Intracerebroventricular delivery of glucocerebrosidase reduces substrates and increases lifespan in a mouse model of neuronopathic Gaucher disease

Gaucher disease is caused by a deficit in the enzyme glucocerebrosidase. As a consequence, degradation of the glycolipids glucosylceramide (GluCer) and glucosylsphingosine (GluSph) is impaired, and their subsequent buildup can lead to significant pathology and early death. Type 1 Gaucher patients can be treated successfully with intravenous replacement enzyme, but this enzyme does not reach the CNS and thus does not ameliorate the neurological involvement in types 2 and 3 Gaucher disease. As one potential approach to treating these latter patients, we have evaluated intracerebroventricular (ICV) administration of recombinant human glucocerebrosidase (rhGC) in a mouse model of neuronopathic Gaucher disease. ICV administration resulted in enzyme distribution throughout the brain and alleviated neuropathology in multiple brain regions of this mouse model. Treatment also resulted in dose-dependent decreases in GluCer and GluSph and significantly extended survival. To evaluate the potential of continuous enzyme delivery, a group of animals was treated ICV with an adeno-associated viral vector encoding hGC and resulted in a further extension of survival. These data suggest that ICV administration of rhGC may represent a potential therapeutic approach for type 2/3 Gaucher patients. Preclinical evaluation in larger animals will be needed to ascertain the translatability of this approach to the clinic.

Addressing the question of the effect of RBC storage on clinical outcomes: the Red Cell Storage Duration Study (RECESS) (Section 7)

The question of whether storage of red blood cells (RBCs) alters their capacity to deliver oxygen and affects patient outcomes remains in a state of clinical equipoise. Studies of the changes which occur while RBCs are stored have led to several physiologically plausible hypotheses that these changes impair RBC function when the units are transfused. Although there is some evidence of this effect in vivo from animal model experiments, the results of several largely retrospective patient studies have not been consistent. Some studies have shown an association between worse clinical outcomes and transfusion of RBC which have been stored for longer periods of time, while others have found no effect. Three multicenter, randomized, controlled trials have been developed to address this important, but currently unanswered, question. Two clinical trials, one in low birth weight neonates and the other in intensive care unit patients, are enrolling subjects in Canada (the Age of Red Blood Cells in Premature Infants; the Age of Blood Study). The third trial, which is being developed in the United States, is the Red Cell Storage Duration Study (RECESS). This is a multicenter, randomized, controlled trial in which patients undergoing complex cardiac surgical procedures who are likely to require RBC transfusion will be randomized to receive RBC units stored for either 10 or fewer days or 21 or more days. Randomization will only occur if the blood bank has enough units of RBC of both storage times to meet the crossmatch request; hence, subjects randomized to the 21 day arm will receive RBC of the same storage time as they would have following standard inventory practice of "oldest units out first". The primary outcome is the change in the Multiple Organ Dysfunction Score (MODS), a composite measure of multiorgan dysfunction, by day 7. Secondary outcomes include the change in the MODS by day 28, all-cause mortality, and several composite and single measures of specific organ system function. The estimated total sample size required will be 1434 evaluable subjects (717 per arm).

Abstract 5174: Characterization of glycolipid ligands for E-selectin

The prevention, treatment, and curing of cancer are three of the most researched and highly anticipated areas of modern medicine. One of the greatest barriers to making advances within these fields is the lack of understanding of the molecular mechanisms responsible for cancer metastasis. Head and neck cancer (HNC) is the fifth most diagnosed cancer in the United States, according to the American Cancer Society, and claims the lives of many of its victims because it is often not diagnosed until metastasis has already occurred. After the onset of metastasis, the five-year survival rate drops to below thirty-five percent. Therefore, the study of how metastasis occurs is essential to finding a treatment for HNC.

