Abstract 55
Abexinostat (PCI-24781) is a novel oral pan-HDACi that has previously demonstrated potent preclinical activity in lymphoma cell lines and animal models (Evens et al, Clin Ca Res 2009) as ...well as a tolerable safety profile in phase I solid tumor clinical studies (Undevia et al, ASCO 2008). In a phase I single-agent clinical trial in patients (pts) with multiply relapsed/refractory lymphoma and leukemia, anti-tumor activity was noted in FL and MCL; 4/4 FL pts showed durable clinical benefit with median time on treatment of >8 months; 1 of 2 MCL pts had a complete remission (CR) and remains on treatment for >3 years. Based on these encouraging single-agent abexinostat data, a phase II extension study was completed in relapsed/refractory FL and MCL.
The primary objective of this phase II study was objective response rate (ORR, complete CR and partial remission PR), while reduction in tumor size (CR + PR + stable disease) and safety were also examined. Abexinostat was given orally twice daily at 45mg/m2 on a 4-week cycle for 7 days/week every other week, which is the previously established dose and schedule identified in the phase I study. For pharmacodynamic correlative analyses, tubulin and histone acetylation were measured in peripheral blood mononuclear cells (PBMCs) at pre-dose and 4 hours after the first dose of abexinostat.
A total of 30 pts were enrolled (n=16 FL and n=14 MCL pts) of which 25 were response-evaluable. The median age was 67 years (36–81) and the median prior therapies were 3 (1–5), 77% of which were rituximab-containing and one-third (33%) had undergone prior autologous stem cell transplant (31% FL, 36% MCL). The ORR in all pts was 48% (12/25). A reduction in tumor size was observed in 86% (12/14) of FL pts, while the ORR in FL was 64% (9/14); the FL intent-to-treat ORR was 56%. With a median follow-up of 10.3 months (1.2–20.9), the progression-free probability was 86% in FL pts. Furthermore, the median duration of response (DOR) in FL pts has not been reached, as 5 responders remain on study. Notably, 4 FL pts were on treatment for over 16 months. Among MCL pts, reduction in tumor size was noted in 27% (3/11), while the ORR was similar at 27% (3/11). The median progression-free survival (PFS) in MCL pts was 4 months (1–12), while the DOR in the 3 responding patients were 2+, 3, and 6+ months. Therapy was overall well tolerated. The most common treatment-related adverse events (AEs) of any grade (> 20% incidence) include: nausea (60%), fatigue (57%), diarrhea (50%), thrombocytopenia (37%), vomiting (30%), anemia (27%), decreased appetite (23%), dysgeusia (20%) and neutropenia (20%). The most common grade 3/4 related AEs (> 5% incidence) were thrombocytopenia (17%), neutropenia (13%), fatigue (13%), and anemia (7%). There were no deaths reported on the study. Pharmacodynamic analyses revealed that a majority of pts had increased tubulin acetylation in PBMCs, however this finding did not correlate with response or toxicity.
In this phase II study, the novel pan-HDACi, abexinostat, was clinically active and overall well tolerated in relapsed/refractory B-cell lymphoma. The safety profile was consistent with this class of agents with <20% of subjects experiencing grade 3/4 cytopenias (during the course of prolonged treatments). Moreover, there was significant clinical activity noted in FL with an ORR of 64%, which included several durable responses in this multiply-relapsed pt population. Further examination of single-agent abexinostat in FL is warranted.
Off Label Use:PCI24781 is not FDA approved; it is an investigational agent. Plasencia:Pharmacyclics: Employment, Equity Ownership. Sirisawad:Pharmacyclics: Employment, Equity Ownership. Yue:Pharmacyclics: Employment, Equity Ownership. Luan:Pharmacyclics: Employment, Equity Ownership. Siek:Pharmacyclics: Employment, Equity Ownership. Zhou:Pharmacyclics: Consultancy. Balasubramanian:Pharmacyclics: Employment, Equity Ownership.
Abstract only
99
Background: Current treatment options for postmenopausal patients with estrogen-receptor–positive breast cancer (BC) who relapse or progress on a nonsteroidal aromatase inhibitor ...(NSAI) are limited. The BOLERO-2 trial supports the activity of everolimus (EVE; an oral mammalian target of rapamycin mTOR inhibitor) added to the steroidal aromatase inhibitor exemestane (EXE) to prolong progression-free survival (PFS) in this patient population. Long-term PFS and survival data are awaited. Methods: BOLERO-2 is a phase 3, double-blind, randomized, international trial comparing EVE (10 mg once daily) + EXE (25 mg once daily) vs. placebo (PBO) + EXE in postmenopausal women with advanced estrogen-receptor–positive BC progressing or recurring after NSAIs (letrozole or anastrozole). Patients were randomized (2:1) to EVE + EXE or PBO + EXE. The primary endpoint was PFS by local investigator assessment. Main secondary endpoints included centrally assessed PFS, overall survival (OS), safety, bone turnover, and overall response rate. Results: Baseline disease characteristics including tumor burden and prior cancer therapy were well balanced between treatment arms (N = 724). Median PFS was doubled and response rates were consistently improved with EVE + EXE (n = 485) vs PBO + EXE (n = 239) in interim analyses. Median PFS by local assessment was ~3 mo with PBO + EXE vs 6.9 mo (hazard ratio HR, 0.43; P < .0001) and 7.4 mo (HR, 0.44; P < .0001) with EVE + EXE at 7.5 mo and 12.5 mo follow-up, respectively. Fewer deaths were reported with EVE + EXE (17.2%) vs PBO + EXE (22.7%) at 12.5 mo follow-up. Safety profiles were consistent with previous reports for mTOR inhibitors. PFS data including 528 events (protocol-specified final analysis), and updated OS and safety data will be presented. Conclusions: Adding EVE to EXE markedly prolonged PFS in patients with NSAI-refractory advanced estrogen-receptor–positive BC. There were fewer deaths among patients receiving EVE, and further follow-up will evaluate the effect of EVE on OS.
