Phase I clinical and pharmacokinetic study of RAD001 (everolimus) administered daily to Japanese patients with advanced solid tumors

Phase II study of BKM120 in patients with advanced esophageal squamous cell carcinoma (EPOC1303)

BACKGROUND

PI3K/AKT/mTOR pathway is frequently overactive in esophageal squamous cell carcinoma (ESCC), making it an attractive treatment target. BKM120 is an oral pan-class I PI3K inhibitor with promising activity in several cancers. We prospectively investigated efficacy, safety, and biomarkers of BKM120 in advanced ESCC. We conducted a multicenter phase II study of BKM120 monotherapy in patients with pretreated advanced ESCC.

METHODS

BKM120 (100 mg/day) was administered orally in a 28-day cycle. The primary end point was disease control rate (DCR). Tumor samples for all patients were collected for gene alteration analysis in a comprehensive genomic profiling assay.

RESULTS

Of 42 patients enrolled, 20 had stable disease and two had confirmed partial response. One ineligible patient was excluded from the primary analysis, which met the primary end point (DCR 51.2%; 95% confidence interval [CI], 35.1-67.1). In the 42 patients, median progression-free survival and overall survival were 2.3 (95% CI 1.8-3.2) and 9.0 (95% CI 6.5-11.4) months, respectively. Common grade 3 or 4 adverse events were rash, anorexia, hyponatremia, and abnormal hepatic function; profiles of these events in this study were similar to those in previous studies of BKM120 monotherapy. No treatment-related deaths occurred. PI3K pathway activation was observed in patients with good clinical response.

CONCLUSIONS

BKM120 monotherapy showed promising efficacy and a manageable toxicity profile even in patients with pretreated advanced ESCC. This study showed the potential target PI3K for ESCC, and further confirmatory trial will be necessary to confirm it. Unique ID issued by UMIN: UMIN 000011217.

Therapeutic Response of CCKBR-Positive Tumors to Combinatory Treatment with Everolimus and the Radiolabeled Minigastrin Analogue [177Lu]Lu-PP-F11N

The inhibition of the mammalian target of rapamycin complex 1 (mTORC1) by everolimus (RAD001) was recently shown to enhance the tumor uptake of radiolabeled minigastrin. In this paper, we investigate if this finding can improve the in vivo therapeutic response to [¹⁷⁷Lu]Lu-PP-F11N treatment. The N-terminal DOTA-conjugated gastrin analogue PP-F11N (DOTA-(DGlu)₆-Ala-Tyr-Gly-Trp-Nle-Asp-Phe) was used to evaluate treatment efficacy in the human A431/CCKBR xenograft nude mouse model in combination with RAD001. Both RAD001 and [¹⁷⁷Lu]Lu-PP-F11N single treatments as well as their combination inhibited tumor growth and increased survival. In concomitantly treated mice, the average tumor size and median survival time were significantly reduced and extended, respectively, as compared to the monotherapies. The histological analysis of kidney and stomach dissected after treatment with RAD001 and [¹⁷⁷Lu]Lu-PP-F11N did not indicate significant adverse effects. In conclusion, our study data demonstrate the potential of mTORC1 inhibition to substantially improve the therapeutic efficacy of radiolabeled minigastrin analogues in CCKBR-positive cancers.

Real-world pharmacokinetics and pharmacodynamics of everolimus in metastatic breast cancer

Purpose This study investigated the relationship between the pharmacokinetics and pharmacodynamics of everolimus in patients with metastatic breast cancer (mBC) in real-world practice.Methods Twenty-two patients with mBC treated with everolimus plus exemestane were enrolled. Blood everolimus concentrations were measured at outpatient visits. The inhibition of the mammalian target of rapamycin (mTOR) activity in peripheral blood mononuclear cells (PBMCs) was examined. The efficacy and safety endpoints were progression-free survival (PFS) and the cumulative incidence of dose-limiting toxicities (DLTs), respectively. Results Blood samples were obtained from 19 consenting patients. Everolimus did not completely inhibit mTOR activity in PBMCs at therapeutic concentrations (~ 56 % maximal inhibition). The most common adverse event was stomatitis (any grade 77 %). The trough concentration (Ctrough) was significantly higher in patients experiencing DLTs than in those without any DLTs (P = 0.030). The optimal Ctrough cutoff predicting DLT development was 17.3 ng/mL. The cumulative incidence of DLTs was significantly higher in patients with Ctrough ≥17.3 ng/mL than in other patients (sub-hazard ratio 4.87, 95 % confidence interval [CI] 1.53-15.5; P = 0.007). Furthermore, the median PFS was numerically longer in patients who maintained a steady-state Ctrough below the threshold than in those who did not (327 days [95 % CI 103-355 days] vs. 194 days [95 % CI 45 days-not estimable]; P = 0.35). Conclusions The suggested upper threshold for the therapeutic window of everolimus Ctrough was 17.3 ng/mL. Pharmacokinetically guided dosing may improve the efficacy and safety of everolimus for mBC, warranting further investigation in a larger study.Clinical trial registry: Not applicable.

Everolimus-Related Pneumonitis in Patients with Metastatic Breast Cancer: Incidence, Radiographic Patterns, and Relevance to Clinical Outcome

BACKGROUND

This study investigated the incidence, radiographic patterns, and relevance to clinical outcome of everolimus-related pneumonitis (ERP) in patients with metastatic breast cancer (MBC).

MATERIALS AND METHODS

Data of patients with MBC treated with everolimus who had baseline and at least one follow-up chest computed tomography (CT) were obtained from a medical electronic database system. An independent review of the CT scans of these patients was conducted by two radiologists (NCT03730428). Log-rank and Cox proportional hazard regression analyses were used for time-to-event analyses.

RESULTS

ERP was radiographically detected in 45 of 86 patients (52.3%). In more than 80% of these patients, ERP occurred during the first 4 months of everolimus treatment. Only 14 of the 45 patients with ERP were symptomatic (31.1%). Symptoms included cough, fever, and shortness of breath. Bilateral and lower distribution of the pneumonitis was most common. In most of the cases, ground-glass opacities and reticular opacities were noticed. Elderly patients were more likely to develop ERP. Patients with ERP had significantly longer progression-free survival (PFS; 6.8 vs. 4.1 months, p = .024) and overall survival (OS; 42.8 vs. 21.3 months, p = .016). ERP was a predictor of OS improvement confirmed by multivariate Cox analysis (hazard ratio, 0.49; 95% confidence interval, 0.25-0.97; p = .040).

CONCLUSIONS

ERP was noted in half of the patients with MBC treated with everolimus. Our data suggested that ERP was associated with improved prognosis and may be used as a biomarker for the efficacy of everolimus in MBC. Close monitoring, prompt diagnosis, and proper treatment for ERP are essential to maintain the quality of life of patients and achieve maximum treatment benefits.

IMPLICATIONS FOR PRACTICE

Everolimus-related pneumonitis (ERP) is one of the most worrying drug adverse events, especially in Asian patients. However, little has been known about the clinical and radiographic details of ERP in patients with metastatic breast cancers (MBCs) treated with everolimus. The present study investigated the clinical characteristics, radiographic patterns, and its correlation with treatment outcome in patients with MBC. ERP was identified in more than half of patients with MBC during everolimus therapy and was associated with improved outcome. Close monitoring and prompt diagnosis and appropriate treatment for ERP are critical for the preservation of patients' quality of life and achievement of maximal treatment benefits.

