L-citrulline and Pulmonary Hypertension Associated With Bronchopulmonary Dysplasia

Early Phase 1

Terminated

Conditions: Infant,Premature
Bronchopulmonary Dysplasia
Pulmonary Hypertension

Interventions: Drug: L-Citrulline

Registration Number: NCT03542812

Lead Sponsor: University of Utah

Brief Summary: Bronchopulmonary dysplasia (BPD) is a chronic lung disease that affects up to 35% of very low birth weight infants (VLBW \< 1500 g). Based on the current numbers of VLBW infants born annually in the U.S., between 5,000-10,000 neonates will develop BPD each year. It is estimated that 8-42% of infants with BPD will develop pulmonary hypertension (PH). Moreover, it has been known since the 1980's that echocardiographic evidence of PH in infants with BPD is associated with up to 40% mortality.

Treatment options to ameliorate PH in infants with BPD (BPD-PH) are limited. There have been no randomized clinical trials of any therapy in infants with BPD-PH. The standard care for the management of BPD-PH is to attempt to resolve the underlying lung disorder and the judicious use of oxygen as a potent pulmonary vasodilator. Using this management approach, which has not changed since the 1980's, the survival rates for infants with BPD-PH in the 2000's has been reported to be 64% at 6 months and 53% at 2 years after diagnosis of PH. The lack of improvement in outcomes for the past 3 decades has led to the widespread agreement that novel and effective therapies are desperately needed for infants with BPD-PH.

The goal is to develop oral L-citrulline clinically for the treatment of pediatric pulmonary hypertension associated with bronchopulmonary dysplasia (BPD-PH); before pursuing a large scale treatment trial, pharmacokinetic (PK) dose-finding, tolerability studies in patients at high risk of developing BPD-PH are warranted.

The hypothesis is that oral L-citrulline will be well tolerated, without significant adverse effects in infants at high risk of developing pulmonary hypertension (PH) associated with BPD. The investigators propose to first characterize the PK profile of oral L-citrulline in order to define an appropriate dose range and treatment interval for infants at high risk of developing BPD-PH. Then using the doses and intervals generated by the PK profile, with a maximum dose of 3 g/kg/d, the investigators propose to evaluate the tolerability and ability to achieve the target study drug level (100-150 micromolar) in babies treated for 72 hours with oral L-citrulline. These studies will provide the data needed to design a full-scale randomized multi-center trial to evaluate the efficacy of oral L-citrulline therapy to ameliorate BPD-PH in human infants, a patient population that has a desperate need of new therapies.

Detailed Description: Not available

Recruitment & Eligibility

Status: TERMINATED

Sex: All

Target Recruitment: 16

Inclusion Criteria

Infants born prematurely at < or = 28 weeks gestation requiring invasive (mechanical ventilation) or non-invasive positive pressure support (nasal continuous positive airway pressure, high flow nasal cannula >1 lpm) and FiO2 of at least 0.30 at 32 +/- 1 weeks postmenstrual age

2.Tolerating at least one-half of full volume oral/gavage tube feedings (using 120 ml/kg/d as full volume oral/gavage tube feedings)

3.The continuous need for some form of respiratory support (supplemental oxygen, flow) for the prior 14 days

4.Hemoglobin > 10 mg/dL

Exclusion Criteria

Known major fetal anomaly or chromosomal aneuploidy
Clinical evidence of congenital heart disease (except patent ductus arteriosus (PDA), atrial septal defect (ASD), or ventricular septal defect (VSD)
Urine output < 1 ml/kg/hr
History of or known to have liver failure
History of or known to have necrotizing enterocolitis
History of or known to have significant feeding intolerance beyond the first week of life
Presence of any acute illness defined by fever >100.4 F, vomiting, or diarrhea
Hemoglobin < 10 mg/dL
Neonatal Intensive Care Unit (NICU) cases determined to be futile (anticipated death prior to hospital discharge)
Multiple births

