ABBOTT PARK, Ill., Nov. 10, 2012 /PRNewswire/ -- Results from Abbott's phase 2b clinical trial, "Aviator," demonstrated high sustained viral response rates at 12 weeks post-treatment (SVR₁₂) in all 8- and 12-week arms, with combinations of direct acting antivirals (DAAs) given with and without ribavirin (RBV). Results will be presented at the President's Press Conference and the latebreaking clinical trials session at the Liver Meeting, the Annual Meeting of the American Association for the Study of Liver Disease (AASLD) in Boston.

Based on promising results from Aviator, Abbott has selected triple-DAA regimens, with and without ribavirin, to move forward into phase 3 clinical trials. Topline intent-to-treat results for the 12-week, triple-DAA regimen with ribavirin are as follows:

• SVR₁₂ in treatment-naïve genotype 1 (GT1) patients was 97.5 percent (77 of 79), and 93.3 percent (42 of 45) in GT1 null responder patients 
• In GT1a patients, SVR₁₂ was achieved in 96 percent (52 of 54) of treatment naïve patients and 89 percent (25 of 28) of null responder patients
• In GT1b patients, SVR₁₂ was achieved in 100 percent of treatment naïve (25 of 25) and null responder patients (17 of 17)

In addition, results from the 12-week triple-DAA regimen without RBV in treatment naïve patients showed:

• SVR₁₂ was achieved in 87.3 percent (69 of 79) of GT1 patients
• SVR₁₂ in GT1a patients was 83 percent (43 of 52)
• SVR₁₂ in GT1b patients was 96 percent (24 of 25)

"Based on the high SVR₁₂ results with Abbott's triple-direct acting antiviral regimen in GT1 patients, it appears we are moving closer to potential oral treatment regimens that do not require interferon to treat HCV," said Kris Kowdley, M.D., director of the Liver Center of Excellence in the Digestive Disease Institute at Virginia Mason Medical Center, and Clinical Professor of Medicine at the University of Washington in Seattle. "This is encouraging news for the many patients who are unable or unwilling to take interferon."

About Study M11-652 (Aviator)
This phase 2b study assesses the safety, and efficacy of ABT-450/r (dosed 100/100mg to 200/100mg QD), ABT-267 (25mg QD), ABT-333 (400mg BID) and ribavirin in non-cirrhotic treatment-naïve patients and prior peg-interferon/ribavirin null responders for 8, 12 or 24 weeks. Enrollment was open to GT1-infected patients regardless of IL28B host genotype and ribavirin dosing was weight-based. Results from the treatment groups are summarized in the chart below. 

¹ITT (Intent-to-treat) population: includes all patients who received at least one dose of study drug

²OD (Observed data): Excludes patients with values missing for reasons other than virologic failure or discontinuation due to AEs

"The 93.3 percent SVR₁₂ seen with triple-DAA therapy with ribavirin in previous null responder patients in Aviator is noteworthy given the limited treatment options with interferon-based therapies for this patient population," said Scott Brun, M.D., divisional vice president, Infectious Disease Development, Abbott. "As the data from the Aviator study have matured, we are encouraged that we have continued to see high SVR₁₂ rates. Results from Aviator have allowed Abbott to confidently move into larger, confirmatory Phase 3 trials with the goal of being the first company to bring an interferon-free treatment regimen to genotype 1 patients."

Aviator Safety Results
Four of 448 patients (one percent) in the 8- and 12-week arms discontinued due to adverse events. Of five serious AEs (1 percent), one (arthralgia or joint pain) was possibly study drug-related. In the trial, the most common adverse events were fatigue (28 and 27 percent) and headache (28 and 31 percent) for treatment naïve and null responders respectively.

About the Hepatitis C Virus
Hepatitis C is a liver disease affecting as many as 170 million people worldwide. The virus is primarily spread through direct contact with the blood of an infected person. HCV increases a person's risk of developing chronic liver disease, cirrhosis, liver cancer and death; and liver disease associated with HCV infection is growing rapidly.

Of the six main genotypes of hepatitis C, genotypes 1, 2 and 3 are the most widespread. Genotype 1 is the most common genotype in the U.S. and the most difficult to treat with interferon based therapies. Patients with genotypes 2 and 3 are more likely than individuals with genotype 1 to respond to therapy with peg-interferon or the combination of peg-interferon and ribavirin.

About Abbott's HCV Development Programs
Abbott's HCV portfolio includes investigational medicines with three different mechanisms of action, including protease (ABT-450/r), polymerase (ABT-333) and NS5A (ABT-267) inhibitors, currently being studied in clinical trials. ABT-450 is being developed with low dose ritonavir which enhances the pharmacokinetic properties of ABT-450. The use of ritonavir 100mg with ABT-450 for the treatment of HCV is investigational.

ABT-450 was discovered during the course of a collaboration between Abbott and Enanta Pharmaceuticals for HCV protease inhibitors and regimens that include protease inhibitors. ABT-450 is being developed by Abbott for use in combination with Abbott's other investigational medicines for the treatment of HCV. Abbott is well-positioned to explore combinations and co-formulations of these medicines.

On Monday, November 12 at 5:30 p.m. EST, Abbott will host an investor webcast to discuss the phase 2b Aviator data, as well as our recently initiated phase 3 registrational program. The webcast can be accessed on Abbott's investor relations website at abbottinvestor.com.

Ritonavir Use in Treatment of HIV
Ritonavir is in a class of medicines called the HIV protease inhibitors. Ritonavir is used in combination with other anti-HIV medicines to treat people with human immunodeficiency virus (HIV) infection. Ritonavir is for adults and for children greater than 1 month in age and older.

Ritonavir does not cure HIV infection or AIDS and does not reduce the risk of passing HIV to others. People taking ritonavir may still get opportunistic infections or other conditions that happen with HIV infection. Some of these conditions are pneumonia, herpes virus infections, and Mycobacterium avium complex (MAC) infections.

Ritonavir Safety in Treatment of HIV
Patients should not take ritonavir with certain medicines, as these can cause serious or life-threatening problems such as irregular heartbeat, breathing difficulties, or excessive sleepiness. Patients should not take ritonavir if they have had a serious allergic reaction to any of its ingredients. Some patients taking ritonavir may develop liver and pancreas problems, which can cause death.

Patients may develop large increases in triglycerides and cholesterol, diabetes, high blood sugar, changes in body fat, increased bleeding in people with hemophilia, allergic reactions, and/or changes in heart rhythm. Patients may develop signs and symptoms of infections that they already have after starting anti-HIV medicines.  For more information, please see Important Safety Information and Full Prescribing Information.

About Abbott
Abbott is a global, broad-based health care company devoted to the discovery, development, manufacturing and marketing of pharmaceuticals and medical products, including nutritionals, devices and diagnostics. The company employs approximately 91,000 people and markets its products in more than 130 countries.

Abbott's news releases and other information are available on the company's website at www.abbott.com.

SOURCE Abbott