Use of calcium and magnesium to prevent chemotherapy-induced neuropathy

Calcium (Ca) and magnesium (Mg) before and after oxaliplatin infusions was a commonly used modality to prevent progression of chemotherapy-induced neuropathy. It seemed like a relatively safe intervention that, at least in small trials, seemed possibly helpful in preventing worsening of the cold-induced neuropathy that plagues the majority of patients receiving oxaliplatin. As such, several randomized trials were undertaken to determine the true effect of Ca and Mg infusions.

One such trial, CONcePT (Combined Oxaliplatin Neurotoxicity Prevention Trial), presented the results of its independent disease monitoring committee assessment in July of 2007. This analysis was based on investigator assessment of response (not central review) and suggested that the Ca and Mg arm had lower response rates. This information was widely distributed to oncologists and patient advocates alike. It was proposed that perhaps this was due to some interaction with bevacizumab and the Ca/Mg or that the drugs were given incorrectly.

Recently the blinded central review of CONcePT was presented, and indeed, with rigorous review of response, the Ca/Mg arm no longer did worse — if anything, that arm seemed to do better. Kudos goes to the study sponsor for undertaking such a rigorous unbiased review of the data. I think the study chairs did the right thing by making the IDMC findings public, but now I think most providers are likely still gun shy about the use of Ca/Mg. Based on this new data, however, I think we can rightfully not be overly concerned about those patients that we did give Ca and Mg to, though what to do with oxaliplatin neurotoxicity remains a conundrum.