Amgen has acquired privately-owned KAI Pharmaceuticals for $315m and gained access to its secondary hyperparathyroidism drug KAI-4169.

The drug, designed for use in patients with chronic kidney disease who are undergoing dialysis, is currently in a Phase II trial and Amgen has provided a loan in order to enable Phase III development of the drug.

Amgen is set to receive worldwide rights to the drug excluding Japan, with Ono Pharmaceutical retaining the rights to market the drug there.

Secondary hyperparathyroidism (SHPT) is a common complication for patients suffering from chronic kidney disease, and KAI-4169 intends to treat the condition by affecting calcium homeostasis by modulating the release of parathyroid hormone.

Amgen has had success with SHPT medications, with its oral treatment for the condition Sensipar, known as Mimpara in Europe, achieving sales of $808m in 2011.

Amgen Research and Development executive vice president Sean Harper said the company was excited about acquiring KAI, whilst also heralding the drug’s recent results.

"KAI has demonstrated encouraging results in the clinic. We are excited about acquiring KAI, as well as the opportunity to potentially deliver a novel therapy for chronic kidney disease patients on dialysis suffering from secondary hyperparathyroidism," added Harper.

Completion of the acquisition is subject to customary closing conditions and regulatory approvals, and KAI Pharma will become a wholly owned subsidiary of Amgen following completion.