Synagis® Liquid 50mg, 100mg for Intramuscular Injection Special Investigation in Immunocompromised Children With Synagis®

This post marketing observational study (PMOS) was conducted in Japan during the 2013-2014 and 2014-2015 Respiratory Syncytial Virus (RSV) seasons to assess the safety and effectiveness of palivizumab for the prevention of serious lower respiratory tract infection caused by RSV in participants 24 months of age and under, who have an immunocompromised medical condition (e.g., combined immunodeficiency disease, antibody deficiency, or other types of immunodeficiency; HIV infection; recovering from organ or bone marrow transplantation; on chemotherapy; on high-dose corticosteroid therapy; on immunosuppressants) or who have Down syndrome.

Palivizumab was prescribed according to the local label and independently of the decision to enroll participants in the study. Palivizumab was administered monthly throughout the Respiratory Syncytial Virus (RSV) infection seasons via intramuscular injection at a dose of 15 mg/kg of body weight. Survey forms were collected after the observation period. The number of adverse events and the frequency of hospitalizations due to RSV infections in surveyed participants were assessed to evaluate the safety and effectiveness of palivizumab.

Eligibility Criteria:
Inclusion Criteria:

1. Availability of a parent or legal guardian who was capable and willing to give written informed consent for his/her newborn, infant or young child to participate in the study
2. Participants receiving palivizumab for prevention of serious lower respiratory tract disease caused by RSV infection
3. Newborns, infants, or young children 24 months of age and under who have an immunocompromised medical condition:

   * combined immunodeficiency, (severe combined immunodeficiency, X-linked hyper-immunoglobulin M (IgM) syndrome, etc.), antibody deficiency (X-linked agammaglobulinemia,common variable immunodeficiency, non-X-linked hyper-IgM syndrome,etc.) or other immunodeficiency (Wiskott-Aldrich syndrome, etc.)
   * acquired T cell dysfunction ( such as human immunodeficiency virus (HIV) infection etc.)
   * history of past organ transplantation
   * history of past bone marrow transplantation
   * receiving immunosuppressive chemotherapy
   * receiving systemic high-dose corticosteroid therapy (prednisone equivalents ≥ 0.5 mg/kg/every other day, other than inhaler or topical use), or
   * receiving other immunosuppressive therapy (azathioprine, methotrexate, mizoribine, mycophenolate mofetil, cyclophosphamide, cyclosporine, tacrolimus, cytokine inhibitors, etc.)
   * receiving biologics (including cytokine inhibitors)
   * Others (nephrotic syndrome, chronic peritoneal dialysis, hemodialysis)
4. Newborns, infants, or young children age of 24 months and under who have Down syndrome without a current hemodynamically significant Congenital Heart Disease. The participant must have had an experience with persistent respiratory symptoms or regular outpatient treatment due to respiratory tract infection prior to current RSV season.

Exclusion criteria:

1. Participants included in the Contraindications section of the package insert
2. Participants with known hypersensitivity to the ingredients of palivizumab
3. Participants with a known positive RSV infection before hospitalization