The aim of this long-term study is to investigate the effect of roflumilast (APTA-2217) on the long-term safety in patients with chronic obstructive pulmonary disease (COPD) who completed the 24-week evaluation of study APTA-2217-06. Roflumilast will be administered orally once daily. The present study consists of a 28 weeks treatment period, and is an extension of the 24-week study APTA-2217-06 (registered study). The study will provide further long-term safety and efficacy data of roflumilast.

Main inclusion criteria:

• Patients with chronic obstructive pulmonary disease (COPD)
• Written informed consent
• Patients who completed the 24-week evaluation of study APTA-2217-06

Main exclusion criteria:

• If patients required hospitalization or received emergency care for COPD exacerbation by the investigator (or sub-investigator) between the informed consent day and the starting day
• Patients with long-term oxygen therapy
• Serious diseases