Sanofi has received Breakthrough Therapy designation from the US Food and Drug Administration (FDA) for its investigational drug venglustat, aimed at treating neurological symptoms associated with type 3 Gaucher disease (GD3).

The designation is supported by results from the phase 3 LEAP2MONO study, where patients treated with venglustat showed significant improvement in neurological function compared to those receiving enzyme replacement therapy (ERT) with imiglucerase. The improvements were measured using global scores that assessed coordination and cognitive ability, with results showing statistical significance.

In terms of safety, venglustat was generally well tolerated. The most commonly reported side effects included headache, nausea, spleen enlargement, and diarrhoea. No new safety concerns were observed when compared with earlier studies.

Gaucher disease is a rare inherited condition caused by a deficiency of the enzyme glucocerebrosidase. This leads to the build-up of certain fatty substances in organs such as the liver, spleen, and bone marrow. The disease has three main types. While type 1 does not affect the central nervous system, type 2 progresses rapidly with severe neurological decline. Type 3, on the other hand, shows a slower but variable progression, often including neurological symptoms.

In GD3 patients, the accumulation of these substances in the brain leads to neurological complications. While existing treatments like ERT can manage systemic symptoms, there are currently no approved therapies that directly address neurological issues.

Venglustat is designed to reduce the accumulation of these harmful substances. It has the added advantage of crossing the blood-brain barrier, allowing it to target the underlying cause of neurological symptoms.

According to Karin Knobe, global head of clinical development for rare diseases at Sanofi, the designation highlights the urgent need for better treatment options for patients with GD3. She noted that the positive study results mark an important step forward, and the company will continue working with the FDA to advance the drug’s development.

Venglustat has already received Fast Track designation from the FDA and Orphan Drug status in the US, Europe, and Japan. Sanofi is planning to move ahead with global regulatory submissions for the drug in 2026.

Breakthrough Therapy designation is granted to drugs that show early clinical evidence of substantial improvement over existing treatments for serious or life-threatening conditions. It is intended to speed up both development and regulatory review.

The LEAP2MONO study is a double-blind, active-controlled trial involving both adult and paediatric patients aged 12 years and above. Participants were randomly assigned to receive either oral venglustat or intravenous ERT. The study is ongoing, and further results from its open-label phase are expected in the future.

Venglustat belongs to a class of drugs known as glucosylceramide synthase inhibitors. By blocking the production of certain lipids, it aims to slow disease progression and reduce cellular damage.

Sanofi continues to focus on advancing treatments for rare diseases, combining research capabilities with emerging technologies to address unmet medical needs.