Background: The Forteo Patient Registry is a voluntary prospective cohort study designed to estimate the incidence of osteosarcoma in patients taking teriparatide (Forteo). Adult patients residing in the United States (US) who provide consent and personal information through a simple, one-time enrollment process during a 10-year enrollment period will be linked with participating state cancer registries for 15 years to ascertain osteosarcoma cases diagnosed after patients started treatment. Due to the rarity of adult osteosarcoma (2.7 cases per million population), this study requires a large number of teriparatide users from across the US and participation by a large number of state cancer registries.
Objective: To provide a study update after 5+ years of patient enrollment and completion of 5 annual data linkages.
Methods: The Forteo Patient Registry was launched on July 23, 2009 and the first annual linkage occurred in August 2010. State cancer registries were enrolled into the study on an ongoing basis from 2009-2013. Patient enrollment will continue through September 2019 and cumulative annual linkages are planned through 2024.Results: In 2009, cancer registries in all 50 states plus the District of Columbia were invited to participate. Cancer registry enrollment was completed in 2013 and a total of 41 state cancer registries, covering 92% of the US population aged 18 years and older, participated in the 5th annual linkage, completed in October 2014. As of September 30, 2014, 44,635 patients had enrolled in the Forteo Patient Registry. No matches were found during the first 5 annual linkages.
Conclusions: The registries did not find any incident cases of osteosarcoma among patients in the Forteo Patient Registry during the first 5 years of the linkage; however, our ability to draw conclusions about the incidence of osteosarcoma among teriparatide users is restricted due to the limited amount of follow-up time currently available.
