Keynote lecture by KateTx Chief Scientific Officer and Scientific Co-founder Sharif Tabebordbar, Ph.D., features non-human primate data demonstrating best-in-class potential of KT809, a novel muscle and heart-targeted, liver de-targeted development candidate for Duchenne muscular dystrophy
Additional preclinical data highlight company’s lead candidate in facioscapulohumeral muscular dystrophy
SAN DIEGO, May 9, 2024 /PRNewswire/ — Kate Therapeutics Inc. (“KateTx”), a next-generation gene therapy company, will present detailed preclinical efficacy and safety results on its pipeline and platform at the American Society of Gene and Cell Therapy (ASGCT) 2024 Annual Meeting being held May 7-11, 2024, in Baltimore, MD and virtually. The results support the best-in-class potential of KateTx’s newest generation of skeletal muscle- and heart-targeted, liver de-targeted engineered MyoAAV capsids and gene regulation technology to treat Duchenne muscular dystrophy (DMD), facioscapulohumeral muscular dystrophy (FSHD), and other devastating genetic skeletal muscle and heart diseases.
KateTx debuted less than a year ago with a $51 million Series A round co-led by Westlake Village BioPartners and Versant Ventures and an exclusive license of KT430 to Astellas Pharmaceuticals for the treatment of X-linked myotubular myopathy. Since that time, the company has used its DELIVER platform to identify a proprietary class of muscle- and heart-targeted, liver de-targeted “MyoAAV-LD” capsids with improved potency and selectivity in non-human primates (NHPs) and selected KT809 as a development candidate to treat DMD. This product incorporates MyoAAV-LD 6.1, which is a sixth generation internally generated and fully owned capsid, as well as a proprietary regulatory element developed to express the transgene in both skeletal muscle and heart in primates. KateTx remains on track to select development candidates for additional muscle and cardiac programs in the near term. In addition, Astellas has formally advanced KT430 into IND enablement.
“KateTx has made significant advances over the past 12 months,” said Kevin Forrest, Ph.D., co-founder, president and CEO of KateTx. “These ASGCT presentations are a meaningful milestone for the company and demonstrate the potential of our medicines to be the preferred therapies in both DMD and FSHD. We look forward to advancing these differentiated products to patients as quickly as possible.”
Key advances in next-generation DMD gene therapy
KateTx will present data on its Duchenne muscular dystrophy (DMD) development candidate showing markedly higher and more uniform expression at lower doses than competing gene therapies in NHPs. KateTx CSO and scientific co-founder, Sharif Tabebordbar, Ph.D., will give a keynote lecture presenting these data at the meeting as recipient of the 2024 Outstanding Investigator Award for contributions to the field of gene therapy. Dr. Tabebordbar’s plenary lecture will take place on Friday, May 10, 2024, at 11:40 AM ET.
“First-generation gene therapies for DMD use very high doses of naturally occurring capsids that primarily target the liver, and promoters that are more active in skeletal muscle than heart in primates,” said Dr. Tabebordbar. “By leveraging our novel capsid and gene regulation technologies, we have developed a DMD gene therapy candidate that potently, uniformly, and selectively expresses high levels of microdystrophin in both skeletal muscle and heart, which are the major affected organs in the disease, while avoiding off-target tissues like the liver.”
In NHPs, KateTx’s product expressed high levels of microdystrophin uniformly in skeletal and cardiac muscles at a dose three times lower than a surrogate version of an FDA-approved DMD gene therapy. In contrast, microdystrophin expression from the surrogate was barely detectable in skeletal muscles and heart of NHPs at the clinical dose of 1.33E+14 vg/kg. High and uniform levels of microdystrophin protein expression across muscle fibers are required to protect muscles against injury and death in DMD and are important factors affecting DMD gene therapy durability.
Furthermore, KateTx’s DMD development candidate resulted in 27 times lower vector genomes per nucleus in the liver compared with animals injected with the surrogate. Collectively, these findings support the potential for superior improvements in skeletal muscle strength, cardiac function (largely responsible for mortality in DMD), and safety.
Strong preclinical data for the FSHD program
KateTx will also present new preclinical data from its program in facioscapulohumeral muscular dystrophy (FSHD), which is a common muscular dystrophy that results from toxic expression in skeletal muscle of a protein called DUX4. KateTx’s results show the potential to give a one-time gene therapy that potently suppresses DUX4 whenever it is expressed in skeletal muscles.
In vitro, the company’s MyoAAV-LD mediated RNAi gene therapy candidate showed potent knockdown of DUX4 in FSHD patient myotubes with no off-target effects. In mice, the therapy reduced DUX4 target gene expression and led to dose-dependent improvements in muscle function and ultimately protected animals from severe impairment in treadmill time to exhaustion at a low dose.
“Both DMD and FSHD are challenging diseases – they require delivery of therapeutic cargoes to a substantial tissue mass, and expression of significant amounts of protein uniformly and durably across skeletal muscle fibers and cardiomyocytes in the case of DMD, and effective inhibition of toxic DUX4 expression in skeletal muscle in the case of FSHD,” said Katherine A. High, M.D., Visiting Professor at Rockefeller University, Professor Emerita of Pediatrics at the Perelman School of Medicine at the University of Pennsylvania, and member of the KateTx Scientific Advisory Board. “The clinical evaluation of these novel bioengineered capsids is in my judgment one of the most exciting near-term developments in our field and I look forward to these programs moving into clinical development.”
A list of KateTx’s presentations and posters at ASGCT is available on the company’s website at https://www.katetherapeutics.com/publications/. Abstracts can be found at https://annualmeeting.asgct.org/abstracts.
About DMD
Duchenne muscular dystrophy (DMD) is a fatal genetic disorder and the most common form of muscular dystrophy. The disease is characterized by progressive weakness and degeneration of muscle, leading to loss of ambulation, cardiomyopathy, ventilatory compromise, and death due to cardiopulmonary causes by early adulthood. DMD affects about 1 in 3,500-5,000 live male births, and about 20,000 children are diagnosed globally each year.
About FSHD
Facioscapulohumeral muscular dystrophy (FSHD) is a heritable muscle disorder affecting approximately 40,000 people in the United States. Onset of FSHD is commonly 15-30 years of age, with weakness affecting the face, shoulders and upper arms, lower legs, and hips. Upper extremity weakness is often most pronounced, but many patients will have significant difficulty walking, and about 20% will require a wheelchair. There are no approved medicines for FSHD.
About Kate Therapeutics
Kate Therapeutics (KateTx) is a patient-focused biotechnology company developing adeno-associated virus (AAV)-based gene therapies to treat genetically defined muscle and heart diseases. The company is applying novel technology platforms that directly address the key limitations of current gene therapies, including tissue-specific delivery and gene regulation. These breakthroughs have the potential to improve the efficacy and safety of gene therapies and enable the pursuit of a broader set of targets that are otherwise difficult to drug with current technologies. For more information, please visit KateTx’s website at https://www.katetherapeutics.com/.
SOURCE Kate Therapeutics
