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CompletedNCT00125918Updated Feb 21, 2008

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

A Phase 3 interventional study of tadalafil and tadalafil in Pulmonary Hypertension, sponsored by Eli Lilly and Company. Completed at 6 sites in 3 countries. Open to participants aged 12 Years and older. Per ClinicalTrials.gov, last updated 2008-02-21.

Sponsored by Eli Lilly and Company · Phase 3, Interventional, and Treatment

Phase
Phase 3
Study type
Interventional
Enrollment
406
Allocation
Randomized
Ages
12 Years and older
Sex
All
01

Study summary

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

Read the 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.

02

Conditions studied

  • Pulmonary Hypertension

Keywords

  • Hypertension, Pulmonary; Pulmonary Heart Disease
03

In context

Hypertension, Pulmonary

1,105 studies on the registry are indexed under Hypertension, Pulmonary; 234 are open to participants now.

This study's enrollment of 406 is above the median of 35 across 649 interventional studies indexed under Hypertension, Pulmonary.

Browse Hypertension, Pulmonary studies →

Lead sponsor

Eli Lilly and Company is the lead sponsor of 2,048 studies on the registry; 140 are open to participants now.

Of its 521 completed or terminated interventional studies of FDA-regulated products, 341 (65%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
12 Years and older
Sexes eligible
All
Accepts 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

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.
05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
406 participants (actual)

Study arms

  • Placebo comparator
    1

    Placebo

    Drug: placebo

  • Active comparator
    2

    2.5 mg tadalafil

    Drug: tadalafil

  • Active comparator
    3

    10 mg tadalafil

    Drug: tadalafil

  • Active comparator
    4

    20 mg tadalafil

    Drug: tadalafil

  • Active comparator
    5

    40 mg tadalafil

    Drug: tadalafil

Interventions

  • Drugtadalafil

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

    Also known as: LY450190, Cialis, IC351

  • Drugtadalafil

    tadalafil 10 mg and placebo tablets taken by mouth once a day for 16 weeks.

    Also known as: LY450190, Cialis, IC351

  • Drugtadalafil

    tadalafil 20 mg and placebo tablets taken by mouth once a day for 16 weeks.

    Also known as: LY450190, Cialis, IC351

  • Drugtadalafil

    tadalafil 40 mg and placebo tablets taken by mouth once a day for 16 weeks.

    Also known as: LY450190, Cialis, IC351

  • Drugplacebo

    placebo tablet taken by mouth once a day for 16 weeks

06

What researchers measure

Primary outcomes

  1. 6 minute walk distance change from baseline to Week 16

    Time frame: 16 weeks

Secondary outcomes

  1. World Health Organization (WHO) functional class, Borg dyspnea, cardiopulmonary hemodynamics, quality of life - change from baseline to Week 16

    Time frame: 16 weeks

  2. Time to first occurrence of clinical worsening

    Time frame: Not defined

07

Study locations

6 sites
  • For additional information regarding investigative sites for this trial, contact 1-877-CTLILLY (1-877-285-4559, 1-317-615-4559) Mon - Fri from 9 AM to 5 PM Eastern Time (UTC/GMT - 5 hours, EST), or speak with your personal physician.
    Tucson, Arizona 85724, United States
  • For additional information regarding investigative sites for this trial, contact 1-877-CTLILLY (1-877-285-4559, 1-317-615-4559) Mon - Fri from 9 AM to 5 PM Eastern Time (UTC/GMT - 5 hours, EST), or speak with your personal physician.
    Minneapolis, Minnesota 55455, United States
  • For additional information regarding investigative sites for this trial, contact 1-877-CTLILLY (1-877-285-4559, 1-317-615-4559) Mon - Fri from 9 AM to 5 PM Eastern Time (UTC/GMT - 5 hours, EST), or speak with your personal physician.
    Salt Lake City, Utah 84143, United States
  • For additional information regarding investigative sites for this trial, contact 1-877-CTLILLY (1-877-285-4559, 1-317-615-4559) Mon - Fri from 9 AM to 5 PM Eastern Time (UTC/GMT - 5 hours, EST), or speak with your personal physician.
    Lille, 59037, France
  • For additional information regarding investigative sites for this trial, contact 1-877-CTLILLY (1-877-285-4559, 1-317-615-4559) Mon - Fri from 9 AM to 5 PM Eastern Time (UTC/GMT - 5 hours, EST), or speak with your personal physician.
    Vandoeuvre Les Nancy, 54511, France
  • For additional information regarding investigative sites for this trial, contact 1-877-CTLILLY (1-877-285-4559, 1-317-615-4559) Mon - Fri from 9 AM to 5 PM Eastern Time (UTC/GMT - 5 hours, EST), or speak with your personal physician.
    Bergamo, 24128, Italy
08

References and documents

Publications

  • Ferguson-Sells L, Velez de Mendizabal N, Li B, Small D. Population Pharmacokinetics of Tadalafil in Pediatric Patients with Pulmonary Arterial Hypertension: A Combined Adult/Pediatric Model. Clin Pharmacokinet. 2022 Feb;61(2):249-262. doi: 10.1007/s40262-021-01052-8. Epub 2021 Aug 11. PubMed 34379314 ↗
  • Galie N, Brundage BH, Ghofrani HA, Oudiz RJ, Simonneau G, Safdar Z, Shapiro S, White RJ, Chan M, Beardsworth A, Frumkin L, Barst RJ; Pulmonary Arterial Hypertension and Response to Tadalafil (PHIRST) Study Group. Tadalafil therapy for pulmonary arterial hypertension. Circulation. 2009 Jun 9;119(22):2894-903. doi: 10.1161/CIRCULATIONAHA.108.839274. Epub 2009 May 26. Erratum In: Circulation. 2011 Sep 6;124(10):e279. Dosage error in article text. PubMed 19470885 ↗
09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 21, 2008, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT00125918
Lead sponsor
Eli Lilly and Company
Collaborators
ICOS Corporation
First posted
Aug 2, 2005
Start date
Aug 2005
Primary completion
Aug 2007
Completion
Aug 2007
Last update
Feb 21, 2008

Study contacts

Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 9 AM - 5 PM Eastern time (UTC/GMT - 5 hours, EST)
study director · Eli Lilly and Company

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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