Merck Serono says Erbitux long-term survival benefit for mCRC patients confirmed with FOLFOX

German drug major Merck KGaA’s (MRK: DE) Merck Serono division this morning highlighted a further analysis of the large randomized Phase II OPUS study demonstrating an association between early tumor shrinkage and long-term median overall survival (OS) of more than two years for patients with KRAS wild-type metastatic colorectal cancer (mCRC) treated with Erbitux (cetuximab) plus FOLFOX standard chemotherapy. This correlation was not seen in the chemotherapy-alone arm of the study. The findings will be presented at the annual Gastrointestinal (GI) Cancers Symposium of the American Society of Clinical Oncology (ASCO).

This latest analysis shows that the majority of patients (69%) with KRAS wild-type mCRC demonstrated tumor shrinkage of 20% or more in the first eight weeks of first line treatment with Erbitux and FOLFOX. These patients experienced a long-term median OS of 26.2 months. Patients treated with FOLFOX chemotherapy alone whose tumors shrank by 20% or more in the same period (46%) experienced median OS of only 21.8 months.

These results support recent findings from the Phase III CRYSTAL trial, which found that early tumor shrinkage achieved with Erbitux in combination with FOLFIRI standard chemotherapy led to a long-term median OS of 2.4 years (28.3 months).]