532P - Hypomagnesemia induced by cetuximab and panitumumab

Date 18 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Cytotoxic agents
Complications/Toxicities of treatment
Presenter Toshihide Onikubo
Citation Annals of Oncology (2016) 27 (suppl_9): ix170-ix176. 10.1093/annonc/mdw599
Authors T. Onikubo, M. Nakamura, K. Nakamura, M. Furukawa, A. Miura, K. Tauchi
  • Aizawa Comprehensive Cancer Center, Aizawa Hospital, 390-8510 - Matsumoto/JP



Anti-EGFR monoclonal antibodies (cetuximab and panitumumab) have been widely used as a standard care for Ras wild-type mCRC. Besides skin toxicity and mucosal damage, hypomagnesemia is also well known as its specific adverse effects. Hypomagnesemia can be a cause of malaise, appetite loss and arrhythmia, and result in unplanned treatment interruptions including dose reduction or treatment delay in severe cases. To investigate the occurrence and severity of hypomagnesemia in the use of anti-EGFR antibody drugs, we concluded a retrospective analysis.


Serum magnesium tests along with other blood tests at each treatment were performed. The incidence of hypomagnesemia, administration period and association with other adverse effects were analyzed. Collection of magnesium was started when grade 2 or higher level was identified according to CTCAE-Ver4.


From January 2011 to January 2016, 93 patients were treated with cetuximab or panitumumab in our hospital. The overall occurrence of hypomagnesemia was observed in 66 patients (71%); grade 1, 2, 3 were 39.8%, 23.7%, and 7.5%, respectively. The median period until the onset of hypomagnesemia in grade 2-3 was earlier than grade 1{43 days (14-439) v.s. 63 days (14-491)}. The median treatment duration was 174 days (35-719) in grade 2-3 and 107.5 days (13-559) in grade 0-1; thus, the administration period was longer in the severe cases. Acne-like skin rash was observed more frequently with hypomagnesemia than without hypomagnesemia (45.5% v.s. 14.8%). Any other association was not observed in terms of adverse events.


Our data revealed incidence of hypomagnesemia was frequent. There was a correlation between severity of hypomagesemia and treatment duration, hypomanesemia may be a predictive marker of anti-EGFR monoclonal antibody. Monitoring and adjustment of hypomanesemia should be performed.

Clinical trial indentification

Legal entity responsible for the study

Aizawa Hospital


Aizawa Hospital


T. Onikubo, M. Nakamura, M. Furukawa, A. Miura: There is no interest should be disclosed. K. Nakamura, K. Tauchi: There is no interest should be disclosed