Current Molecular Targeted Agents for Advanced Gastric Cancer

Gastric cancer is the third leading cause of malignant tumor-related mortality worldwide. Traditional cytotoxic agents prolong the overall survival and progression-free survival of patients with advanced gastric cancer (AGC) compared to that with best supportive care. Due to the occurrence of serious adverse drug reactions that result in discontinued treatment, the survival benefit in AGC remains unsatisfactory. Systemic chemotherapy regimens have changed greatly, especially since the introduction of trastuzumab. Nevertheless, HER2 positivity is present in only approximately 20% of tumors. Due to the genetic heterogeneity and complexity of patients, there are many studies in progress that are exploring novel targeted drugs as an alternative to chemotherapy or adjuvant treatment in early-stage, progressive, and advanced gastric cancer. On the basis of the differences in gene expression profiles among patients, searching for specific and sensitive predictive biomarkers is important for identifying patients who will benefit from a specific targeted drug. With the development of targeted therapies and available chemotherapeutic drugs, there is no doubt that, over time, more patients will achieve better survival outcomes. Recently, immune checkpoint blockade has been well developed as a promising anticancer strategy. This review outlines the currently available information on clinically tested molecular targeted drugs and immune checkpoint inhibitors for AGC to provide support for decision-making in clinical practice.

Impact of race on dose selection of molecular-targeted agents in early-phase oncology trials

Background

We examined the impact of race on the maximum tolerated doses (MTD) and final approved doses (FAD) of single-agent molecular-targeted agents (MTA) in North America/Europe (NA/EU) and Asia.

Methods

We searched PubMed and regulatory databases to identify targeted drugs approved globally and compared their FAD and MTD in corresponding phase I/II studies conducted separately in NA/EU and Asia. To evaluate this further, we conducted parallel, prospective, first-in-human studies of DS-7423, a dual PI3K/mTOR inhibitor, in patients with advanced solid tumours in the US and Japan. We pooled and compared the pharmacokinetics (PK), pharmacodynamics (PD), toxicity, and efficacy between these populations.

Results

17 MTA were approved in NA/EU and Asia from 2001 to 2015. Recommended phase 2 doses (RP2D) were identical across races in 14 of 17 (80%) studies and differences were not clinically meaningful. FAD were identical across all regions. 42 and 27 patients from US and Japan, respectively, were enrolled in the phase I studies of DS-7423. Despite differences in race, body weight, and body mass index, the RP2D were 240 mg/day with no differences in toxicities, PK, PD, or efficacy.

Conclusions

Conducting separate clinical trials of single-agent MTA in Caucasian and Asian populations may be redundant.

Population Pharmacokinetics of Everolimus in Relation to Clinical Outcomes in Patients With Advanced Renal Cell Carcinoma

BACKGROUND

Everolimus has been used for the treatment of unresectable or metastatic renal cell carcinoma (RCC). Here, we measured blood concentrations of everolimus to obtain the population pharmacokinetic parameters and to examine the relationship between blood concentration and clinical outcomes.

METHODS

Twenty-two Japanese patients were enrolled. Blood samples were collected before and 2, 4, 8, and 24 hours after drug administration on days 1 and 8 of everolimus therapy (5 or 10 mg) from inpatients; occasional samples were collected from outpatients. Blood concentrations of everolimus were measured by high-performance liquid chromatography with tandem mass spectrometry. Population pharmacokinetic analysis was conducted using the NONMEM software.

RESULTS

Everolimus pharmacokinetics was best described by a 2-compartment model with population mean estimates of apparent oral clearance of 10.0 L/h and an interindividual variability of 42.4%. There was no relationship between overall best responses and the predicted trough concentrations at day 8. The predicted trough concentration in patients who terminated everolimus treatment owing to adverse drug reactions (ADRs) was significantly higher than in patients who stopped the treatment owing to disease progression or other reasons (27.6 ± 3.1 versus 15.7 ± 2.3 ng/mL; mean ± SEM). Patients who terminated the treatment owing to ADRs had significantly shorter time-to-treatment failure than other patients (112 versus 187 days, median).

CONCLUSIONS

This study reports the first population pharmacokinetic parameters of everolimus in patients with RCC. Individual dose adjustment based on everolimus blood concentrations helps to avoid early drug cessation due to ADRs.

Prediction of Apparent Oral Clearance of Small-Molecule Inhibitors in Pediatric Patients

The purpose of this study was to build regression models for the prediction of apparent oral clearance (CL/F) for small-molecule inhibitors in the pediatric population using data obtained from adults. Two approaches were taken; a simple allometric regression model which considers no interdrug or interindividual variability and an allometric regression model with mixed-effects modeling where some variability parameters are included in the model. Average CL/F values were obtained for 15 drugs at various dosages from 31 literatures (a total of 139 data sets) conducted in adults and for 15 drugs from 26 literatures (62 data sets) conducted in children. Data were randomly separated into the "modeling" or "validation" data set, and the 2 allometric regression models were applied to the modeling data set. The predictive ability of the models was examined by comparing the observed and model-predicted CL/F in children using the validation data set. The percentage root mean square error was 17.2% and 26.3% in the simple allometric regression model and the allometric regression model with mixed-effects modeling, respectively. The predictive ability of the 2 models seems acceptable, suggesting that they could be useful for predicting the CL/F of new small-molecule inhibitors and for determining adequate doses in clinical pharmacotherapy for children.

Efficacy and safety of everolimus in combination with trastuzumab and paclitaxel in Asian patients with HER2+ advanced breast cancer in BOLERO-1

Background

The current exploratory analysis was performed to evaluate the efficacy and safety of everolimus for treatment of human epidermal growth factor receptor 2-positive (HER2+) advanced breast cancer in the Asian subset of patients in the BOLERO-1 trial.

Methods

Postmenopausal women with HER2+ advanced breast cancer, who had not received systemic therapy for advanced disease, were randomized 2:1 to receive everolimus or placebo, plus trastuzumab and paclitaxel. The two primary end points were investigator-assessed progression-free survival (PFS) in the full population and in the hormone receptor-negative (HR–) subpopulation. Secondary end points included assessment of the objective response rate, the clinical benefit rate, and safety.

Results

In the Asian subset, median PFS was similar in the everolimus (n = 198) and placebo (n = 105) arms in the full analysis set (hazard ratio = 0.82 (95% CI 0.61–1.11)). In the HR– subpopulation, everolimus prolonged median PFS by 10.97 months vs placebo (25.46 vs 14.49 months; hazard ratio = 0.48 (95% CI 0.29–0.79)). In the everolimus arm of the Asian subset, the most common adverse events of any grade were stomatitis (62.2%), diarrhea (48.0%), rash (43.4%) and neutropenia (42.3%). Neutropenia (grade 3: 27.6%; grade 4: 4.6%) and decreased neutrophil count (grade 3: 11.2%; grade 4: 3.6%) were the most frequent grade 3/4 adverse events. Serious adverse events included pneumonia (5.1%), pneumonitis (3.1%), and interstitial lung disease (3.1%). There were three deaths (1.5%) during treatment in the everolimus arm vs none in the placebo arm.

Conclusions

The efficacy and safety of everolimus plus trastuzumab and paclitaxel as first-line treatment for HER2+ advanced breast cancer in the Asian subset was consistent with that reported previously in the overall population.

Trial registration

ClinicalTrials.gov, NCT00876395. Registered on 2 April 2009.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-017-0839-0) contains supplementary material, which is available to authorized users.

EVESOR, a model-based, multiparameter, Phase I trial to optimize the benefit/toxicity ratio of everolimus and sorafenib

AIM

This novel multiparameter Phase I study aimed to optimize doses/dosing schedules of everolimus and sorafenib drug combination, based on modeling/simulation (NCT01932177).

PATIENTS & METHODS

About 26 patients with solid tumors were treated in four different dosing schedules. Everolimus once daily + sorafenib twice daily were given continuously in arms A and B, and intermittently in arms C (alternating every other week) and D (everolimus continuous and sorafenib 3 days on/4 days off).

RESULTS

Continuous schedules exhibited higher toxicity risks than intermittent schedules (64.1 vs 35.9%; p < 0.0001), and trends for lower disease control rates (80 vs 100%). No significant pharmacokinetic interaction was identified.