It is believed that metastasis occurs when cancer cells break free from the primary tumor and travel through the blood stream, attaching themselves onto endothelium of blood vessel walls and in turn, forming secondary tumors in new organs. The cell adhesion mediated by glycolipids on cancer cells to E-selectin on vascular endothlelium may be a significant contributor to cancer metastasis. E-selectin plays a significant role in the first two steps of the adhesion cascade, tethering and rolling, which initiate the recruitment process. In our preliminary studies, it has been shown that HNC cells express glycolipids that can bind to E-selectin. Flow cytometry shows that HNC cells express sialofucosylated molecules that could act as E-selectin ligands, and flow chamber adhesion assays confirm that HNC cells bind to cytokine-stimulated endothelial cells in a wholly E-selectin-dependent manner. Enzyme treatment further reveals that sialofucosylated glycolipids are major adhesive ligand(s) for E-selectin. Through the use of specialized flow chambers mimicking physiological conditions, optical tweezers, gas chromatography-mass spectrometry, the mediators of these adhesive interactions can be studied in depth, leading to the discovery of characteristics of cancer glycolipids that promote adhesion.

The purpose of this investigation is to gain further insight as to which specific glycolipids located on HNCcells are potent ligands for E-selectin binding. With increased understanding of selectin-ligand adhesion interactions, the identity and properties of molecules responsible for metastasis can be used to determine possible therapeutic methods.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5174.

A cyclic peptide targeted against PSD-95 blocks central sensitization and attenuates thermal hyperalgesia

Post-synaptic density protein PSD-95 is emerging as a valid target for modulating nociception in animal studies. Based on the key role of PSD-95 in neuronal plasticity and the maintenance of pain behavior, we predicted that CN2097, a peptide-based macrocycle of nine residues that binds to the PSD-95 Discs large, Zona occludens 1 (PDZ) domains of PSD-95, would interfere with physiologic phenomena in the spinal cord related to central sensitization. Furthermore, we tested whether spinal intrathecal injection of CN2097 attenuates thermal hyperalgesia in a rat model of sciatic neuropathy. Results demonstrate that spinal CN2097 reverses hyperexcitability of wide dynamic range (WDR) neurons in the dorsal horn of neuropathic rats and decreases their evoked responses to peripheral stimuli (brush, low caliber von Frey and pressure), whereas CN5125 ("negative control") has no effect. CN2097 also blocks C-fiber long-term potentiation (LTP) in the dorsal horn, which is linked to neuronal plasticity and central sensitization. At a molecular level, CN2097 attenuates the increase in phosphorylated p38 MAPK, a key intracellular signaling pathway in neuropathic pain. Moreover, spinal injection of CN2097 blocks thermal hyperalgesia in neuropathic rats. We conclude that CN2097 is a small molecule peptide with putative anti-nociceptive effects that modulates physiologic phenomena related to central sensitization under conditions of chronic pain.

The UK Sport perspective on detecting growth hormone abuse

BACKGROUND AND OBJECTIVES

Human growth hormone (hGH) is seen as a doping risk in sport because of its possible anabolic and lipolytic effects. As a result of this hGH is prohibited for athletes to use both in and out-of-competition by the World Anti-Doping Agency (WADA) requiring Anti-Doping Organisations to work with research teams in identifying ways to detect hGH abuse.

APPROACH

This paper reviews and discusses the UK Sport perspective on the challenges faced in detecting hGH and in particular draws upon the experiences gained during the collaborative efforts with the GH-2004 research team in achieving the implementation of the Marker Method for hGH detection.

CONCLUSIONS

In 2008 significant progress has been made; there is one test for detecting HGH approved for use in anti-doping and a second detection method pending. This is a strong reflection of the ongoing research efforts in anti-doping and the progress being made by the Anti-Doping Organisations in reducing the risk that doping poses to sport.

H2O at the Phoenix landing site

The Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5 degrees and 148 degrees ). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost blanketed the surface at night; H(2)O ice and vapor constantly interacted with the soil. The soil was alkaline (pH = 7.7) and contained CaCO(3), aqueous minerals, and salts up to several weight percent in the indurated surface soil. Their formation likely required the presence of water.

Impact of cerebrovascular pathology on behavioural and neuropsychiatric symptoms in patients with Alzheimer's dementia: findings from a retrospective, naturalistic study

AIM

Cerebrovascular disease (CVD) has been associated with depression and a host of neuropsychiatric conditions including dementia. This study assessed the relationship between cerebrovascular findings reported on MRI brain scans and neuropsychiatric symptoms (NPS) and behavioural problems in patients with Alzheimer's disease (AD).

