DepYmed Receives FDA Rare Pediatric Disease & Orphan Drug Designations for its Lead Clinical Candidate for the Treatment of Rett Syndrome

DepYmed Inc. recently announced that the US FDA has granted Rare Pediatric Disease and Orphan Drug designations for its lead clinical candidate, a small molecule PTP1B inhibitor for the treatment of patients with Rett Syndrome (RTT).

“FDA’s decision to grant these designations for our lead clinical candidate for the treatment of Rett Syndrome is a significant achievement for DepYmed,” said Andreas Grill, DepYmed’s President & CEO. “Further, it perfectly aligns with our mission to provide treatments for patients where few if any options exist and highlights the urgent need to develop a treatment for patients with Rett Syndrome, a devastating rare genetic neurological disorder that occurs primarily in girls.”

Protein tyrosine phosphatases are major players in the control of cell signaling pathways that are disrupted in many diseases; however, to date, development of drug modulators of these enzymes has not been successful. DepYmed is the first company to develop a new class of orally bioavailable drug candidates that act by inhibiting PTP1B, one of the most important PTP drug targets. One of its lead compounds has shown promising efficacy in preclinical models of Rett syndrome, and the Company hopes to initiate a Phase 1 clinical trial later this year.

A company is granted a rare pediatric disease designation by the FDA when it identifies a drug that treats a serious or life-threatening disease that primarily affects individuals aged from birth to 18 years. Notably, the sponsor of an FDA New Drug Application which receives an approval for a drug or biologic for a “rare pediatric disease” may qualify for a voucher that can be redeemed to receive a priority review of a subsequent marketing application for a different product.

Orphan Drug status is given to drugs and biologics defined as “those intended for the safe and effective treatment, diagnosis or prevention of rare diseases/disorders that affect fewer than 200,000 people in the US, or that affect more than 200,000 persons but are not expected to recover the costs of development.” These definitions, and the benefits that come with it, including significant tax credits for qualified clinical trials, exemption from user fees, and a potential of seven years of marketing exclusivity following FDA approval, were all part of the Orphan Drug Act of 1983.

Rett syndrome is a progressive neurodevelopmental disorder that almost exclusively affects females. Infants with Rett syndrome generally develop normally for 6 to 18 months after birth. At this point, they lose previously acquired skills (developmental regression) such as purposeful hand movements and the ability to communicate. Affected children often develop autistic-like behaviors, breathing irregularities, feeding and swallowing difficulties, growth retardation, and seizures. Most Rett syndrome cases are caused by mutations of the MECP2 gene on the X chromosome and can present with a wide range of disability ranging from mild to severe. The expression of PTP1B, DepYmed’s target in Rett syndrome, is regulated by MECP2; in turn, PTP1B controls important cell functions that are disrupted in the disease.

DepYmed Inc., is a New York based rare disease and cancer therapeutic development company that was founded to capitalize on the scientific discoveries of the Tonks lab in the physiological function of PTP1B and ways to modulate its role in various human diseases. DepYmed is currently developing a new class of potent, orally bioavailable small molecule inhibitors of the PTP1B enzyme as potential novel therapeutics for Rett Syndrome and different types of cancer. In addition, DepYmed has also discovered a novel class of small molecules with copper chelating properties that it is developing as potential therapeutic agents for such diseases as Wilson disease and various cancers. The company is actively developing a deep pipeline of new compounds in these emerging drug classes, in collaboration with Cold Spring Harbor Laboratory, to exploit their broad therapeutic potential. For more information, visit