- Patients must have been enrolled in previously completed clinical studies of infliximab in the treatment of COPD that are targeted for long term safety follow-up (ie, primary studies). Primary studies are defined as studies that have evaluated infliximab on an investigational basis and that have been identified by Centocor or health authorities as requiring long-term safety follow-up. These include Centocor protocol C0168T54, conducted in the USA, and 2 smaller studies conducted in the Netherlands (EU0016 C0168X09 and EU0073 C0168X57). Patients must have received at least one dose of study agent to be eligible.