Summary Background In the randomised, parallel assignment, open-label, phase 3 TH3RESA study, progression-free survival was significantly longer with trastuzumab emtansine versus treatment of ...physician's choice in previously treated patients with HER2-positive advanced breast cancer. We report results from the final overall survival analysis of the TH3RESA trial. Methods Eligible patients for the TH3RESA trial were men and women (aged ≥18 years) with centrally confirmed HER2-positive advanced breast cancer previously treated with both trastuzumab and lapatinib (advanced setting) and a taxane (any setting) and with progression on two or more HER2-directed regimens in the advanced setting. Patients had to have an Eastern Cooperative Oncology Group performance status of 0–2, left ventricular ejection fraction of at least 50%, and adequate organ function. Patients were randomly assigned (2:1) by an interactive voice and web response system with permuted block randomisation in blocks of six to receive trastuzumab emtansine (3·6 mg/kg intravenously every 21 days) or treatment of physician's choice administered per local practice. Randomisation was stratified by world region, number of previous regimens for advanced breast cancer, and presence of visceral disease. On Sept 12, 2012, the study protocol was amended to allow patients with disease progression to crossover from treatment of physician's choice to trastuzumab emtansine. The coprimary endpoints for TH3RESA were investigator-assessed progression-free survival and overall survival in the intention-to-treat population. We report results from a preplanned second interim analysis of overall survival, which was planned for when approximately 67% (n=330) of 492 expected deaths had occurred. This study is registered with ClinicalTrials.gov , number NCT01419197. Findings Between Sept 14, 2011, and Nov 19, 2012, 602 patients were enrolled from 146 centres in 22 countries and randomly assigned to trastuzumab emtansine (n=404) or treatment of physician's choice (n=198). At data cutoff (Feb 13, 2015), 93 (47%) of 198 patients in the physician's choice group had crossed over to trastuzumab emtansine. Overall survival was significantly longer with trastuzumab emtansine versus treatment of physician's choice (median 22·7 months 95% CI 19·4–27·5 vs 15·8 months 13·5–18·7; hazard ratio 0·68 95% CI 0·54–0·85; p=0·0007). As the stopping boundary for overall survival was crossed, this overall survival analysis serves as the final and confirmatory analysis of overall survival and the study was terminated according to the protocol. The incidence of grade 3 or worse adverse events was 161 (40%) of 403 patients in the trastuzumab emtansine group and 87 (47%) of 184 patients in the treatment of physician's choice group. Of the most common grade 3 or worse adverse events (affecting ≥2% of patients in either group), those with a 3% or greater difference in incidence between groups that were more frequent with treatment of physician's choice than with trastuzumab emtansine were diarrhoea (three 1% of 403 patients in the trastuzumab emtansine group vs eight 4% of 184 patients in the treatment of physician's choice group), neutropenia (ten 3% vs 29 16%), and febrile neutropenia (one <1% vs seven 4%); whereas those that were more frequent with trastuzumab emtansine were thrombocytopenia (24 6% of 403 patients vs five 3% of 184 patients) and haemorrhage of any type (17 4% of 403 vs one <1% of 184). Serious adverse events were reported in 102 (25%) of 403 patients in the trastuzumab emtansine group and 41 (22%) of 184 in the physician's choice group. Deaths from adverse events were reported in three patients (2%) in the physician's choice group (of which one was judged to be treatment related) and nine (2%) in the trastuzumab emtansine group (of which three were judged to be treatment related). Interpretation In patients who had progressed on two or more HER2-directed regimens, trastuzumab emtansine treatment resulted in a significant improvement in overall survival versus treatment of physician's choice. These data further solidify the role of trastuzumab emtansine in the management of patients with previously treated HER2-positive advanced breast cancer, and validate HER2 as a therapeutic target even after multiple lines of previous therapy. Funding F Hoffman-La Roche/Genentech.
