Genzyme Corporation / Bone Care International, Inc.

Secondary Hyperparathyroidism in Chronic Kidney Disease

Disease Overview

Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease in which damaged kidneys cannot maintain calcium, phosphorus, and vitamin D balance, driving the parathyroid glands to over-secrete PTH. Untreated SHPT contributes to renal bone disease, vascular calcification, and excess cardiovascular mortality, making it a defining management challenge for dialysis and late-stage CKD populations.

Competitive Landscape

At the 2005 deal close, the SHPT vitamin D analog market in dialysis was dominated by Abbott's Zemplar (paricalcitol) IV, with Bone Care's Hectorol (doxercalciferol) the only vitamin D2 prohormone competitor available in both IV and oral formulations. Calcijex (calcitriol, Abbott) and generic calcitriol served the legacy first-generation segment, while Amgen's Sensipar (cinacalcet, calcimimetic) had launched in 2004 as a non-vitamin-D mechanism that increasingly cannibalized escalating vitamin-D doses. Hectorol's oral formulation gave Genzyme a unique handle on the earlier, pre-dialysis CKD Stage 3-4 population that Zemplar IV did not address. Strategically, the deal stacked Hectorol on top of Genzyme's existing dialysis franchise — Renagel (sevelamer) phosphate binder plus the Renvela follow-on — creating a single-vendor SHPT/phosphate bundle for nephrologists and dialysis chains. Analysts modeled combined-sales-force uplift to $200-250M in North America and up to $300M with planned EU launches, framing the asset as a synergistic bolt-on rather than a platform pivot. The deal mattered because it transitioned Genzyme's renal business from monotherapy phosphate management to a comprehensive mineral-and-bone-disorder portfolio at a time when KDOQI/KDIGO guidelines were tightening PTH control targets. (Source: BioWorld, https://www.bioworld.com/articles/399094-bone-care-acquired-for-600m-as-addition-to-genzyme-renal)