CONCLUSION

Feasibility of EVESOR trial is demonstrated. Intermittent schedules might provide better tolerance and efficacy than continuous schedules.

Concordance between PIK3CA mutations in endoscopic biopsy and surgically resected specimens of esophageal squamous cell carcinoma

Background

PIK3CA mutations are expected to be potential therapeutic targets for esophageal squamous cell carcinoma (ESCC). We aimed to clarify the concordance between PIK3CA mutations detected in endoscopic biopsy specimens and corresponding surgically resected specimens.

Methods

We examined five hotspot mutations in the PIK3CA gene (E542K, E545K, E546K, H1047R, and H1047L) in formalin-fixed and paraffin-embedded tissue sections of paired endoscopic biopsy and surgically resected specimens from 181 patients undergoing curative resection for ESCC between 2000 and 2011 using a Luminex technology-based multiplex gene mutation detection kit.

Results

Mutation analyses were successfully performed for both endoscopic biopsy and surgically resected specimens in all the cases. A PIK3CA mutation was detected in either type of specimen in 13 cases (7.2%, 95% confidence interval: 3.9–12.0). The overall concordance rate, positive predictive value, and negative predictive value were 98.3% (178/181), 90.9% (10/11), and 98.8% (168/170), respectively. Among patients with a PIK3CA mutation detected in both types of specimens, the concordance between PIK3CA mutation genotypes was 100%. There were three cases with a discordant mutation status between the types of specimens (PIK3CA mutation in surgically resected specimen and wild-type in biopsy specimen in two cases, and the opposite pattern in one case), suggesting possible intratumoral heterogeneity in the PIK3CA mutation status.

Conclusions

The PIK3CA mutation status was highly concordant between endoscopic biopsy and surgically resected specimens from the same patient, suggesting that endoscopic biopsy specimens can be clinically used to detect PIK3CA mutations in patients with ESCC.

To Excavate Biomarkers Predictive of the Response for Capecitabine plus RAD001 through Nanostring-Based Multigene Assay in Advanced Gastric Cancer Patients

Comprehensive characterization of individual patients' tumour is important to realize personalized medicine. Here, we investigate to identify subsets that benefit from capecitabine plus RAD001 in advanced gastric cancer (GC) patients by comprehensive high-throughput genomic analysis (nCounter assay). Archival tumour tissue blocks, if possible, were collected at phase II trial of capecitabine plus RAD001 in 47 refractory GC patients (at clinicaltrials.gov NCT#01099527). A total of 42 formalin-fixed, paraffin-embedded (FFPE) tumour samples were available for nanostring based-multigene Assay. An nCounter assay of 519 kinase panels has been used. We performed correlation analyses between expression levels of kinase genes and response for capecitabine plus RAD001. Among 42 patients with An nCounter assay of 519 kinase panels, 4 patients achieved confirmed partial response and 15 patients revealed stable disease, resulting in an overall response rate (ORR) of 9.5%. No difference in ORR was observed in terms of gender, performance status, primary tumour site, gastric resection, histologic subtype, Lauren classification, No. of metastatic site and No. of chemotherapy. In subgroups with response for capecitabine plus RAD001, there is significant overexpression of 6 genes among 519 kinase gene such as EPHA2 (P = 0.0025), PIM1 (P = 0.0031), KSR1 (P = 0.0033), and EIF2AK4 (P = 0.0046) that are related to the activation of mTOR signalling. This study is first report that investigated to identify biomarkers predictive of the response for RAD001 containing treatment in refractory GC patients, by comprehensive high-throughput genomic analysis (nCounter assay).

New advances in targeted gastric cancer treatment

Despite a decrease in incidence over past decades, gastric cancer remains a major global health problem. In the more recent period, survival has shown only minor improvement, despite significant advances in diagnostic techniques, surgical and chemotherapeutic approaches, the development of novel therapeutic agents and treatment by multidisciplinary teams. Because multiple genetic mutations, epigenetic alterations, and aberrant molecular signalling pathways are involved in the development of gastric cancers, recent research has attempted to determine the molecular heterogeneity responsible for the processes of carcinogenesis, spread and metastasis. Currently, some novel agents targeting a part of these dysfunctional molecular signalling pathways have already been integrated into the standard treatment of gastric cancer, whereas others remain in phases of investigation within clinical trials. It is essential to identify the unique molecular patterns of tumours and specific biomarkers to develop treatments targeted to the individual tumour behaviour. This review analyses the global impact of gastric cancer, as well as the role of Helicobacter pylori infection and the efficacy of bacterial eradication in preventing gastric cancer development. Furthermore, the paper discusses the currently available targeted treatments and future directions of research using promising novel classes of molecular agents for advanced tumours.

Pharmacokinetics and pharmacodynamics of everolimus in patients with renal angiomyolipoma and tuberous sclerosis complex or lymphangioleiomyomatosis

AIMS

The purpose was to determine the exposure-response relationship of everolimus in patients with angiomyolipoma from the EXIST-2 trial and to analyze the correlation between exposure and plasma concentrations of angiogenic biomarkers in these patients.

METHODS

One hundred and eighteen patients with angiomyolipoma associated with tuberous sclerosis complex (TSC) or sporadic lymphangioleiomyomatosis (sLAM) were randomly assigned 2 : 1 to receive everolimus 10 mg (n = 79) or placebo (n = 39) once daily. Blood samples for determining everolimus concentration were collected at weeks 2, 4, 12, 24 and 48 during double-blind treatment. Plasma samples for biomarker analysis were collected at baseline and weeks 4, 12, 24, 36, 48 and at the end of treatment. Concentrations of eight angiogenic biomarkers associated with tumour growth were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Peak and trough concentrations of everolimus in blood remained stable over time and similar to those reported in other indications. Substantial pharmacodynamic effects were observed in the everolimus, but not placebo, arm for three biomarkers: After 24 weeks of treatment, reduction of vascular endothelial growth factor D (VEGF-D) and collagen type IV (COL-IV) (mean fold-changes with 95% confidence intervals [CI] were 0.36 [0.33, 0.40], and 0.54 [0.51, 0.57], respectively, P < 0.001 for both), along with increased VEGF-A (mean fold-change of 1.59 [1.39, 1.80], P < 0.001), were seen. Furthermore, baseline VEGF-D and COL-IV levels were associated with angiomyolipoma size at baseline and with angiomyolipoma response to everolimus.

CONCLUSIONS

These findings suggest that plasma angiogenic markers may provide an objective measure of patient response to everolimus.

Targeted therapies in gastric cancer and future perspectives

Advanced gastric cancer (AGC) is associated with a high mortality rate and, despite multiple new chemotherapy options, the survival rates of patients with AGC remains poor. After the discovery of targeted therapies, research has focused on the new treatment options for AGC. In the last two decades, many targeted molecules were developed against AGC. Currently, two targeted therapy molecules have been approved for patients with AGC. In 2010, trastuzumab was the first molecule shown to improve survival in patients with HER2-positive AGC as part of a first-line combination regimen. In 2014, ramucirumab was the second targeted molecule to improve survival rates and was suggested as treatment for patients with AGC who had progressed after first-line platinum plus fluoropyrimidine with or without anthracycline chemotherapy. Ramucirumab was the first targeted therapy acting as a single agent in patients with advanced gastroesophageal cancers. Although these two molecules were introduced into clinical use, many other promising molecules have been tested in phase I-II trials. It is obvious that in the near future many different targeted therapies will be in use for treatment of AGC. In this review, the current status of targeted therapies in the treatment of AGC and gastroesophageal junction tumors, including HER (2-3) inhibitors, epidermal growth factor receptor inhibitors, tyrosine kinase inhibitors, antiangiogenic agents, c-MET inhibitors, mammalian target of rapamycin inhibitors, agents against other molecular pathways fibroblast growth factor, Claudins, insulin-like growth factor, heat shock proteins, and immunotherapy, will be discussed.