METHODS

Medical notes were retrospectively reviewed in patients undergoing brain MRI following referral for cognitive impairment to a memory clinic between January 2004 and June 2008. Patients with AD were graded into four categories of CVD severity based on neuroradiology reports and assessed for behavioural and NPS and activities of daily living using Neuropsychiatric Inventory (NPI), Geriatric Depression Scale (GDS) and Bristol Activities of Daily Living (BADL). Frontal lobe symptoms and parkinsonian features were also evaluated.

RESULTS

Of the initial 232 patients who underwent MRI 72% were diagnosed with AD. 89% of AD patients had CVD findings reported on MRI. Moderate-to-severe CVD was present in 47% of patients. None of the AD patients satisfied a diagnosis of vascular dementia. There was no significant relationship observed between level of MRI CVD findings and scores on NPI (p = 0.57), GDS (p = 0.26) and BADL (p = 0.46). The level of CVD severity did not appear to influence frontal lobe and parkinsonian assessments (p = 0.60).

CONCLUSION

The contribution of CVD to the pathogenesis of various NPS is still debated. Our study, based on patients diagnosed with AD in a memory clinic setting, suggests that there is no relationship between the extent of CVD pathology and neuropsychiatric and behavioural measures in AD patients. Further prospective quantitative studies are needed to assess the role of CVD, if any, in neuropsychiatric and behavioural symptoms in AD. It is possible that the relatively small pathological contribution of CVD to the development of these symptoms is obscured by the effect of the wider neurodegeneration encountered in AD.

Antopol-Goldman lesion of the kidney diagnosed by radiology: a case report of observation

Antopol-Goldman lesions are extremely rare and are characterized by subepithelial hematoma in the renal pelvis. There have been at least 28 case reports in the literature, with all being diagnosed histologically after partial or total nephrectomy for a presumed malignancy. We report the first case in the literature to be diagnosed by radiological imaging and followed on an observatory basis.

Green fluorescent protein in the study of neuronal signaling pathways

In recent years, techniques have been established for transiently co-transfecting cells with cDNA of the jellyfish green fluorescent protein (GFP), a reporter gene that encodes a non-toxic marker. This approach can be applied to primary neurons where it has become especially useful for the study of neuronal second messenger pathways. This unit describes procedures for transfecting neurons in primary culture: transfection with GFP DNA, including co-transfecting with separate GFP and gene-of-interest constructs, transfecting with a single construct containing the gene of interest fused to a GFP gene, and transfecting with a single construct containing separate gene-of-interest and GFP cassettes. Also included is a method for the rapid, large-scale preparation of a nearly homogeneous population of neurons from rat cerebellum. The Commentary provides several examples of how this approach can be applied to specific biological questions on neuronal signaling pathways.

Changes in neuropsychological functioning during alcohol detoxification

This study investigates changes in neuropsychological functioning during early abstinence from alcohol. 30 alcohol-dependent inpatients were tested at intake (day 4 of admission) and post detoxification (day 26), using a test-retest design. The neuropsychological battery included measures of pre-morbid IQ, full-scale IQ, verbal and non-verbal measures of memory and executive function. IQ was within the normal range at intake and comparable with age-adjusted normative values and there were some impairments in memory and executive function. There were significant increases in performance scores post detoxification in working memory, verbal fluency and verbal inhibition but not in non-verbal executive function tasks (mental flexibility and planning ability). Despite increased scores on tests of verbal and memory skills after 3 weeks of abstinence, complex executive abilities showed little change. These may have a negative impact on engagement and response to treatment and compromise clinical outcomes, heightening the risk of relapse.

Sequence analysis and molecular characterization of larval midgut cDNA transcripts encoding peptidases from the yellow mealworm, Tenebrio molitor L

Peptidase sequences were analysed in randomly picked clones from cDNA libraries of the anterior or posterior midgut or whole larvae of the yellow mealworm, Tenebrio molitor Linnaeus. Of a total of 1528 sequences, 92 encoded potential peptidases, from which 50 full-length cDNA sequences were obtained, including serine and cysteine proteinases and metallopeptidases. Serine proteinase transcripts were predominant in the posterior midgut, whereas transcripts encoding cysteine and metallopeptidases were mainly found in the anterior midgut. Alignments with other proteinases indicated that 40% of the serine proteinase sequences were serine proteinase homologues, and the remaining ones were identified as either trypsin, chymotrypsin or other serine proteinases. Cysteine proteinase sequences included cathepsin B- and L-like proteinases, and metallopeptidase transcripts were similar to carboxypeptidase A. Northern blot analysis of representative sequences demonstrated the differential expression profile of selected transcripts across five developmental stages of Te. molitor. These sequences provide insights into peptidases in coleopteran insects as a basis to study the response of coleopteran larvae to external stimuli and to evaluate regulatory features of the response.

