for people ages 18-99 (full criteria)
at San Francisco, California and other locations
study started
completion around
Principal Investigator
by Yvonne Kelly, MD



The purpose of this study is to assess the safety, tolerability and possible benefit of letrozole compared to placebo in patients with Hepatopulmonary Syndrome.


This study is a phase II randomized, double-blind, placebo-controlled parallel trial of 20 subjects with hepatopulmonary syndrome designed to assess the effect of letrozole 2.5 mg orally daily or placebo for 6 months on the alveolar-arterial oxygen gradient (AaPO2).

Subjects at each site will be screened at outpatient clinic visit appointments and interested qualified subjects will be consented and offered participation in this trial. Once consent has been obtained baseline values will be established and subjects will begin letrozole with follow-up clinic visits and testing at 3 months, and 6 months.


Hepatopulmonary Syndrome, Syndrome, Letrozole


You can join if…

Open to people ages 18-99

  • Diagnosis of moderate to very severe hepatopulmonary syndrome which consists of having all 3 of the following conditions:
    • Presence of liver disease or portal hypertension
    • Intrapulmonary shunting on contrast-enhanced echocardiogram
    • Hypoxemia [A-a gradient ≥15mmHg (or ≥20mmHg if age >64) and PaO2<80mmHg on arterial blood gas testing]
  • Child-Pugh class A or B liver disease
  • MELD score < 20
  • ≥ 18 years old
  • Female subjects must be post-menopausal (defined as 12 months of spontaneous amenorrhea or 6 weeks postsurgical bilateral oophorectomy without or without hysterectomy)
  • Ability to provide informed consent

You CAN'T join if...

  • Enrollment in a clinical trial or concurrent use of another investigational drug or device therapy (i.e., outside of study treatment) during, or within 28 days of baseline
  • Current hepatic encephalopathy
  • Expectation of liver transplant within six months of randomization
  • MELD exception score > 28
  • Concomitant lung disease defined as restriction (TLC < 70%) or obstruction (FEV1 < 80% & FEV1/FVC < 70%)
  • Inability to comply with the study protocol
  • Osteoporosis
  • Premenopausal women (those who have not reached 1 year absence of menarche)
  • Vulnerable study population, including imprisoned individuals, non-English speaking patients


  • UCSF accepting new patients
    San Francisco California 94143 United States
  • Mayo Clinic accepting new patients
    Rochester Minnesota 55902 United States

Lead Scientist at UCSF


accepting new patients
Start Date
Completion Date
Mayo Clinic
Phase 2 Hepatopulmonary Syndrome Research Study
Study Type
Expecting 20 study participants
Last Updated