Targeted therapy in gastric cancer

Gastric cancer is often diagnosed at an advanced stage. Although chemotherapy prolongs survival and improves quality of life, the survival of gastric cancer patients with advanced disease is short. Thanks to recent insights into the molecular pathways involved in gastric carcinogenesis, new targeted treatment options have become available for gastric cancer patients. Trastuzumab, an antibody targeted to HER-2, was shown to improve survival of advanced gastric cancer patients harboring HER-2 overexpression due to gene amplification in their tumor cells, and is currently also explored in adjuvant and neoadjuvant settings. Another agent with promising results in clinical trials is ramucirumab, an antibody targeting VEGFR-2. No clear survival benefit, however, were experienced with agents targeting EGFR (cetuximab, panitumumab), VEGF-A (bevacizumab), or mTOR (everolimus). Drugs targeting c-MET/HGF are currently under investigation in biomarker-selected cohorts, with promising results in early clinical trials. This review will summarize the current status of targeted treatment options in gastric cancer.

Phase II study of capecitabine and the oral mTOR inhibitor everolimus in patients with advanced pancreatic cancer

Purpose

The combination of an mTOR inhibitor with 5-fluorouracil-based anticancer therapy is attractive because of preclinical evidence of synergy between these drugs. According to our phase I study, the combination of capecitabine and everolimus is safe and feasible, with potential activity in pancreatic cancer patients.

Methods

Patients with advanced adenocarcinoma of the pancreas were enrolled. Eligible patients had a WHO performance status 0–2 and adequate hepatic and renal functions. The treatment regimen consisted of capecitabine 1000 mg/m² BID day 1–14 and everolimus 10 mg daily (5 mg BID) in a continuous 21-day schedule. Tumor assessment was performed with CT-scan every three cycles. Primary endpoint was response rate (RR) according to RECIST 1.0. Secondary endpoints were progression-free survival, overall survival and 1-year survival rate.

Results

In total, 31 patients were enrolled. Median (range) treatment duration with everolimus was 76 days (1–431). Principal grade 3/4 toxicities were hyperglycemia (45 %), hand-foot syndrome (16 %), diarrhea (6 %) and mucositis (3 %). Prominent grade 1/2 toxicities were anemia (81 %), rash (65 %), mucositis (58 %) and fatigue (55 %). RR was 6 %. Ten patients (32 %) had stable disease resulting in a disease control rate of 38 %. Median overall survival was 8.9 months (95 % CI 4.6–13.1). Progression-free survival was 3.6 months (95 % CI 1.9–5.3).

Conclusions

The oral regimen with the combination of capecitabine and everolimus is a moderately active treatment for patients with advanced pancreatic cancer, with an acceptable toxicity profile at the applied dose level.

A Phase I/II Study of the mTOR Inhibitor Everolimus in Combination with HyperCVAD Chemotherapy in Patients with Relapsed/Refractory Acute Lymphoblastic Leukemia

PURPOSE

Previous studies suggest a potential therapeutic role for mTOR inhibition in lymphoid malignancies. This single-center phase I/II study was designed to test the safety and efficacy of the mTOR inhibitor everolimus in combination with HyperCVAD chemotherapy in relapsed/refractory acute lymphoblastic leukemia (ALL).

EXPERIMENTAL DESIGN

Twenty-four patients were treated; 15 received everolimus 5 mg/day and 9 received 10 mg/day with HyperCVAD.

RESULTS

The median age of patients was 25 years (range, 11-64) and median number of prior treatments was 2 (range, 1-7). Grade 3 mucositis was the dose-limiting toxicity and the maximum tolerated everolimus dose was 5 mg/day. Responses included complete remission (CR) in 6 patients (25%), CR without platelet recovery (CRp) in 1 (4%), and CR without recovery of counts (CRi) in 1 (4%), for an overall response rate of 33%. In addition, partial response (PR) was noted in 2 patients (8%). Seven of 11 patients treated in first salvage achieved CR/CRp (64%). The median OS was 29 weeks for patients in first salvage versus 15 weeks for patients in second salvage and beyond (P ≤ 0.001). A response was noted in 5 of 10 (50%) heavily pretreated T-ALL patients (median of 4 prior salvage regimens). Everolimus significantly inhibited phosphorylation of S6RP, but this did not correlate with response. No significant decreases in p4EBP1 and pAkt levels were noted. Responders had higher everolimus dose-adjusted area under the curve (P = 0.025) and lower clearance (P = 0.025) than nonresponders.

CONCLUSIONS

The combination of HyperCVAD and everolimus is well tolerated and moderately effective in relapsed ALL, specifically T-ALL.

Pharmacokinetics of everolimus when combined with cyclosporine in Japanese de novo renal transplant recipients

BACKGROUND

Currently, there are no published data on pharmacokinetics (PK) of everolimus in combination with cyclosporine in Japanese renal transplant patients. We evaluated the PK of everolimus in Japanese de novo renal transplant patients who received everolimus in combination with cyclosporine.

METHODS

In this phase 3, multicenter, randomized, open-label study, patients were randomized (1:1) to 1 of the 2 groups: everolimus 1.5 mg (targeted C0 of 3-8 ng/mL) plus reduced-dose cyclosporine or mycophenolate mofetil 2 g/d plus standard-dose cyclosporine. PK assessments for everolimus were performed on day 28 (month 1) in the PK subpopulation.

RESULTS

A total of 11 patients (7 men), mean age 47.5 ± 11.21 years, were enrolled for PK analysis of everolimus. Starting at 1.5 mg (0.75 mg twice a day), the mean dose over a period of 28 days was 0.705 ± 0.1011 mg. Everolimus mean trough concentration was 4.307 ± 1.2459 ng/mL and mean peak concentration was 13.539 ± 3.5330 ng/mL, which peaked at 1 to 2 hours postdose. The average concentration was 7.558 ± 1.4723 ng/mL, area under the concentration-time curve was 90.70 ± 17.667 ng·h/mL, and peak-trough fluctuation was 122.6%. The PK parameters of everolimus were comparable to those in the earlier phase 3 studies (A2306 and A2307). The mean everolimus trough levels were within the target ranges at all time points ranging from 3.4 to 5.5 ng/mL (everolimus 0.75 mg twice a day, safety population). The majority of patients (>85% from day 7 onward) were maintained within the targeted everolimus trough blood levels (safety population). These data were similar to a non-Japanese study (A2309).

CONCLUSIONS

The pharmacokinetic characteristics of everolimus in Japanese de novo renal transplant patients did not differ from those previously observed in non-Japanese patients, hence the same dosage of everolimus may be acceptable in Japanese patients.

Current status of novel agents in advanced gastroesophageal adenocarcinoma

Gastroesophageal (GE) adenocarcinomas are highly lethal malignancies and despite multiple chemotherapy options, 5-year survival rates remain dismal. Chemotherapy is the mainstay of treatment but patients are often limited by toxicity and poor performance status. Because of molecular heterogeneity, it is essential to classify tumors based on the underlying oncogenic pathways and develop targeted therapies that act on individual tumors. Trastuzumab, a human epidermal growth factor receptor type 2 (HER2) monoclonal antibody, was the first such agent shown to improve response rate, progression free survival (PFS), and overall survival (OS) when added to cisplatin based chemotherapy in patients with HER2 over-expressing GE junction (GEJ) and gastric adenocarcinomas. However, HER2 over expressing GE tumors are in the minority and the need for additional targeted agents is urgent. Though many agents are in development, incorporating targeted therapy in the treatment of GE cancers comes with a unique set of challenges. In this review, we outline oncogenic pathways relevant to GE adenocarcinomas, including HER2, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), hepatocyte growth factor (HGF), and c-Met, and discuss recent trials with agents targeting these pathways.

