Dabrafenib plus trametinib in patients with BRAFV600E-mutant low-grade and high-grade glioma (ROAR): a multicentre, open-label, single-arm, phase 2, basket trial.

BACKGROUND: Effective treatments are needed to improve outcomes for high-grade glioma and low-grade glioma. The activity and safety of dabrafenib plus trametinib were evaluated in adult patients with recurrent or progressive BRAFV600E mutation-positive high-grade glioma and low-grade glioma. METHODS: This study is part of an ongoing open-label, single-arm, phase 2 Rare Oncology Agnostic Research (ROAR) basket trial at 27 community and academic cancer centres in 13 countries (Austria, Belgium, Canada, France, Germany, Italy, Japan, the Netherlands, Norway, South Korea, Spain, Sweden, and the USA). The study enrolled patients aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0, 1, or 2. Patients with BRAFV600E mutation-positive high-grade glioma and low-grade glioma received dabrafenib 150 mg twice daily plus trametinib 2 mg once daily orally until unacceptable toxicity, disease progression, or death. In the high-grade glioma cohort, patients were required to have measurable disease at baseline using the Response Assessment in Neuro-Oncology high-grade glioma response criteria and have been treated previously with radiotherapy and first-line chemotherapy or concurrent chemoradiotherapy. Patients with low-grade glioma were required to have measurable non-enhancing disease (except pilocytic astrocytoma) at baseline using the Response Assessment in Neuro-Oncology low-grade glioma criteria. The primary endpoint, in the evaluable intention-to-treat population, was investigator-assessed objective response rate (complete response plus partial response for high-grade glioma and complete response plus partial response plus minor response for low-grade glioma). This trial is ongoing, but is closed for enrolment, NCT02034110. FINDINGS: Between April 17, 2014, and July 25, 2018, 45 patients (31 with glioblastoma) were enrolled into the high-grade glioma cohort and 13 patients were enrolled into the low-grade glioma cohort. The results presented here are based on interim analysis 16 (data cutoff Sept 14, 2020). In the high-grade glioma cohort, median follow-up was 12·7 months (IQR 5·4-32·3) and 15 (33%; 95% CI 20-49) of 45 patients had an objective response by investigator assessment, including three complete responses and 12 partial responses. In the low-grade glioma cohort, median follow-up was 32·2 months (IQR 25·1-47·8). Nine (69%; 95% CI 39-91) of 13 patients had an objective response by investigator assessment, including one complete response, six partial responses, and two minor responses. Grade 3 or worse adverse events were reported in 31 (53%) patients, the most common being fatigue (five [9%]), decreased neutrophil count (five [9%]), headache (three [5%]), and neutropenia (three [5%]). INTERPRETATION: Dabrafenib plus trametinib showed clinically meaningful activity in patients with BRAFV600E mutation-positive recurrent or refractory high-grade glioma and low-grade glioma, with a safety profile consistent with that in other indications. BRAFV600E testing could potentially be adopted in clinical practice for patients with glioma. FUNDING: Novartis.

A first-in-human phase 1 and pharmacological study of TAS-119, a novel selective Aurora A kinase inhibitor in patients with advanced solid tumours.

BACKGROUND: This is a first-in-human study with TAS-119, an Aurora A kinase (AurA) inhibitor. METHODS: Patients with advanced, refractory, solid tumours were enrolled into 5 dose escalation cohorts (70-300 mg BID, 4 days on/3 days off, 3 out of 4 weeks or 4 out of 4 weeks). The expansion part consisted of patients with small-cell lung cancer, HER2-negative breast cancer, MYC-amplified/ß-catenin-mutated (MT) tumours or other (basket cohort). RESULTS: In the escalation part (n = 34 patients), dose-limiting toxicities were one grade 3 nausea, two grade 2 and one grade 3 ocular toxicity and a combination of fatigue, ocular toxicity and nausea in one patient (all grade 2) at dose levels of 150, 200, 250 and 300 mg, respectively. Most frequent treatment-related adverse events were fatigue (32%), diarrhoea (24%) and ocular toxicity (24%). Toxicity grade ≥3 in ≥10% of patients were diarrhoea (15%) and increased lipase (12%). The maximum tolerated dose was 250 mg BID. Due to one additional grade 1 ocular toxicity, the RP2D was set at 200 mg BID (4 days on/3 days off, 3 out of 4 weeks), which was further explored in the expansion part (n = 40 patients). Target inhibition in paired skin biopsies was shown. CONCLUSIONS: TAS-119 has a favourable and remarkably distinct safety profile from other AurA inhibitors. CLINICAL TRIAL REGISTRATION: NCT02448589.