Safety and efficacy of first-line irinotecan/fluoropymidine combinations in mCRC patients >65 years compared with those ≤65: The BICC-C study

4076

Background: BICC-C was a multicenter, randomized study that assessed efficacy & safety of irinotecan/fluoropyrimidines combinations in previously untreated mCRC patients. This study showed that FOLFIRI or FOLFIRI+bev were superior to their comparators (Proc ASCO 2006). We conducted a secondary analysis of efficacy & safety among all patients >65 years compared with those =65. Methods: Pts were randomized to: infusional FOLFIRI, modified bolus IFL (mIFL), or CapeIri; and concurrent celecoxib or placebo in a double-blind fashion. The protocol was amended in April 2004 and bevacizumab (bev) was added to the FOLFIRI and mIFL arms whereas CapeIri was discontinued. Period 1 (P1) and Period 2 (P2) designate subjects enrolled before or after the amendment. Results: Of 430 pts enrolled in P1, 150 were age >65 (median 71; range, 66–87) and 280 were = 65 (median, 56; 20–65). Of 117 pts in P2, 75 were >65 (median, 73; 66–84) and 42 were = 65 (median, 54; 32–65). No significant differences in efficacy or safety were observed between the two age groups. Results for P1: median progression free survival (PFS) was 6.5 and 6.7 mos; and median overall survival (OS) was 18.8 and 19.2 for >65 and =65, respectively. For the FOLFIRI regimen specifically median PFS was 7.5 and 7.6 mos, and median OS was 20.1 and 24.3 mos for >65 and =65, respectively. Results for P2: median PFS was 10.3 and 10.6 mos; and median OS was 19.8 and 23 mos for >65 and =65, respectively. For the FOLFIRI+bev regimen specifically median PFS was 11.1 and 11.2 mos for >65 and =65 respectively, and median OS has not yet been reached for either subgroup at time of analysis. Common grade = 3 AEs are listed below. Conclusions: Efficacy and safety for first line irinotecan/fluoropyrimidine regimens and for FOLFIRI & FOLFIRI+bev, specifically, did not differ for older and younger mCRC patients.

[Table: see text]

[Table: see text]

A phase I study of BMS-582664 (brivanib alaninate), an oral dual inhibitor of VEGFR and FGFR tyrosine kinases, in combination with full-dose cetuximab in patients (pts) with advanced gastrointestinal malignancies (AGM) who failed prior therapy

14018

Background: Brivanib is an oral prodrug of BMS-540215, a dual tyrosine kinase inhibitor of VEGFR and FGFR signaling. Prior studies have validated both VEGF and EGF signaling pathways as targets in AGM. The MTD of single-agent brivanib is 800 mg qd (ASCO #3051, 2006). Methods: An open-label Phase I dose-escalation study of brivanib in combination with cetuximab was conducted in pts with AGM who failed prior therapy. Brivanib was given po Day 1 and qd from Day 8, starting at 320 mg. Cetuximab was given IV Day 8 (400 mg/m2) then weekly (250 mg/m2). Dose escalation of brivanib continued to 800 mg qd, when an expansion cohort for pts with colorectal cancer (CRC) was opened for additional safety and efficacy. Fresh tissue and blood sampling for biomarker and pharmacokinetic (PK) analysis was performed. FDG-PET was obtained at Baseline X 2, Days 15 and 56. Tumor response (modified WHO) was evaluated q 8 weeks. Results: 18 pts (15 CRC, 2 esophageal, 1 other) were treated with 320, 600 or 800 mg qd of brivanib in combination with cetuximab for a median of 8 weeks (range 1 - 20+). A single DLT, bilateral pulmonary emboli, occurred at 320 mg qd. Few treatment-related AEs occurred across the 3 cohorts (Table). PK/biomarker data is pending. Available FDG-PET results from measurements in 8 pts with 2–3 target lesions showed good baseline reproducibility in SUVpeak, SUVmean and SUVmax, with intra-subject CV of 3.6%, 7.2% and 9.3%, respectively. Conclusions: Brivanib in combination with full-dose cetuximab was well tolerated at ≤800 mg qd and did not result in enhancement of cetuximab associated AEs. Pre-treatment FDG-PET is a highly reproducible imaging modality.

