Phase II Study of Preoperative Treatment with External Radiotherapy Plus Panitumumab in Low‐Risk, Locally Advanced Rectal Cancer (RaP Study/STAR‐03)

Conclusion.The pCR rate (our primary endpoint), at only 10.9%, did not reach the specified level considered suitable for further testing. However, the analysis showed a good toxicity profile and compliance to concomitant administration of panitumumab and RTE in preoperative treatment of LARC. The pCR evaluation in all wild‐type RAS is ongoing.Implications for Practice.The aim of the RaP/STAR‐03 study was to evaluate the activity and safety of monoclonal antibody anti‐epidermal growth factor receptor (EGFR) panitumumab as a single agent without chemotherapy in low‐risk, locally advanced rectal cancer (LARC) preoperative treatment. Nevertheless, the use of panitumumab in combination with radiotherapy in preoperative treatment in patients with KRAS wild type and low‐risk LARC did not reach the pathologic complete response primary endpoint. This study showed a good toxicity profile and compliance to combination treatment. Further analysis of NRAS and BRAF on tissue and circulating levels of the EGFR ligands and vascular factors (soluble vascular endothelial growth factor, E‐selectin) may provide insight on the potential molecular pathways involved in the anti‐EGFR response.
Source: The Oncologist - Category: Cancer & Oncology Authors: Tags: Gastrointestinal Cancer Source Type: research