The findings on Raptiva were presented at an American Academy of Dermatology meeting in Chicago, according to a news release.
"The results show a high percentage of patients experiencing clinically meaningful response to Raptiva with 24 weeks of continuous therapy," says Kenneth Gordon, MD, professor of dermatology at Loyola University in Chicago, in the news release.
Psoriasis is a chronic skin condition that involves abnormal growth of new skin cells (plaques) resulting in scaling and inflammation of the skin. It can vary in severity from small patches of irritation on the elbows, knees, and scalp to potentially disabling flare-ups that affect large portions of the body. It can negatively affect a person's functional status and well-being, social relationships, and ability to perform activities of daily living, writes Gordon.
Raptiva works by blocking T-cells (immune cells) that cause the development and maintenance of psoriasis plaques.
In one study, 368 patients received at least one dose of Raptiva for the first 12 weeks; another treatment group received a placebo. After the initial 12-week study period, patients could elect to continue with once-weekly doses for another 12 weeks.
Longer-term psoriasis treatment produced the best results:
- At 12 weeks, almost a fourth of the patients achieved a 75% reduction in test scores that measure psoriasis symptoms.
- At 24 weeks, almost half the patients treated achieved a 75% reduction of symptom scores.
In a 21-month study of Raptiva, there were similar results. Patients received 2 mg doses of Raptiva weekly for the first 12 weeks. Those who reduced their symptom scores by 50% then continued a 1 mg maintenance dose for the duration of the study period. The researchers showed that patients receiving 21 months of continuous therapy with Raptiva could maintain or improve their symptoms after three months of therapy. They also showed that this therapy was safe and tolerable.
Though some patients had reactions during the first 12 weeks of psoriasis treatment -- headache, colds, chills, pain, nausea, and fever -- the reactions mostly decreased over time and were not serious.
In fact, results pooled from four phase III "gold-standard" trials of 2,335 patients support the safety and tolerability of Raptiva for moderate to severe psoriasis treatment.