A Multicenter, Open-label Extension Study to Assess the Long-term Safety and Efficacy of an Oral Calcimimetic Agent AMG 073 (Cinacalcet) in Primary Hyperparathyroidism

Subjects began open-label treatment with 30 mg cinacalcet twice daily (BID) at the start of the current study. The study consisted of 2 phases planned to total approximately 4¾ years: a 12-week dosetitration phase (visits at weeks 2, 3, 4, 6, 9, and 12) during which 1 possible dose increase of cinacalcet from 30 mg BID to 50 mg BID could occur at week 6, and a maintenance phase (week 12 to 234; visits approximately every 4 weeks until week 24 and approximately every 14 weeks thereafter) during which doses also could be titrated. After July 2004, because of a change in dose strengths, the daily doses used in the study were 30 and 60 mg BID with the option to reduce to 30 mg once daily (QD), if necessary. Ongoing subjects receiving 50 mg BID were switched at that time to 60 mg BID.