Immune response to pneumococcus and tetanus toxoid in patients with moderate-to-severe psoriasis following long-term ustekinumab use.

BACKGROUND: Little is known about the impact of long-term use of immunosuppressive agents on immune response. OBJECTIVES: Assess the impact of continuous maintenance ustekinumab treatment on patients' ability to mount immune responses to pneumococcal (T-cell-independent) and tetanus toxoid (T-cell-dependent) vaccines. PATIENTS AND METHODS: Ustekinumab-treated patients with moderate-to-severe psoriasis treated in the long-term extension of the Phase 3 PHOENIX 2 trial (n=60) were compared with control psoriasis patients not receiving systemic therapy (n=56). Patients were vaccinated with both 23-valent pneumococcal and tetanus toxoid vaccines. Serum samples collected pre-vaccination and 4 weeks post-vaccination were assessed for antibody responses. RESULTS: No differences in the ability of ustekinumab-treated patients to respond to pneumococcal or tetanus toxoid vaccinations were observed compared with controls. A ≥2-fold increase in antibody levels in ≥7 of 14 serotypes of the pneumococcal vaccine was observed in ustekinumab-treated (96.6%) and untreated control (92.6%) patients following vaccination. Ustekinumab-treated patients achieved a ≥4-fold increase (84.7%) in anti-tetanus antibody vs. 77.8% in the control group. No differences were detected in ex-vivo responses to anti-CD3/CD28 or tetanus toxoid between ustekinumab-treated and control groups. CONCLUSION: Long-term treatment (≥3 years) with ustekinumab does not compromise the immune response to T-cell-dependent/-independent vaccines in patients with moderate-to-severe psoriasis.