Lexeo Therapeutics has agreed to acquire Mantle Therapeutics via an upfront payment of $8.3 million, aiming to expand its Friedreich’s ataxia (FA) portfolio while locking in three strategic collaborations to support its lead asset.
As the company looks to expand its pipeline, Lexeo will also be eligible for $13 million in potential milestone payments, bringing the potential deal to $21.3 million, according to a Tuesday release.
The acquired portfolio will include four FA assets, led by LX3010 (formerly MTL-104), a clinical-stage oral combination therapy for FA patients. According to Lexeo, early clinical data across 11 patients showed the drug brought about a 6-point improvement in the modified Friedreich Ataxia Rating Scale (mFARS) score, which is measured on a 0-to-93 scale.
FA is a genetic, degenerative multisystem disorder that causes a loss of balance and coordination. Present in one in 50,000 people in the U.S., 80% of those with FA develop cardiomyopathy, according to Lexeo.
The deal also includes three preclinical assets: LX3030 (MTL-707), LX3050 (MTL-501) and LX3070 (MTL-801), all focused on FA patients. All three assets target frataxin protein, which is needed for normal cellular energy production and iron balance in the cell’s mitochondria. FA is caused by an expanded GAA trinucleotide repeat on the FXN gene, which causes the gene to be under-expressed and leads to a shortage of frataxin protein.
After the deal closes, Lexeo will continue evaluating the acquired programs. With cash runway through 2028, it plans to advance one of the Mantle programs through clinical development. Early next year, Lexeo plans to provide a program prioritization and submit an IND for its next FA development candidate in 2027.
The Mantle assets will add to Lexeo’s previous focus on FA, led by AAV-based gene therapy LX2006. The phase 2/3 drug has received Breakthrough Therapy and Orphan Drug designations from the FDA. Earlier this year, Lexeo published data from the drug’s phase 1/2 trial in the Journal of the American Medical Association showing clinically meaningful improvements across both cardiac and neurologic measures of Friedreich ataxia.
Despite running into some trouble with a gap in evidence in an earlier trial, Lexeo announced in August that it had initiated a pivotal study for LX2006 in Friedreich ataxia cardiomyopathy, which Lexeo CEO R. Nolan Townsend said “could be the first disease-modifying gene therapy for FA cardiomyopathy.” Lexeo said it is on track to provide a topline data readout in the second half of 2027.
The company locked in the pivotal trial plan last year and released data connecting the gene therapy to FA improvements after an earlier cut of the data disappointed investors. In April 2025, Lexeo laid off 15% of its staff to fund LX2006 and other lead cardiac programs.
Lexeo also announced three strategic collaborations to support sequential dosing of CNS-targeted Friedreich ataxia gene therapy, including a research agreement with Weill Cornell Medicine to evaluate the intracisternal administration of LX2006.
It signed an option agreement with Vivet Therapeutics to secure an exclusive license for VTX-PID, an IgG-degrading enzyme intended to support immune-suppression strategies that may expand the treatable population with immunization against AAV and facilitate repeat administration of LX2006.
Finally, Lexeo inked an option agreement with Apertura Gene Therapy to license a novel, intravenously administered, blood-brain barrier-crossing capsid that is expected to enable a less invasive route of administration to the CNS following the initial systemic administration of LX2006.
Despite the acquisition and new collaborations, Townsend said LX2006 continues to be the company’s highest priority, but noted the importance of the new deals. “The addition of Mantle’s pipeline, combined with new research collaborations will broaden our technology platform with multiple complementary CNS-targeted therapeutic strategies designed to restore frataxin in the brain and further improve outcomes for individuals living with FA,” he said in the release. “Together, these initiatives will strengthen our leadership position in the disease category while supporting disciplined portfolio advancement and capital allocation.”