Phase 1b/2 trial of tepotinib in sorafenib pretreated advanced hepatocellular carcinoma with MET overexpression.

BACKGROUND: This Phase 1b/2 study evaluated tepotinib, a highly selective MET inhibitor, in US/European patients with sorafenib pretreated advanced hepatocellular carcinoma (aHCC) with MET overexpression. METHODS: Eligible adults had aHCC, progression after ≥4 weeks of sorafenib, and, for Phase 2 only, MET overexpression. Tepotinib was administered once daily at 300 or 500 mg in Phase 1b ('3 + 3' design), and at the recommended Phase 2 dose (RP2D) in Phase 2. Primary endpoints were dose-liming toxicities (DLTs; Phase 1b) and 12-week investigator-assessed progression-free survival (PFS; Phase 2). RESULTS: In Phase 1b (n = 17), no DLTs occurred and the RP2D was confirmed as 500 mg. In Phase 2 (n = 49), the primary endpoint was met: 12-week PFS was 63.3% (90% CI: 50.5-74.7), which was significantly greater than the predefined null hypothesis of ≤15% (one-sided binomial exact test: P < 0.0001). Median time to progression was 4 months. In Phase 2, 28.6% of patients had treatment-related Grade ≥3 adverse events, including peripheral oedema and lipase increase (both 6.1%). CONCLUSIONS: Tepotinib was generally well tolerated and the RP2D (500 mg) showed promising efficacy and, therefore, a positive benefit-risk balance in sorafenib pretreated aHCC with MET overexpression. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02115373.

Dabrafenib plus trametinib in patients with BRAFV600E-mutated biliary tract cancer (ROAR): a phase 2, open-label, single-arm, multicentre basket trial.

BACKGROUND: Effective treatments for patients with cholangiocarcinoma after progression on gemcitabine-based chemotherapy are urgently needed. Mutations in the BRAF gene have been found in 5% of biliary tract tumours. The combination of dabrafenib and trametinib has shown activity in several BRAFV600E-mutated cancers. We aimed to assess the activity and safety of dabrafenib and trametinib combination therapy in patients with BRAFV600E-mutated biliary tract cancer. METHODS: This study is part of an ongoing, phase 2, open-label, single-arm, multicentre, Rare Oncology Agnostic Research (ROAR) basket trial in patients with BRAFV600E-mutated rare cancers. Patients were eligible for the biliary tract cancer cohort if they were aged 18 years or older, had BRAFV600E-mutated, unresectable, metastatic, locally advanced, or recurrent biliary tract cancer, an Eastern Cooperative Oncology Group performance status of 0-2, and had received previous systemic treatment. All patients were treated with oral dabrafenib 150 mg twice daily and oral trametinib 2 mg once daily until disease progression or intolerance of treatment. The primary endpoint was the overall response rate, which was determined by Response Evaluation Criteria in Solid Tumors version 1.1 in the intention-to-treat evaluable population, which comprised all enrolled patients regardless of receiving treatment who were evaluable (ie, had progression, began a new anticancer treatment, withdrew consent, died, had stable disease for 6 weeks or longer, or had two or more post-baseline assessments). The ROAR trial is registered with ClinicalTrials.gov, NCT02034110. These results are based on an interim analysis; the study is active but not recruiting. FINDINGS: Between March 12, 2014, and July 18, 2018, 43 patients with BRAFV600E-mutated biliary tract cancer were enrolled to the study and were evaluable. Median follow-up was 10 months (IQR 6-15). An investigator-assessed overall response was achieved by 22 (51%, 95% CI 36-67) of 43 patients. An independent reviewer-assessed overall response was achieved by 20 (47%, 95% CI 31-62) of 43 patients. The most common grade 3 or worse adverse event was increased γ-glutamyltransferase in five (12%) patients. 17 (40%) patients had serious adverse events and nine (21%) had treatment-related serious adverse events, the most frequent of which was pyrexia (eight [19%]). No treatment-related deaths were reported. INTERPRETATION: Dabrafenib plus trametinib combination treatment showed promising activity in patients with BRAFV600E-mutated biliary tract cancer, with a manageable safety profile. Routine testing for BRAFV600E mutations should be considered in patients with biliary tract cancer. FUNDING: GlaxoSmithKline and Novartis.