Summary Background Patients with progressive disease after two or more HER2-directed regimens for recurrent or metastatic breast cancer have few effective therapeutic options. We aimed to compare ...trastuzumab emtansine, an antibody–drug conjugate comprising the cytotoxic agent DM1 linked to trastuzumab, with treatment of physician's choice in this population of patients. Methods This randomised, open-label, phase 3 trial took place in medical centres in 22 countries across Europe, North America, South America, and Asia-Pacific. Eligible patients (≥18 years, left ventricular ejection fraction ≥50%, Eastern Cooperative Oncology Group performance status 0–2) with progressive HER2-positive advanced breast cancer who had received two or more HER2-directed regimens in the advanced setting, including trastuzumab and lapatinib, and previous taxane therapy in any setting, were randomly assigned (in a 2:1 ratio) to trastuzumab emtansine (3·6 mg/kg intravenously every 21 days) or physician's choice using a permuted block randomisation scheme by an interactive voice and web response system. Patients were stratified according to world region (USA vs western Europe vs other), number of previous regimens (excluding single-agent hormonal therapy) for the treatment of advanced disease (two to three vs more than three), and presence of visceral disease (any vs none). Coprimary endpoints were investigator-assessed progression-free survival (PFS) and overall survival in the intention-to-treat population. We report the final PFS analysis and the first interim overall survival analysis. This study is registered with ClinicalTrials.gov , number NCT01419197. Findings From Sept 14, 2011, to Nov 19, 2012, 602 patients were randomly assigned (404 to trastuzumab emtansine and 198 to physician's choice). At data cutoff (Feb 11, 2013), 44 patients assigned to physician's choice had crossed over to trastuzumab emtansine. After a median follow-up of 7·2 months (IQR 5·0–10·1 months) in the trastuzumab emtansine group and 6·5 months (IQR 4·1–9·7) in the physician's choice group, 219 (54%) patients in the trastuzumab emtansine group and 129 (65%) of patients in the physician's choice group had PFS events. PFS was significantly improved with trastuzumab emtansine compared with physician's choice (median 6·2 months 95% CI 5·59–6·87 vs 3·3 months 2·89–4·14; stratified hazard ratio HR 0·528 0·422–0·661; p<0·0001). Interim overall survival analysis showed a trend favouring trastuzumab emtansine (stratified HR 0·552 95% CI 0·369–0·826; p=0·0034), but the stopping boundary was not crossed. A lower incidence of grade 3 or worse adverse events was reported with trastuzumab emtansine than with physician's choice (130 events 32% in 403 patients vs 80 events 43% in 184 patients). Neutropenia (ten 2% vs 29 16%), diarrhoea (three <1% vs eight 4%), and febrile neutropenia (one <1% vs seven 4%) were grade 3 or worse adverse events that were more common in the physician's choice group than in the trastuzumab emtansine group. Thrombocytopenia (19 5% vs three 2%) was the grade 3 or worse adverse event that was more common in the trastuzumab emtansine group. 74 (18%) patients in the trastuzumab emtansine group and 38 (21%) in the physician's choice group reported a serious adverse event. Interpretation Trastuzumab emtansine should be considered as a new standard for patients with HER2-positive advanced breast cancer who have previously received trastuzumab and lapatinib. Funding Genentech.
A wide variety of human malignancies exhibit sustained c-Met stimulation, overexpression, or mutation, including carcinomas of the breast, liver, lung, ovary, kidney, and thyroid. Notably, activating ...mutations in c-Met have been positively identified in patients with a particular hereditary form of papillary renal cancer, directly implicating c-Met in human tumorigenesis. Aberrant signaling of the c-Met signaling pathway due to dysregulation of the c-Met receptor or overexpression of its ligand, hepatocyte growth factor (HGF), has been associated with an aggressive phenotype. Extensive evidence that c-Met signaling is involved in the progression and spread of several cancers and an enhanced understanding of its role in disease have generated considerable interest in c-Met and HGF as major targets in cancer drug development. This has led to the development of a variety of c-Met pathway antagonists with potential clinical applications. The three main approaches of pathway-selective anticancer drug development have included antagonism of ligand/receptor interaction, inhibition of the tyrosine kinase catalytic activity, and blockade of the receptor/effector interaction. Several c-Met antagonists are now under clinical investigation. Preliminary clinical results of several of these agents, including both monoclonal antibodies and small-molecule tyrosine kinase inhibitors, have been encouraging. Several multitargeted therapies have also been under investigation in the clinic and have demonstrated promise, particularly with regard to tyrosine kinase inhibition.
Targeted therapy directed against oncogenic BRAF mutations and immune checkpoint inhibitors have transformed melanoma therapy over the past decade and prominently improved patient outcomes. However, ...not all patients will respond to targeted therapy or immunotherapy and many relapse after initially responding to treatment. This unmet need presents two major challenges. First, can we elucidate novel oncogenic drivers to provide new therapeutic targets? Second, can we identify patients who are most likely to respond to current therapeutic strategies in order to both more accurately select populations and avoid undue drug exposure in patients unlikely to respond? In an effort to evaluate the current state of the field with respect to these questions, we provide an overview of some common oncogenic mutations in patients with metastatic melanoma and ongoing efforts to therapeutically target these populations, as well as a discussion of biomarkers for response to immune checkpoint inhibitors—including tumor programmed death ligand 1 expression and the future use of neoantigens as a means of truly personalized therapy. This information is becoming important in treatment decision making and provides the framework for a treatment algorithm based on the current landscape in metastatic melanoma.
