FDA grants Monoamine Oxidase Deficiency Orphan Drug Designation

GALVESTON, Texas, June 15, 2026 /PRNewswire/ -- Families affected by monoamine oxidase deficiency (MAOD), a rare neurodevelopmental disorder, have historically faced delayed diagnosis, limited clinical guidance and scant treatment options. MAOD is an X-linked genetic condition caused by impaired activity or the total lack of the monoamine oxidase A and/or monoamine oxidase B enzymes, which play a critical role in regulating neurotransmitters such as serotonin, dopamine, and norepinephrine. Disruption of these pathways leads to very high levels of serotonin resulting in profound neurodevelopmental challenges, such as developmental delays, intellectual disability, autism and significant growth impairment.

Monoamine Oxidase Deficiency Foundation seeks a treatment for this devastating condition. Over the last year, the organization has pursued an Orphan Drug Designation (ODD) for para-cloro-phenylalanine (pCPA) that we believe is uniquely suited to treat MAO-D through its inhibition of serotonin synthesis throughout the body. In prior studies, pCPA successfully lowered body serotonin in patients, but unfortunately it also lowered normal serotonin levels in the brain, causing side effects. Unique to MAOD patients, serotonin levels become extremely high in both the body and the brain. Once considered a limitation, pCPA's ability to reach the brain may be a critical therapeutic advantage for MAOD.

Last month, the U.S. Food and Drug Administration (FDA) granted the ODD for this potential therapy. This designation from the FDA represents an important milestone for MAO-D patients and for the rare disease community. Orphan Drug Designation is intended to encourage therapeutic development for conditions that affect small patient populations that have historically been overlooked. For MAOD, the ODD designation signals regulatory recognition of a distinct unmet medical need and supports a pathway for future clinical research and therapeutic development.

The Monoamine Oxidase Deficiency Foundation was established because families could not afford to wait for progress. By bringing together researchers, clinicians, and patient advocates, the Foundation is working to translate scientific understanding of monoamine oxidase biology into effective therapeutics for individuals with MAOA, and Combined MAO-A/B deficiencies.

While Orphan Drug Designation is not a cure, it represents a step forward for families living with MAOD and reinforces the Foundation's commitment to advancing research toward effective treatments.

About the Monoamine Oxidase Deficiency Foundation
The Monoamine Oxidase Deficiency Foundation is a 501(c)(3) nonprofit organization dedicated to improving understanding, diagnosis, and treatment of monoamine oxidase deficiencies through research support, collaboration, and patient advocacy.

Contact:
Monoamine Oxidase Deficiency Foundation
Email: [email protected]
Website: https://maodf.org

SOURCE Monoamine Oxidase Deficiency Foundation