
CONFIDENTIAL
23
Key Safety findings (from non-clinical studies)
ion channel activities in vitro and as expected
from the pharmacology of muscarinic
antagonists, a number of cardiovascular
effects, including tachycardia in dogs. In
repeat dose inhaled studies, increased pulse
rates/heart rates were generally accompanied
with the secondary loss of respiratory sinus
arrhythmia but no additional treatment-related
waveform abnormalities were observed.
Single dose oral moxifloxacin 400 mg (positive
control) demonstrated assay sensitivity with
mean increases in time-matched QTcF
compared with placebo greater than 5 msec at
1, 2, 4, 8 and 12 hours after dosing. Upper
90% confidence limit exceeded 10 msec at 4
and 8 hours.
• The estimated treatment difference from
placebo of QTcF (msec) was negative at all
time points post last dose on Day 10, and the
upper limit of the 90% CI for the estimated
treatment difference was less than 10 msec,
indicating a lack of UMEC 500 mcg effect on
QTcF compared with placebo which is eight
times the proposed dose of UMEC. No
categorical QTcF effects were observed for
UMEC 500 mcg.
• There were no clinically relevant changes from
baseline in heart rate in the participants with
COPD following treatment with UMEC
compared with placebo at the proposed
commercial dose. In the thorough QT study in
healthy volunteers, the maximum mean
time-matched change in heart rate for UMEC
500 mcg compared with placebo was 2.1 bpm
at 8 hours post-dose (90% CI: 0.7, 3.5).
Mechanisms for drug interactions
• In vitro, UMEC is a substrate of CYP2D6 and
the P-gp transporter and organic cation
transporters; OCT1 and OCT2.
• In vitro studies conducted using human
recombinant cytochrome P450 (CYP)
enzymes showed that UMEC was metabolized
mainly by CYP2D6. The contribution of OCT1
to the clearance of UMEC is unclear as there
was no evidence of an increase in systemic
exposure for UMEC following inhaled UMEC
(125 mcg) in participants with moderate
hepatic impairment compared to healthy
controls (Study DB2114637). It can therefore
be implied that an interaction with a
transporter such as OCT1 would not result in a
clinically significant increase in systemic
exposure of UMEC.
• In an additional in vitro study, UMEC was
found not to be a substrate of BCRP,
• There was no evidence of a clinically relevant
increase in systemic exposure of UMEC in
healthy human – CYP2D6 poor metabolizer
participants at 8-fold higher dose (500 mcg)
compared to healthy normal metabolizers.
• A clinical study showed a moderate interaction
with verapamil (an inhibitor of P-gp).
• The extent of the role of OCT1 or OCT2 in the
clearance of UMEC in humans is unclear and
there is no clear guidance on clinical probes to
study inhibition of OCTs in humans. It is
considered that any mechanism (including an
interaction) which limits the clearance of
UMEC by one of these routes will be
compensated for by another route of
clearance. This is supported by the lack of a
clinically significant increase in systemic
exposure of UMEC in studies performed in
participants with severe renal impairment
(DB2114636), participants with moderate
hepatic impairment (DB2114637) or in a