytotoxic metabolite accumulation: pemetrexed causes ZMP accumulation, AMPK activation, and mammalian target of rapamycin inhibition

Pemetrexed represents the first antifolate cancer drug to be approved by the Food and Drug Administration in 20 years; it is currently in widespread use for first line therapy of mesothelioma and non-small cell lung cancer. Pemetrexed has more than one site of action; the primary site is thymidylate synthase. We now report that the secondary target is the downstream folate-dependent enzyme in de novo purine synthesis, aminoimidazolecarboxamide ribonucleotide formyltransferase (AICART). The substrate of the AICART reaction, ZMP, accumulated in intact pemetrexed-inhibited tumor cells, identifying AICART as the step in purine synthesis that becomes rate-limiting after drug treatment. The accumulating ZMP causes an activation of AMP-activated protein kinase with subsequent inhibition of the mammalian target of rapamycin (mTOR) and hypophosphorylation of the downstream targets of mTOR that control initiation of protein synthesis and cell growth. We suggest that the activity of pemetrexed against human cancers is a reflection of its direct inhibition of folate-dependent target proteins combined with prolonged inhibition of the mTOR pathway secondary to accumulation of ZMP.

The potential role of mTOR inhibitors in non-small cell lung cancer

The mammalian target of rapamycin (mTOR), a serine/threonine kinase, is a downstream mediator in the phosphatidylinositol 3-kinase/Akt signaling pathway, which plays a critical role in regulating basic cellular functions including cellular growth and proliferation. Currently, the mTOR inhibitor rapamycin and its analogues (CCI-779, RAD001, AP23573), which induce cell-cycle arrest in the G(1) phase, are being evaluated in cancer clinical trials. The mTOR inhibitors appear to be well tolerated, with skin reactions, stomatitis, myelosuppression, and metabolic abnormalities the most common toxicities seen. These adverse events are transient and reversible with interruption of dosing. Several pieces of evidence suggest a certain antitumor activity, including tumor regressions and prolonged stable disease, which has been reported among patients with a variety of malignancies, including non-small cell lung cancer (NSCLC). These promising preliminary clinical data have stimulated further research in this setting. Here, we review the basic structure of the pathway together with current results and future developments of mTOR inhibitors in the treatment of NSCLC patients.