Study & Design

Study Type: INTERVENTIONAL

Study Design: SEQUENTIAL

Arm && Interventions

Group	Intervention	Description
Single-dose	L-Citrulline	Participants will be enrolled into the two groups, Group 1 (which will consist of 10 participants) and Group 2 (which will consist of 8 participants) in an alternating basis. Both Group 1 and Group 2 participants will receive a single, 150 mg/kg dose of oral L-citrulline. Population PKs will be done for both groups, at up to 3 time points. Multiple interim time points and following completion of enrollment into Groups 1 and 2, data analysis will be done and results reviewed by the data safety monitoring board (DSMB). After the DSMB review is complete, enrollment into Group 3 will begin.
Steady-state	L-Citrulline	To evaluate the tolerability and ability to achieve target trough L-citrulline levels of 100-150 µM, an additional group of 18 infants (group 3) will be given oral L-citrulline doses at intervals over a total of 72 hours. If the participant is not nipple feeding, the dose will be delivered via the participant's indwelling gavage feeding tube. The dose and interval of L-citrulline will be based on results from the studies that assess pharmacokinetic parameters using a maximum daily dose of 3 g/kg/d. Blood draws for PKs will be done at baseline and prior to last dose of L-citrulline. Urine will be collected to measure nitric oxide metabolites.

Primary Outcome Measures

Name	Time	Method
Evaluate L-citrulline Plasma Levels at Baseline and Prior to the Last Dose of Study Drug Dose (Dose #12)- Arm 2	10 min to 1 hour prior to first study drug dose and 10-30 minutes prior to last dose (approx 65.5 hours after the first dose given).	Evaluate the ability to achieve the target trough L-citrulline plasma level of approx.50-80 µM in patients at high risk of developing BPD-PH treated for 72 hours with oral L-citrulline by measuring baseline L-citrulline levels and L-citrulline plasma levels drawn prior to last dose of L-citrulline study drug. Study drug is given orally every 6 hours over 72 hours for a total of 12 doses. A PK will be done on all subjects at baseline (10 minutes to 6 hours prior to first dose) and again 10-30 minutes prior to last dose. If all 12 doses of study drug are given, this will be at approximately 65.5 hours after the first study drug dose is given.
Number of Participants With Feedings Being Stopped Following L-citrulline Administration	48 hours after last study drug dose	The safety outcome of the tolerability of L-citrulline will be measured by whether a subject has feedings held within 48 hours of receiving oral L-citrulline administration for reasons not attributable to underlying condition. For the stead state arm, feeding tolerance was monitored during the 72 hour period in which study was given and then for another 48 hours after the last study drug was given.
Number of Participants With Hypotension Developing Following L-citrulline Administration	12 hours after last study drug dose	The safety outcome of tolerability of L-citrulline will be measured by whether a subject develops a decrease in blood pressure more than 25% below baseline within 12 hours of receiving a dose of oral L-citrulline for reasons not attributable to underlying condition
Plasma L-citrulline Levels Following Administration of a Single Dose of L-citrulline- Arm 1	Group 1- Baseline, 1 hr post-study drug dose, and 2.5 hours post-study drug dose, Group 2- Baseline, 15 minutes post-study drug dose and 3 hours post-study drug dose	Plasma L-citrulline levels will be measured using population pharmacokinetics (PK) before and at intervals following administration of a single dose of oral L-citrulline and used to generate a population pharmacokinetic model in patients at high risk of developing BPD-PH. This arm will be split into two groups of 5 subjects each. Group 1 will have PKs done at baseline (24-48 hours prior to first dose), 1 hour (+/- 10 minutes) after dose given and 2.5 hours (+/- 10 minutes) after dose given. Group 2 will have PKs done at baseline (24-48 hours prior to first dose), 15 minutes (+/- 10 minutes) after dose given and 3 hours (+/- 10 minutes) after dose given.

Secondary Outcome Measures

Name	Time	Method
Urinary Nitrite and Nitrate Levels Will be Measured in Subjects Enrolled Into the Steady State (Second Arm) of the Study.	Baseline (within 24 hours prior to first study drug dose) and 4-8 hours after last study drug dose given (approximately 70 to 78 hours after first study drug dose)	Urine samples will be obtained to assess baseline levels of nitric oxide metabolites (nitrite/nitrate) in the urine within 24 hours prior to first dose and again 4-8 hours after the last dose of study drug given. The purpose is to assess whether there is an increase in levels of nitric oxide metabolites in the urine in response to 72 hours of L-citrulline dosing. Urine samples are only being obtained in infants enrolled in the steady state (second arm) of the study.