Proliferation and estrogen signaling can distinguish patients at risk for early versus late relapse among estrogen receptor positive breast cancers.

INTRODUCTION: We examined if a combination of proliferation markers and estrogen receptor (ER) activity could predict early versus late relapses in ER-positive breast cancer and inform the choice and length of adjuvant endocrine therapy. METHODS: Baseline affymetrix gene-expression profiles from ER-positive patients who received no systemic therapy (n = 559), adjuvant tamoxifen for 5 years (cohort-1: n = 683, cohort-2: n = 282) and from 58 patients treated with neoadjuvant letrozole for 3 months (gene-expression available at baseline, 14 and 90 days) were analyzed. A proliferation score based on the expression of mitotic kinases (MKS) and an ER-related score (ERS) adopted from Oncotype DX® were calculated. The same analysis was performed using the Genomic Grade Index as proliferation marker and the luminal gene score from the PAM50 classifier as measure of estrogen-related genes. Median values were used to define low and high marker groups and four combinations were created. Relapses were grouped into time cohorts of 0-2.5, 0-5, 5-10 years. RESULTS: In the overall 10 years period, the proportional hazards assumption was violated for several biomarker groups indicating time-dependent effects. In tamoxifen-treated patients Low-MKS/Low-ERS cancers had continuously increasing risk of relapse that was higher after 5 years than Low-MKS/High-ERS cancers [0 to 10 year, HR 3.36; p = 0.013]. High-MKS/High-ERS cancers had low risk of early relapse [0-2.5 years HR 0.13; p = 0.0006], but high risk of late relapse which was higher than in the High-MKS/Low-ERS group [after 5 years HR 3.86; p = 0.007]. The High-MKS/Low-ERS subset had most of the early relapses [0 to 2.5 years, HR 6.53; p < 0.0001] especially in node negative tumors and showed minimal response to neoadjuvant letrozole. These findings were qualitatively confirmed in a smaller independent cohort of tamoxifen-treated patients. Using different biomarkers provided similar results. CONCLUSIONS: Early relapses are highest in highly proliferative/low-ERS cancers, in particular in node negative tumors. Relapses occurring after 5 years of adjuvant tamoxifen are highest among the highly-proliferative/high-ERS tumors although their risk of recurrence is modest in the first 5 years on tamoxifen. These tumors could be the best candidates for extended endocrine therapy.

A first-in-human phase 1/2 study of FGF401 and combination of FGF401 with spartalizumab in patients with hepatocellular carcinoma or biomarker-selected solid tumors.

BACKGROUND: Deregulation of FGF19-FGFR4 signaling is found in several cancers, including hepatocellular carcinoma (HCC), nominating it for therapeutic targeting. FGF401 is a potent, selective FGFR4 inhibitor with antitumor activity in preclinical models. This study was designed to determine the recommended phase 2 dose (RP2D), characterize PK/PD, and evaluate the safety and efficacy of FGF401 alone and combined with the anti-PD-1 antibody, spartalizumab. METHODS: Patients with HCC or other FGFR4/KLB expressing tumors were enrolled. Dose-escalation was guided by a Bayesian model. Phase 2 dose-expansion enrolled patients with HCC from Asian countries (group1), non-Asian countries (group2), and patients with other solid tumors expressing FGFR4 and KLB (group3). FGF401 and spartalizumab combination was evaluated in patients with HCC. RESULTS: Seventy-four patients were treated in the phase I with single-agent FGF401 at 50 to 150 mg. FGF401 displayed favorable PK characteristics and no food effect when dosed with low-fat meals. The RP2D was established as 120 mg qd. Six of 70 patients experienced grade 3 dose-limiting toxicities: increase in transaminases (n = 4) or blood bilirubin (n = 2). In phase 2, 30 patients in group 1, 36 in group 2, and 20 in group 3 received FGF401. In total, 8 patients experienced objective responses (1 CR, 7 PR; 4 each in phase I and phase II, respectively). Frequent adverse events (AEs) were diarrhea (73.8%), increased AST (47.5%), and ALT (43.8%). Increase in levels of C4, total bile acid, and circulating FGF19, confirmed effective FGFR4 inhibition. Twelve patients received FGF401 plus spartalizumab. RP2D was established as FGF401 120 mg qd and spartalizumab 300 mg Q3W; 2 patients reported PR. CONCLUSIONS: At biologically active doses, FGF401 alone or combined with spartalizumab was safe in patients with FGFR4/KLB-positive tumors including HCC. Preliminary clinical efficacy was observed. Further clinical evaluation of FGF401 using a refined biomarker strategy is warranted. TRIAL REGISTRATION: NCT02325739 .

