Disposition of GDC-0879, a B-RAF kinase inhibitor in preclinical species

1. The pharmacokinetics and disposition of GDC-0879, a small molecule B-RAF kinase inhibitor, was characterized in mouse, rat, dog, and monkey. 2. In mouse and monkey, clearance (CL) of GDC-0879 was moderate (18.7-24.3 and 14.5 +/- 2.1 ml min(-1) kg(-1), respectively), low in dog (5.84 +/- 1.06 ml min(-1) kg(-1)) and high in rat (86.9 +/- 14.2 ml min(-1) kg(-1)). The volume of distribution across species ranged from 0.49 to 1.9 l kg(-1). Mean terminal half-life values ranged from 0.28 h in rats to 2.97 h in dogs. Absolute oral bioavailability ranged from 18% in dog to 65% in mouse. 3. Plasma protein binding of GDC-0879 in mouse, rat, dog, monkey, and humans ranged from 68.8% to 81.9%. 4. In dog, the major ketone metabolite (G-030748) of GDC-0879 appeared to be formation rate-limited. 5. Based on assessment in dogs, the absorption of GDC-0879 appeared to be sensitive to changes in gut pH, food and salt form (solubililty), with approximately three- to four-fold change in areas under the curve (AUCs) observed.

House dust mite induces direct airway inflammation in vivo: implications for future disease therapy?

House dust mite (HDM) is the major source of allergen in house dust and is strongly associated with the development of asthma. HDM can evoke a direct, nonallergic inflammatory reaction in vitro. We aimed to determine whether this apparent nonallergic, inflammatory response can be observed in a more complex in vivo setting. Vehicle, Alum or HDM (Dermatophagoides pteronyssinus 5 microg, i.p. with Alum) sensitised Brown-Norway rats were challenged intratracheally with vehicle (saline), HDM (Der p 10 microg) or heat-inactivated HDM on day 21. Lung function changes and the associated inflammatory response were evaluated. Tissue and bronchoalveolar lavage from Alum sensitised Der p challenged animals exhibited strong eosinophilia and neutrophilia associated with an early release of pro-inflammatory cytokines (interleukin-13 and 1beta, eotaxin and thymus and activation-regulated chemokine). This response was not attenuated by removal of HDM-associated protease activity. Interestingly, the vehicle sensitised group (no Alum) lacked this inflammatory response. HDM allergen evokes nonallergic airways inflammation with an inflammatory profile similar to that of the asthmatic airway. This response, independent of the protease activity of the HDM extract, appeared to be linked to prior administration of the adjuvant Alum and the subsequent increase in total immunoglobulin E. This finding could have important implications in the development of future asthma therapies.

Invariant natural killer (iNK) T cell deficiency in patients with common variable immunodeficiency

Common variable immunodeficiency (CVID) is a B cell immunodeficiency disorder characterized frequently by failure of memory B cell development and antibody secretion. A unifying cellular pathogenesis for CVID has not been forthcoming, but given the immunoregulatory role of invariant NK (iNK) T cells and their absence in several other immunodeficiencies, we quantified these cells in the blood of 58 CVID patients. There was a marked decrease in the proportion of iNK T cells in CVID patients compared with controls. This was particularly notable in those with low isotype-switched memory B cells, but subset analysis demonstrated no difference when stratified by specific clinical features. We propose that the decreased proportion of iNK T cells in CVID might be linked to the failure of memory B cell generation, which may contribute to reduced antibody production in these patients.

Waiting to be weighed: a pilot study of the effect of delayed newborn weighing on breastfeeding outcomes

Although breastfeeding initiation rates are rising in Canada, rates of continued breastfeeding remain far below international recommendations. Two factors that can have a positive influence on breastfeeding outcomes are maternal confidence and support and education provided by public health nurses (PHNs). The weighing of newborns by PHNs within the first days after birth is standard practice in monitoring neonatal health. However, little is known about the effect of the timing of PHN neonatal weighing on maternal confidence or on outcomes such as intended duration of breastfeeding and formula supplementation rates. This pilot study compared breastfeeding self-efficacy, intended duration of breastfeeding and formula supplementation rates in two groups of mothers and newborns randomly assigned to different weighing protocols. Newborns in the standard care group were weighed post hospital discharge on day 2 or 3 after birth (n = 23), while those in the experimental group were weighed on day 5 (n = 26). No statistically significant differences were found between the two groups. However, a statistically significant increase in formula supplementation over the two-week study period was observed in the standard-weighing group and not in the delayed-weighing group. This finding suggests that further research is needed to assess the impact of PHN infant weighing protocols on breastfeeding outcomes.