[Table: see text]

[Table: see text]

A phase I trial of RX-0201 (AKT anti-sense) in patients with an advanced cancer

3564

Background: Akt-1, a proto-oncogene, plays a vital role in cancer progression by stimulating proliferation and inhibiting apoptosis of cancer cells. RX-0201, a 20-mer oligonucleotide with sequence complementary to Akt-1 mRNA, is designed to inhibit the expression of Akt-1 within cancer cells in cancer patients (pts). Non-clinical studies conducted on RX-0201 demonstrated that RX-0201 bears significant in vitro and in vivo anti-cancer activities with favorable safety. Purposes: The aims of the current phase I trial were to determine the maximum tolerated dose (MTD) and to establish pharmacokinetic (PK) and safety profiles of RX-0201 in pts with an advanced cancer. Methods: RX-0201 was administered to pts with an advanced cancer by up to 2 cycles of continuous infusion; each cycle of infusion lasted for 14 days which was followed by a 7-day rest. Rapid dose escalation had been used until at least a grade (G) 2 toxicity was observed, and then a traditional dose escalation followed. Entry criteria included Karnofsky Performance Status score =70, advanced cancer, tumor accessible for paired biopsy, and signed informed consent. 17 pts were enrolled and treated at a dose level ranging from 6 to 315 mg/m2/d on D1–14, repeated q 21 d. Results: G 3 fatigue was observed in two pts at the 315 mg/m2/d dose; three pts dosed at 250 mg/m2/d were not noted with any G 3 toxicity, which make this dose (250 mg/m2/d) the recommended phase II trial dose. No other significant, compound-related, adverse events were observed in those 17 pts participated. Pts PK profiles of RX-0201 and AKT-1 immunohistochemistry results on pts’ tumor biopsy samples will also be presented. Conclusion: MTD of RX-0201 is 315 mg/m2/d in pts with an advanced cancer when the compound is administered in the current continuous infusion regimen.

No significant financial relationships to disclose.

Updated results of BICC-C study comparing first-line irinotecan/fluoropymidine combinations with or without celecoxib in mCRC: Updated efficacy data

4027

Background: This multicenter, randomized study assessed efficacy & safety for irinotecan/fluoropyrimidines combinations in previously untreated mCRC. Methods: Pts were randomized to: infusional FOLFIRI, modified bolus IFL (mIFL), or CapeIri; and concurrent celecoxib or placebo in a double-blind fashion. The protocol was amended in April 2004: bevacizumab (bev) was added to the FOLFIRI and mIFL arms, whereas CapeIri was discontinued. Period 1 (P1) and Period 2 (P2) designate subjects enrolled before or after the amendment. Initial efficacy & safety analyses were reported at ASCO ’06. We now report follow-up of 46 months for P1 and 31 months for P2. Results: 430 pts were treated in P1 and 117 pts in P2. Baseline characteristics and post-study treatment were balanced. P1 results: Median progression free survival (PFS) was 7.6 mos for FOLFIRI; 5.9 mos for mIFL (p=0.004); and 5.8 mos for CapeIri (p=0.015). Median overall survival (OS) was 23.1 mos for FOLFIRI; 17.6 mos for mIFL (p=0.087); and 18.9 mos for CapeIri (p=0.27). One-year survival rate favored FOLFIRI (75%) compared to either mIFL (65%) or CapeIri (66%). Overall Response Rate (ORR) was 47% in FOLFIRI, 43% in mIFL, 39% in CapeIri (not significantly different). P2 results: Median PFS was 11.2 mos for FOLFIRI+bev and 8.3 mos for mIFL+bev (p=0.28). Median OS was not reached for FOLFIRI+bev but was 19.2 mos for mIFL+bev (p=0.007). One-year survival rate favored FOLFIRI+bev (87%) when compared to mIFL+bev (61%). ORR was 58% for FOLFIRI+bev and 54% for mIFL+bev (p=0.73). Common grade = 3 AEs are listed below. Celecoxib did not impact safety or efficacy. Conclusions: First line FOLFIRI or FOLFIRI+bev were superior to their comparators and show favorable results in survival and tolerability in untreated mCRC. Median survival for FOLFIRI+bev has not been reached.

