Biogen Discontinues AAV Gene Therapy Work, Reshuffles Staff Amid Cost-Cutting Measures

Biogen Ends AAV Program, Affecting 20 Employees

Biogen, a leading pharmaceutical company, has announced the complete discontinuation of its adeno-associated virus (AAV) gene therapy program. This decision has led to a staff reshuffle within the unit, impacting approximately 20 employees. According to a company spokesperson, the majority of affected staff have been reassigned to other roles within Biogen, though the exact number of job losses remains unclear.

The move comes as part of Biogen's broader cost-cutting initiative, which aims to generate $1 billion in savings by 2025. This restructuring effort, initiated in July 2023, initially targeted around 1,000 jobs for elimination. The company's shares have fallen 50% over the past five years, reflecting growing investor skepticism about Biogen's commercial and pipeline prospects.

Industry-Wide Shift in AAV Gene Therapy Landscape

Biogen's decision to halt AAV gene therapy work follows a similar move by Vertex Pharmaceuticals in May. Vertex not only ended its work on AAV capsids but also terminated a gene editing agreement with Verve Therapeutics earlier this year, which had focused on liver diseases.

The AAV platform has faced additional challenges recently, particularly with the controversy surrounding Sarepta Therapeutics' gene therapies. Sarepta reported three deaths in 2025: two associated with its Duchenne muscular dystrophy therapy Elevidys, and one linked to an investigational gene therapy for limb-girdle muscular dystrophy. All three deaths were attributed to liver failure, raising concerns about the safety of AAV-based gene therapies.

Despite these setbacks, some industry leaders remain optimistic about the future of AAV technology. Emil Kakkis, CEO of Ultragenyx, stated in a recent interview that his company has successfully tested AAV gene therapies in various conditions, including Wilson disease and Sanfilippo syndrome, without encountering safety issues. Kakkis expressed confidence in the safety of AAV delivery to the liver and predicted that "with continued improvement in AAV technology, it'll be around for a very long time."

Biogen's Strategic Shift and Research Focus

Jane Grogan, Biogen's head of research, emphasized the company's "disciplined approach to capital allocation" in light of the AAV program discontinuation. Moving forward, Biogen plans to concentrate its resources on "pioneer modalities" and therapies with the highest potential to deliver improved patient outcomes.

This strategic shift aligns with Biogen's efforts to reinvigorate its drug discovery pipeline. In January 2025, the company let go of an undisclosed number of research staff as part of this initiative. As of the end of 2024, Biogen employed more than 7,600 people worldwide, underscoring the significant scale of its operations and the potential impact of ongoing restructuring efforts.