Shire Pharmaceuticals Group plc / Transkaryotic Therapies, Inc. (TKT)

Fabry Disease

$77M Replagal 2004 global sales

Disease Overview

Fabry disease is an X-linked lysosomal storage disorder caused by alpha-galactosidase A deficiency, leading to globotriaosylceramide accumulation in vasculature, kidneys, heart, and nerves. Manifestations include neuropathic pain, progressive renal failure, cardiomyopathy, and stroke; untreated males have markedly reduced life expectancy.

Competitive Landscape

At deal time (2005) the Fabry treatment landscape was a duopoly between TKT's Replagal (agalsidase alfa, EU-approved 2001 in 34 countries) and Genzyme's Fabrazyme (agalsidase beta, FDA-approved 2003, EU-approved 2001) — two recombinant enzyme replacement therapies with different cell-line origins competing on dosing, immunogenicity, and switch data. Replagal generated $77M in 2004 sales but had failed to secure FDA approval, leaving the US market to Fabrazyme. The strategic logic for Shire centered on (1) acquiring a marketed orphan biologic with high pricing power, (2) inheriting TKT's pipeline including idursulfase (later Elaprase for Hunter syndrome) and velaglucerase alfa (later VPRIV for Gaucher), and (3) building a Human Genetic Therapies division as a third growth pillar alongside ADHD and GI franchises. The Fabrazyme 2009 manufacturing shortage at Genzyme later allowed Replagal to gain US emergency-use traction, but Shire withdrew the BLA in 2012 after FDA required additional controlled trials. Galafold (migalastat, Amicus) entered as oral chaperone therapy in 2018, and Sanofi later acquired Genzyme. Dynepo (epoetin delta) was discontinued post-deal as ESA biosimilars eroded pricing.