Charles Lynde1, James Krell2, Neil Korman3, Barbara Mathes4. 1. Lynde Center for Dermatology, Markham, Ontario, Canada. Electronic address: derma@lynderma.com. 2. Total Skin and Beauty Dermatology Center, Birmingham, Alabama. 3. University Hospitals of Cleveland, Cleveland, Ohio. 4. University of Pennsylvania, Philadelphia, Pennsylvania.
Abstract
BACKGROUND: Alefacept is a T cell-modulating biologic therapy for psoriasis that could affect patients' ability to mount immune responses. OBJECTIVE: This open-label, phase IV, multicenter study assessed the ability of adults with chronic plaque psoriasis receiving alefacept to generate antibodies to a pneumococcal polysaccharide vaccine (PPV). METHODS: Patients were treated with a standard 12-week course of alefacept and administered the 23-valent PPV at week 6. Antipneumococcal antibodies were measured at baseline and weeks 6, 9, 12, and 33. The primary end point was the percentage of patients with a 2-fold or greater increase from prevaccination (week 6) to 6 weeks postvaccination (week 12) in antibody titers to 2 or more of 5 designated PPV antigens. RESULTS: Of 43 patients enrolled, 42 were included in the full analysis set, with 86% of patients exhibiting a 2-fold or greater increase and 57% of patients exhibiting a 4-fold or greater increase in antibody titers to 2 or more of 5 designated antigens from prevaccination to 6 weeks postvaccination. At 6 months postvaccination, 78% of patients had a 2-fold or greater increase and 47% of patients had a 4-fold or greater increase in antibody titers to 2 or more of the 5 designated antigens. There were statistically significant increases in mean antibody titers to all 23 antigens in PPV from prevaccination to 6 weeks postvaccination. LIMITATIONS: This was an open-label study with no comparator. CONCLUSIONS: Most patients mounted immune responses to PPV; increases in antibody titers in these patients were consistent with those seen in healthy individuals.
BACKGROUND: Alefacept is a T cell-modulating biologic therapy for psoriasis that could affect patients' ability to mount immune responses. OBJECTIVE: This open-label, phase IV, multicenter study assessed the ability of adults with chronic plaque psoriasis receiving alefacept to generate antibodies to a pneumococcal polysaccharide vaccine (PPV). METHODS:Patients were treated with a standard 12-week course of alefacept and administered the 23-valent PPV at week 6. Antipneumococcal antibodies were measured at baseline and weeks 6, 9, 12, and 33. The primary end point was the percentage of patients with a 2-fold or greater increase from prevaccination (week 6) to 6 weeks postvaccination (week 12) in antibody titers to 2 or more of 5 designated PPV antigens. RESULTS: Of 43 patients enrolled, 42 were included in the full analysis set, with 86% of patients exhibiting a 2-fold or greater increase and 57% of patients exhibiting a 4-fold or greater increase in antibody titers to 2 or more of 5 designated antigens from prevaccination to 6 weeks postvaccination. At 6 months postvaccination, 78% of patients had a 2-fold or greater increase and 47% of patients had a 4-fold or greater increase in antibody titers to 2 or more of the 5 designated antigens. There were statistically significant increases in mean antibody titers to all 23 antigens in PPV from prevaccination to 6 weeks postvaccination. LIMITATIONS: This was an open-label study with no comparator. CONCLUSIONS: Most patients mounted immune responses to PPV; increases in antibody titers in these patients were consistent with those seen in healthy individuals.