Chart trends for bone and mineral metabolism in CKD

BioTrends Research Group, LLC has released findings from the 2011 ChartTrends^®: Bone and Mineral Metabolism in Chronic Kidney Disease report, the fifth in an on-going annual series. The study was conducted with 204 U.S. nephrologists who completed detailed chart reviews for 1,037 patients in CKD Stage 3, 4 and 5 not yet on dialysis.

The study found that nephrologists tend to overestimate the percent of Stage 3 & 4 patients being treated with phosphate binders and that, compared to just two years ago, Stage 3 prevalence has declined by more than 50 percent and Stage 4 prevalence is off by nearly 20 percent. While 50 percent of participating nephrologists reported that they typically initiate phosphate binders when serum phosphorus levels are less than 4.5g/dL, in reality, only 4 percent of the patients were initiated at this level; more than 60 percent had a phosphorus level above 5.5g/dL at initiation. However, by the time patients are in Stage 5, a pre-cursor to dialysis, the majority are treated with phosphate binders, usually in combination with active vitamin D such as Abbott's Zemplar, Genzyme/Sanofi's Hectorol or generic calcitriol. Patients with known or suspected arterial calcification were significantly more likely to be treated with phosphate binders compared to those without calcification. From a brand perspective, Genzyme/Sanofi's sevelamer products (Renagel / Renvela) had the greatest market share gains offsetting both Shire's Fosrenol and generic calcium carbonate.

The use of nutritional vitamin D (ergocalciferol, cholecalciferol) increased across all stages compared to the prior year while the use of active vitamin D remained stable. Similar to the phosphate binder market, nephrologists reported initiating vitamin D at a mean iPTH level of 155pg/dL but the audited levels were significantly higher with 85 percent of patients initiated when iPTH levels exceeded 100pg/dL. There were no significant changes in brand utilization compared to the prior year and, among the treated patients, the vast majority remains on their first line agent.

The study also evaluated referral patterns, co-morbidities, concomitant medications, hospitalizations and a host of other patient demographics and laboratory data. A parallel report was conducted in Europe during the same period.