P07 A Phase 3 randomized, double-blind, comparator-controlled study to evaluate safety, tolerability and immunogenicity of V114 pneumococcal vaccine in haematopoietic cell transplant recipients (PNEU-STEM)

Abstract Background Allogeneic haematopoietic cell transplant (allo-HCT) represents a definitive therapy for a variety of haematological diseases. Immunosuppressive therapy following allo-HCT and graft-versus-host disease (GVHD) render the patient susceptible to infectious complications, including invasive pneumococcal disease. Post-allo-HCT pneumococcal vaccination is recommended 3–6 months after transplant in a multi-dose series to help prevent pneumococcal disease. Objectives V114 is a 15-valent pneumococcal conjugate vaccine (PCV) approved in adults, containing all 13 serotypes in Prevnar 13™ (PCV13; contains serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F) as well as epidemiologically important serotypes 22F and 33F. This study evaluated safety and immunogenicity of V114 when given to allo-HCT recipients. Methods Individuals ≥3 years of age were randomized 1:1 to receive 3 doses of V114 or PCV13 in one-month intervals starting 3–6 months after allo-HCT. At 12 months after HCT, participants received either PNEUMOVAXTM 23 or a fourth dose of PCV if they experienced chronic GVHD. All participants or their legal representatives provided informed consent at enrolment. Primary safety objective was to evaluate the proportion of participants with adverse events (AEs) within each vaccination group for 3 to