FDA Lifts Hold on LogicBio’s Gene Editing Program

After months in crisis mode, LogicBio has finally broken free of the US FDA’s clinical hold on its genome editing program LB-001 for methylmalonic acidemia (MMA), a rare genetic disorder. However, the investigational drug is not expected to resume patient dosing until the third quarter of 2022. 

MMA is caused by mutations in the methymalonyl-CoA mutase gene (MMUT), which prevents the body from properly processing certain fats and proteins. As a result, toxic metabolites build up in organs and tissues in the body. 

Related article: TALED Tool Launches a New Era of Mitochondrial Genome Editing

The FDA Put LB-001 On Hold Due to TMA

The Sunrise study, a Phase 1/2. Clinical trial conducted by LogicBio, was designed to test LB-001, an adeno-associated virus (AAV) genome editing therapy that delivers a corrective copy of the MMUT into the body to restore levels of MMUT expression in the liver, the main site of the gene’s activity. 

The therapy is administered once, while the Sunrise study tested two doses at 5e13 vg/kg and 1e14 vg/kg. Four patients were dosed in the study. 

However, things started going downhill last year. In December, the company reported its third patient had experienced a serious adverse event identified as thrombotic microangiopathy (TMA), a potential side effect of AAV therapies. The fourth patient suffered the same adverse event, leading the FDA to declare a clinical hold on LB-001 in February. 

New Protocol Was Amended 

Months later, the FDA finally lifted the clinical hold on LogicBio, after acknowledging its efforts to address the trial issues. 

LB-001’s release from clinical hold occurred after the company amended the Sunrise protocol, which included enhanced monitoring measures, frequent testing for complement activation (a characteristic of TMA), and the use of a complement inhibitor in case of a potential TMA. The dosing of the next patients, who may be as young as six months old, will be at the 5e13 vg/kg dose.

According to LogicBio, interim clinical data from the trial will be presented by the end of the second quarter of 2022. 

Author

Joy Lin

Without knowledge, there is no imagination. Without imagination, knowledge is meaningless