Beneficial Effects of the mTOR Inhibitor Everolimus in Patients with Advanced Medullary Thyroid Carcinoma: Subgroup Results of a Phase II Trial

Objective. Until recently, advanced medullary thyroid cancer (MTC) had few treatment options except surgery. The mTOR inhibitor everolimus has shown encouraging results in neuroendocrine tumors. As part of a prospective phase II study, we analyzed the safety and efficacy of everolimus in advanced MTC. Methods. Seven patients with per RECIST 1.1 documented advanced MTC were included and received everolimus 10 mg daily. The primary objective was determining treatment efficacy. Secondary endpoints included progression-free survival (PFS), overall survival (OS), toxicity, and pharmacokinetics (PK). Results. Median follow-up duration was 28 weeks (17-147). Five patients (71%) showed SD, of which 4 (57%) showed SD >24 weeks. Median PFS and OS were 33 (95%CI: 8-56) and 30 (95%CI: 15-45) weeks, respectively. Toxicity was predominantly grade 1/2 and included mucositis (43%), fatigue (43%), and hypertriglyceridemia (43%). Four MTCs harbored the somatic RET mutation c.2753T>C, p.Met918Thr. The best clinical response was seen in a MEN2A patient. PK characteristics were consistent with phase I data. One patient exhibited extensive toxicity accompanying elevated everolimus plasma concentrations. Conclusions. This study suggests that everolimus exerts clinically relevant antitumor activity in patients with advanced MTC. Given the high level of clinical benefit and the relatively low toxicity profile, further investigation of everolimus in these patients is warranted.

Efficacy of everolimus with exemestane versus exemestane alone in Asian patients with HER2-negative, hormone-receptor-positive breast cancer in BOLERO-2

BACKGROUND

The addition of mTOR inhibitor everolimus (EVE) to exemestane (EXE) was evaluated in an international, phase 3 study (BOLERO-2) in patients with hormone-receptor-positive (HR(+)) breast cancer refractory to letrozole or anastrozole. The safety and efficacy of anticancer treatments may be influenced by ethnicity (Sekine et al. in Br J Cancer 99:1757-62, 2008). Safety and efficacy results from Asian versus non-Asian patients in BOLERO-2 are reported.

METHODS

Patients were randomized (2:1) to 10 mg/day EVE + EXE or placebo (PBO) + EXE. Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival, response rate, clinical benefit rate, and safety.

RESULTS

Of 143 Asian patients, 98 received EVE + EXE and 45 received PBO + EXE. Treatment with EVE + EXE significantly improved median PFS versus PBO + EXE among Asian patients by 38 % (HR = 0.62; 95 % CI, 0.41-0.94). Median PFS was also improved among non-Asian patients by 59 % (HR = 0.41; 95 % CI, 0.33-0.50). Median PFS duration among EVE-treated Asian patients was 8.48 versus 4.14 months for PBO + EXE, and 7.33 versus 2.83 months, respectively, in non-Asian patients. The most common grade 3/4 adverse events (stomatitis, anemia, elevated liver enzymes, hyperglycemia, and dyspnea) occurred at similar frequencies in Asian and non-Asian patients. Grade 1/2 interstitial lung disease occurred more frequently in Asian patients. Quality of life was similar between treatment arms in Asian patients.

CONCLUSION

Adding EVE to EXE provided substantial clinical benefit in both Asian and non-Asian patients with similar safety profiles. This combination represents an improvement in the management of postmenopausal women with HR(+)/HER2(-) advanced breast cancer progressing on nonsteroidal aromatase inhibitors, regardless of ethnicity.

Molecular targeting to treat gastric cancer

Trastuzumab that targets human epidermal growth factor receptor 2 (HER2) protein is the only approved molecular targeting agent for treating gastric cancer in Japan and the outcomes have been favorable. However, trastuzumab is effective for only 10% to 20% of the population with gastric cancer that expresses HER2 protein. Molecular targeting therapy with bevacizumab against vascular endothelial growth factors (VEGF) and with cetuximab and panitumumab against the epidermal growth factors pathway that have been approved for treating colorectal cancer are not considered effective for treating gastric cancer according to several clinical trials. However, ramucirumab that targets VEGF receptor-2 prolonged overall survival in a large phase III clinical trial and it might be an effective molecular targeting therapy for gastric cancer. The significance of molecular targeting therapy for gastric cancer remains controversial. A large-scale randomized clinical trial of novel molecular targeting agents with which to treat gastric cancer is needed.

The 4E-BP1/eIF4E ratio is a determinant for rapamycin response in esophageal cancer cells

OBJECTIVES

Rapamycin inhibits products of molecular pathways in esophageal squamous cell carcinoma and limits tumor cell growth by targeting 4E-BP1- and eIF4E-dependent gene translation. In this study, we investigate the influence of 4E-BP1-to-eIF4E ratio on rapamycin response in esophageal squamous cell carcinoma cells, and the underlying mechanism is discussed.

METHODS

The response to rapamycin treatment was examined in 6 esophageal cancer cell lines. Adjustment of the 4E-BP1/eIF4E ratio was carried out by knockdown or overexpression of 4E-BP1 and eIF4E. The relationship between Egr-1 and 4E-BP1 expression in esophageal cancer cells was also studied.

RESULTS

The 4E-BP1/eIF4E ratio was adjusted to evaluate the response to rapamycin treatment in TE1 and TE2 esophageal cancer cells. TE2 cells are sensitized to rapamycin treatment after overexpression of 4E-BP1 or knockdown of eIF4E; TE1 cells become resistant to rapamycin after knockdown of 4E-BP1 or overexpression of eIF4E. These data suggest that the 4E-BP1/eIF4E ratio is a determinant for the response of TE1 and TE2 cells to rapamycin treatment. Egr-1 expression was higher in TE2 cells compared with other esophageal cancer cell lines, and its knockdown increased 4E-BP1 expression in TE2 cells, which became sensitive to rapamycin treatment.

CONCLUSIONS

The 4E-BP1/eIF4E ratio is a determinant of the response of rapamycin treatment in esophageal cancer cells. Egr-1 can reduce 4E-BP1 gene expression and render esophageal squamous cell carcinoma cells resistant to rapamycin with a relatively low 4E-BP1/eIF4E ratio. Thus, the 4E-BP1/eIF4E ratio may represent a therapeutic index for the prediction of clinical outcome of rapamycin treatment in patients with esophageal squamous cell carcinoma.

Recent advances and future trends in the targeted therapy of metastatic gastric cancer

The better understanding of the molecular mechanisms behind gastric cancer has led to the development of new therapeutic strategies that are likely to improve patient outcomes in the near future. Recently, targeting the HER2 and the VEGF pathways with trastuzumab and ramucirumab, respectively, have been found to improve survival, while directed therapies against a number of other pathways are under clinical evaluation. These include the hepatocyte growth factor and its receptor c-MET, the insulin-like growth factor 1, the fibroblast growth factor, the mammalian target of rapamycin (mTOR), the epidermal growth factor receptor, and other pathways, as well as relevant immunotherapeutic strategies. This article reviews recent advances and future trends of these concepts for gastric cancer and adenocarcinoma of the gastroesophageal junction.

The challenge of targeted therapies for gastric cancer patients: the beginning of a long journey

INTRODUCTION

Despite significant improvements in systemic chemotherapy over the last two decades, the prognosis of patients with advanced disease remains dismal. Collaborative, high-quality research and advances in high-throughput technologies have contributed to elucidate molecular pathways underpinning disease progression and have stimulated many clinical studies testing target therapies in the advanced disease setting. Although progress has been made thanks to trastuzumab in HER2 positive tumours, antiangiogenic drugs have produced conflicting results and EGFR-inhibitors have failed to show major improvements.

