Lanthanum and phosphate: science, policy, and survival.

Mineral metabolism in chronic kidney disease is attracting intense interest and unprecedented levels of research. The pharmaceutical industry has responded by developing various new agents. Bervoets et al. report the use of an unusual combination of basic-science techniques to increase understanding of the kinetics of one such agent--lanthanum carbonate--in the gastrointestinal tract and liver. However, do we need to answer more fundamental clinical questions before we can definitively identify the role of similar new and expensive drugs?