Schering-Pough
Halts Phase II Study of CCR5 Entry Inhibitor Vicriviroc
Schering-Plough
Corporation (SP) announced yesterday evening termination of its
Phase II trial of the CCR5
HIV entry inhibitor vicriviroc
in treatment-naïve HIV patients. The Data Safety Monitoring Board
(DSMB) recommended halting the trial after observing virologic
rebound in some naïve patients in the vicriviroc-containing
arm of the study versus the Combivir
plus Sustiva control arm.
A
halt of the Phase vicriviroc trial by SP follows the announcement
by GlaxoSmithKline earlier this week of the termination
of its Phase III trials in both treatment-naïve and treatment
experienced patients receiving aplaviroc,
also a CCR5 entry inhibitor. GKS
halted those studies due to concerns about severe
hepatotoxicity in some
patients on aplaviroc.
The
SP announcement said the decision to stop the vicriviroc
Phase II trial was not based on hepatotoxicity
or on other safety-related issues in patients receiving vicriviroc
in the study or in another Phase II study in treatment-experienced
patients, but rather on the observance of loss
of virologic suppression by some patients in the
vicriviroc arm. The study of the drug in the treatment-experienced
patients is continuing. Following is the text of the announcement
from SP:
“Schering-Plough
Corporation (NYSE: SGP) today reported that it has discontinued a Phase II study with its
investigational CCR5 receptor antagonist, vicriviroc, used in combination with Combivir
in treatment-naïve HIV patients.
This decision was due to a return of detectable virus in some
patients late in therapy compared to the control regimen of Combivir and Sustiva, a current
standard of care for treatment-naïve patients living with HIV.
“The
company noted that this decision was not based on hepatotoxicity
or other significant safety issues in patients receiving vicriviroc
in the study or in a second Phase II study in treatment-experienced
HIV patients, which is continuing. The Phase II study in U.S.
treatment-experienced patients is being conducted by the NIH-sponsored
AIDS Clinical Trials Group (ACTG) and is fully enrolled.
“Schering-Plough
said that it discontinued its Phase II treatment-naïve study following
a recommendation from the independent Data Safety Monitoring Board
(DSMB), which has been meeting regularly to conduct reviews of
the safety and efficacy data. The increased incidence of detectable
virus was only seen in some patients after several weeks of treatment.
“The
study had been under way since spring 2004 in 23 centers in Europe
and Canada, with 92
patients enrolled. Patients already enrolled in the treatment-naïve
study will continue to receive vicriviroc until they can be switched to an alternative regimen
in consultation with their physician. Clinical trial investigators
for the study, their Ethics Committees and Health Authorities
are being notified.
“We
believe this decision is the appropriate action to take to ensure
that patients receive the most effective treatment available,”
said Robert J. Spiegel, M.D., chief medical officer and senior
vice president of medical affairs, Schering-Plough Research Institute.
“We will continue to evaluate the potential use of vicriviroc
in combination with other treatment regimens, including those
used in the treatment-naïve patient population.”
10/28/05
Source
Schering-Plough
Corporation