AREAS COVERED

While commenting on the results of many key Phase III randomized trials, the Authors discuss the most promising classes of novel targeted agents and present the current challenges toward a customized treatment.

EXPERT OPINION

Palliative chemotherapy became the worldwide standard of care for patients with advanced gastric cancers, producing significant life prolongation and improvement of life quality. Nevertheless, long-term outcomes of those patients remain poor. Because of the encouraging advancement in novel targeted therapies, such a disappointing scenario is now evolving. While results serve as a springboard for future research, more comprehensive efforts are needed to clarify the biological mechanisms underpinning cancer progression and help clinicians to develop new effective treatments.

The progress of targeted therapy in advanced gastric cancer

Although palliative chemotherapy has been shown to prolong survival and improve quality of life, the survival of advanced gastric cancer (AGC) patients remains poor. With the advent of targeted therapy, many molecular targeted agents have been evaluated in clinical studies. Trastuzumab, an anti-HER2 monoclonal antibody, has shown activity against HER2-positive AGC and becomes the first targeted agent approved in AGC. Drugs that target epidermal growth factor receptor, including monoclonal antibody and tyrosine kinase inhibitor, do not bring survival benefit to patients with AGC. Additionally, vascular endothelial growth factor inhibitors are also under investigation. Ramucirumab has shown promising result. Other targeted agents are in preclinical or early clinical development, such as mammalian target of rapamycinm inhibitors and c-MET inhibitors.

Phase II trial of capecitabine and everolimus (RAD001) combination in refractory gastric cancer patients

BACKGROUND

The aim of this study was to assess the efficacy and safety of combination regimen of capecitabine plus everolimus in patients with refractory gastric cancer who have failed to at least two cytotoxic regimens.

METHODS

Patients received capecitabine 650 mg/m(2) twice daily (D1-14) and everolimus 5 mg twice daily (D1-21) every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint of the study was overall response (partial or complete response) and the secondary endpoints were progression-free survival (time between registration and disease progression or death) and overall survival. Pharmacokinetic analysis was also performed. Patients who have failed to at least two cytotoxic regimens were enrolled.

RESULTS

Between March 2010 and June 2012, 47 patients were enrolled. 33 patients (70.2%) had received more than three previous regimens prior to enrolment. Among 43 evaluable patients for treatment response, 5 patients achieved confirmed partial response and 18 patients showed stable disease, resulting in an overall response rate (ORR) of 10.6% (95% C.I.: 1.8-19.4%) and disease control rate of 48.9% (95% C.I.:34.6-63.2%). At a median follow-up of 106 weeks (range, 21-141 weeks), the median progression-free survival and overall survival were 11.0 weeks (95% C.I.: 5.7-16.3 weeks) and 21.0 weeks (95% C.I.: 14.3-27.7 weeks), respectively. Grade 3 nausea, diarrhea and stomatitis occurred in two, three and three patients, respectively. Elevated liver enzyme was observed in 21 patients and no patient had pulmonary fibrosis.

CONCLUSIONS

The combination of capecitabine 650 mg/m(2) twice daily and everolimus 5 mg twice daily was found to be effective in a small subset of GC patients who were heavily pre-treated.

Targeted treatments for metastatic esophageal squamous cell cancer

Squamous cell carcinoma, one of the two major sub-types of esophageal carcinomas, constitutes the great majority of tumors in the upper and middle third of the organ. Declining in incidence in western countries, it continues to be a significant public health problem in the far east. Targeted treatments are novel therapies introduced in the clinical therapeutic armamentarium of oncology in the last 10-15 years. They represent a rational way of treating various cancers based on their molecular lesions. Although no such agent has been approved so far for the treatment of esophageal squamous cell carcinomas (ESCC), several are in clinical trials and several others have displayed pre-clinical activity that would justify the efforts and risks of pursuing their clinical development in this disease. This paper discusses some of these targeted agents in more advanced development in metastatic ESCC, as well as some promising drugs with pre-clinical or initial clinical data in the disease.

Utilization of quantitative in vivo pharmacology approaches to assess combination effects of everolimus and irinotecan in mouse xenograft models of colorectal cancer

Purpose

The PI3K/AKT/mTOR pathway is frequently dysregulated in cancers and inhibition of mTOR has demonstrated the ability to modulate pro-survival pathways. As such, we sought to determine the ability of the mTOR inhibitor everolimus to potentiate the antitumor effects of irinotecan in colorectal cancer (CRC).

Experimental Design

The combinatorial effects of everolimus and irinotecan were evaluated in vitro and in vivo in CRC cell lines harboring commonly found mutations in PIK3CA, KRAS and/or BRAF. Pharmacokinetically-directed dosing protocols of everolimus and irinotecan were established and used to assess the in vivo antitumor effects of the agents. At the end of treatment, 3–6 tumors per treatment arm were harvested for biomarker analysis by NMR metabolomics.

Results

Everolimus and irinotecan/SN38 demonstrated synergistic anti-proliferative effects in multiple CRC cell lines in vitro. Combination effects of everolimus and irinotecan were determined in CRC xenograft models using clinically-relevant dosing protocols. Everolimus demonstrated significant tumor growth inhibition alone and when combined with irinotecan in HT29 and HCT116 tumor xenografts. Metabolomic analysis showed that HT29 tumors were more metabolically responsive than HCT116 tumors. Everolimus caused a decrease in glycolysis in both tumor types whilst irinotecan treatment resulted in a profound accumulation of lipids in HT29 tumors indicating a cytotoxic effect.

Conclusions

Quantitative analysis of tumor growth and metabolomic data showed that the combination of everolimus and irinotecan was more beneficial in the BRAF/PIK3CA mutant HT29 tumor xenografts, which had an additive effect, than the KRAS/PIK3CA mutant HCT116 tumor xenografts, which had a less than additive effect.

Randomised clinical trial: comparison of two everolimus dosing schedules in patients with advanced hepatocellular carcinoma

BACKGROUND

Deregulation of mammalian target of rapamycin (mTOR) signalling is common in human hepatocellular carcinoma (HCC).

AIM

To determine the maximum tolerated dose (MTD) of the oral mTOR inhibitor everolimus in advanced HCC patients.

METHODS

Patients with locally advanced or metastatic HCC (Child-Pugh class A or B) were enrolled in an open-label phase 1 study and randomly assigned to daily (2.5-10 mg) or weekly (20-70 mg) everolimus in a standard 3 + 3 dose-escalation design. MTD was based on the rate of dose-limiting toxicities (DLTs). Secondary endpoints included safety, pharmacokinetics and tumour response. In a post hoc analysis, serum hepatitis B virus (HBV) DNA levels were quantified.

RESULTS

Thirty-nine patients were enrolled. DLTs occurred in five of 21 patients in the daily and two of 19 patients in the weekly cohort. Daily and weekly MTDs were 7.5 mg and 70 mg respectively. Grade 3/4 adverse events with a ≥10% incidence were thrombocytopenia, hypophosphataemia and alanine transaminase (ALT) elevation. In four hepatitis B surface antigen (HBsAg)-seropositive patients, grade 3/4 ALT elevations were accompanied by significant (>1 log) increases in serum HBV levels. The incidence of hepatitis flare (defined as ALT increase >100 IU/mL from baseline) in HBsAg-seropositive patients with and without detectable serum HBV DNA before treatment was 46.2% and 7.1% respectively (P < 0.01, Fisher exact test). Disease control rates in the daily and weekly cohorts were 71.4% and 44.4% respectively.

CONCLUSIONS

The recommended everolimus dosing schedule for future hepatocellular carcinoma studies is 7.5 mg daily. Prophylactic anti-viral therapy should be mandatory for HBsAg-seropositive patients (ClinicalTrials.gov NCT00390195).

