The Toxicologist - Society of Toxicology

imals dosed with 167 mg/kg THU alone or 167 mg/kg THU/0.4 to 2 mg/kg DAC
showed no adverse clinical signs, body weight effects, gross necropsy findings or
changes in serum chemistry. At terminal sacrifice (SD 16), decreases in leukocyte
counts (total and differential, specifically neutrophils and lymphocytes), erythrocyte
counts, hemoglobin and hematocrit values were noted in all THU/DAC
treated animals. Following the recovery period, all parameters were normal, suggesting
reversibility. Cmax was attained at 30 minutes postdose and both Cmax and
AUC values were generally proportional to dose. In conclusion, seven doses
(3x/week) of 167 mg/kg THU administered alone or 167 mg/kg THU/0.4 mg/kg
DAC were generally well-tolerated in male and female CD-1 mice, with the major
target of DAC being the hematologic system.
(Supported by NCI contract N01-CM-42204, N01-CM-52205, and NHLBI and
NIDDK under NIH-RAID Pilot Program).
800 CONSEQUENCES OF REPEATED COMPLEMENT
ACTIVATION AFTER CHRONIC TREATMENT IN
CYNOMOLGUS MONKEYS.
L. Shen 1 , T. Machemer 1 , P. Giclas 2 and S. Henry 1 . 1 ISIS Pharmaceuticals, Inc.,
Carlsbad, CA and 2 National Jewish Health, Denver, CO.
Antisense oligonucleotide (ASO)-induced complement activation is a class related
effect and has been only found in monkeys and not in other species including
human. This is a threshold event and associated with higher doses. The consequences
of repeated complement activation after chronic ASO treatment were evaluated
in cynomolgus monkeys. Animals were treated once weekly with ISIS
104838 for 9 months at 30 mg/kg/week with either subcutaneous (s.c.) injection or
30-minute intravenous (i.v.) infusion. There were transient increases in complement
split products (Bb and C3a) and decrease in C3 on Day 1 after a single treatment,
which later returned to the baselines. Repeated complement activation resulted
in a sustained decrease in plasma C3 after 3 months of treatment that
progressed over the course of the study. The complement C3 levels at termination
were about 47% and 56% of the baseline for weekly s.c. and weekly i.v. group, respectively.
There were also increases in predose levels of the split products for both
groups with slightly higher levels (especially Bb) found in the s.c. group. As the results
of chronic complement C3 depletion, there were time-dependent increases in
circulating immune complex (CIC-C3d) and possible immune-complex mediated
pathologies found in the vasculatures of heart, liver and kidney. The incidence and
severity of pathology was correlated with the decrease in C3. IgM deposition on
vessel wall and C3 staining on macrophages was also confirmed using immunohistochemistry
staining in affected tissues. In summary, we found chronic complement
activation with ASO in monkey caused C3 depletion which was correlated
with impairment of the complement function. These findings are important for the
preclinical monkey toxicology evaluation, but have limited impact to clinical safety
assessment due to the absence of complement activation in human
801 SINGLE INTRA-CEREBROVENTRICULAR INFUSION
TOXICITY, TOXICOKINETICS, AND DISTRIBUTION
STUDY OF TRIPEPTIDYL PEPTIDASE-1 IN
CYNOMOLGUS MONKEYS.
B. Vuillemenot 1 , L. Tsuruda 1 , D. Kennedy 1 , D. Musson 1 , S. Keve 1 , R. Reed 2 ,
R. Boyd 2 , M. Butt 3 and C. O’Neill 1 . 1 BioMarin Pharmaceutical Inc., Novato, CA,
2 Northern Biomedical Research, Inc., Muskegon, MI and 3 ToxPath Specialists, LLC,
Hagerstown, MD.
Neuronal ceroid lipofuscinosis-2 (NCL2) is a lysosomal storage disease caused by
tripeptidyl peptidase-1 (TPP1) deficiency and therefore a candidate for enzyme replacement
therapy. The objective of this study was to characterize the toxicity, toxicokinetics
(TK), and distribution of TPP1 after a single intracerebroventricular
(ICV) infusion to cynomolgus monkeys. Animals received 5, 14, or 20 mg recombinant
human TPP1 or artificial cerebrospinal fluid (CSF) vehicle via a lateral ventricular
catheter. Plasma and CSF were collected for TK analysis during the 3.6
hour infusion and the 14 day recovery period. Animals at all dose levels were
necropsied 14 days post-dose. In the vehicle and 14 mg dose groups, animals were
also necropsied 3 and 7 days post-dose for temporal assessment of histopathology.
Selected CNS tissues were harvested from the 14 mg dose group for TPP1 analysis
to assess the tissue distribution. TPP1 infusion had no effect on clinical observations,
ECG, or clinical pathology. CSF TPP1 levels peaked at the end of the infusion
and displayed biphasic elimination. At the end of the infusion, TPP1 was present
in plasma at between 0.1% and 1% of CSF levels. TPP1 was detected in brain
tissues 3 days post-dose at 1- to 6-fold endogenous levels. An increase in CSF
leukocytes was observed in animals from all groups, including vehicle controls, 24
hours post-dose. There were no differences in blood leukocytes. No TPP1 antibodies
were detected in blood or CSF. There were no gross or microscopic pathological
effects on the CNS, heart, liver, lung, or kidney attributable to TPP1. This study
indicates that ICV infusion of up to 20 mg TPP1 is well tolerated and not associated
with any adverse effects over a 14 day recovery period. In addition, the favorable
brain distribution and TK of TPP1 after ICV infusion offer promise for the
treatment of NCL2.
802 THE SAFETY OF CBD IN SOCIAL ANXIETY DISORDER
PATIENTS.
M. M. Bergamaschi 1, 2 , M. Chagas 2 , D. Oliveira 2 , B. Martinis 3 , J. Hallak 2 , A.
Zuardi 2 , J. Crippa 2 and R. Queiroz 1 . 1 School of Pharmaceutical Science of Ribeirão
Preto, University of São Paulo, Ribeirão Preto, SP, Brazil, 2 School of Medicine of
Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil and 3 School of
Philosophy, Science and Literature of Ribeirão Preto, University of São Paulo, Ribeirão
Preto, SP, Brazil.
Introduction: Generalized Social Anxiety Disorder (SAD) is one of the most common
anxiety conditions, with lifetime prevalence estimates of 7–12% of the general
population. SAD is characterized by excessive and persistent fear and anxiety avoidance
of a wide variety of social situations. Cannabidiol (CBD), one major non-psychotomimetic
compound from the Cannabis sativa, has shown anxiolytic effects
both in animals and in human studies. Objective: This study aimed to compare the
physiological effects on healthy control (HC) patients and on treatment-naïve SAD
patients who received a single dose of CBD or placebo. Method: Twenty-four
never-treated patients with SAD were allocated to receive either CBD (600mg;
n=12) or placebo (n=12) in a double-blind, randomized design test. The same
number of HC (n=12) performed the simulation public speaking test (SPST) without
receiving any medication. The protocol was approved by the local Ethical
Committee. The groups were matched according to gender, age, years of education
and socioeconomic level. Physiological measures [systolic pressure (SP), diastolic
pressure (DP), heart rate (HR), spontaneous fluctuation (SF) in skin conductance
and skin conductance level (SCL)] were measured at six different time points during
the SPST. The results were submitted to a repeated measures analysis of variance
(ANOVA). Results: SP, DP, HR, SCL and SF did not show significant differences
among the three groups in the all measures, but the HR, which showed a
reduction from the initial to the pretest measures significantly greater (p