Abstract CT320: Longitudinal observational study to simultaneously evaluate multiple blood-based biomarkers to track the emergence of metastasis and drug resistance in colorectal cancer

Background. Colorectal cancer (CRC) is the 3rd most common cancer globally. In cancer, the 2 most critical events that adversely affect outcomes are the emergence of metastasis and drug resistance. Blood-based markers permit the non-invasive serial monitoring of patients in order to study and track the emergence and evolution of metastasis and drug resistance. The multiple varied platforms utilize different components of blood (buffy coat, whole blood, plasma). We seek to establish a longitudinal observational study to simultaneously evaluate multiple blood-based biomarkers to track patient outcomes in colorectal cancer.

Methods. In a planned 800 patient study, we prospectively recruit patients with all stages of CRC, focusing on patients with stage 3/4 CRC. At each patient's venipuncture performed during his/her routine clinical care, we serially collect additional blood specimens. All major components of the collected blood (buffy coat, red cells, whole blood and plasma) are stored. In patients undergoing primary tumor resection or metastasectomy, frozen tissue specimens are also prospectively collected and banked for subsequent biomarker analysis. A prospective electronic database of clinical information and patient outcomes is simultaneously maintained for the purpose of correlation with molecular assays.

Results. To date, we have recruited 450 patients and obtained their serial blood samples. Blood is prospectively collected in an optimized manner to support the pre-analytical requirements of the different platforms. This includes whole blood for immediate assay performance (circulating tumor cells), buffy coat for immediate analysis or storage for pooled analysis (cell based assays, germline polymorphisms, white cell gene expression and assays on peripheral blood mononuclear cells), plasma for storage for pooled analysis (circulating cell free nucleic acids including DNA, miRNA, RNA and methylated DNA, novel proteomic tumor markers, cytokines). Optimization of pre-analytical processing, transport and storage parameters was carried out to enable studies across multiple platforms in this same cohort of patients to be performed in a prospective longitudinal manner.

Conclusions. In this ongoing study, we have established a system for the simultaneous evaluation of multiple blood-based biomarkers operating on the various components of blood. Together with paired tissue specimens and a prospectively maintained electronic clinical database, comprehensive comparisons and correlative studies to monitor for metastasis and drug resistance and clinical outcomes in CRC across time can be carried out.

Citation Format: Clarinda Chua, Rachel Ten, Thinzar Aung, Maricel Ang, Thein Htut Oo, Su Pin Choo, Matthew Ng, Iain Beehuat Tan. Longitudinal observational study to simultaneously evaluate multiple blood-based biomarkers to track the emergence of metastasis and drug resistance in colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT320. doi:10.1158/1538-7445.AM2014-CT320

A phase 2 study of trastuzumab in combination with S-1 and cisplatin in first-line human epidermal growth factor receptor (HER)-2-positive advanced gastric cancer

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Background: The addition of trastuzumab to cisplatin and 5-fluorouracil or capecitabine has been shown to have superior survival benefit. In this study, the addition of trastuzumab to chemotherapy combination, S-1 (tegafur, gimeracil, oteracil potassium; TS-ONER) and cisplatin, a standard first line therapy for advanced gastric cancer in Japan, was evaluated for efficacy and safety. Methods: This was a single-arm, phase II trial recruiting patients with advanced HER-2 positive (IHC 3+ or FISH +) gastric adenocarcinoma who had not had prior systemic therapy. Patients included had measurable disease, ECOG 0-2, creatinine clearance >60ml/min, LVEF at least 50%. Patients accrued received cisplatin at 60mg/m2 on day 1 of each cycle, trastuzumab at 8mg/kg as loading dose followed by 6mg/kg on day 1 of each cycle and oral S-1 for 14 days ( dosing based on BSA), every 3 weeks. Treatment continued till progressive disease or unbearable toxicity. Primary endpoint was response rate (ORR) and secondary endpoints were PFS, OS, CBR and safety. The study was designed to distinguish a favorable ORR of 55% from a null rate of 30% at 5% significance level and 80% power. Results: A total of 30 patients were recruited. Median age was 61.9 years, 73% were males and 90% had no prior resection of primary tumor. 56.7% were Chinese, 23.3% Japanese and 20% Korean. One patient achieved complete response, 16 had partial response and 2 had stable disease >24 weeks (ORR 63%; CBR 70.4%). Three patients did not have evaluable disease. With a median follow-up of 7.2 months, the median PFS was 7.4 months with 67.7% free of disease progression at the 6-month mark. Median OS was 14.6 months. The most common AEs were anorexia (50%), fatigue (47%), diarrhea ( 47%), nausea (37%), neutropenia (33%), anemia (27%) and mucositis ( 27%). LVEF decreased <50% in 14 patients and none led to treatment discontinuation nor death. Two patients had fatal SAEs that were deemed related to study drug ( neutropenic sepsis and hypotensive shock). Correlative studies will be reported later. Conclusions: The combination of trastuzumab with S-1 and cisplatin in advanced gastric cancer is active and tolerable. Clinical trial information: NCT01736410.

