Bayer has scaled back its gene therapy ambitions for Pompe disease, discontinuing development of one of two programs acquired through its $2 billion buyout of AskBio in 2021. The decision, reported by Fierce Biotech, reflects a strategic shift toward a different gene therapy candidate for the rare genetic disorder.
Pompe disease, also known as glycogen storage disease type II, is a progressive muscle disorder caused by a deficiency of the acid alpha-glucosidase (GAA) enzyme. This deficiency leads to the buildup of glycogen in muscle cells, causing weakness and, in severe cases, heart problems and respiratory failure. The disease affects an estimated 1 in 20,000 live births, according to the National Institutes of Health. Current treatment options include enzyme replacement therapy, but gene therapy offers the potential for a more durable, one-time correction of the underlying genetic defect.
Bayer’s Gene Therapy Pipeline and the Shift in Focus
Bayer’s acquisition of AskBio was largely driven by the promise of its gene therapy platform and pipeline, including two separate programs targeting Pompe disease. The company is now prioritizing development of an alternative AAV-based gene therapy, according to Fierce Biotech. The specific reasons for discontinuing the first program were not detailed in the report, but Bayer confirmed the strategic realignment.
The remaining Pompe disease gene therapy candidate utilizes an adeno-associated virus (AAV) vector to deliver a functional copy of the GAA gene to muscle cells. AAV vectors are commonly used in gene therapy because they are relatively safe and can effectively transduce muscle tissue. The program has recently entered Phase 1/2 clinical trials, as reported by Rare Disease Advisor, offering hope for patients with late-onset Pompe disease.
AB-1009: A Novel Hope for Late-Onset Pompe Disease
The clinical trials for AB-1009, the gene therapy Bayer is now focusing on, are designed to evaluate its safety and efficacy in adults with late-onset Pompe disease. This form of the disease typically manifests later in life and progresses more slowly than the infantile-onset form. The Phase 1/2 trial will assess different doses of AB-1009 to determine the optimal dose for future studies. Researchers will be monitoring patients for improvements in muscle strength, respiratory function and overall quality of life.
Gene therapy for Pompe disease is not without its challenges. One major hurdle is achieving sufficient gene expression in muscle tissue to produce enough GAA enzyme to overcome the deficiency. Another challenge is the potential for immune responses to the AAV vector or the newly expressed GAA protein. Researchers are working to address these challenges by optimizing the AAV vector, using immunosuppressive agents, and developing strategies to minimize immune responses.
Current Treatment Landscape for Pompe Disease
Before the advent of gene therapy, enzyme replacement therapy (ERT) was the primary treatment for Pompe disease. ERT involves intravenous infusions of a recombinant GAA enzyme to replace the deficient enzyme in the body. While ERT can improve some symptoms, it requires lifelong treatment and does not address the underlying genetic defect. The current avenues of gene therapy are being explored as a potential one-time curative treatment.
What’s Next for Bayer and Pompe Disease Research?
Bayer’s decision to focus on a single Pompe disease gene therapy candidate reflects the inherent risks and complexities of drug development. The company will now concentrate its resources on advancing AB-1009 through clinical trials and, if successful, seeking regulatory approval. The results of the Phase 1/2 trial are eagerly awaited by the Pompe disease community, as they will provide valuable insights into the potential of gene therapy to transform the lives of patients with this devastating disorder.
The next major milestone for AB-1009 will be the completion of the Phase 1/2 clinical trial and the release of preliminary data, expected in late 2026 or early 2027. Bayer will also continue to monitor patients enrolled in the trial for long-term safety and efficacy. Further research is needed to optimize gene therapy approaches and to develop new therapies for both early-onset and late-onset Pompe disease.
Disclaimer: This article is for informational purposes only and should not be considered medical advice. Please consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
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