New Dosing Regimen Approved for Erbitux

April 6, 2021 – The U.S. FDA has approved a new dosing regimen for Erbitux® (cetuximab), manufactured by ImClone. The drug may now be administered once every two weeks to treat KRAS wild-type, eGFR-expressing metastatic colorectal cancer (mCRC) or squamous cell carcinoma of the head and neck (SCCHN). Previously, it was approved for once-weekly dosing for these cancers.

In colorectal cancer, the presence of a KRAS mutation is associated with aggressive disease that is resistant to certain types of targeted therapies. Patients with mCRC have a poor prognosis, with a five -year survival rate of 14% for CRC that has spread to distant parts of the body. Survival rates for SCCHN, which is a cancer that affects the outer layer of skin and the mucous membranes, are better but not excellent. Approximately 50% of individuals diagnosed with SCCHN survive more than five years.

Recommended Erbitux dosing under the new regimen is 500mg/m 2 of body surface area, administered via intravenous infusion over the course of 120 minutes every two weeks. Recommended weekly dosing is 400mg/m 2 . Pharmacokinetic analyses (evaluation of how a drug moves through the body) and real- world trials found consistent efficacy on both dosing regimens.

A black box warning cautions that Erbitux can cause serious and fatal infusion reactions. There is also a black box warning for cardiopulmonary arrest or sudden death, which have been recorded in patients with SCCHN receiving cetuximab (the active pharmaceutical ingredient of Erbitux) with radiation therapy or platinum-based therapy and fluorouracil.

Based on the wholesale acquisition cost (WAC), weekly dosing is significantly more expensive than dosing every other week – $130,560 for a patient with a body surface area of 2m 2 who undergoes a 24-week course of treatment, compared to $81,600 for the same patient on a 24-week course where Erbitux is administered once every other week.