Phase I trial of oral mTOR inhibitor everolimus in combination with trastuzumab and vinorelbine in pre-treated patients with HER2-overexpressing metastatic breast cancer.

To determine the feasible dose and schedule for everolimus, an oral mTOR inhibitor, combined with vinorelbine and trastuzumab for patients with HER2-overexpressing metastatic breast cancer pretreated with trastuzumab. In this phase Ib multicenter, Bayesian dose-escalation study, 50 patients received everolimus 5 mg/day, 20 mg/week, or 30 mg/week plus vinorelbine (25 mg/m² on day 1 and 8 every 3 weeks) and trastuzumab (2 mg/kg weekly). Endpoints included end-of-cycle-1 dose-limiting toxicity (DLT) rate (primary endpoint), safety, relative dose intensity, overall response rate (ORR), and pharmacokinetics. Grade 3/4 neutropenia was the most common end-of-cycle-1 DLT and occurred in 10 of 30 and 4 of 14 patients in the 5 mg/day and 30 mg/week cohorts, respectively. Other end-of-cycle-1 DLTs included single cases of febrile neutropenia, grade 3 stomatitis with concomitant fatigue, grade 2 stomatitis, grade 3 anorexia, and grade 2 acneiform dermatitis, all in the 5-mg/day cohort. Based on the recorded DLTs and global safety, everolimus 5 mg/day and 30 mg/week were chosen as the optimal dose levels for the daily and weekly arms. Forty-seven patients were evaluable for efficacy. ORR was 19.1%, with a disease control rate of 83.0% and median progression-free survival of 30.7 weeks. No drug interaction was observed between everolimus and vinorelbine. Everolimus combined with weekly vinorelbine and trastuzumab generally was well tolerated and had encouraging antitumor activity in heavily pretreated patients with HER2-overexpressing metastatic breast cancer that progressed on trastuzumab (NCT00426530).

Phase Ib Study of Ribociclib plus Fulvestrant and Ribociclib plus Fulvestrant plus PI3K Inhibitor (Alpelisib or Buparlisib) for HR+ Advanced Breast Cancer.

PURPOSE: Resistance to treatment with endocrine therapy in patients with HR+, HER2- advanced breast cancer (ABC) is common and dual inhibition of CDK4/6 and PI3K pathways may delay the development of resistance. This phase Ib trial evaluates the safety and tolerability of triple and double regimens containing the CDK4/6 inhibitor ribociclib. PATIENTS AND METHODS: In this open-label, multicenter, phase Ib study, 70 postmenopausal women with HR+, HER2- ABC were enrolled into one of four treatment combinations: ribociclib (once daily, 3 weeks on, 1 week off) plus fulvestrant; ribociclib (continuous dosing) plus fulvestrant; ribociclib plus alpelisib plus fulvestrant; or ribociclib plus buparlisib plus fulvestrant. RESULTS: The recommended phase II dose (RP2D) of ribociclib was confirmed to be 600 mg (3 weeks on, 1 week off) and 400 mg (continuous dosing) plus fulvestrant 500 mg. For the triple combination with buparlisib, the RP2D was ribociclib 400 mg plus buparlisib 30 mg plus fulvestrant 500 mg. Enrollment for the triple combinations was stopped due to unexpected toxicity. No RP2D was determined for the alpelisib combination. The safety profiles of the ribociclib plus fulvestrant combinations were consistent with those in previous studies. There was no marked difference in ribociclib exposure in the presence of triple-combination partners. The highest overall response rate was seen in the buparlisib triple combination (25.0%; 95% confidence interval, 9.8-46.7). CONCLUSIONS: Ribociclib plus fulvestrant demonstrated safety in the treatment of patients with HR+, HER2- ABC. Triple combinations with alpelisib or buparlisib plus fulvestrant are not recommended for phase II investigation.See related commentary by Clark et al., p. 371.

