Results of VICTOR-E1 Phase II Study Presented at 15th Conference on
Retroviruses and Opportunistic Infections (CROI)
BOSTON, Feb. 6 /PRNewswire-FirstCall/ -- Schering-Plough Corporation (NYSE: SGP) today reported that final results of a Phase II clinical study showed vicriviroc, its investigational CCR5 antagonist, demonstrated potent and sustained viral suppression through 48 weeks of therapy in treatment- experienced HIV-infected patients, when administered once-daily as a single tablet in combination with an optimized ritonavir-boosted protease inhibitor containing antiretroviral regimen. Vicriviroc is a next-generation extracellular inhibitor of HIV infection designed to block entry of infectious virions into uninfected CD4 cells via antagonism of the CCR5 co-receptor.
Researchers reported the data in a late-breaker oral presentation at the 15th Conference on Retroviruses and Opportunistic Infections (CROI) on Feb. 4.
In the study, significantly more patients who added vicriviroc 30 mg once daily to a new optimized background therapy (OBT) had fully suppressed HIV-RNA (less than 50 copies/ml) at 48 weeks compared to patients receiving new OBT alone (56 percent vs. 14 percent, p=0.0002).
"These 48-week results demonstrate that vicriviroc added to OBT provides significant and durable viral suppression compared to OBT alone in this treatment-experienced HIV-infected patient population," said Barry S. Zingman, M.D., medical director - AIDS Center, Montefiore Medical Center and the Einstein/Montefiore Center for AIDS Research, and associate professor of clinical medicine, Albert Einstein College of Medicine, Bronx, N.Y., who presented the data. "Importantly, this benefit of vicriviroc was observed regardless of the number of active HIV drugs in a patient's background therapy."
The study, known as VICTOR-E1 (Vicriviroc in Combination Treatment with Optimized Antiretroviral Therapy Regimen in Experienced Subjects), evaluated the safety and efficacy of vicriviroc (30 mg or 20 mg once daily) in combination with an optimized ritonavir-boosted, protease inhibitor-containing antiretroviral regimen compared to a control group receiving new OBT alone. The primary endpoint of the study was change in HIV-RNA at week 48. A total of 116 treatment-experienced adult HIV-infected patients with R5-type virus at screening were randomized in this placebo-controlled, double-blind study at 37 sites throughout Europe, South Africa and North and South America.
Results of the study through 48 weeks demonstrated potent and sustained viral suppression in the vicriviroc arms, with significantly greater decreases in mean HIV-RNA, as well as greater increases in mean CD4 counts, compared to the control arm. At 48 weeks, patients in the 30 mg and 20 mg vicriviroc treatment groups achieved mean decreases from baseline in viral load of -1.77 and -1.75 (log10 copies/mL), respectively, compared to -0.79 for the control group (p=0.0017 and p=0.0026, respectively). Mean increases from baseline in CD4 cell counts in the vicriviroc groups were +102 and +134 (cells/mm3), respectively, compared to +65 in the control group. Fewer patients in the vicriviroc groups discontinued from the study due to virologic failure compared to those in the control group (13 percent and 8 percent vs. 38 percent, respectively).
No clinically relevant differences in safety profile between the vicriviroc and control groups were observed in this study, including liver toxicity, opportunistic infections, malignancies or other conditions. There were no cases of grade 3/4 elevated ALT reported in the vicriviroc groups compared to one case in the control group, and there were one, two and one cases of grade 3/4 elevated total bilirubin reported among atazanavir recipients in each of the groups, respectively. There were no opportunistic infections reported in the vicriviroc groups compared to two in the control group, and no systemic malignancies reported in any of the groups in the 48- week study.
These results supported the selection of the 30 mg once-daily vicriviroc dose for use in ongoing Phase III clinical studies.
About Vicriviroc Ongoing Phase III Studies
Building on the results of the VICTOR-E1 study, Schering-Plough is currently enrolling patients in two large global Phase III clinical studies with vicriviroc administered once-daily as a single 30 mg tablet in adult treatment-experienced HIV patients with R5-type virus only.
The two ongoing Phase III studies, known as VICTOR-E3 and VICTOR-E4 (Vicriviroc in Combination Treatment with an Optimized Antiretroviral Therapy Regimen in HIV-Infected Treatment-Experienced Subjects), evaluate the virologic benefit of adding vicriviroc 30 mg once daily to an optimized background therapy compared to a control group receiving new optimized background therapy alone. The optimized background therapy must include at least two drugs to which the patient's HIV is susceptible. Patients coinfected with hepatitis B or C may be included in these studies and there are no exclusions of commonly prescribed drugs or need for dose adjustments based on the known vicriviroc drug-drug interaction profile. The two studies are currently enrolling approximately 375 patients each at more than 160 sites in North America, Latin America, Europe, Australia and South Africa.
For more information about the VICTOR-E3 and VICTOR-E4 clinical studies, please visit http://www.clinicaltrials.gov, search term: vicriviroc.
Schering-Plough is an innovation-driven, science-centered global health care company. Through its own biopharmaceutical research and collaborations with partners, Schering-Plough creates therapies that help save and improve lives around the world. The company applies its research-and-development platform to human prescription and consumer products as well as to animal health products. In November 2007, Schering-Plough acquired Organon BioSciences, with its Organon human health and Intervet animal health businesses, marking a pivotal step in the company's ongoing transformation. Schering-Plough's vision is to "Earn Trust, Every Day" with the doctors, patients, customers and other stakeholders served by its approximately 50,000 people around the world. The company is based in Kenilworth, N.J., and its Web site is http://www.schering-plough.com.
SCHERING-PLOUGH DISCLOSURE NOTICE: The information in this press release includes certain "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including statements relating to the company's clinical development plans and the potential for vicriviroc. Forward-looking statements relate to expectations or forecasts of future events. Schering-Plough does not assume the obligation to update any forward-looking statement. Many factors could cause actual results to differ materially from Schering-Plough's forward-looking statements, including market forces, economic factors, product availability, patent and other intellectual property protection, current and future branded, generic or over-the-counter competition, the regulatory process, and any developments following regulatory approval, among other uncertainties. For further details of these and other risks and uncertainties that may impact forward-looking statements, see Schering-Plough's Securities and Exchange Commission filings, including Part II, Item 1A, "Risk Factors" in the company's third quarter 2007 10-Q.
|SOURCE Schering-Plough Corporation|
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