Everolimus for advanced pancreatic neuroendocrine tumours: a subgroup analysis evaluating Japanese patients in the RADIANT-3 trial

OBJECTIVE

Everolimus, an inhibitor of the mammalian target of rapamycin, has recently demonstrated efficacy and safety in a Phase III, double-blind, randomized trial (RADIANT-3) in 410 patients with low- or intermediate-grade advanced pancreatic neuroendocrine tumours. Everolimus 10 mg/day provided a 2.4-fold improvement compared with placebo in progression-free survival, representing a 65% risk reduction for progression. The purpose of this analysis was to investigate the efficacy and safety of everolimus in the Japanese subgroup enrolled in the RADIANT-3 study.

METHODS

Subgroup analysis of the Japanese patients was performed comparing efficacy and safety between everolimus 10 mg/day orally (n = 23) and matching placebo (n = 17). The primary endpoint was progression-free survival. Safety was evaluated on the basis of the incidence of adverse drug reactions.

RESULTS

Progression-free survival was significantly prolonged with everolimus compared with placebo. The median progression-free survival was 19.45 months (95% confidence interval, 8.31-not available) with everolimus vs 2.83 months (95% confidence interval, 2.46-8.34) with placebo, resulting in an 81% risk reduction in progression (hazard ratio, 0.19; 95% confidence interval, 0.08-0.48; P< 0.001). Adverse drug reactions occurred in all 23 (100%) Japanese patients receiving everolimus and in 13 (77%) patients receiving placebo; most were grade 1/2 in severity. The most common adverse drug reactions in the everolimus group were rash (n = 20; 87%), stomatitis (n = 17; 74%), infections (n = 15; 65%), nail disorders (n = 12; 52%), epistaxis (n = 10; 44%) and pneumonitis (n = 10; 44%).

CONCLUSIONS

These results support the use of everolimus as a valuable treatment option for Japanese patients with advanced pancreatic neuroendocrine tumours.

Inhibition of mTOR in carcinoid tumors

Neuroendocrine neoplasms (NEN) are a heterogeneous group of tumors, whose incidence and prevalence are increasing. The clinical behavior of NEN is variable, ranging from well-differentiated slow growing tumors to highly aggressive poorly differentiated neuroendocrine carcinomas. The term carcinoid is commonly used for the more benign variants of these neoplasms. Most frequently, carcinoids have their origin in the small intestine, followed by in the lung and other sites. Some of these tumors are associated with the carcinoid syndrome. The use of somatostatin analogs has revolutionized the clinical management of patients with carcinoids. However, although symptomatic relief and stabilization of tumor growth for various periods of time are observed in many patients treated with somatostatin analogs, tumor regression is rare. Currently, there is no other powerful antiproliferative agent available for carcinoids. Mammalian target of rapamycin (mTOR), a main protein kinase in the phosphoinositide 3-kinase/Akt/p70S6K signaling pathway, is an important intracellular mediator involved in multiple cellular functions including proliferation, differentiation, apoptosis, tumorigenesis, and angiogenesis. Alterations of the normal activity of mTOR and of mTOR-related kinases in this pathway have been found in a diversity of human tumors, including NEN; therefore, mTOR pathway represents an attractive target for new anticancer therapies. While mTOR inhibitors, such as everolimus, are established therapy in pancreatic NEN, results from recent clinical trials indicate that mTOR inhibitors may be also of value in the management of carcinoids. However, further clinical trials will have to confirm efficacy and elucidate, in which subtypes and in which setting, these drugs might be most usefully applied.

Targeted therapy for esophagogastric cancers: a review

The incidence of esophagogastric cancers is increasing rapidly in the Western population. Despite better understanding of the biology and intense research in the treatment of these cancers, the long-term survival remains poor both in the locally advanced and metastatic settings. The addition of combined modality strategies has resulted in modest improvement in 5-year survival rates. A number of biologic agents targeting epidermal-derived growth factor receptor, vascular endothelial derived growth factor and its receptor, and mammalian target of rapamycin (mTOR) are being currently evaluated in Phase II and III clinical trials. Some of these, like trastuzumab, cetuximab, and bevacizumab, have shown promising results. This review provides a brief overview of the recent developments in biologic agents for the treatment of esophagogastric cancers.

Phase I and II clinical trials for gastric cancer

Gastric cancer remains a global public health problem with considerable heterogeneity in pathogenesis and clinical presentation across geographic regions. Improved understanding of the molecular biology of this disease has opened avenues for targeted intervention. An individualized treatment approach is required for optimal management of this cancer. Overcoming resistance to therapy requires combining targeted agents with the traditional options of chemotherapy/radiation therapy, and also targeting more than 1 pathway of carcinogenesis at a time. Encouraging molecular hypothesis and biomarker-driven trials will lead to improved patient outcomes and may eventually enable the therapeutic nihilism associated with gastric cancer to be overcome.

Everolimus: in patients with subependymal giant cell astrocytoma associated with tuberous sclerosis complex

Everolimus is an orally administered inhibitor of the mammalian target of rapamycin (mTOR). Everolimus (starting dosage 3.0 mg/m(2)) was associated with a significant reduction in the volume of the largest subependymal giant cell astrocytoma (SEGA) in 28 patients aged ≥3 years with tuberous sclerosis complex (TSC) in a phase II trial (C2485). At 6 months, 32% of patients treated with everolimus had a ≥50% reduction in the volume of their largest SEGA lesion (assessed via an independent central radiology review); 75% had a ≥30% reduction. No patients developed new lesions. During the extension phase of this trial (median duration 34 months), the reduction in SEGA volume was maintained, with no everolimus recipient requiring surgery or other therapy for SEGA or hydrocephalus. In a phase III trial (EXIST-1) in 117 patients with SEGA associated with TSC, 35% of everolimus recipients (starting dosage 4.5 mg/m(2)) versus none of the placebo recipients (p < 0.0001) had an overall response (a reduction in the sum of all target SEGA volumes of ≥50% relative to baseline, nonworsening of non-target SEGA lesions, no new SEGA lesions, and no new/worsening hydrocephalus). Everolimus was generally well tolerated in patients with SEGA associated with TSC; most drug-related adverse reactions were mild to moderate in severity.

Phase I study for ridaforolimus, an oral mTOR inhibitor, in Japanese patients with advanced solid tumors

Purpose

Ridaforolimus is a non-prodrug mTOR inhibitor. The safety, pharmacokinetics (PK), and antitumor activity of oral ridaforolimus were assessed in Japanese patients with refractory solid tumors.

Methods

Ridaforolimus (20 or 40 mg) was administered as a single dose on Day 1, followed by once daily dosing five times a week for a 3-week cycle beginning on Day 8. Full PK sampling was performed on Days 1 and 26.

Results

Thirteen patients (7 at 20 mg and 6 at 40 mg) were enrolled. The median treatment duration was 82 days. The most common drug-related adverse events were stomatitis, hypertriglyceridemia, and proteinuria. Two patients had dose-limiting toxicities (grade 3 stomatitis at 20 mg, and grade 3 anorexia and vomiting at 40 mg). Four patients had grade 1 interstitial pneumonitis. Ridaforolimus in the whole blood was rapidly absorbed and slowly eliminated with a half-life of approximately 56–58 h after a single dose. Two patients (with non-small cell lung cancer and angiosarcoma, respectively) achieved a partial response, and five patients (one with thymic cancer and four with soft tissue sarcomas) had a stable disease for ≥16 weeks.

Conclusions

Ridaforolimus was well tolerated up to a dose of 40 mg in Japanese patients. Preliminary evidence of antitumor activity was observed for patients with solid tumors. Further investigation at this dose is warranted.