[Table: see text]

No significant financial relationships to disclose.

Saccades in presymptomatic and early stages of Huntington disease

OBJECTIVE

To evaluate quantitative measures of eye movements as possible biomarkers in prediagnostic and early stages of Huntington disease (HD).

METHODS

The study sample (n = 215) included individuals both at risk and recently diagnosed with HD. All participants completed a uniform clinical evaluation which included administration of the Unified Huntington's Disease Rating Scale (UHDRS) by a movement disorder neurologist and molecular testing to determine HD gene status. A high resolution, video-based eye tracking system was employed to quantify measures of eye movement (error rates, latencies, SD of latencies, velocities, and accuracies) during a computerized battery of saccadic and steady fixation tasks.

RESULTS

Prediagnostic HD gene carriers and individuals with early HD demonstrated three types of significant abnormalities while performing memory guided and anti-saccade tasks: increased error rate, increased saccade latency, and increased variability of saccade latency. The eye movement abnormalities increased with advancing motor signs of HD.

CONCLUSIONS

Abnormalities in eye movement measures are a sensitive biomarker in the prediagnostic and early stages of Huntington disease (HD). These measures may be more sensitive to prediagnostic changes in HD than the currently employed neurologic motor assessment.

Influence of colostrum deprivation and concurrent Cryptosporidium parvum infection on the colonization and persistence of Escherichia coli O157 : H7 in young lambs

Escherichia coliO157 : H7 andCryptosporidium parvuminfections of man have been associated with direct contact with small ruminants. Colostrum protects neonates against gastrointestinal pathogens, and orphan lambs, which are common on petting farms, may be deprived of this protection. In a recent study, it was demonstrated that high shedding ofE. coliO157 : H7 by an 8-week-old goat kid was associated with coincidentalC. parvuminfection. Furthermore, both pathogens were co-located in the distal gastrointestinal tract. It was hypothesized that colostrum deprivation and pre-infection withC. parvumpredisposed young ruminants to colonization and increased shedding ofE. coliO157 : H7. To test this, 21 lambs 5 weeks of age were divided into four groups as follows: (A) colostrum-deprived and inoculated withE. coliO157 : H7, (B) colostrum-deprived and inoculated withC. parvumand thenE. coliO157 : H7, (C) conventionally reared and inoculated withE. coliO157 : H7, (D) conventionally reared and inoculated withC. parvumand thenE. coliO157 : H7.C. parvumwas detected between 8 and 12 days post-inoculation in most of the infected lambs. At 24 h post-inoculation withE. coliO157 : H7, all lambs were shedding between 5×104and 5×107 c.f.u.E. coliO157 : H7 per gram of faeces.E. coliO157 : H7 was shed in higher numbers in the groups pre-inoculated withC. parvum, whether conventionally reared or colostrum-deprived. Interestingly, for the colostrum-deprived lambs on day 3, a significant difference in shedding ofE. coliO157 : H7 was observed (P=0.038), with the lambs inoculated withE. colialone yielding higher counts than those pre-inoculated withC. parvum. From day 15 onwards, shedding ofE. coliO157 : H7 was highest from the colostrum-deprivedC. parvum-infected lambs, then (in descending order of shedding) the colostrum-deprived lambs, the conventionally reared lambs infected withC. parvum, and the conventionally reared animals. In total, four animals were euthanized, two at 24 h and two at 96 h post inoculation withE. coliO157 : H7 (two conventionally reared and two colostrum-deprived). All animals euthanized were from groups pre-inoculated withC. parvumprior to challenge withE. coliO157 : H7. On examination of tissues, in three of the four animals examined, multifocal attaching and effacing lesions were observed in the caecum, colon, rectum and at the recto-anal junction, and were confirmed by immunohistochemistry to be associated withE. coliO157 : H7.