For many years, oncology phase I trials have been referred to as 'toxicity trials' and have been believed to have low clinical utility other than that of establishing the adverse event profile of ...novel therapeutic agents. The traditional distinction of clinical trials into three phases has been challenged in the past few years by the introduction of targeted therapies and immunotherapies into the routine management of patients with cancer. This transformation has especially affected early phase trials, leading to the current situation in which response rates are increasingly reported from phase I trials. In this Perspectives, we highlight key elements of phase I trials and discuss how each one of them contributes to a new paradigm whereby preliminary measurements of the clinical benefit from a novel treatment can be obtained in current phase I trials, which can therefore be considered to have a therapeutic intent.
Pre-analytical factors can significantly affect circulating cell-free DNA (cfDNA) analysis. However, there are few robust methods to rapidly assess sample quality and the impact of pre-analytical ...processing. To address this gap and to evaluate effects of DNA extraction methods and blood collection tubes on cfDNA yield and fragment size, we developed a multiplexed droplet digital PCR (ddPCR) assay with 5 short and 4 long amplicons targeting single copy genomic loci. Using this assay, we compared 7 cfDNA extraction kits and found cfDNA yield and fragment size vary significantly. We also compared 3 blood collection protocols using plasma samples from 23 healthy volunteers (EDTA tubes processed within 1 hour and Cell-free DNA Blood Collection Tubes processed within 24 and 72 hours) and found no significant differences in cfDNA yield, fragment size and background noise between these protocols. In 219 clinical samples, cfDNA fragments were shorter in plasma samples processed immediately after venipuncture compared to archived samples, suggesting contribution of background DNA by lysed peripheral blood cells. In summary, we have described a multiplexed ddPCR assay to assess quality of cfDNA samples prior to downstream molecular analyses and we have evaluated potential sources of pre-analytical variation in cfDNA studies.
To estimate the maximum tolerated dose (MTD) for continuous oral administration of the γ-secretase inhibitor PF-03084014, determine the recommended phase II dose (RP2D), and evaluate safety and ...preliminary activity in patients with advanced solid tumors.
This open-label, phase I study consisted of a dose-finding portion based on a 3+3 design, followed by an expansion cohort. PF-03084014 was administered orally, twice daily (BID) for 21 continuous days. Tested doses ranged from 20 to 330 mg BID. In the expansion cohort, patients were to receive the estimated MTD or a lower dose of PF-03084014.
A total of 64 patients received treatment. The MTD was estimated to be 220 mg BID. The RP2D was determined to be 150 mg BID, based on the better safety profile versus the 220-mg BID dose, given comparable NOTCH-related target inhibition. The most common treatment-related adverse events were diarrhea, nausea, fatigue, hypophosphatemia, vomiting, rash, and decreased appetite, which were generally mild to moderate in severity. One patient with advanced thyroid cancer had a complete response, and five of seven response-evaluable patients with desmoid tumor achieved a partial response (71.4% objective response rate). Tumor responses were mostly durable, ranging from 1.74+ to 24+ months. PF-03084014 demonstrated a generally dose-dependent pharmacokinetic profile at doses ranging from 20 to 330 mg BID. Consistent downmodulation of NOTCH-related HES4 gene expression was observed in peripheral blood from all evaluable patients.
Further development of PF-03084014 for the treatment of patients with advanced solid tumors is warranted and currently under evaluation.
Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate in clinical development for the treatment of human epidermal growth factor receptor 2 (HER2)-positive cancers. Herein, we describe a series ...of studies to assess T-DM1 absorption, distribution, metabolism, and excretion (ADME) in rats as well as to assess human exposure to T-DM1 catabolites. Following administration of unlabeled and radiolabeled T-DM1 in female Sprague Dawley rats as a single dose, plasma, urine, bile and feces were assessed for mass balance, profiling and identification of catabolites. In rats, the major circulating species in plasma was T-DM1, while DM1 concentrations were low (1.08 to 15.6 ng/mL). The major catabolites found circulating in rat plasma were DM1, N-maleimidomethyl cyclohexane-1- carboxylate-DM1 (MCC-DM1), and Lysine-MCC-DM1. These catabolites identified in rats were also detected in plasma samples from patients with HER2-positive metastatic breast cancer who received single-agent T-DM1 (3.6 mg/kg every 3 weeks) in a phase 2 clinical study. There was no evidence of tissue accumulation in rats or catabolite accumulation in human plasma following multiple dosing. In rats, T-DM1 was distributed nonspecifically to the organs without accumulation. The major pathway of DM1-containing catabolite elimination in rats was the fecal/biliary route, with up to 80% of radioactivity recovered in the feces and 50% in the bile. The rat T-DM1 ADME profile is likely similar to the human profile, although there may be differences since trastuzumab does not bind the rat HER2- like receptor. Further research is necessary to more fully understand the T-DM1 ADME profile in humans.
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