Background
Lanthanum carbonate (LC), an effective phosphate (P) binder, is widely used to manage hyperphosphatemia in hemodialysis patients. However, the long-term safety of LC treatment in clinical practice has not been completely established.
Methods
In an observational multicenter study, we retrospectively investigated the long-term tolerability in Japanese hemodialysis patients who had completed a 3-year phase III extension study of LC. Among 39 patients who completed the phase III extension study, those who gave written informed consent to allow a retrospective examination of their medical records for up to 8 years were enrolled. During the period spanning 2009 to 2013, a tolerability assessment was performed by monitoring adverse events, laboratory parameters, and vital signs.
Results
Among the 34 enrolled patients, 30 were included for analysis. In this 5-year follow-up observational study, 18 of 30 patients (60.0 %) received LC with or without some other P binders (PBs), 10 patients (33.3 %) switched from LC to another PB, and 2 patients (6.7 %) did not use PB. During the phase III study, 16 patients (53.3 %) experienced a drug-related adverse event, with the most common being gastrointestinal disorder, already known to be a common adverse event of LC. No drug-related adverse events were reported during the follow-up observational study. Five of 18 patients (27.8 %) who continued LC and 3 of 12 patients (25.0 %) who did not continue LC experienced serious adverse events during the follow-up observational study. However, none of these events except for constipation were drug-related.
Mean serum P concentrations was kept within the guideline-recommended management target range during the study period. No clinically significant changes in laboratory parameters and vital signs were observed except for pronounced decreases in intact parathyrois hormone (PTH) and blood pressure during the follow-up observational study period.
Conclusions
In patients who completed a 3-year phase III extension study of LC, there was no evidence of delayed adverse events or any increase in the incidence of LC-related adverse events with increasing LC exposure for up to 8 years.
Trial registration
UMIN-CTR UMIN000015227