A novel non-HLA-restricted cellular immune assay for monitoring patient (pt) response to targeted immunotherapeutics

2567

Background: Many therapeutic cancer vaccines are designed to elicit T-cell immunity. In vitro monitoring of pt response is limited by the HLA-restriction of ELISPOT assays. We report a novel, non-restricted assay for measuring immune responses generated by PANVAC-VF, which comprises 2 recombinant viral vectors in a heterologous prime-boost immunization regimen. Each vector contains genes encoding the tumor antigens CEA and MUC-1, and 3 immunologic costimulatory molecules B7.1, LFA-3, and ICAM-1. The safety of PANVAC-VF was tested in a Phase 1 study of 10 pts with advanced pancreatic cancer (ASCO 2005 abstr 2576). Methods: Peripheral blood mononuclear cells (PBMCs) were drawn at baseline and each subsequent timepoint (∼2 wks after each injection) to measure cellular immune responses. PBMCs were separated from whole blood over a Ficoll gradient; isolated PBMCs were frozen in liquid nitrogen until analysis. A monkey breast cancer cell line (CMMT 110/C1) was infected with PANVAC-F or control fowlpox recombinant. On Day 2, PBMCs were incubated 10:1 with infected CMMT 110/C1 cells, and the mixtures co-cultivated for 72 h. Supernatants were assayed for interferon γ production. Results: Of 8 pts with PBMCs sufficient for testing, 5 developed an antigen-specific immune response to CEA and/or MUC-1. In general, interferon γ production steadily increased with repeat boosting immunizations. Cellular depletion experiments suggest that the result is dependent on CD4+ cells, allowing analysis of samples from all pts, unlike the ELISPOT, which is restricted to HLA-A2 peptide presentation. Preliminary analysis suggests a positive correlation of immune response with overall survival. Conclusions: We developed a novel, non-restricted cellular assay to assess immune response to a targeted immunotherapeutic, PANVAC-VF. Five of 8 assayed pts developed an antigen-specific cellular immune response. Pt numbers are small, but there appears to be a correlation between immune response and overall survival. This assay will be used for samples from a randomized Phase 3 study in pancreatic cancer and a randomized Phase 2 study in prostate cancer, generating a large data set of immune responses from all pts.

[Table: see text]

Randomized single institute pilot study of vaccinia-CEA(6D)-tricom and fowlpox-CEA (6D)-tricom with GM-CSF (V) in combination with docetaxel (D) in patients with colorectal cancer (CC)

13538

Background: Our previous study demonstrated 40% patients with CC achieved stable disease at 4 months with V (JCO, 23(4):720–31, 2005.). Preclinical studies showed taxene enhanced tumor vaccine in delaying tumor growth and increasing the antigen-specific T cells. We report the results of a Randomized phase II pilot study of V in combination with docetaxel (D) in CC patients. Methods: 27 patients with metastatic CC were randomly assigned to 3 arms, stratified for HLA-A2. All patients received a ‘prime’ dose of vaccinia-Tricom on Day 0, followed by ‘boost’ doses of fowlpox-Tricom on Days 21 and q 21 days for 4 months; all vaccinations were followed by local GM-CSF (100 μg) for 4 days. Arm 1 received V; Arm II and III received V and D on D1, D8 during each fowlpox vaccination at 10mg/m2 and 30mg/m2, respectively. Patients with stable disease continued vaccinations monthly after study completed. Safety data was evaluated. Primary endpoints included the impact of varying doses of D on CEA-specific T cell immune responses (CTL) using the ELISPOT assay, the recommended dose for further study as defined by the best immune response with acceptable toxicity, and objective clinical response. Results: The most common AE related to the vaccines was grade (g) 1 injection site reactions. Other common AEs were g1 fatigue, nausea, vomiting, fever, headache, and myalgia. There were 1 g3 fever and 1 g3 abdominal pain. The AE from the combination arm were contributed by D as expected, included g3: hyperglycemia (1), fatigue (1), elevation of liver function tests (2), pulmonary infection (1), abdominal pain (1), vomiting (1) or diarrhea (1). 6/ 27 patients have died 17 months after starting V. Patients received 2 to 12 cycles of therapy before disease progression. Observed clinical benefit was significantly lower than the 40% previously documented with V alone. The immune data is to be presented. Conclusions: Inferior clinical benefit as compared to our previous experiment could be explained by more heavily pretreated patients in this trial or negative impact of D on V. CTL data should explain this observation.

No significant financial relationships to disclose.