KAI-4169 is a novel pharmaceutical agent for the treatment of secondary hyperparathyroidism (SHPT), which is a frequent complication of chronic kidney disease (CKD). KAI-4169 has the potential to be best in class with superior efficacy and tolerability than other currently marketed therapies for SHPT. In July 2010, KAI completed enrollment in a Phase 1 study of KAI-4169. Data from the study demonstrated KAI-4169 to be safe and well-tolerated and have confirmed the potency and activity of KAI-4169 by demonstrating dose-dependent reductions in parathyroid hormone and serum calcium levels.

SHPT develops early in CKD and worsens as renal function declines and progresses to end-stage renal disease (ESRD). SHPT, which affects approximately 90% of patients with ESRD, is associated with bone disease (high-turnover renal osteodystrophy) and cardiovascular disease and can lead to significant morbidity. Several factors contribute to the development of SHPT. Mineral metabolism disturbances (hypocalcemia and hyperphosphatemia) and impaired vitamin D synthesis are crucial determinants of excess parathyroid hormone (PTH) secretion in patients with renal failure. Increased PTH levels, in turn, mobilize bone calcium, maintaining serum calcium levels at the expense of bone mineralization.

SHPT represents a significant unmet medical need. There are roughly 350,000 and 8 million patients in the U.S. with ESRD and CKD, respectively.

KAI-4169 can be formulated to be administered intravenously to manage the treatment of SHPT in ESRD patients during regular hemodialysis sessions or formulated to be administered as a daily transdermal patch to manage non-hemodialysis indications (HPT) such as primary hyperparathyroidism, ESRD patients receiving peritoneal dialysis, Stage 4 CKD patients with SHPT and renal transplant.