Secondary resection in a general mCRC population with cetuximab-based first-line treatment: Interim analysis of the German noninterventional study ERBITAG.

Abstract

e14532 Background: Resection of liver and/or lung metastases (LM) are a potentially curative option for patients with mCRC. Cetuximab in combination with irinotecan- or oxaliplatin-based chemotherapy has shown to increase the resection rate of primarily unresectable LM in mCRC patients. After approval of cetuximab in Germany for first-line treatment of pts with unresectable mCRC, this noninterventional study was initiated to evaluate safety and efficacy of cetuximab in combination with various first-line chemotherapy regimens in patients with unresectable mCRC. Methods: We conducted an interim analysis of the first 124 fully documented pts to evaluate the response rate (RR) and resection rate of LM. Enrolment was restricted to pts with mCRC with proven KRAS wildtype mutation status without prior systemic treatment in the metastatic stage. Predefined endpoints were amongst others RR, LM resection rate, TTF, PFS, OS, and safety. Results: From May 2010 to May 2012 360 eligible pts were enrolled at 109 sites (75% office-based physicians), documentation for 124 was finalised (data cut-off for this analysis 03 May 2012) and evaluated. The median age was 68 [range 34-84] years, ECOG performance status was 0, 1, 2 in 29%, 60%, and 9% of pts, respectively, in 2% of pts ECOG performance status was missing. Resection rate was 18.5% (n=23) performed at 18 sites with 16.9% R0 resections (n=21). 42% of pts (n=52) had liver-limited disease (LLD). Resection rate in pts with LLD was 34.6% (n=18) with a 30.6% R0-resection rate (n=16). Median treatment duration from start of cetuximab-based therapy to resection of LM was 3.7 months [0.7-12.0]. Objective response rate was 46.8% (CR 4.8%, PR 41.9%) and 59.6% (CR 5.8%, PR 53.8%) for pts with LLD. Conclusions: In a clinical practice setting cetuximab-based first-line treatment of an unselected population with KRAS wildtype mCRC resulted in an R0-resection rate of 16.9% overall, and 30.6% for LLD pts. These data compare fairly well with data from clinical trials: CRYSTAL, OPUS, and CELIM.