Influenza-associated hospitalisation

The disease burden associated with influenza includes not only acute respiratory diseases but also cerebrovascular disease, ischaemic heart disease and diabetes mellitus.

Phase I and pharmacokinetic (PK) study of IHL-305 (pegylated liposomal irinotecan) in patients with advanced solid tumors

2547

Background: Irinotecan (CPT-11) is a prodrug of SN-38 that has antitumor activity in a wide range of solid tumors. IHL- 305 is a PEGylated-liposomal formulation of irinotecan designed to increase the therapeutic index by prolonging the duration of exposure in both plasma and tumors. IHL-305 demonstrates superior anti-tumor activity in preclinical models. Methods: Eligible patients (pts) had advanced solid tumors, ECOG ≤2, adequate organ function and no prior exposure to CPT-11. In a standard 3+3 escalation, IHL-305 was infused over 60 minutes q 28 days. UGT1A1*28 genotyping was performed with the homozygous (*28/*28) variants treated at 50% of current dose (subsequent escalation allowed). The area under the plasma concentration- time curve (AUC) of sum total (encapsulated + released) CPT-11, released CPT-11, SN-38, and SN-38 glucuronide (SN-38G) was calculated. The % CPT-11 released was calculated as the ratio of released CPT-11 AUC to sum total CPT-11 AUC x 100. The primary objectives were to determine the dose limiting toxicities (DLTs), phase II recommended dose (P2RD), and clinical pharmacology of IHL- 305. Results: 42 pts treated; homozygous wild-type (wt/wt; n=23), heterozygous (wt/*28; n=13) and homozygous variants (*28/*28; n= 6). 10 dose levels explored; 7, 14, 28, 37, 50, 67, 88, 120, 160 and 210 mg/m2. DLTs included: 1 Gr 3 acute nausea/vomiting at 67 mg/ m2 (subsequent pts received premedication), 1 Gr 3 delayed-onset diarrhea at 160 mg/m2, and 1 Gr 3 delayed nausea/vomiting and one Gr 3 febrile neutropenia at 210mg/m2. Pts received repeated courses of IHL-305 with no delays for myelosuppression or diarrhea. 7 pts had stable disease ≥ 6 cycles. The mean ± SD PK parameters are summarized in the table below. Conclusions: The MTD and P2RD of IHL-305 is 160 mg/m2 IV q 28 days. IHL-305 shows a high and prolonged exposure of sum total and released CPT-11 and SN-38.

[Table: see text]

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Phase I dose escalation study of continuous oral dosing of OSI-906, an insulin like growth factor-1 receptor (IGF-1R) tyrosine kinase inhibitor, in patients with advanced solid tumors

2559

Background: OSI-906 is a potent small molecule inhibitor of IGF-1R, a receptor tyrosine kinase activated by insulin like growth factor, which is overexpressed in numerous malignancies and implicated in resistance to chemotherapy. Methods: Patients with advanced cancer entered escalating dose cohorts of OSI-906. Study objectives included assessment of: safety; determination of MTD; pharmacokinetics (PK), pharmacodynamics (PD) including IGF-1R levels in peripheral blood cells; and tumor response (RECIST). Results: To date, 32 pts have been treated (22M/10F, median age 62y) at 10, 20, 40, 75, 150, and 300 mg QD and at 20, 40 mg and 75 mg BID. Median number of weeks on trial was 6 (range 0–44). No DLTs have been observed. Hyperglycemia (5/20 pts) related to OSI-906 was transient and mild (grade 1 only). In addition to hyperglycemia, grade 1–2 nausea and vomiting (5/20 pts) were the most frequent related adverse events (AEs). There was grade 3 elevated lipase in 1 pt. At doses of 10–150 mg, OSI-906 exhibited linear PK, median terminal t1/2 ranged from 2.18–4.30 hr, AUC0-inf from 284–10200 ng.hr/mL, and Cmax 76.6–1440 ng/mL. There was no relationship between glucose or insulin levels and OSI-906 plasma concentrations. Stable disease > 12 weeks was seen in 7/20 pts (range 12–34 weeks), including 1 pt each with thymic (27 w), adrenocortical (28w), and colorectal (34w) cancer. PD data on IGF-1R phosphorylation will be presented. Conclusions: Plasma concentrations of OSI-906 achieved in this trial exceed concentrations required for antitumor efficacy in preclinical models. PD target modulation and preliminary anti-tumor activity have been observed. It is interesting to note that clinically meaningful hyperglycemia has yet to occur. Minimal toxicity was observed and further dose escalation is in progress.

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Determination of phenobarbitone population clearance values for physically and mentally handicapped Chinese children with epilepsy

OBJECTIVE

To estimate population clearance values of phenobarbitone in epileptic children of Chinese origin in Hong Kong.