Phase I, pharmacokinetic, and pharmacodynamic evaluation of BNC105P, a novel anticancer agent that is both a vascular disrupting agent (VDA) and an inhibitor of cancer cell proliferation

e14512

Background: BNC105P is a novel anticancer agent that inhibits tubulin polymerization and acts as a VDA. BNC105P is a phosphorylated parent compound which rapidly becomes the active agent BNC105. BNC105 exhibits 100-fold specificity for activated endothelial cells compared to quiescent endothelial cells. Methods: BNC105P (2.1 to 18.9 mg/m2) was given IV over 10 min on day 1 and 8 every 21 days to patients (pts) with advanced solid tumors (ECOG 0–2) and adequate organ function. The objectives were to determine safety, tolerability, MTD and pharmacokinetics (PK). A pharmacodynamic response was evaluated using DCE-MRI with two baseline and two post dose assessments (3–6, 24 h). DLTs were determined during the first 21 days. Results: 9 pts (7 M; 2 F), median age 60 years have been enrolled with one pt each at 2.1 and 4.2 mg/m2. At 8.4 mg/m2, one pt experienced Grade 2 (Gr 2) mucositis and a switch to a ‘3+3’ design occurred. No DLTs have been observed in 3 pts at 12.6 mg/m2 and 1 pt at 18.9 mg/m2. Notable toxicity includes one episode of Gr 1 febrile episode possibly related to infusion, two episodes of Gr 1 fatigue and one Gr 1 rash. PK data of BNC105 indicates a linear increase in plasma AUC levels (Table) and plasma half life of < 0.5 h. Best observed responses were SD in 2/9 pts including one pt with mesothelioma (progression at entry) with SD up to week 22 (8.4 mg/m2). At doses ≥ 8.4 mg/m2, DCE-MRI images indicate changes in tumor perfusion post-dose. Two pts at 12.6 mg/m2 had a decrease in Ktrans values of 6 and 15 % compared to baseline. Conclusions: Pharmacodynamically active doses have been achieved with plasma drug levels correlating with active preclinical plasma exposure. To date, no excess toxicity has been observed at doses up to 18.9 mg/m2.

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Longitudinal oncology registry of head and neck carcinoma (LORHAN): First report of outcomes

6071

Background: Registries can be invaluable for describing patterns of care and outcomes for a population of patients (pts). We report the initial survival findings from LORHAN, a prospective, longitudinal, observational national registry of head and neck carcinoma (HNC) pts. Methods: Pts are eligible for LORHAN if they have newly diagnosed HNC, are scheduled to receive radiotherapy (RT) or drug therapy, are ≥18 years of age and have provided written informed consent. Data are entered in the registry electronically and transferred via Secure HTTP protocols. Patient confidentiality is strictly maintained. Pts are followed from time of initial diagnosis and for a minimum of 2 and up to 10 years. When information is complete and has been verified and signed off by the investigator, a record is locked. Only locked records are summarized and reported. Results: 2,354 pts have been enrolled in LORHAN since Dec. 2005. Of these, 1,326 pts have completed initial cancer treatment and have locked records. 1- and 2-year follow-up data are available for 583 and 56 pts, respectively. Baseline characteristics were similar between settings, except that pts treated at academic centers were significantly younger (58 vs. 62 years of age), had poorer performance status (mean Zubrod: 0.9 vs. 0.7), had fewer laryngeal tumors (17% vs. 27% of pts) but more oropharyngeal tumors (42% vs. 37% of pts) and presented with more advanced disease (stage IV: 70% vs. 48% of pts) compared to pts treated in community. Treatment did not differ by setting. Treatment and survival data are shown below. Conclusions: LORHAN demonstrates it is feasible to collect more detailed information about patient and tumor features and treatment other than surgery. Changes in the pattern of care and survival findings are expected to emerge as newer regimens, including IC and targeted agents, are incorporated more broadly into clinical practice, and data in LORHAN matures.

[Table: see text]

[Table: see text]

A phase III comparison of prophylactic cranial irradiation versus observation in patients with locally advanced non-small cell lung cancer: Initial analysis of Radiation Therapy Oncology Group 0214

7506

Background: The incidence of central nervous system (CNS) metastases is high in patients with locally advanced non-small cell lung cancer. Brain as an only site of relapse appears increasingly common as loco-regional and extra-cranial systemic treatment improves. There is not standard agreement as to how to address this risk. Methods: Patients with stage III NSCLC without progression of disease after loco-regional treatment with surgery and/or radiation therapy with or without chemotherapy were eligible. Participants were randomized to prophylactic cranial irradiation (PCI) or observation and stratified by stage (IIIA or B), histology (non-squamous or squamous) and therapy (surgery or no surgery). PCI was delivered once daily at 2Gy per fraction to 30Gy. The primary endpoint of the study was overall survival (OS). Secondary endpoints were disease free survival (DFS) and the impact of PCI on incidence of CNS metastases, neuropsychological function, and quality of life (QoL). Kaplan- Meier estimation with the log-rank test was used for OS and DFS and the logistic regression model was used for calculating the incidence of CNS metastasis. Results: Total accrual was 356 patients of the targeted 1058 between 9/19/02 and 8/30/07. The study was closed early due to slow accrual. 340 patients were evaluable. One year OS (p=0.86, 75.6 % and 76.9% for PCI and observation) and one year DFS (p=0.11, 56.4% and 51.2% for PCI and observation) were not statistically significantly different. However, CNS metastatic rate at 1 year was statistically significantly different with CNS relapse 7.7% vs. 18% for PCI vs. observation (p=0.004). Logistic regression showed that the patients in the observation arm are 2.52 times more likely to develop CNS metastases than those in the PCI arm (odds ratio=2.52, 95% CI=(1.32–4.80)). Conclusions: PCI in patients without progressive disease after loco-regional therapy for III NSCLC significantly decreases the rate of CNS metastases. This study did not show a statistically significant difference in OS or DFS. Forthcoming analysis of the impact of PCI on neuropsychological function and QoL will influence the recommendations regarding the standard use of PCI.

No significant financial relationships to disclose.