Bayer AG / Asklepios BioPharmaceutical, Inc. (AskBio)

Pompe disease (acid maltase deficiency / GAA deficiency) and broader AAV gene therapy platform

8K US cases/yr · $4.5B Global cell & gene therapy revenue 2020 (USD MM, including approved gene therapies) · 1000 Sanofi Myozyme/Lumizyme global revenue 2020 (USD MM)

Disease Overview

Pompe disease (glycogen storage disease type II / acid maltase deficiency) is an autosomal recessive lysosomal storage disorder caused by GAA gene mutations resulting in deficient acid alpha-glucosidase enzyme activity and pathologic glycogen accumulation in skeletal, cardiac, and smooth muscle. Incidence is approximately 1 in 40,000 live births; US prevalence is estimated at 5,000-10,000 patients across infantile-onset (IOPD, presents <12 months with hypertrophic cardiomyopathy and respiratory failure — historically fatal by age 1) and late-onset (LOPD, presents in childhood through adulthood with progressive proximal muscle weakness and respiratory insufficiency). The standard of care since 2006 has been Sanofi/Genzyme's Myozyme/Lumizyme (alglucosidase alfa) — a recombinant GAA enzyme replacement therapy administered IV every 2 weeks — generating approximately $1.0B in 2020 global sales. ERT extends survival but produces incomplete clearance of glycogen in skeletal muscle (where mannose-6-phosphate receptor density is low), elicits immunogenicity, and requires lifelong infusions. AAV gene therapy with AAV-mediated GAA delivery (AskBio's AT845, AT-GAA being the prior generation) targets durable single-dose GAA expression, addressing the unmet need in late-onset Pompe and avoiding chronic ERT burden. The broader AAV gene therapy ecosystem in 2020 was rapidly expanding beyond Pompe — including Parkinson's (AskBio's AB-1005 GDNF), congestive heart failure (AskBio's NAN-101 / BNP116.sc.CMV.I-1c), Duchenne (Sarepta SRP-9001), spinal muscular atrophy (Zolgensma, Novartis), hemophilia (Roctavian, BioMarin), and inherited retinal disease (Luxturna, Spark/Roche).

Competitive Landscape

At deal date (Oct 2020) the AAV gene therapy and Pompe disease landscape were both crowded and consolidating. AAV vector pioneers acquired or partnered in 2018-2020: Spark Therapeutics ($4.8B Roche acquisition closed Dec 2019, Luxturna inherited retinal dystrophy), Audentes Therapeutics ($3B Astellas acquisition closed Jan 2020, AT132 X-linked myotubular myopathy), Avexis (~$8.7B Novartis acquisition 2018, Zolgensma SMA), and Dimension Therapeutics ($600M REGENXBIO acquisition 2017). Direct AAV-Pompe competitors at deal date: Sarepta Therapeutics (SRP-9003 in collaboration with Lacerta, IND-stage Pompe — Sarepta inherited from Lacerta acquisition 2018; preclinical), Spark/Roche (early discovery), and Amicus Therapeutics (AT-GAA / cipaglucosidase alfa-atga + miglustat — chaperone + ERT combination, not AAV but next-gen Pompe asset, Phase 3 PROPEL, approved as Pombiliti+Opfolda in 2023). Late-onset Pompe ERT competitors: Avalglucosidase alfa (Nexviazyme, Sanofi — next-gen ERT with improved M6P targeting, approved Aug 2021 post-deal). Broader AAV gene therapy field: Sarepta (SRP-9001 micro-dystrophin DMD, Phase 3, accelerated approval Jun 2023), BioMarin (Roctavian valoctocogene roxaparvovec hemophilia A, EMA-approved Aug 2022, FDA Jun 2023), uniQure (Hemgenix etranacogene dezaparvovec hemophilia B, FDA Nov 2022, sold to CSL Behring), Adverum, REGENXBIO, Solid Biosciences, Voyager Therapeutics, 4D Molecular Therapeutics, Generation Bio. AskBio's differentiation: proprietary Pro10 manufacturing platform (HEK293-based, scalable AAV production), broad capsid library, and clinical pipeline in Pompe (AT845), Parkinson's (AB-1005 GDNF), and congestive heart failure (NAN-101, partnered Bayer 2018) — together giving Bayer entry to neuromuscular, CNS, cardiovascular gene therapy in one transaction.