A first-in-human phase I trial of AR-12, a PDK-1 inhibitor, in patients with advanced solid tumors

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Background: AR-12 (OSU-03012) is an oral celecoxib analogue lacking COX-2 inhibitory activity that inhibits pyruvate dehydrogenase kinase isoenzyme 1 (PDK-1), AKT and impacts the endoplastic reticulum stress pathway. Preclinical studies indicate antitumor activity of AR-12 in various models and enhanced activity in combination. We completed a first in human clinical trial to determine its safety and tolerability, maximum tolerated dose (MTD) and recommended phase II dose (RD). Secondary objectives included assessment of tumor response, pharmacokinetics (PK) and pharmacodynamics (PD) including food effect. Methods: Patients (pts) with advanced solid tumors, ECOG PS 0-1, and adequate organ function were recruited in a modified 3+3 dose-escalation study. Pts received a run-in dose of AR-12 to analyze PK-PD and food effect, followed by continuous daily (QD) dosing in 28-day cycles. A twice daily (BID) cohort was initiated based on safety data. PD analysis was performed in platelet-rich plasma (PRP) and paired tumor biopsies when feasible. Results: 35 pts received at least one dose of study drug; 30 were evaluable for dose limiting toxicities (DLT) at dose ranges 100-3200mg QD and 800-1600mg BID. No DLT were observed in the QD cohort; DLT in the BID cohort are listed in table 1. Drug-related events (NCI-CTCAE v3) included rash (G2-2pts; G3-1pt), fatigue (G2-2pts; G3-4pts), nausea (G2-7pts; G3-1pt) and bloating (G2-1pt). Cmax after single dose was dose-proportional but high PK variability was observed, likely due to inadequate disintegration and dissolution of the formulation in the stomach. At RD, partial GSK3ß inhibition in PRP after 4 hours suggests AKT-pathway modulation. Best response (RECIST v1.0) was stable disease >6 cycles for 2 pts. Conclusions: The RD based on safety data is 800mg BID. Signs of pathway modulation were observed in concordance with the expected mechanism of action but were short-lasting. Considering limited drug absorption and PK variability, a new formulation of the drug will be developed to overcome these limitations. Clinical trial information: NCT00978523. [Table: see text]

A first-in-human (FIH) dose-escalation study of the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of intravenous BAL101553, a novel microtubule inhibitor, in adult patients with advanced solid tumors

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Background: BAL101553, a pro-drug of the small molecule BAL27862, is a novel microtubule targeting agent (MTA) with cytotoxic and vascular disrupting properties. Pre-clinical data showed anti-proliferative activity in several in vitro and xenograft tumour models, including tumours refractory to conventional MTAs through diverse resistance mechanisms. Primary objectives of this FIH study were determination of the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT). Secondary objectives included the evaluation of PK, PD and anti-tumour activity. Methods: An accelerated titration dose-escalation design was used. Eligible patients (pts) with advanced solid tumours, who had failed standard therapy, received BAL101553 as a 2-h intravenous infusion on days 1, 8 and 15 of a 28-day cycle. Adverse events (AEs) were assessed according to CTCAEv4. Disease response was assessed by RECIST 1.1 every 2 cycles. Results: 16 pts (7 male; median age 52 years; range 29-80) with solid tumours were treated at 4 dose levels (15, 30, 45 and 60 mg/m2). DLTs were observed at 60 mg/m2 and included rapidly reversible grade (G) 3 hypertension (HTN) and G3 reduced mobility/ dizziness. DLT criteria for HTN were subsequently modified. Frequent drug-related AEs were injection site reactions, nausea, vomiting (all G1-2), and G2-3 HTN (transient during the infusion; responding to nifedipine). One pt experienced G2 peripheral neuropathy at 60 mg/m2. PK analyses indicated conversion of BAL101553 to the active BAL27862, dose proportional exposure for both compounds and a half-life of BAL27862 in a range of 11 to 27 h. Preliminary tumour PD data comparing pre/post biopsies showed loss of CD34+ capillaries and focally decreased proliferation. A confirmed partial response was demonstrated in 1 pt with ampullary (pancreaticobiliary) cancer maintained on treatment for >16 cycles with intra-pt dose escalation. 2 pts (laryngeal and rectal cancer) demonstrated stable disease >16 weeks. Conclusions: BAL101553 is well tolerated up to 60 mg/m2 with evidence of anti-tumour activity. Dose escalation continues to determine the MTD. Clinical trial information: NCT01397929.

Erythropoietin facilitates resuscitation from ventricular fibrillation by signaling protection of mitochondrial bioenergetic function in rats

OBJECTIVE

We previously reported beneficial myocardial effects during chest compression after administration of high-dose erythropoietin. We hypothesized that erythropoietin also elicits post-resuscitation myocardial benefits partly linked to protection of mitochondrial bioenergetic function.

METHODS

Two series of 10 rats each underwent ventricular fibrillation for 10 minutes (series-1) and 8 minutes (series-2) and were randomized to erythropoietin (5,000 U/kg) or 0.9% NaCl before chest compression. Dobutamine was infused post-resuscitation in series-2 harvesting their hearts at 120 minutes.

RESULTS

During chest compression, a statistically insignificant trend showing progressively higher coronary perfusion pressure in the erythropoietin group was observed consistent with previously reported preservation of left ventricular distensibility. Post-resuscitation, in the absence of dobutamine (series-1) erythropoietin failed to improve post-resuscitation myocardial function or survival; in the presence of dobutamine (series-2) all rats survived and those treated with erythropoietin reversed post-resuscitation myocardial dysfunction yielding higher cardiac work index (CWI; 39±3 vs 25±10 mmHg·ml/kg, p<0.01) and higher mean aortic pressure (MAP; 99±4 vs 83±16, p<0.01) at 120 minutes post-resuscitation. Better myocardial function was associated with lesser increases in plasma cytochrome c, attaining levels which inversely correlated with CWI (p=0.026) and MAP (p=0.025). Hearts from erythropoietin-treated rats had higher phosphorylation levels of cytosolic Akt and higher phosphorylation levels of cytosolic and mitochondrial PKCε and maintained cytochrome c oxidase activity.

CONCLUSION

Erythropoietin activated mitochondrial protective mechanisms that helped maintain bioenergetic function enabling reversal of post-resuscitation myocardial dysfunction in the presence of dobutamine.