Long-term Outcome of N-Carbamylglutamate Treatment in Propionic Acidemia and Methylmalonic Acidemia
Background: Very few drugs exist that treat hyperammonemia, specifically PA and MMA. Diet restrictions and alternate pathway agents are the current primary treatments, but they frequently fail to prohibit brain damage.
Orthotopic liver transplantation cures the hyperammonemia of urea cycle disorders, but organ availability is limited and the procedure is highly invasive and requires life-long immunosuppression.
A drug that could repair or stimulate a dysfunctional urea cycle such as this would have several advantages over current therapy. A drug called N-carbamyl-L-glutamate, Carglumic acid (NCG or Carbaglu)has recently been found to be virtually curative of another urea cycle defect called NAGS deficiency. In this disorder, treatment with NCG alone normalizes ureagenesis, blood ammonia and glutamine levels, allows normal protein tolerance and restores health. Knowledge from this study is being applied to acquired hyperammonemia, specifically in patients with propionic PA and MMA, to try and improve neurodevelopmental outcomes by improving the hyperammonemia.
Aims: The overall objective of this project is to determine whether treatment of acute hyperammonemia with Carglumic acid in propionic acidemia (PA), methylmalonic acidemia (MMA) changes the long-term outcome of disease and to determine if it is effective in restoring urine ammonia levels to normal levels.
Propionic Acidemia (PA)
Methylmalonic Acidemia (MMA)
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Long-term Outcome of N-Carbamylglutamate Treatment in Propionic Acidemia and Methylmalonic Acidemia|
- Neurodevelopment [ Time Frame: Intake through 7 days or discharge ] [ Designated as safety issue: No ]Neurodevelopmental outcome as measured by Cognitive Composite (Bayley III), Motor Composite (Bayley III) and Functional Status Scale and safety of NCG treatment as measured by adverse events and laboratory blood tests
- Safety and Efficacy [ Time Frame: Intake through 7 days or discharge ] [ Designated as safety issue: Yes ]Safety as measured by adverse events. Efficacy as measured by resolution of hyperammonemia.
|Study Start Date:||September 2012|
|Study Completion Date:||February 2015|
|Primary Completion Date:||February 2015 (Final data collection date for primary outcome measure)|
Active NCG & Standard of Care
Chemical Composition: N-carbamyl-L-glutamic acid (NCG) The daily dose will be 100 mg/kg/ day. The doses are to be divided into 2 equal doses and administered orally or enterally by nasogastric or gastrostomy tube (standard of care will prevail when choosing the mode of drug administration).
The tablets must be dispersed in a minimum of 2.5-10 ml of water and ingested immediately or administered by fast push through a syringe via a nasogastric or gastrostomy tube. The suspension has a slightly acidic taste.
This drug will be administered for 7 days after admission or until discharge (whichever is sooner).
Placebo Comparator: Placebo
Standard of Care therapy
Methods/Design This 5-year, Phase II, double-blind study aims to recruit and enroll 34 PA and MMA patients during acute episodes of hyperammonemia.
The primary aim is to circumvent the long-term neurodevelopmental decline due to having a prolonged levels of ammonia during crisis in the blood and urine. After treatment and crisis resolution with Carbaglu or placebo and standard of care therapy, measures of neurodevelopmental outcomes (Bayley II and Functional Status Scale) are being measured at 9, 15,21 and 30 months post-discharge from the hospital. Safety of NCG treatment will also be monitored as measured by close examination of adverse events and laboratory blood tests. To test for the effectiveness of NCG, longitudinal models to evaluate the groupwise difference (NCG vs. Placebo) in the trajectory of change in neurodevelopmental outcomes and safety analyses between drug and placebo patients.
Subsequent Episodes At any time after the initial episode, participants may present to the hospital with PA- or MMA-associated symptoms. If the plasma ammonia level verified as a bonafide episode of HA (plasma ammonia is ≥ 100 µmol/l), that participant will receive the same study medication that they received during their initial episode in a double-blinded fashion, (i.e. If the participant received NCG at the time of initial randomization, he/she will continue to receive NCG at each subsequent HA episode. If the participant received PLBO at the time of initial randomization, he/she will continue to receive PLBO at each subsequent HA episode). Only the pharmacist will know if the participant receives NCG or PLBO. The same study assessments (previously stated) will be conducted at each qualifying HSA episode.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01597440
|United States, California|
|University of California Los Angeles|
|Los Angeles, California, United States, 90095|
|Lucile Packard Children's Hospital at Stanford|
|Palo Alto, California, United States, 94304|
|United States, Colorado|
|The Children's Hospital of Colorado|
|Aurora, Colorado, United States, 80045|
|United States, District of Columbia|
|Children's National Medical Center|
|Washington, District of Columbia, United States, 20010|
|United States, Massachusetts|
|Children's Hospital Boston|
|Boston, Massachusetts, United States, 02115|
|United States, Ohio|
|University Hospitals of Cleveland/Rainbow Babies and Children's Hospital|
|Cleveland, Ohio, United States, 44106|
|United States, Pennsylvania|
|The Children's Hospital of Philadelphia|
|Philadelphia, Pennsylvania, United States, 19104|
|Principal Investigator:||Mendel Tuchman, MD||Children's Research Institute|