In the Phase I trial, 41 patients were treated with various doses of CetuGEX™ to evaluate the safety and tolerability profile of this novel compound and to define the recommended Phase II dosing regimen. Secondary endpoints included the preliminary evaluation of anti-tumor activity of CetuGEX™. In conclusion, CetuGEX™ was well tolerated with a favourable side-effect profile clearly lower than those observed with other EGFR-targeting molecules and showed clear signs of therapeutic activity as a single agent.

Activity was seen over all dose levels, with a clinical benefit rate of 76% (19/25) in the per protocol population in this single agent study. All patients were progressive upon inclusion into the study and heavily pre-treated with 78% having received three or more prior chemotherapies.

Four major clinical and RECIST responses were observed besides long lasting disease stabilization, including two complete and two partial responders in non-small cell lung cancer (NSCLC), metastatic colorectal cancer, esophageal and gastric cancer. All responders show continuing sustained responses and hence are still under treatment, with the longest duration of over 18 months (Complete Responder stage IV NSCLC).

Additional 15 patients achieved sustained stable disease lasting from eight weeks to over 14 months. CetuGEX™ showed a favourable side-effect profile with few occurrence and low grades of EGFR-typical toxicities, including acneiform skin rashes in 25% of patients and no skin reactions of grade 3 or higher as well as ≤10% low grades of digestion track toxicities. Infusion reactions were restricted to the first infusions only and occurred in 57% with the final dosing schedule. Pharmacokinetic data allow weekly or two-weekly administration schedules. Clinical trial information: NCT01222637.

Prof. Dr. Walter Fiedler from University Hospital Hamburg-Eppendorf, who presented the results of the study, concluded his presentation saying, that CetuGEX™ showed high tolerability and clear signs of anti-cancer activity as a single agent and should be further developed in Phase II. Steven R. Alberts, M.D., from Mayo Clinic in Rochester, the discussant of the study, highlighted the activity in heavily pretreated cancer patients and concluded that CetuGEX™ results suggest a more tolerable EGFR antibody which he recommended to develop further in clinic studies.