Clinical effectiveness and safety experience with alefacept in the treatment of patients with moderate-to-severe chronic plaque psoriasis in Taiwan: results of an open-label, single-arm, multicentre pilot study

Background  The effectiveness and safety of alefacept for the treatment of moderate-to-severe chronic plaque psoriasis has been established in several clinical trials conducted in the United States and Europe. No clinical trial of alefacept has been conducted in Asia.
Objective  To determine the effectiveness and safety of alefacept in the treatment of psoriasis in Chinese population.
Design and methods  This was an open-label, single-arm, multicentre pilot study conducted at three centres. Patients with a body surface area ≥ 10% and psoriasis area and severity Index (PASI) ≥ 12 were given 15 mg alefacept intramuscularly once a week for 12 weeks and were then followed up for a further 12 weeks.
Results  A total of 46 patients was enrolled. Only one subject (2%) achieved a ≥ 75% improvement in PASI at week 14. The median improvement in PASI at week 14 after the 12-week treatment was 39%. At any time during the 6-month course, 3 subjects (7%) achieved a Physician Global Assessment (PGA) of 'almost clear', and a ≥ 50% and ≥ 75% improvement in PASI was seen in 46% and 9%, respectively. There is a trend for decreased counts of CD4⁺ and CD8⁺ cells after alefacept treatment, but subjects who achieved PASI50 showed a lesser degree of decrease in CD4⁺ and CD8⁺ counts compared with those in patients who did not achieve PASI50.
Conclusions  This small pilot study indicated that intramuscular alefacept was effective and safe in psoriasis in Chinese patients over 12 weeks of treatment. Further studies are needed to clarify the reason for low PASI 75 effectiveness and the paradoxical lesser decline of CD4⁺ and CD8⁺ T cells in those who responded.