Molecular targeted agents for gastric and gastroesophageal junction cancer

Despite recent improvements in surgical techniques and chemotherapy, advanced cancers of the stomach and gastroesophageal junction (GEJ) continue to have poor clinical outcomes. However, molecules intimately related to cancer cell proliferation, invasion, and metastasis have been studied as candidates for molecular targeted agents. Target molecules, such as the epidermal growth factor receptor, vascular endothelial growth factor receptor, and P13k/Akt/mTor pathway, as well as the insulin-like growth factor receptor, c-Met pathways, fibroblast growth factor receptor, and other pathways are considered to be promising candidates for molecular targeted therapy for gastric and GEJ cancer. In this review we focus on the recent developments in targeting relevant pathways in these types of cancer.

mTOR as a therapeutic target in patients with gastric cancer

The poor long-term outcomes associated with current chemotherapy treatment of patients with advanced gastric cancer suggest a need for novel targeted agents that may confer a better survival benefit. Evidence of mammalian target of rapamycin (mTOR) activation has been demonstrated in patient-derived gastric cancer cells and tumors. This review explores the relevance of the mTOR pathway to gastric cancer pathogenesis and its potential as a therapeutic target in patients with gastric cancer as well as presenting the first available clinical data on mTOR inhibitors in this disease setting. Preclinical data suggest that suppression of the mTOR pathway inhibited the proliferation of gastric cancer cells and delayed tumor progression in in vitro and animal models. In the clinical setting, the mTOR inhibitor everolimus has been active and well tolerated in phase I/II studies of patients with chemotherapy-refractory metastatic gastric cancer. Based on these promising results, everolimus currently is being investigated as a monotherapy or in combination with chemotherapeutic agents in ongoing phase II/III clinical studies.

Phase I and pharmacokinetic study of capecitabine and the oral mTOR inhibitor everolimus in patients with advanced solid malignancies

Background Everolimus is an oral mTOR-inhibitor. Preclinical data show synergistic effects of mTOR inhibition in combination with 5-fluorouracil-based anticancer therapy. The combination of everolimus with capecitabine seems therefore an attractive new, orally available, treatment regimen. Patients and methods Safety, preliminary efficacy and pharmacokinetics of everolimus in combination with capecitabine were investigated in patients with advanced solid malignancies. Patients were treated with fixed dose everolimus 10 mg/day continuously, plus capecitabine bid for 14 days in three-weekly cycles. Dose escalation of capecitabine proceeded according to the standard 3 × 3 phase I design in four predefined dose levels (500–1,000 mg/m² bid). Results In total, 18 patients were enrolled. Median (range) treatment duration with everolimus was 70 days (21–414). Capecitabine 1,000 mg/m² bid combined with 10 mg/day everolimus was declared the maximum tolerated dose, at which level one patient developed dose-limiting toxicity (stomatitis grade 3). Drug-related adverse events were mostly grade ≤2 and included mainly fatigue (56%), stomatitis (50%), and hand-foot syndrome (33%). Partial response was documented in three patients, and four had stable disease. There was no pharmacokinetic interaction between everolimus and capecitabine. Conclusion Everolimus 10 mg/day continuously combined with capecitabine 1,000 mg/m² bid for 14 days every 3 weeks is a patient-convenient, safe and tolerable oral treatment regimen. This is the first study to demonstrate feasibility of this combination at doses with proven single agent efficacy in a number of tumors. Prolonged clinical benefit was observed in an encouraging 39% of patients with advanced solid malignancies.

The mTOR protein as a target in thyroid cancer

INTRODUCTION

The mammalian target of rapamycin (mTOR) protein is a downstream effector of the phosphatidilinositol-3 kinase (PI3K)/Akt pathway, which regulates not only cell proliferation and viability, but also iodide uptake in thyroid cells. Genetic alterations in the PI3K/Akt/mTOR pathway are common during thyroid cancer progression, and thus, these proteins are attractive targets for cancer therapy. So far, specific mTOR inhibitors, such as rapamycin analogs, have been developed and studied as anti-cancer agents.

AREAS COVERED

This review discusses evidence that justifies the potential use of mTOR signaling pathway inhibitors as therapeutic agents for thyroid cancer.

EXPERT OPINION

In the near future, mTOR-targeted drugs might represent a new approach for the therapy of thyroid cancer patients; rapamycin analogs have already been developed and are currently being clinically tested. Besides the antiproliferative action of mTOR inhibition, the stimulatory effect on thyroid iodide uptake can also be useful in the treatment of recurrent thyroid cancer. Therefore, if rapamycin analogs are able to increase iodide uptake in thyroid cancer, either alone or in combination with other agents, this will represent a new approach for the treatment of thyroid cancer, which may possibly improve the treatment of patients in which radioiodine therapy is not effective.

Two-dose-level confirmatory study of the pharmacokinetics and tolerability of everolimus in Chinese patients with advanced solid tumors

Background

This phase I, randomized, multicenter, open-label study investigated the pharmacokinetics, safety, and efficacy of the oral mammalian target of rapamycin inhibitor everolimus in Chinese patients with advanced solid tumors.

Methods

A total of 24 patients with advanced breast cancer (n = 6), gastric cancer (n = 6), non-small cell lung cancer (n = 6), or renal cell carcinoma (n = 6) who were refractory to/unsuitable for standard therapy were randomized 1:1 to oral everolimus 5 or 10 mg/day. Primary end points were pharmacokinetic parameters and safety and tolerability. Pharmacokinetic 24-h profiles were measured on day 15; trough level was measured on days 2, 8, 15, 16, and 22. Tolerability was assessed continuously. This final analysis was performed after all patients had received 6 months of study drug or had discontinued.

Results

Everolimus was absorbed rapidly; median T_max was 3 h (range, 1-4) and 2 h (range, 0.9-6) in the 5 and 10 mg/day groups, respectively. Pharmacokinetic parameters increased dose proportionally from the 5 and 10 mg/day doses. Steady-state levels were achieved by day 8 or earlier. The most common adverse events suspected to be related to everolimus therapy were increased blood glucose (16.7% and 41.7%) and fatigue (16.7% and 33.3%) in the everolimus 5 and 10 mg/day dose cohorts, respectively. Best tumor response was stable disease in 10 (83%) and 6 (50%) patients in the 5 and 10 mg/day groups, respectively.

Conclusions

Everolimus 5 or 10 mg/day was well tolerated in Chinese patients with advanced solid tumors. The observed safety and pharmacokinetic profile of everolimus from this study were consistent with previous studies.

Trial registration

Chinese Health Authorities 2008L09346

Phase I study of the oral mammalian target of rapamycin inhibitor everolimus (RAD001) in Japanese patients with relapsed or refractory non-Hodgkin lymphoma

Phase I study was conducted to evaluate the safety, pharmacokinetics (PK) and efficacy of the oral mammalian target of rapamycin inhibitor, everolimus (RAD001), in patients with relapsed or refractory non-Hodgkin lymphoma (NHL). Patients received everolimus 5 or 10 mg orally once daily. Dose escalation was based on the safety assessment and the probability of dose-limiting toxicities (DLTs) using a Bayesian logistic model. DLTs were evaluated in six patients at each dose level during the initial 28 days of study treatment. A total of 13 patients were enrolled; 5 mg (seven) and 10 mg (six). No DLTs were observed at either dose level. Frequently observed potentially drug-related adverse events included leukopenia (8/13), thrombocytopenia (8/13), elevated hepatic transaminase (9/13), stomatitis (7/13), anemia (6/13), and nasopharyngitis (6/13). All adverse events were reversible. Non-infectious pneumonitis (grade 1) in one patient resolved following discontinuation of everolimus. Two patients with diffuse large B cell lymphoma and two patients with follicular lymphomas achieved objective responses with an overall response rate of 31% (4/13). The pharmacokinetic profiles were not different from those in non-Japanese patients. Everolimus was well tolerated at doses up to 10 mg/day and showed potential efficacy in relapsed or refractory NHL, warranting further investigation.