Lexeo acquires Mantle for $8.3 million, expanding rare disease treatment portfolio

U.S. biotech company Lexeo Therapeutics is expanding its Friedreich ataxia (FA) treatment portfolio by acquiring Mantle Therapeutics.

According to U.S. biotech publication Fierce Biotech on the 22nd, Lexeo agreed to acquire Mantle for an upfront payment of $8.3 million (about 11.1 billion won). The deal could be worth up to $21.3 million if milestone payments of $13 million are included.

The acquisition gives Lexeo four FA assets. The lead asset is LX3010 (formerly MTL-104), an oral combination therapy in clinical development. According to Lexeo, in an early-stage clinical trial involving 11 patients, the drug improved scores on the modified Friedreich Ataxia Rating Scale (mFARS) by 6 points. The mFARS is measured on a 0-93-point scale.

FA is a genetic, degenerative multisystem disease that causes loss of balance and motor coordination. It affects 1 in 50,000 people in the United States, and 80% of patients have cardiomyopathy, Lexeo said.

The acquisition also includes the preclinical assets LX3030 (MTL-707), LX3050 (MTL-501) and LX3070 (MTL-801). All target frataxin, a protein needed for cellular energy production and iron balance. FA is caused by a deficiency of frataxin resulting from a GAA trinucleotide repeat expansion in the FXN gene.

Lexeo plans to continue evaluating the acquired programs after the deal closes. With cash expected to fund operations through 2028, the company aims to advance one of Mantle’s programs into clinical development. It plans to announce program priorities early next year and submit an investigational new drug (IND) application for its next FA development candidate in 2027.

Lexeo also signed three strategic collaborations to support sequential administration of CNS-targeted gene therapies for FA. It entered into a research agreement with Weill Cornell Medicine to evaluate intrathecal administration of LX2006.

It also signed an exclusive license option agreement with VIVE Therapeutics for VTX-PID, an IgG-degrading enzyme intended to support immunosuppression strategies. With Apertura Gene Therapy, Lexeo entered into an option agreement for a novel blood-brain barrier-crossing capsid, which could reduce the burden of invasive administration into the CNS.

Despite the acquisition, Lexeo’s top priority remains its existing lead candidate, LX2006. LX2006 is an adeno-associated virus (AAV)-based gene therapy that has received breakthrough therapy and orphan drug designations from the U.S. Food and Drug Administration (FDA). Lexeo began the pivotal trial of LX2006 for FA cardiomyopathy in August and plans to report topline results in the second half of 2027.

Lexeo CEO R. Nolan Townsend said, "The Mantle pipeline and new research collaborations will expand our technology platform with complementary CNS-targeted therapeutic strategies designed to restore frataxin in the brain," adding, "These actions will strengthen our leadership in this disease area."