Long-term trial of bosentan monotherapy for pulmonary arterial hypertension in Japanese patients.
OBJECTIVE
To determine the efficacy and safety of long-term bosentan monotherapy in Japanese patients with pulmonary arterial hypertension (PAH).


METHODS
The present study was an extension to a 12-week open-label trial of bosentan in which 21 Japanese patients with PAH received bosentan, 125 mg twice daily. Of the 21 patients in the initial trial, 20 elected to participate in the long-term study and to continue to receive bosentan for up to 3 years.


METHODS
The primary efficacy measure was comparison of World Health Organization (WHO) functional class for pulmonary arterial hypertension following long-term (> 2.5 years) therapy compared with baseline (prior to initiation of bosentan). Secondary outcomes included time from initiation of bosentan therapy to clinical worsening and safety assessments.


RESULTS
Bosentan treatment was continued for a median of 2.7 years (range 0.4-3.0 years); 12 patients received bosentan monotherapy for at least 2.5 years. Following long-term treatment, improvement of WHO functional class compared with baseline was observed in 9/12 patients (75.0%) and in 3/12 patients (25.0%) the functional class remained stable; no patient experienced a worsening of WHO functional class compared with baseline. Overall, long-term treatment with bosentan was well tolerated.


CONCLUSIONS
Long-term treatment with bosentan is well tolerated and is associated with sustained clinical improvement in Japanese patients with PAH. Bosentan, therefore, represents a valuable treatment option for Japanese patients with this devastating disease.
Sasayama
Shigetake
S
Cardiac Bio-Mechanics Center, Doshisha University, Japan. sasayama@wonder.ocn.ne.jp
Satoh
Toru
T
Izumi
Tohru
T
Yoshida
Shunji
S
Kyotani
Shingo
S
Tahara
Nobuhiro
N
D000328:Adult; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D000077300:Bosentan; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy*; D007564:Japan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013449:Sulfonamides / Q000627:therapeutic use*; D016896:Treatment Outcome
D047228:Angiotensin II Type 1 Receptor Blockers; D013449:Sulfonamides; D000077300:Bosentan