Efalizumab effective in treatment of heavy psoriasis

Aug 3 2007

A meta-analysis of four randomized Phase III placebo-controlled trials confirms that the injectable drug Efalizumab, a humanized therapeutic antibody designed to selectively and reversibly block the activation, reactivation and trafficking of T-cells that lead to the development of psoriasis, had an acceptable safety and efficacy profile in the treatment of psoriasis in heavy patients, researchers at Mount Sinai School of Medicine announced today.

Efalizumab showed similar safety and efficacy for non-heavy patients (those weighing under 200 lbs) and the more difficult-to-treat subpopulation of heavy patients (those weighing over 200 lbs). Additionally, treatment response was maintained for up to 36 months in both groups. The results were presented at the annual summer meeting of the American Academy of Dermatology in New York City.

“Overweight and obese psoriasis patients have a higher unmet need than typical psoriasis patients and present unique treatment challenges,” said Dr. Mark Lebwohl, Professor and Chairman, Department of Dermatology at Mount Sinai School of Medicine. “This patient subpopulation may have larger lesions and skin folds that limit the use of topical agents and phototherapy, as well as comorbidities such as cardiovascular and metabolic diseases that restrict the use of some systemic agents. Our study shows that Efalizumab, because of its weight-based dosing and long-term safety profile, may be an excellent choice of therapy in heavy psoriasis patients.”

A meta-analysis of four randomized Phase III placebo-controlled trials was performed to evaluate the safety and efficacy of subcutaneous Efalizumab in patients with chronic moderate-to-severe plaque psoriasis with respect to patient weight. The Psoriasis Area and Severity Index (PASI) score was used to characterize efficacy, and adverse events were examined for safety.

The median patient weight was 91kg (200 lbs.), and a total of 3,877 patients were separated into two groups above and below 91kg: heavy (n=1980) and non-heavy (n=1897). At 12 weeks, efficacy was similar for the two groups with 28 percent of non-heavy patients and 25 percent of patients achieving PASI-75. At 24 weeks, efficacy was similar for the two groups with 42 percent of non-heavy patients and 43 percent of heavy patients achieving PASI-75. The incidence of adverse events and rate of infection was similar in both patient groups. The most common adverse events observed were a symptom complex that included headache, chills, fever, nausea, and myalgia within 48 hours following the first 2 injections.

Psoriasis occurs when new skin cells grow abnormally, resulting in thick, red, and scaly, inflamed patches. Plaque psoriasis, the most common form of the disease, affects millions of Americans and is characterized by inflamed patches of skin ("lesions") topped with silvery white scales.

Patients with psoriasis are twice as likely to be overweight compared to the general population. They often gain weight because the disease limits their physical activity, or erodes their self-esteem and causes depression, leading the patient to eat excessively. Obesity is also associated with more severe psoriasis. Certain co-morbidities associated with heavy individuals such as hypertension, diabetes, or high cholesterol may influence a dermatologist's choice of therapy for this subpopulation.

Efalizumab, marketed by Genentech as Raptiva®, is a humanized therapeutic antibody designed to selectively and reversibly block the activation, reactivation and trafficking of T-cells that lead to the development of psoriasis. In October 2003, Raptiva received U.S. Food and Drug Administration approval for the treatment of chronic moderate-to-severe plaque psoriasis in adults 18 years or older who are candidates for systemic therapy or phototherapy. Raptiva can be self-administered by patients as a single dose, once-weekly, subcutaneous injection after proper training by a healthcare professional

The most serious side effects experienced by patients in trials with RAPTIVA® (efalizumab) were low platelet counts (thrombocytopenia), low blood counts (anemia), new or worsening psoriasis, and new or worsening arthritis. Because RAPTIVA is an immunosuppressive agent, it has the potential to increase the risk of infection and cancer. The most common side effects of RAPTIVA include headache, chills, fever, nausea, and muscle aches.