Press release

PA21 Pivotal phase III data presented at American Society of Nephrology (ASN) Kidney Week demonstrate successful control of hyperphosphatemia with lower pill burden for patients

Monday, 5 November 2012, ↓ directly to download

Data from a pivotal phase III clinical study of new phosphate binder PA21 was presented in a late breaking poster session at the American Society of Nephrology (ASN) Kidney Week in San Diego, California. The abstract “Efficacy and safety of PA21 in Hyperphosphatemic CKD Patients on Dialysis” showed that PA21 was well tolerated and successfully controlled hyperphosphatemia with a lower pill burden than sevelamer carbonate, a current standard treatment. As announced in July, the study met its primary and secondary endpoints, and will be used as the basis for regulatory filings in the USA, Europe and Switzerland.

Professor Jürgen Floege, the Principal Investigator in the phase III study, commented that the study results fulfilled the expectations of the study investigators: “This large phase III study provided robust data demonstrating that PA21 achieves good phosphorus control comparable to that with sevelamer with a substantially smaller number of tablets. This will offer a new option for patients in the area where treatment adherence and consequently an effective serum-phosphorus control remain a challenge.”

PA21 is a chewable, iron-based phosphate binder containing a mixture of polynuclear iron(III)-oxyhydroxide, sucrose and starches. Results of the 6-month, study with more than 1,000 patients conducted in the USA, Europe as well as in Croatia, Russia, Serbia, Ukraine and South Africa established the superiority of maintenance doses of PA21 versus a PA21 inactive low-dose in sustaining the phosphate-lowering effect in dialysis patients. In addition, PA21 was shown to be as good as sevelamer carbonate, a current standard of therapy, in lowering serum phosphorus levels after 12 weeks of treatment, using an average of 3-4 tablets of PA21 per day (compared to 8-9 of sevelamer carbonate). PA21 appears to be generally well-tolerated and efficacious with the advantage of a lower pill burden.

Hyperphosphatemia, the accumulation of phosphorus in the blood, is a common and serious condition in patients with CKD, particularly those requiring dialysis. While most dialysis patients are treated with phosphate binders, less than 50% achieve and maintain their target serum phosphorus levels. Hyperphosphatemia is a risk factor for CKD complications such as cardiovascular disease, secondary
hyperparathyroidism and renal bone disease.

Results will be used as the basis for regulatory filings in the USA, Europe and Switzerland. First submission is planned for fourth quarter of 2012.

Full results from the phase III study will be submitted to peer review journals.

Vifor Pharma, a company of the Galenica Group, is a world leader in the discovery, development, manufacturing and marketing of pharmaceutical products for the treatment of iron deficiency. The company also offers a diversified portfolio of prescription medicines as well as over-the-counter (OTC) products. Vifor Pharma, headquartered in Zurich, Switzerland, has an increasingly global presence and a broad network of affiliates and partners around the world.

PA21 is a chewable, iron-based phosphate binder containing a mixture of polynuclear iron(III)-
oxyhydroxide, starch and sucrose. Each tablet of PA21 contains the equivalent of 500mg of insoluble elemental iron. When taken with meals, PA21 adsorbs the dietary phosphate in the gastrointestinal tract, preventing its uptake into the blood. The phosphate bound to PA21 is subsequently eliminated through the faeces.

PA21’s prior Phase II clinical trial met both its primary and secondary endpoints. The serum
phosphorus lowering efficacy of the two lowest active doses was numerically comparable to 4.8g/day sevelamer hydrochloride. PA21 was also well tolerated, with a comparable overall safety and tolerability profile.

The recently completed Phase III trial was an open-label, randomised, active controlled, parallel group study to investigate the safety and efficacy of PA21 compared to sevelamer carbonate, followed by a randomized comparison of PA21 maintenance dose versus PA21 inactive low-dose in dialysis patients with hyperphosphatemia. It is followed by a six-month safety extension study.

PA21 is developed in collaboration with Fresenius Medical Care ( It is also currently undergoing Phase II clinical development in Japan by Kissei Pharmaceuticals Co., Ltd.


Beatrix Benz

Head of Global Communications & Public Affairs

Vifor Pharma Ltd.

Global Communications
Flughofstrasse 61
P.O. Box
CH-8152 Glattbrugg

+41 58 851 80 00
+41 58 851 80 01

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