PD-1 Blockade in Anaplastic Thyroid Carcinoma.

PURPOSE: Anaplastic thyroid carcinoma is an aggressive malignancy that is almost always fatal and lacks effective systemic treatment options for patients with BRAF-wild type disease. As part of a phase I/II study in patients with advanced/metastatic solid tumors, patients with anaplastic thyroid carcinoma were treated with spartalizumab, a humanized monoclonal antibody against the programmed death-1 (PD-1) receptor. METHODS: We enrolled patients with locally advanced and/or metastatic anaplastic thyroid carcinoma in a phase II cohort of the study. Patients received 400 mg spartalizumab intravenously, once every 4 weeks. The overall response rate was determined according to RECIST v1.1. RESULTS: Forty-two patients were enrolled. Adverse events were consistent with those previously observed with PD-1 blockade. Most common treatment-related adverse events were diarrhea (12%), pruritus (12%), fatigue (7%), and pyrexia (7%). The overall response rate was 19%, including three patients with a complete response and five with a partial response. Most patients had baseline tumor biopsies positive for PD-L1 expression (n = 28/40 evaluable), and response rates were higher in PD-L1-positive (8/28; 29%) versus PD-L1-negative (0/12; 0%) patients. The highest rate of response was observed in the subset of patients with PD-L1 ≥ 50% (6/17; 35%). Responses were seen in both BRAF-nonmutant and BRAF-mutant patients and were durable, with a 1-year survival of 52.1% in the PD-L1-positive population. CONCLUSION: To our knowledge, this is the first clinical trial to show responsiveness of anaplastic thyroid carcinoma to PD-1 blockade.

Trastuzumab as adjuvant systemic therapy for HER2-positive breast cancer.

Trastuzumab has an established role for the treatment of HER2-positive early-stage breast cancer because of the success of this agent in the adjuvant setting. Several key questions about the value of trastuzumab for the treatment of breast cancer, however, still need to be answered. Various differences in patient characteristics and treatment regimens were present in the randomized trials discussed in this Review; therefore, the details of trastuzumab use need clarification. For example, the optimum timing, the ideal administration schedule, and the appropriate length of treatment are not known. Cardiotoxicity is major concern even though the results of all randomized trials have shown that the degree of cardiotoxicity with trastuzumab is acceptable -- the incidence of cardiac damage caused by trastuzumab ranged from 0.4% to 4.1% in the different trials (cumulative incidence of congestive heart failure, New York Heart Association class 3-4). Current data do not support the use of trastuzumab for more than 1 year. The analysis of 2-year treatment with trastuzumab is expected to be available in 2009.

Capecitabine/Cyclophosphamide/Methotrexate for patients with metastatic breast cancer: a dose-finding, feasibility, and efficacy study.

BACKGROUND: Capecitabine is a fluoropyrimidine carbamate that acts as a prodrug, mimics continuous infusion of 5-fluorouracil (5-FU), and has encouraging antitumor activity in women with metastatic breast cancer. We performed a feasibility study in which the 5-FU of the cyclophosphamide/methotrexate/5-FU regimen was substituted with capecitabine in a novel regimen applicable to women with breast cancer. Three doses of capecitabine were explored (1650 mg/m2, 1850 mg/m2, and 2000 mg/m2 per day from day 1 to day 14) in combination with intravenous bolus cyclophosphamide (600 mg/m2) and methotrexate (40 mg/m2), given on day 1 and day 8 every 4 weeks. PATIENTS AND METHODS: From June 2002 to August 2004, 39 women with metastatic breast cancer were enrolled and were evaluable for toxicity and response. RESULTS: Hematologic toxicity was mild for the majority of patients: grade 4 neutropenia and anemia and grade 3 thrombocytopenia occurred in 1 patient. Nonhematologic toxicity of grade > or = 3 occurred only at the highest dose level. Overall response rate was 44% (complete response rate, 13%; partial response rate, 31%). Clinical benefit including long-lasting (> or = 6 months) stable disease overall accounted for 82%. Responses were observed at each dose level. The median duration of response was 14 months (95% confidence interval, 10-28 months). At a median observation of 24 months (range, 8-36 months), time to progression was 13 months (95% confidence interval, 9-24 months). CONCLUSION: The data of our study show that cyclophosphamide/methotrexate/capecitabine is feasible and active. The capecitabine dose of 1850 mg/m(2) orally on days 1-14 every 28 days was selected as the recommended dose in view of the higher likelihood of "on time" chronic therapy compared with the 2000-mg/m(2) dose.

