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Sildi-Safe: Safety of Sildenafil in Premature Infants with Severe Bronchopulmonary Dysplasia (BPD)

  • Status
    Accepting Candidates
  • Age
  • Sexes
  • Healthy Volunteers


This is a multicenter, randomized, placebo-controlled, sequential dose-escalating, double-masked, safety study of sildenafil in premature infants with severe bronchopulmonary dysplasia (BPD). Premature infants will be randomized in a dose escalating approach 3:1 (sildenafil: placebo) sequentially, into each of 3 cohorts. There will be approximately 40 randomized and dosed participants in each cohort for a total of up to 120 participants.


Protocol number CED000000503


Participant Inclusion Criteria

To be eligible to participate in this study, an individual must meet all of the following criteria:

  1. Documented informed consent from parent or guardian, prior to study procedures

  2. < 29 weeks gestational age at birth

  3. 32-44 weeks postmenstrual age

  4. Receiving respiratory support at enrollment: o If 32 0/7–35 6/7 weeks postmenstrual age: mechanical ventilation (high frequency or conventional) o If 36 0/7–44 6/7 weeks postmenstrual age: mechanical ventilation (high frequency or conventional) OR continuous positive airway pressure (CPAP)


o Criteria 3 and 4 define severe BPD for the purposes of this study

O Cpap is defined as any of the following:

• Nasal cannula > 2 liters per minute (LPM)

• Nasal continuous positive airway pressure (NCPAP)

• Nasal intermittent positive pressure ventilation (NIPPV)

• Noninvasive neurally adjusted ventilatory assist (NAVA)

• Any other device designed to provide positive pressure through a nasal device (e.g., RAM cannula, etc.) Participant Exclusion Criteria

An individual who meets any of the following criteria will be excluded from participation in this study:

  1. Previous enrollment and dosing in this study, protocol number (NHLBI-2019-SIL), “Safety of Sildenafil in Premature Infants with Severe Bronchopulmonary Dysplasia (BPD)”

  2. Previous exposure to sildenafil within 7 days prior to randomization*

  3. Previous exposure to vasopressors within 24 hours prior to randomization*

  4. Previous exposure to inhaled nitric oxide within 24 hours prior to randomization*

  5. Previous exposure to milrinone within 24 hours prior to randomization*

  6. Evidence of pulmonary hypertension or moderate/large patent ductus arteriosus (PDA) on the most recent echocardiogram performed within 14 days prior to randomization

  7. Known major congenital heart defect requiring medical or surgical intervention in the neonatal period

  8. Known allergy to sildenafil

  9. Known sickle cell disease Safety of Sildenafil in Premature Infants with Severe Bronchopulmonary Dysplasia Version 3.0 NHLBI-2019-SIL 20 APRIL 2023 13 10. Aspartate aminotransferase (AST) > 225 U/L < 72 hours prior to randomization 11. Alanine aminotransferase (ALT) > 150 U/L < 72 hours prior to randomization 12. Any condition that would make the participant, in the opinion of the investigator, unsuitable for the study.

Lead researchers

Participate in a study

Here are some general steps to consider when participating in a research study:

  1. Step

    Contact the research team

    Call or email the research team listed within the specific clinical trial or study to let them know that you're interested. A member of the research team, such as the researcher or study coordinator, will be available to tell you more about the study and to answer any questions or concerns you may have.

  2. Step

    Get screened to confirm eligibility

    You may be asked to take part in prescreening to make sure you are eligible for a study. The prescreening process ensures it is safe for you to participate. During the prescreening process, you will be asked some questions and you may also be asked to schedule tests or procedures to confirm your eligibility.

  3. Step

    Provide your consent to participate

    If you are eligible and want to join the clinical trial or study, a member of the research team will ask for your consent to participate. To give consent, you will be asked to read and sign a consent form for the study. This consent form explains the study's purpose, procedures, risks, benefits and provides other important information, such as the study team's contact information.

  4. Step


    If you decide to participate in a clinical trial or study, the research team will keep you informed of the study requirements and what you will need to do to throughout the study. For some trials or studies, your health care provider may work with the research team to ensure there are no conflicts with other medications or treatments.