Clinical Trial: Long-term Outcome of N-Carbamylglutamate Treatment in Propionic Acidemia and Methylmalonic Acidemia

Study Status: Terminated
Recruit Status: Terminated
Study Type: Interventional

Official Title: Long-term Outcome of N-Carbamylglutamate Treatment in Propionic Acidemia and Methylmalonic Acidemia

Brief Summary:

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.


Detailed Summary:

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.


Sponsor: Mendel Tuchman

Current Primary Outcome: Neurodevelopment [ Time Frame: 30 months ]

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


Original Primary Outcome: Neurodevelopment [ Time Frame: Intake through 7 days or discharge ]

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


Current Secondary Outcome: Number of Participants With Adverse Events [ Time Frame: Start of episode through 7 days or discharge (if earlier) ]

Safety is measured by tracking and detailing the number and type of adverse events and their severity based on the CTCAE.


Original Secondary Outcome: Safety and Efficacy [ Time Frame: Intakle through 7 days or discharge ]

Safety as measured by adverse events. Efficacy as measured by resolution of hypoammonemia.


Information By: Children's Research Institute

Dates:
Date Received: May 10, 2012
Date Started: September 2012
Date Completion:
Last Updated: March 15, 2017
Last Verified: March 2017