The study comprised two parts. The objective of the first study period was to assess the safety and pharmacokinetics of 500 mg of BIRT 2584 XX tablets administered with and without food in male healthy volunteers and to determine the relative bioavailability of the BIRT 2584 XX tablet formulation compared by historical comparison to BIRT 2584 XX powder in PEG 400 (U05-2074) (part 1). The second and major phase of the trial was aimed at evaluating the safety, tolerability, pharmacokinetics, and pharmacodynamics of multiple rising doses of BIRT 2584 XX (100 mg, 250 mg, and 500 mg bid on the first 2 days and qd on the following 12 days, or 750 mg qd for 28 days) in healthy male subjects (part 2)