Spur Therapeutics Completes Phase 1/2 FLT201 Trial Enrollment in Gaucher Disease and Chooses Phase 3 Dose

Spur Therapeutics, previously known as Freeline Therapeutics, has announced the completion of enrollment for its Phase 1/2 GALILEO-1 clinical trial for FLT201, an adeno-associated virus (AAV) gene therapy aimed at treating Gaucher disease. The trial data have demonstrated both safety and efficacy, leading Spur to proceed with a single infusion of FLT201 at a 4.5e11 vg/kg dosage. The company is preparing to initiate a Phase 3 trial next year based on these promising results.

Michael Parini, CEO of Spur Therapeutics, expressed satisfaction with the progress and data from the GALILEO-1 trial. He emphasized the potential of FLT201 to set a new benchmark for Gaucher disease treatment, highlighting the strong safety and efficacy signals observed at the current dosage. Spur is committed to starting the Phase 3 trial next year and aims to bring this innovative gene therapy to patients.

The GALILEO-1 trial, an international, multicenter, first-in-human study, involved six adult patients with Gaucher disease Type 1. Each participant received a single infusion of FLT201 at the specified dose. Two patients have completed the nine-month follow-up, while the remaining four have been monitored between 16 and 38 weeks. Safety analysis included all six patients, while the efficacy analysis included five patients, excluding one with pre-existing neutralizing antibodies to the AAVS3 capsid.

Data up to June 30, 2024, indicate favorable safety and tolerability. Significant reductions in glucosylsphingosine (lyso-Gb1), a biomarker predictive of disease severity and clinical response, were observed in patients with persistent high levels despite existing treatments. Maintenance or improvement of lyso-Gb1 levels, normal hemoglobin and platelets levels, and bone marrow burden were reported. One patient with chronic pain and fatigue experienced clinically relevant improvements in pain and fatigue, enhancing their functionality. These benefits were noted regardless of antibodies to glucocerebrosidase (GCase), the deficient enzyme in Gaucher disease.

Further data from the GALILEO-1 trial is anticipated in the latter half of 2024. FLT201 has obtained various designations aimed at expediting its development: Regenerative Medicine Advanced Therapy (RMAT) from the US FDA, Priority Medicines (PRIME) from the European Medicines Agency, and the Innovative Licensing and Access Pathway (ILAP) by the UK Medicines and Healthcare products Regulatory Agency. These designations facilitate enhanced regulatory interactions and expedited reviews.

FLT201 utilizes Spur’s potent AAVS3 capsid to deliver GCase85, a longer-acting version of the deficient enzyme in Gaucher disease, potentially stopping disease progression, reducing symptoms, and allowing patients to discontinue lifelong treatments. Preclinical and clinical data have shown robust expression and significant reduction in the substrate buildup caused by the enzyme deficiency.

Gaucher disease, resulting from a GBA1 gene mutation, leads to low levels of glucocerebrosidase (GCase), causing harmful substrate accumulation in tissues and organs. This buildup results in inflammation and dysfunction, with many patients experiencing severe symptoms despite current treatments. The disease affects approximately 18,000 people across the US, UK, France, Germany, Spain, Italy, and Israel.

Spur Therapeutics focuses on developing transformative gene therapies for chronic conditions. By optimizing every component of its products, Spur aims to achieve significant clinical outcomes. The company is advancing gene therapy candidates for Gaucher disease and adrenomyeloneuropathy, and exploring therapies for more prevalent diseases, including Parkinson’s, dementia, and cardiovascular diseases.