METHOD

Steady-state concentration data were gathered during routine care at a special chronic centre for the physically and mentally handicapped. Age, gender, body weight and concurrent medication (taking additional carbamazepine (CBZ) or phenytoin (PTO)) were the four fixed effects tested simultaneously for their influence on the population mean of phenobarbitone clearance, using the nonlinear mixed-effects model.

RESULTS

No age or gender-related effect was found. Both body weight and concurrent medication were the important determinants of phenobarbitone clearance. The population mean values of phenobarbitone clearance obtained were 0.250 litres/day/kg for children on phenobarbitone only and 0.208 litres/day/ kg for those on concomitant CBZ or PTO. Their corresponding interindividual and intraindividual variability values were 34.9% and 15.1% for mono-pharmacy and 29.3% and 7.84% for polypharmacy patient groups.

CONCLUSION

The correlation between phenobarbitone clearance and body weight found may allow dosage adjustment to be made to achieve target steady-state plasma concentrations.

Stability of morphine sulphate in saline under simulated patient administration conditions

OBJECTIVE

To study the stability of morphine sulphate solutions under simulated administration conditions in a patient-controlled analgesic device.

METHOD

Concentrations of 1 mg/ml and 10 mg/ml morphine sulphate in saline were monitored over 16 days under slow continuous delivery from Deltec Medication cassettes kept in the dark at a controlled temperature of 32 degrees C and a humidity between 36 and 38%. The morphine concentrations in the samples, collected at 0, 1, 2, 5, 6, 7, 9, 12, 14 and 16 days, were measured by a stability indicating high-performance liquid chromatographic method.

RESULTS

Throughout the study period, the reservoir concentrations varied within 10% of their initial values and there was no chromatographic evidence of degradation. However, the pH of both reservoirs decreased with time, but morphine is expected to be stable within the observed pH range.

CONCLUSION

This study demonstrated that the concentrating effect due to evaporation under the storage conditions described, over 16 days, was not of significance and the product was stable.

Molecular and genetic characterisation of the SARS coronavirus auxiliary protein X1 in Drosophila

1. We have generated monoclonal antibodies against the SARS coronavirus (SARS-CoV) X1/3a protein (3a), which are suitable for western blotting, immunocytochemistry, and immunohistochemistry. 2. We have established and characterised an in-vivo 3a transgenic Drosophila model, and demonstrated its usefulness in studying SARS-CoV 3a gene function. 3. We validated our in-vivo findings on 3a gene function in mammalian Vero E6 cells. 4. Our findings raise the possibility of using ion channel blockers as a novel approach to suppress SARS-CoV-induced cell death.

Challenges for coring deep permafrost on Earth and Mars

A scientific drilling expedition to the High Lake region of Nunavut, Canada, was recently completed with the goals of collecting samples and delineating gradients in salinity, gas composition, pH, pe, and microbial abundance in a 400 m thick permafrost zone and accessing the underlying pristine subpermafrost brine. With a triple-barrel wireline tool and the use of stringent quality assurance and quality control (QA/QC) protocols, 200 m of frozen, Archean, mafic volcanic rock was collected from the lower boundary that separates the permafrost layer and subpermafrost saline water. Hot water was used to remove cuttings and prevent the drill rods from freezing in place. No cryopegs were detected during penetration through the permafrost. Coring stopped at the 535 m depth, and the drill water was bailed from the hole while saline water replaced it. Within 24 hours, the borehole iced closed at 125 m depth due to vapor condensation from atmospheric moisture and, initially, warm water leaking through the casing, which blocked further access. Preliminary data suggest that the recovered cores contain viable anaerobic microorganisms that are not contaminants even though isotopic analyses of the saline borehole water suggests that it is a residue of the drilling brine used to remove the ice from the upper, older portion of the borehole. Any proposed coring mission to Mars that seeks to access subpermafrost brine will not only require borehole stability but also a means by which to generate substantial heating along the borehole string to prevent closure of the borehole from condensation of water vapor generated by drilling.

Cetuximab-related hypersensitivity reactions associated with pre-existing cetuximab-specific IgE antibody

