Successful rechallenge with cetuximab after an infusion related reaction to panitumumab in a patient with locally advanced rectal cancer

Incidence of infusion related reaction (IR) is more common with cetuximab (Cmab) than with panitumumab (Pmab). Although little is known about rechallenge IR with monoclonal antibodies, we experienced a successful rechallenge to Cmab after IR to Pmab. A 67-year-old female patient was scheduled for chemotherapy with mFOLFOX6 plus Pmab against unresectable advanced rectal cancer in the hope of tumor shrinkage. On the first administration of Pmab, she complained of dyspnea with shortness of breath and wheezing, even after premedication with steroids and antihistamines. Her reaction was judged as Grade 2 IR to Pmab. For the next course, we tried Cmab. No IRs were observed. Since then, she has undergone seven further courses of treatment, followed by surgical resection. The patient benefited from administration of Cmab after experiencing IR to Pmab, suggesting this treatment to be an option for patients of this type who experience IR to Pmab.