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PHIRST-1: Tadalafil in the Treatment of Pulmonary Arterial Hypertension

PHIRST-1: Randomized, Double-Blind, Placebo-Controlled Phase 3 Study of the Phosphodiesterase Type 5 (PDE5) Inhibitor Tadalafil in the Treatment in Patients With Pulmonary Arterial Hypertension

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00125918
Enrollment
406
Registered
2005-08-02
Start date
2005-08-31
Completion date
2007-08-31
Last updated
2008-02-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Pulmonary Hypertension

Keywords

Hypertension, Pulmonary; Pulmonary Heart Disease

Brief summary

The purpose of this study is to evaluate the safety and effectiveness of tadalafil for the treatment of pulmonary arterial hypertension.

Detailed description

This is a randomized, double-blind, placebo-controlled, multicenter study. The key measure of effectiveness of the study drug will be determined using a 6-minute walk test. Eligible patients will be treated for 16 weeks and may be eligible to enter a 52-week extension phase study (PHIRST-2). Study procedures for both studies (PHIRST-1 and PHIRST-2) will include routine blood tests, medical history, physical exams, questionnaire responses, and exercise tests.

Interventions

DRUGtadalafil

tadalafil 2.5 mg and placebo tablets taken by mouth once a day for 16 weeks.

DRUGplacebo

placebo tablet taken by mouth once a day for 16 weeks

Sponsors

ICOS Corporation
CollaboratorINDUSTRY
Eli Lilly and Company
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
12 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* At least 12 years of age. * Body weight at least 40 kg (approximately 88 pounds). * Pulmonary hypertension (PAH) that is either idiopathic; related to collagen vascular disease; related to anorexigen use; associated with an atrial septal defect (resting SaO2 greater than or equal to 88%); with surgical repair, of at least 1 year duration, of a congenital systemic-to-pulmonary shunt. * If on bosentan, must be at the maximal dose of 125 mg twice daily for a minimum of 12 weeks prior to screening and have an AST/ALT less than 3 times normal. * History of PAH established by a resting mean pulmonary artery pressure greater than or equal to 25 mm Hg, pulmonary artery wedge pressure less than or equal to 15 mm Hg, and pulmonary vascular resistance greater than or equal to 3 Wood units via right heart catheterization * Have World Health Organization functional class I, II, III or IV status. * Have a qualifying 6-minute walk test distance at screening * Have no evidence of significant parenchymal lung disease

Exclusion criteria

* Are nursing or pregnant. * PAH due to conditions other than noted in the above inclusion criteria. * History of left-sided heart disease. * History of atrial septostomy within 3 months before study entry * History of angina pectoris or other condition that was treated with long-or short-acting nitrates within 12 weeks before administration of study drug. * History of symptomatic coronary disease. * Have any therapy with a prostacyclin or analogue, L-arginine, phosphodiesterase (PDE) inhibitor, or investigational drug within 4 weeks before administration of study drug.

Design outcomes

Primary

MeasureTime frame
6 minute walk distance change from baseline to Week 1616 weeks

Secondary

MeasureTime frame
World Health Organization (WHO) functional class, Borg dyspnea, cardiopulmonary hemodynamics, quality of life - change from baseline to Week 1616 weeks
Time to first occurrence of clinical worseningNot defined

Countries

France, Italy, United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 2, 2026