An analysis from the Phase III CRYSTAL study with cetuximab (Erbitux?, Merck Serono/ Merck KgaA) in metastatic colorectal cancer (MCRC) presented during 35th ESMO Congress Poster Presentation II, on October 10 2010, by Professor H Piessevaux shows that patients with KRAS wild-type metastatic colorectal cancer (mCRC) who experienced early tumor shrinkage (within 8 weeks) during 1st line cetuximab based treatment lived a median of 28.3 months.1 Such a correlation between early tumor shrinkage and long-term survival was not observed in the chemotherapy-alone arm, in which survival did not exceed 21 months.
Cetuximab is a first-in-class and highly active IgG1 monoclonal antibody targeting the epidermal growth factor receptor (EGFR). As a monoclonal antibody, the mode of action of cetuximab is distinct from standard non-selective chemotherapy treatments in that it specifically targets and binds to the EGFR. This binding inhibits the activation of the receptor and the subsequent signal-transduction pathway, which results in reducing both the invasion of normal tissues by tumor cells and the spread of tumors to new sites. It is also believed to inhibit the ability of tumor cells to repair the damage caused by chemotherapy and radiotherapy and to inhibit the formation of new blood vessels inside tumors, which appears to lead to an overall suppression of tumor growth
“These new data indicate that early tumor shrinkage with personalized Erbitux therapy correlates with significantly improved survival,? said study author Professor Eric Van Cutsem, Professor of Medicine and Digestive Oncology from the University Hospital Gasthuisberg in Leuven, Belgium. ?Tumor shrinkage is important for providing symptom relief and vital for increasing the potential for curative surgery. These new findings go a step further in suggesting that early tumor shrinkage may also be an indicator for extended survival for patients treated with an Erbitux-based therapy.?
The Phase III CRYSTAL trial has previously demonstrated that mCRC patients with KRAS wild-type tumors treated with Erbitux achieved a median survival of 23.5 months. The new findings, derived from further analysis of the trial data, have shown that patients who experienced early tumor shrinkage with Erbitux-based treatment lived a median of 28.3 months.1 Early tumor shrinkage was defined as a 20% or greater tumor reduction within 8 weeks.
?Erbitux-based treatments have consistently achieved meaningful tumor shrinkage. The correlation between early tumor shrinkage and long-term survival seems to be Erbitux-specific as it has not been reported with any other mCRC therapies,? said Dr. Wolfgang Wein, Executive Vice President for Oncology at Merck Serono. ?These data have the potential to establish Erbitux as the first-choice, 1st line therapy for all mCRC patients with KRAS wild-type tumors.?
– Piessevaux H, et al. ESMO Congress 2010. Abstract No: 596P.
– Van Cutsem E, et al.. ASCO GI Congress 2010. Abstract No: 281.
– Scientific Discussion (EMEA)