GENEVA, June 30, 2011 /PRNewswire/ --

Merck Serono, a division of Merck KGaA, Darmstadt, Germany, today announced the enrollment of the first patients in SPARK[1]. The SPARK study will investigate the safety, efficacy and population pharmacokinetics of Kuvan(R) (sapropterin dihydrochloride) in patients younger than four years, who suffer from Phenylketonuria (PKU).

PKU is a rare inborn metabolic disorder causing the toxic accumulation in brain and blood of an essential amino acid, Phenylalanine (Phe), found in all protein-containing foods. Until recently, the only way to prevent or reduce Phe blood level was a strict, life-long binding diet. In December 2008, Kuvan(R) received a European marketing authorization in patients four years of age and older in PKU indication and in patients of all age in the indication of Tetrahydrobiopterin (BH4) deficiency.

"Beyond the implementation of SPARK as follow-up measure agreed with the European Medicines Agency, we want to make Kuvan(R) available for patients who could benefit from it, including children younger than four years suffering from PKU", said Dr. Bernhard Kirschbaum, Executive Vice President Global Research and Development at Merck Serono.

SPARK is a Phase IIIb, multi-center, open-label, randomized and controlled study that will be conducted in Europe and in Turkey. Fifty pediatric patients with PKU, younger than four years old, are expected to be included in SPARK. They will randomly receive either Kuvan(R) therapy in conjunction with a Phe-restricted diet or the dietary therapy alone, over a period of 26 weeks.

Patients who complete the 26-weeks study period will be eligible to enter in an extension period, during which all subjects will undergo continued treatment with Kuvan(R), along with a Phe-restricted diet, over a period of up to three years.

[1] SPARK: Safety Pediatric EfficAcy PhaRmacokinetic with Kuvan(R) (sapropterin dihydrochloride).