A novel radiation targeted therapy is investigated for HER-2 positive breast cancers. The proposed concept combines two known approaches, but never used together for the treatment of advanced, ...relapsed or metastasized HER-2 positive breast cancers. The proposed radiation binary targeted concept is based on the anti HER-2 monoclonal antibodies (MABs) that would be used as vehicles to transport the nontoxic agent to cancer cells. The anti HER-2 MABs have been successful in targeting HER-2 positive breast cancers with high affinity. The proposed concept would utilize a neutral nontoxic boron-10 predicting that anti HER-2 MABs would assure its selective delivery to cancer cells. MABs against HER-2 have been a widely researched strategy in the clinical setting. The most promising antibody is Trastuzumab (Herceptin). Targeting HER-2 with the MAB Trastuzumab has been proven to be a successful strategy in inducing tumour regression and improving patient survival. Unfortunately, these tumours become resistant and afflicted women succumb to breast cancer. In the proposed concept, when the tumour region is loaded with boron-10 it is irradiated with neutrons (treatment used for head and neck cancers, melanoma and glioblastoma for over 40 years in Japan and Europe). The irradiation process takes less than an hour producing minimal side effects. This paper summarizes our recent theoretical assessments of radiation binary targeted therapy for HER-2 positive breast cancers on: the effective drug delivery mechanism, the numerical model to evaluate the targeted radiation delivery and the survey study to find the neutron facility in the world that might be capable of producing the radiation effect as needed. A novel method of drug delivery utilizing Trastuzumab is described, followed by the description of a computational Monte Carlo based breast model used to determine radiation dose distributions. The total flux and neutron energy spectra of five currently available neutron irradiation treatment facilities are examined for this application. The tumour boron concentrations and tumour to healthy tissue concentration ratios required to deliver 50 Gy-Eq to the tumour without exceeding 18 Gy-Eq in the skin are determined, as well as the associated therapeutic ratios. Discussion is provided to address the future research direction for assessing the feasibility of the proposed concept.
Circulating tumor cells (CTCs) provide a readily accessible source of tumor material from patients with cancer. Molecular profiling of these rare cells can lead to insight on disease progression and ...therapeutic strategies. A critical need exists to isolate CTCs with sufficient quantity and sample integrity to adapt to conventional analytical techniques. We present a microfluidic platform (IsoFlux) that uses flow control and immunomagnetic capture to enhance CTC isolation. A novel cell retrieval mechanism ensures complete transfer of CTCs into the molecular assay. Improved sensitivity to the capture antigen was demonstrated by spike-in experiments for three cell lines of varying levels of antigen expression. We obtained spike-in recovery rates of 74%, 75%, and 85% for MDA-MB-231 (low), PC3 (middle), and SKBR3 (high) cell lines. Recovery using matched enumeration protocols and matched samples (PC3) yielded 90% and 40% recovery for the IsoFlux and CellSearch systems, respectively. In matched prostate cancer samples (
N
= 22), patients presenting more than four CTCs per blood draw were 95% and 36% using IsoFlux and CellSearch, respectively. An assay for detecting KRAS mutations was described along with data from patients with colorectal cancer, of which 87% presented CTCs above the assay's limit of detection (four CTCs). The CTC KRAS mutant rate was 50%, with 46% of patients displaying a CTC KRAS mutational status that differed from the previously acquired tissue biopsy data. The microfluidic system and mutation assay presented here provide a complete workflow to track oncogene mutational changes longitudinally with high success rates.
PROSTATIC PARAGANGLIOMA: 5-YEAR FOLLOWUP JIMENEZ, RAFAEL E.; TIGUERT, RABI; HARB, JOHN F. ...
The Journal of urology,
06/1999, Letnik:
161, Številka:
6
Journal Article
Based on the first results, the French government estimates that the tax on cancelled orders, considered as tax on High Frequency Trading (HFT), generated no revenue in 2012. Our paper question the ...effectiveness of a modified cancelled order tax with no exemptions, all orders cancelled or modified within half-second time span are taxed. Our study has important implications for the regulation of HFT; we provide recommendations for regulators in relation to market rules which have yet to be introduced, using an artificial market framework. This paper addresses the question of whether this tax leads to a reduction in HFT activities and, as a result, to deterioration or amelioration of market quality. The evidence we provide should help market regulators to better understand the role played by HFT firms as liquidity suppliers. We show that HFT liquidity is short-lived. With the implementation of tax, decreased HFT activities do not have a statistically significant impact on market volatility and market liquidity measured by bid/ask spreads, but decrease dollar volumes as a liquidity measure. In addition, reduced HFT activities lead to less efficient markets as the deviation from fundamentals increases.
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