Molecular Alterations and Everolimus Efficacy in Human Epidermal Growth Factor Receptor 2-Overexpressing Metastatic Breast Cancers: Combined Exploratory Biomarker Analysis From BOLERO-1 and BOLERO-3.

PURPOSE: Two recent phase III trials, BOLERO-1 and BOLERO-3 (Breast Cancer Trials of Oral Everolimus), evaluated the addition of everolimus to trastuzumab and chemotherapy in human epidermal growth factor receptor 2-overexpressing advanced breast cancer. The current analysis aimed to identify biomarkers to predict the clinical efficacy of everolimus treatment. METHODS: Archival tumor samples from patients in BOLERO-1 and BOLERO-3 were analyzed using next-generation sequencing, immunohistochemistry, and Sanger sequencing. RESULTS: Biomarker data were available for 549 patients. PIK3CA activating mutations and PTEN loss were reported in 30% and 16% of BOLERO-1 samples and in 32% and 12% of BOLERO-3 samples, respectively. PI3K pathway was hyperactive (PIK3CA mutations and/or PTEN loss and/or AKT1 mutation) in 47% of BOLERO-1 and 41% of BOLERO-3 samples. In both studies, differential progression-free survival (PFS) benefits of everolimus were consistently observed in patient subgroups defined by their PI3K pathway status. When analyzing combined data sets of both studies, everolimus was associated with a decreased hazard of progression in patients with PIK3CA mutations (hazard ratio [HR], 0.67; 95% CI, 0.45 to 1.00), PTEN loss (HR, 0.54; 95% CI, 0.31 to 0.96), or hyperactive PI3K pathway (HR, 0.67; 95% CI, 0.48 to 0.93). Patients with wild-type PIK3CA (HR, 1.10; 95% CI, 0.83 to 1.46), normal PTEN (HR, 1.00; 95% CI, 0.80 to 1.26), or normal PI3K pathway activity (HR, 1.19; 95% CI, 0.87 to 1.62) did not derive PFS benefit from everolimus. CONCLUSION: This analysis, although exploratory, suggests that patients with human epidermal growth factor receptor 2-positive advanced breast cancer having tumors with PIK3CA mutations, PTEN loss, or hyperactive PI3K pathway could derive PFS benefit from everolimus.

Clinical Development Strategies and Outcomes in First-in-Human Trials of Monoclonal Antibodies.

PURPOSE: We conducted a comprehensive review of the design, implementation, and outcome of first-in-human (FIH) trials of monoclonal antibodies (mAbs) to clearly determine early clinical development strategies for this class of compounds. METHODS: We performed a PubMed search using appropriate terms to identify reports of FIH trials of mAbs published in peer-reviewed journals between January 2000 and April 2013. RESULTS: A total of 82 publications describing FIH trials were selected for analysis. Only 27 articles (33%) reported the criteria used for selecting the starting dose (SD). Dose escalation was performed using rule-based methods in 66 trials (80%). The median number of planned dose levels was five (range, two to 13). The median of the ratio between the highest planned dose and the SD was 27 (range, two to 3,333). Although in 56 studies (68%) at least one grade 3 or 4 toxicity event was reported, no dose-limiting toxicity was observed in 47 trials (57%). The highest planned dose was reached in all trials, but the maximum-tolerated dose (MTD) was defined in only 13 studies (16%). The median of the ratio between MTD and SD was eight (range, four to 1,000). The recommended phase II dose was indicated in 34 studies (41%), but in 25 (73%) of these trials, this dose was chosen without considering toxicity as the main selection criterion. CONCLUSION: This literature review highlights the broad design heterogeneity of FIH trials testing mAbs. Because of the limited observed toxicity, the MTD was infrequently reached, and therefore, the recommended phase II dose for subsequent clinical trials was only tentatively defined.

Targeting mTOR pathways in human malignancies.