9097

Background: Cetuximab is a chimeric (mouse/human) IgG1 monoclonal antibody against the epidermal growth factor receptor and is approved for use in patients (pts) with colorectal cancer and head and neck squamous cell carcinoma. Hypersensitivity reactions caused by cetuximab (C-HSR) have been reported; however, the mechanism underlying these reactions is unknown. We hypothesize that C-HSR are mediated by pre-existing cetuximab-specific IgE antibodies (C-IgE). Methods: A total of 140 serum samples were obtained under IRB approved protocols and retrospectively analyzed across 2 cohorts: 1) 71 pretreatment sera from cetuximab-treated pts collected from multiple centers (47 pts with no HSR and 24 pts with any grade HSR; samples were biased for HSR pts), and 2) 69 sera from healthy volunteers in the Nashville TN area. The samples were analyzed for total-, cetuximab-specific and mouse-specific IgE levels using a modified ImmunoCAP assay (Phadia US Inc.). Severe HSR was defined as grade 3/4 reactions during the first infusion by NCI CTC version 3.0 Allergic reaction/hypersensitivity criteria by a reviewer blinded to the immunoCAP assay results. Results: Of the 71 cetuximab-treated pts from cohort 1, 21 experienced severe HSR by retrospective evaluation. All C-IgE(+) pts (15/15) experienced severe HSR and were immediately discontinued from therapy. Of the remaining 6 severe HSR pts with C-IgE(-), 4 pts were re-challenged and completed their cetuximab infusion without any further reaction, suggestive of a non-IgE mediated mechanism, while 2 pts were not re-challenged. Also, the C- IgE(+) pts tended to have higher levels of total IgE compared to the C-IgE(-) pts. All 47 non-HSR pts were C-IgE(-). Mouse-specific IgE was not detected in any sera from the pts. Analysis of sera from healthy volunteers from the cohort 2 revealed that 15/69 (21.7%) were C-IgE(+), suggestive of pre-existing C-IgE; however, the association with C-HSR could not be made. Conclusion: Our data suggest that C-IgE antibodies are present prior to treatment and appears highly predictive of severe HSR during the first infusion; however, IgE-mediated reactions may not account for all cases of HSR. Prospective validation of the association between C-IgE and cetuximab-induced HSR is warranted.

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Phase II study of the clinical and biological activity of cetuximab and celecoxib in patients (pts) with refractory colorectal cancer (CRC)

14516

Background: The epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) pathways play key roles in colon carcinogenesis. EGFR and COX-2 signaling can be mutually reinforcing. Celecoxib, a selective COX-2 inhibitor, inhibits the EGFR pathway through inhibition of PI3/Akt and NF-κB pathways. This study explores the clinical and biological effects of blockade of complementary pathways of the EGFR by combining cetuximab with celecoxib. Methods: Cetuximab-naive pts with refractory CRC were treated with cetuximab (400 mg/m2 loading dose followed by weekly cetuximab at 250 mg/m2) and celecoxib (200 mg orally twice daily). Patients were assessed for response every 8 weeks. Urinary PGE-M, a metabolite of PGE-2 which correlates with in vivo COX-2 activity, and serum TGF-a, a ligand that binds to EGFR, were measured to assess the biological effect of COX-2 and EGFR blockade. Results: Seventeen of a planned 40 pts accrued to this study. Currently, data is available on 12 of these patients. Three pts had to stop treatment on 1st infusion due to a grade 3 cetuximab infusion reaction. One pt had a mild infusion reaction and was successfully rechallenged after pre-medication and a slower infusion rate. By RECIST criteria, 1 pt (8.3%) achieved a partial response (PR) and 4 pts (33%) had a best response of stable disease (SD). The mean time on study for the 9 pts without grade 3 infusion reaction was 95.7 days (range 28- 175). Pts with SD or PR were on study for a mean of 135 days (range 107–175 days) and pts with progressive disease (PD) were on study for a mean of 47 days (range 28–56 days). Baseline urinary PGE-M levels in pts with SD or PR were higher than in pts with PD (30.5+17.6 vs 18.1+9.4 ng/mg Cr). Baseline serum TGF-a levels were similar between the two groups (27.1+9.6 vs 25.4+10.3 pg/ml respectively). Conclusions: In preliminary analysis, this regimen resulted in response rates similar to published response rates for single agent cetuximab. Pts with at least SD had higher baseline urinary PGE-M levels, which may serve as a marker for efficacy of this combined therapy. Data on serial TGF-a and PGE-M levels will be presented. Response data on all 17 pts will be presented. Supported by P50 CA95103 and Bristol-Myers Squibb. Celecoxib provided by Pfizer.

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Characterization of anatomically compliant linear cardiac lesions created by the CARDIMA radiofrequency surgical ablation system

This study investigated anatomical cardiac linear lesion characteristics created by the CARDIMA RF surgical ablation system. We developed an in vitro porcine cardiac model that simulates cardiac tissue during an on-pump open chest procedure. We used the INTELLITEMP energy management device to deliver RF energy to an 8 electrode, 8 thermocouple deflectable linear surgical probe, to form curvilinear and linear lesions on porcine myocardium. Ablations were at two target temperatures (70 degrees C and 80 degrees C) and durations (60 sec. and 90 sec.). The results show that this system is capable of forming clinically relevant deep and contiguous lesions of desired length.