Spinogenix Announces Positive Type C Meeting with the FDA for SPG601 in Patients with Fragile X Syndrome (FXS)

• Spinogenix has reached agreement with the FDA on important design elements for a Phase 2B/3 clinical trial of SPG601 for the treatment of FXS
• There Are No FDA-Approved Treatments for FXS, a Leading Inherited Form of Intellectual Disability and Known Cause of Autism   

LOS ANGELES, Sept. 2, 2025 /PRNewswire/ -- Spinogenix, Inc., a clinical-stage biopharmaceutical company pioneering first-in-class therapeutics that restore synapses to improve the lives of patients worldwide, today announced positive feedback from its Type C meeting with the U.S. Food and Drug Administration (FDA) supporting the advancement of  SPG601 for the treatment of people with Fragile X syndrome (FXS), based on data from the Phase 2a trial completed earlier this year at Cincinnati Children's Hospital .

"We are pleased with the positive feedback we received from the FDA regarding SPG601 in FXS patients. There are currently no FDA approved treatments for this condition and SPG601 represents a first-in-class oral drug targeting BK channels, indicating promise for a new mechanism to address this significant unmet need," said Dr. Stella Sarraf, Chief Executive Officer and founder of Spinogenix. "We are excited to continue our journey to develop a treatment for this rare and debilitating genetic disorder, which not only impacts individuals but entire families, economically and emotionally"

FXS, a genetic disorder caused by the silencing of the Fmr1 gene, is the leading inherited form of intellectual disability and a major known cause of autism. It can produce a wide range of disabling symptoms, with many individuals requiring lifelong around-the-clock supportive care.

Spinogenix requested the Type C meeting based on positive results from a Phase 2a study completed at Cincinnati Children's Hospital that integrated both neurophysiological and behavioral assessments.  The Phase 2a randomized, double-blind, placebo-controlled, crossover study of SPG601 therapy in adult men with FXS met its primary goal, significantly reducing high-frequency gamma band activity in the FXS subjects as assessed by electroencephalography (EEG).  Excessive gamma band activity is a consistent finding in FXS and correlates with symptom severity. In addition, SPG601 treatment was associated with significant improvement vs placebo on the Flanker task, a component of the NIH Toolbox test battery used in FXS trials that measures selective attention and inhibitory control functions in which FXS subjects show profound impairment.

The productive meeting provided the Company with a clear path forward on the overall design of a registrational directed trial to assess the safety and efficacy of SPG601 in patients with FXS. Foundational alignment on the trial length, patient size and primary and secondary endpoints were reached. The planned Phase 2b adaptive trial design will allow a seamless transition into a Phase 3 trial.

"The results of our Phase 2a trial of SPG601 in FXS participants are particularly encouraging in light of the safety and tolerability data indicating no sedation or clinical impairment and the unprecedented effects observed on neurophysiology measures of gamma band activity and clinical outcome measures of attention and inhibitory control" shared Dr. Craig Erickson, Spinogenix Chief Medical Advisor and Director of the Cincinnati Fragile X Research and Treatment Center.  "The FDA's feedback advances our preparation for upcoming clinical trials and allows us to continue accelerating development of a much-needed therapy in the hope of addressing an underserved community"

About SPG601
SPG601 is an oral medication being developed to treat FXS, and potentially other conditions on the autism spectrum, by mitigating key underlying abnormalities in synaptic function and neural excitability. FXS involves a reduction in the activity of large conductance, calcium-activated potassium (BK) channels, which contributes to synaptic dysfunction, cortical hyperexcitability, and multiple symptoms of FXS.  SPG601, a novel small molecule, is the first positive modulator of BK channels to be clinically evaluated in FXS and has the potential to improve cognitive, emotional, and sensory symptoms by boosting BK channel activity.  SPG601 has received both Orphan Drug designation and Fast Track designation from the FDA for FXS, as well as orphan disease designation from the EMA.

About Fragile X Syndrome 
Fragile X Syndrome (FXS) is the leading inherited form of intellectual disability and a known cause of autism that results from the silencing of the Fmr1 gene. FXS is an orphan disease affecting approximately 1 in 4-5000 men and 1 in 6-8000 women globally. In addition to intellectual disability, FXS patients endure a wide range of disabling symptoms, including severe anxiety, social aversion, hyperactivity and attention deficit, sensory hypersensitivity, aggression, developmental seizures, and others. Providing care for individuals with FXS often becomes a full-time commitment for at least one parent and imposes significant financial strain, with direct family healthcare costs totaling $4.1 billion annually in the United States alone. Despite the considerable impact of FXS, there are currently no FDA-approved drugs available for those with the condition.

About Spinogenix  
Current treatments for neurodegenerative, neuropsychiatric and neurodevelopmental conditions primarily focus on slowing disease progression or minimizing symptoms, leaving many without hope for improvement. Spinogenix is aiming to transform the treatment of these conditions through its pioneering first-in-class and paradigm-shifting synaptic regenerative and synaptic corrective therapeutics designed to restore depleted synapses and reverse synaptic degeneration and dysfunction – offering patients and their families a new reality of hope.

Spinogenix is developing two novel therapeutics: SPG302, which triggers neurons to produce new glutamatergic synapses and restore cognitive, motor, and other functions in ALS, Alzheimer's disease, schizophrenia and other diseases; and SPG601, which works at the synaptic level to correct specific dysfunctions in Fragile X Syndrome (FXS) that underlie many core symptoms. The company has received FDA and EMA Orphan Drug designations for both ALS and FXS as well as FDA Fast Track designation for FXS. More information on Spinogenix can be found at www.spinogenix.com or follow us on LinkedIn. 

Media Contact 
Arielle Bernstein Pinsof 
FINN Partners
[email protected] 

Investor Relations 
Dan Albosta
Spinogenix, Inc.
[email protected]  

SOURCE Spinogenix