BACKGROUND: The mammalian target of rapamycin (mTOR) is a protein kinase involved in the phosphatidylinositol 3-Kinase (PI3K)/AKT signalling pathway with a central role in the control of cell growth, survival and angiogenesis. Multiple and frequent dysregulations of this pathway in human tumors make it a central target in the development of new anticancer treatments. OBJECTIVE: To review the most significant data on mTOR pathway, role of mTOR inhibitors in cancer treatment, preclinical and clinical data of the three first generation mTOR inhibitors (temsirolimus, everolimus and deferolimus), rationales, preclinical and clinical data of second generation mTOR inhibitors. METHODS: Review of published literature on mTOR and related pathways, rapalogs and novel mTOR inhibitors. RESULTS/CONCLUSIONS: Temsirolimus and everolimus have been approved for the treatment of metastatic Renal Cell Carcinoma (RCC), temsirolimus also for Mantle Cell Lymphoma (MCL) and everolimus will be approved for pancreatic neuroendocrine tumors; all three rapalogs are currently evaluated in phase III studies in several tumors. Only limited published data are available on new mTOR inhibitors; however, in vitro and in vivo in preclinical studies they have shown a significant antiproliferative activity against a broad panel of tumors and a favourable safety profile, with disease stabilization or even tumor regression, either as single agent or in combination.

Current and future directions in mammalian target of rapamycin inhibitors development.

INTRODUCTION: The mammalian target of the rapamycin (mTOR) signalling pathway has a central role in the regulation of cell growth, survival and angiogenesis and the frequent dysregulation of this pathway in tumor cells makes it a crucial target in the treatment of cancer. Temsirolimus and everolimus are approved for use in metastatic renal cell carcinoma and temsirolimus is also approved for mantle cell lymphoma. All three rapalogs, temsirolimus, everolimus and deforolimus, are currently being evaluated in Phase III studies in several tumors. AREAS COVERED: This paper provides a review of the published literature on the mTOR pathway and related pathway signaling, analogs and novel mTOR inhibitors. The most recent and important data on the mTOR pathway, the role of mTOR inhibitors in cancer treatment and the current status of development of second-generation highly potent and selective mTOR inhibitors are overviewed. EXPERT OPINION: The published data on new mTOR inhibitors are still limited, but the available preclinical results indicate that they have a potent antiproliferative activity against a broad panel of tumor cell lines, have a favorable safety profile, can obtain disease stabilization or even tumor regression and, in some cases, enhance the efficacy of other targeted or standard-of-care anticancer drugs when used in vivo in preclinical studies.

Translational research in phase I trials.

"Translational research" (TR) has the main aim of transferring the results of preclinical research into clinical practice and includes the study of the biology of the disease to provide solid rationales for the development or improvement of new drugs, the evaluation of the biological effects of the drugs in animals to define how to best use those drugs in humans and the study of the biological effects of those drugs in humans. To facilitate the development of new cancer targeted therapies, TR focuses its efforts on the discovery and validation of biomarkers, defined as "a characteristic that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes or pharmacologic responses to a therapeutic intervention". Biomarkers could allow a rational development of targeted agents, based on the mechanistic assessment of their effects. This knowledge can then be used during the subsequent steps of drug discovery, screening, preclinical and clinical testing. This review will focus on the contributions provided by biomarkers to facilitate the development of new targeted therapies.

mTOR inhibitors in the treatment of cancer.

BACKGROUND: The mammalian target of rapamycin (mTOR) is a protein kinase of the phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway with a central role in the control of cell proliferation, survival, mobility and angiogenesis. Dysregulation of mTOR pathway has been found in many human tumours; therefore, the mTOR pathway is considered an important target for the development of new anticancer drugs. OBJECTIVE: To review the mTOR pathway, the role of the mTOR inhibitors in cancer treatment, the preclinical features and clinical results of the three mTOR inhibitors currently in development, temsirolimus, everolimus and deforolimus. METHODS: Review of the published literature (abstracts, full papers) since 1995 on mTOR pathway and related pathway signalling, rapamycin and analogues. RESULTS/CONCLUSION: With each of the three mTOR inhibitors temsirolimus (CCI-779), everolimus (RAD001) and deforolimus (AP23573), a safe schedule of treatment has been defined and promising results of antitumour activity have been achieved in a variety of solid tumours, thus confirming the preclinical expectations.