HQ Team
October 2, 2025: The US regulator has declined to approve an experimental pediatric drug of Fortress Biotech Inc., an American biotechnology company, due to certain production deficiencies.
The drug CUTX-101 is intended to treat a rare pediatric disease called Menkes disease caused by gene mutations.
The Food and Drug Administration has issued a Complete Response Letter relating to the New Drug Application for CUTX-101 (copper histidinate), according to a company statement.
The letter noted that Current Good Manufacturing Practice deficiencies had been observed at the facility where CUTX-101 is manufactured, the company stated. The practice is enforced by the FDA. It provides for systems that assure proper design, monitoring, and control of manufacturing processes and facilities.
India’s Zydus Lifesciences
The facility, owned by a fully-owned US subsidiary of India’s Zydus Lifesciences, Ltd., recently responded to the regulator’s September 2025 re-inspection of the facility.
Sentynl Therapeutics Inc., the facility’s owner, is expected to request a meeting with the regulators to discuss the letter and resubmit it.
The letter did not cite any other approvability concerns, nor did it “identify any deficiencies in CUTX-101’s efficacy and safety data.”
Menkes disease is a rare genetic illness that mostly affects boys. It is a disorder that affects copper levels in the body. Occipital horn syndrome (sometimes called X-linked cutis laxa) is a less severe form of Menkes syndrome that begins in early to middle childhood.
No cure yet
Symptoms of the disease include thin, light-colored, and kinky hair. It also causes issues with connective tissues and serious brain problems, including seizures, weak muscle tone, poor growth, and developmental delays.
Without treatment, many children with Menkes disease do not survive past two to three years old. There are milder forms of this gene problem that cause other health issues, but there is currently no approved medicine to cure or treat Menkes disease effectively.
CUTX-101 was initially granted Priority Review by the regulators and is supported by positive topline clinical efficacy results, according to the company statement.
