BUENOS AIRES, Argentina, Oct. 1 /PRNewswire-FirstCall/ -- Results from an extension to a Phase II study evaluating the effectiveness of Abbott’s (NYSE: ABT - News) investigational anti-IL-12/23 antibody ABT-874 showed that a majority of patients who initially responded to treatment maintained a high level of response following discontinuation of therapy. In the study, patients who achieved 75 percent improvement in psoriasis signs and symptoms (PASI 75) at 12 weeks stopped receiving ABT-874. At 24 weeks, more than two- thirds of these patients maintained at least 50 percent improvement (PASI 50). The Phase II study, conducted in patients with moderate to severe psoriasis, will be presented at the World Congress of Dermatology in Buenos Aires.