Kate Therapeutics Debuts with $51 Million and Deal with Astellas

Rare Daily Staff

Kate Therapeutics emerged from stealth mode with $51 million in a series A financing to advance skeletal- and cardiac muscle-targeted capsid and cargo delivered systemically.

In addition, the company granted Astellas Pharma an exclusive, worldwide license to develop, manufacture and commercialize KT430 to treat X-linked myotubular myopathy (XLMTM).

Founding co-investors Westlake Village BioPartners and Versant Ventures led the financing, with participation from Osage University Partners and UF Innovate | Ventures.

Proceeds from the financing and license agreement will support the advancement of KateTx’s initial internal portfolio of muscle and heart disease programs, including myotonic dystrophy type 1 (DM1) and facioscapulohumeral muscular dystrophy (FSHD), two of the leading causes of adult-onset muscular dystrophy, both of which have no approved medicines.

DM1 is a rare progressive multisystem disorder that leads to weakness and myotonia (inability to relax muscles) of the lower legs, hands, neck, and face, causing upper extremity disability and difficulty walking, and extra muscular symptoms including cognitive problems, daytime sleepiness, and sleep disturbance, and arrhythmias. Adult-onset forms are the most common; child-onset and congenital forms are more severe and sometimes life-threatening.

FSHD is a rare genetic muscle disorder with typical onset around 15 to 30 years of age. Weakness usually progresses in a descending pattern, affecting the face, shoulders and upper arms, lower legs, and hips. Upper extremity weakness is often pronounced, but many patients will have significant difficulty walking, and about 20 percent eventually require a wheelchair.

“We are excited to announce KateTx’s launch and what this means for patients suffering from muscle and heart diseases,” said Kevin Forrest, president and CEO of KateTx. “KateTx is applying novel capsid and cargo technology platforms to enable skeletal and cardiac muscle targeting and liver de-targeting. We believe our technologies can provide safer and more effective medicines for patients.”

There are a large number of genetically defined and complex muscle and heart diseases that cannot currently be addressed due to a lack of specific and effective delivery to these tissues. Adeno-associated virus (AAV)-based capsids have shown promise to deliver therapeutic cargoes in other organs but have been hampered for use in muscle and heart by limited potency, lack of tissue selectivity and minimal regulation of cargoes.

For capsids, KateTx’s DELIVER platform leverages directed evolution, stringent RNA-based selection of functional capsid variants and machine learning in various in vivo models. The platform already has yielded the MyoAAV class of capsids, which were developed by KateTx scientific co-founder and Chief Scientific Officer Sharif Tabebordbar, and colleagues at the Broad Institute of MIT and Harvard while he was a supervisor and research scientist in the lab of Pardis Sabeti. Results were first published in Cell in 2021. Technologies related to Tabebordbar’s work are licensed to KateTx. Internally, the company is also developing next-generation MyoAAV capsids with further targeting enhancements.

MyoAAV capsids target skeletal and cardiac muscle with dramatically higher efficiency across species compared with naturally occurring AAV capsids including AAV8, AAV9 and AAVrh74. These breakthroughs have the potential to improve efficacy and safety of gene therapy and enable the pursuit of a broader set of targets that are otherwise difficult to treat with current technologies.

KateTx’s cargo platform includes both internally generated proprietary capabilities and technologies licensed from the University of Florida that were developed in the laboratory of KateTx scientific co-founder Eric Wang. The overarching goal of the cargo platform is to ensure the company’s therapies are produced only in tissues of interest and not elsewhere in the body.

In addition to launching, KateTx entered into an exclusive license agreement with Astellas Pharma to develop and commercialize KT430. KT430 is a preclinical next-generation investigational gene therapy that delivers a functional copy of the MTM1 gene via a novel MyoAAV capsid to treat X-linked myotubular myopathy, a serious, life-threatening, rare neuromuscular disease characterized by extreme muscle weakness, respiratory failure, and early death.

Under the terms of the agreement, Astellas will make an undisclosed upfront payment to KateTx, which is also eligible to receive development, regulatory and commercial milestone payments, plus royalties on worldwide sales. Astellas will receive an exclusive worldwide license to develop, manufacture, and commercialize KT430.

Photo: Kevin Forrest, president and CEO of KateTx