Lexeo Therapeutics thinks its gene therapy has the potential for accelerated approval following positive interim data from two early-stage studies, the company announced Monday.
Executives say the data bode well for regulatory discussions about a pivotal trial, but stopped short of giving concrete timelines. Lexeo’s stock $LXEO dropped over 20% on Monday morning.
Lexeo is developing the therapy, dubbed LX2006, for Friedreich’s ataxia cardiomyopathy, a fatal disorder that currently has no treatment. The disorder is caused by a loss of function mutations in the frataxin gene, and cardiac dysfunction is the cause of death in up to 80% of patients with the disease.
Across two trials — a Phase 1/2 trial dubbed SUNRISE-FA and a Phase 1a investigated-initiated study conducted at Weill Cornell Medicine — patients saw improvements in cardiac biomarkers that increased over time. That includes hypertrophy, a hallmark of FA cardiomyopathy, according to Lexeo development chief Sandi See Tai.
Sandi See Tai“Together with the increases in frataxin protein expression observed in SUNRISE-FA cardiac biopsies to date, these results further highlight the potential of LX2006 to positively impact outcomes for people with FA cardiomyopathy,” Tai said.
The interim data come from just eight patients who had at least six months of follow-up. Of the four patients with an elevated left ventricular mass index (LVMI) at baseline, 75% saw a 10% reduction at one year. Out of all patients evaluated at 12 months, 50% achieved a 10% reduction in LVMI. Elevated LVMI can be a predictor of sudden cardiac death.
The company reported improvements in other biomarkers at 12 months: Six patients saw their left ventricle wall thickening reduced by 13.6% on average, while a biomarker of myocardial injury called troponin I was reduced by 53.3% on average among five patients.
Lexeo CMO Eric Adler said in a statement that the company is looking into “expedited” clinical development of the gene therapy as well as the potential for accelerated approval.
On a Monday morning investor call, company leaders said they will take the interim data into regulatory discussions for a future pivotal study.
Lexeo CEO Nolan Townsend said that a timeline will be given at a later time, but that the data give “a pretty clear picture of what endpoints we’re able to impact with this therapy: LVMI, lateral wall thickness and troponin.”
“Many of those have regulatory precedents associated with them,” Townsend added. “We think the data set’s pretty robust. So at a minimum, this data set can allow a productive discussion about the right endpoints for the [pivotal] study.”
While Biogen, through its acquisition of Reata Pharmaceuticals, markets a treatment for Friedreich’s ataxia, it treats the neurological manifestations rather than cardiological ones. Other companies are also working on a gene therapy in FA cardiomyopathy: Astellas is hoping to dose the first patient in the second half of this year for its gene therapy AT808, which it’s developing in two different programs to target two different aspects of FA cardiomyopathy.
Editor’s Note: This story has been updated to include quotes from the Monday investor call.