You are being asked to consider permitting your baby to take part in this research study, because your baby was born prematurely and is at risk for developing a lung disease called bronchopulmonary dysplasia (BPD). We are interested in learning about the safety of a medicine called sildenafil when given to premature babies at risk of BPD.

We will share the information gained from this study with other researchers. The study team will record your baby’s sex, date of birth, and other birth information. They will also record your baby’s medical and medication history. Your baby will be in this study for up to 62 days. Your baby may receive study drug for up to 34 days. Your baby will be monitored during the period they receive study drug and for the following 28 days after they stop receiving study drug. Biological samples, like blood, will be collected from your baby at certain times during the study. You can choose not to participate or to withdraw your baby from the study at any time without penalty or loss of benefits to which you or your baby are otherwise entitled. There are risks in this study that are described in this form. Low blood pressure could occur after receiving sildenafil. Your baby’s blood pressure will be checked closely during the study. Full details are included in the risk section of this form. It is possible that babies who get sildenafil have improved breathing and a lower risk for BPD. However, it is possible that there will be no benefit. We hope the information that we learn from this study will help us to take care of premature babies in the future.

Inclusion Criteria

1. Documented informed consent from parent or guardian, prior to study procedures
2. Receiving positive airway pressure (nasal continuous airway pressure, nasal intermittent
positive pressure ventilation, or nasal cannula flow > 1LPM) or mechanical ventilation (high
frequency or conventional) at time of randomization*
3. < 29 weeks gestational age at birth
4. 7-28 (inclusive) days postnatal age at time of randomization

Exclusion

1. Previous enrollment and dosing in NICHD-2015-SIL02 “Safety of Sildenafil in Premature
Infants at Risk of Bronchopulmonary Dysplasia”
2. Previous exposure to sildenafil within 7 days prior to randomization*
3. Currently receiving vasopressors*
4. Currently receiving inhaled nitric oxide*
5. Baseline mean arterial pressure < gestational age (in weeks) plus postnatal age (in weeks)
within 24 hours of randomization*; e.g. an infant at 25 weeks gestational age and 3 weeks
postnatal age with MAP <28 mm Hg would be ineligible
6. Known allergy to sildenafil
7. Known sickle cell disease
8. AST > 225 U/L < 72 hours prior to randomization*
9. ALT > 150 U/L < 72 hours prior to randomization*
10. Any condition which would make the participant, in the opinion of the investigator,
unsuitable for the study*