665TiP - Use of panitumumab in patients with recurrent or progressive colorectal cancer - an interim analysis of the VECTIS study

Date 01 October 2012
Event ESMO Congress 2012
Session Poster presentation III
Topics Anti-Cancer Agents & Biologic Therapy
Colon Cancer
Rectal Cancer
Presenter Radek Lakomy
Authors R. Lakomy1, W. Rogowski2, B. Pikó3, C. Andras4, E. Molnar5
  • 1Masaryk Memorial Cancer Institute, 65653 - Brno/CZ
  • 2Department Of Oncology, ZOZ MSWiA z Warmińsko Mazurskim Centrum Onkologii, Olsztyn/PL
  • 3Dep. Of Clinical Oncology, 3Pándy Kálmán County Hospital, Center of Oncology, Gyula, Gyula/HU
  • 4Dpt. Of Clinical Oncology, 4Medical University, Dpt. of Oncology, Debrecen, Debrecen/HU
  • 5Medical, Amgen, Budapest/HU

Abstract

Registry Number

20080618

Background

Panitumumab (Pmab; Vectibix®) is a fully human monoclonal antibody, which binds specifically to the human epidermal growth factor receptor (EGFr). Skin toxicity (ST), a pharmacological effect observed with EGFr inhibitors, appears in almost all patients (pts) treated with Pmab and is usually mild to moderate in severity. The VECTIS study was designed to determine the safety and efficacy of Pmab as monotherapy in daily practice with special reference to ST and its management.

Methods

This is an open-label, prospective, non-interventional study collecting data from pts from CEE countries, aged ≥18 years, who have EGFr expressing mCRC with wild type KRAS gene tumour status receiving Pmab monotherapy (6 mg/kg Q2W) after failure of chemotherapy regimens containing 5-FU, oxaliplatin and irinotecan. This interim analysis includes the data collected between 12/2008 and 06/2011 from pts in Hungary, Poland, and the CzechRepublic. The observation period was limited to 18 cycles.

Results

At the time of reporting, 177/205 (86.3%) enrolled pts have experienced a total of 266 ST events with an incidence rate (IR) (events per pt per year) of 3.47 (95% confidence interval [CI] = 3.07, 3.91); 15 pts experienced Grade 3 ST with an IR of 0.20 (95% CI = 0.11, 0.32) and no pts had ST Grade ≥4. Of the recorded ST events, 25.9% have resolved; 3.4% have resolved with consequences; 19.9% continue but are improving; and 50.8% have not resolved. Overall, 69.8% of pts required therapeutic measures for ST. Four serious Adverse Drug Reactions (ADRs) were reported. Of 6 deaths that occurred, none was related to Pmab. Four pts have stopped Pmab therapy due to ADRs including ST or other toxicity.

Overall (N = 205) % (95% CI) ST Grade ≥ 2 (N = 112) % (95% CI)
Tumor response 26.8 (20.9, 33.4) 30.4 (22.0, 39.8)
Disease control rate 67.8 (60.9, 74.1) 70.5 (61.2, 78.8)
Free from progression (18 cycles) 12.7 (8.5, 18.0) 13.4 (7.7, 21.1)

A statistically significant positive correlation was observed between severity of ST and the best response (r = 0.13) as well as tumor response (r = 0.15).

Conclusion

In clinical practice, Pmab monotherapy appears to be well tolerated and effective in pts who have heavily pre-treated mCRC with wild-type KRAS status. This study is sponsored by Amgen GmbH CEE Headquarters.

Disclosure

R. Lakomy: Vectis study.

W. Rogowski: Vectis study, Pegfilgrastim study.

B. Pikó: Vectis study, Pegfilgrastim study.

C. András: Vectis study, Pegfilgrastim study, Amgen sponsored scientific event speaker.

E. Molnar: employment possition Amgen, stock