Citation: European Journal of Cancer Supplements, Vol 7 No 2, September 2009, Page 476

A. Fortin¹, A. Cmelak², R. Mesía³, H. Minn⁴, A.T.C. Chan⁵, A.C. Yunes⁶, M.C. Merlano⁷, S. Singh⁸, M. Smitt⁹, M. Henke<sup>10

1</sup>L'Hotel-Dieu de Quebec, Departement de Radiotherapie, Quebec, Canada
²Vanderbilt University Medical Center, The Vanderbilt Clinic, Nashville, USA
³Institut Catala d'Oncologia (ICO) - L'Hospitalet, Medical Oncology Department, Barcelona, Spain
⁴Turku University Hospital, Department of Oncology and Radiotherapy, Turku, Finland
⁵State Key Laboratory in Oncology in South China The Chinese University of Hong Kong, The Sir YK Pao Centre for Cancer, Hong Kong, China
⁶Unidad de Oncología Servicios de Salud del Estado de Puebla, Servicio de Radioterapia, Puebla, Mexico
⁷A.S.O.S. Croce E Carle, Oncologia Medica, Cuneo, Italy
⁸Sunnybrook Odette Cancer Centre, Department of Medical Oncology, Toronto, Canada
⁹Amgen Inc, Oncology, Thousand Oaks, USA
¹⁰Universitätsklinikum, Klinik für Strahlenheilkunde, Freiburg, Germany

Background: Panitumumab (pmab), a fully human monoclonal antibody against the epidermal growth factor receptor (EGFR), is indicated as monotherapy for the treatment of metastatic colorectal cancer. This ongoing study sponsored by Amgen is designed to estimate the difference in 2 year local regional control (LRC) rates in pts receiving chemoradiotherapy (CRT) alone or CRT plus panitumumab (PCRT) as first-line treatment of locally advanced SCCHN (ClinicalTrials.gov Identifier: NCT00500760).
Methods: This is a phase 2, open-label, randomized, international, multicenter study. Eligible pts were randomized 2:3 to CRT or PCRT. CRT included radiotherapy (RT) and cisplatin (100 mg/m² – days 1, 22, and 43 of RT). PCRT included RT and pmab (9.0 mg/kg Q3W) + cisplatin (75 mg/m² Q3W), both administered on days 1, 22, and 43 of RT. Standard fractionation RT (70 Gy delivered in 2 Gy fractions for 5 days/week ×7 weeks) was planned for all pts and was delivered by either the intensity-modulated (IMRT) modality or the three-dimensional conformal (3D-CRT) modality. The primary endpoint is LRC rate at 2 years. Key secondary endpoints include PFS, OS, and safety. An external, independent data monitoring committee (DMC) conducts planned safety and efficacy reviews during the course of the trial.
Results: Pooled data from this planned interim safety analysis includes the first 54 of 150 planned pts; 50 (93%) pts are male; median (range) age is 56 (37–74) years; ECOG PS 0: 69%, PS 1: 31%; 32 (59%) pts received IMRT, and 22 (41%) pts received 3D-CRT. Forty-eight (89%) pts completed all RT, and 48 pts received RT per protocol without a major deviation. The median (range) total RT dose administered was 70 (16, 70) Gy. The most common grade ≥ 3 adverse events (AEs) graded using the CTCAE version 3.0 are shown (Table).
Conclusions: After this interim safety analysis, the DMC recommended the CONCERT-1 study continue per protocol. Enrollment into the study completed (n = 153) on 26 March 2009. Updated pooled safety data for this group will be presented.
Table: Most common grade ≥ 3 adverse events¹ – safety analysis set (n = 53)

Adverse event	Any grade n (%)	Grade 3 n (%)	Grade 4 n (%)
Mucosal inflammation	35 (66)	21 (40)	0 (0)
Radiation-induced skin injury2	34 (64)	6 (11)	1 (2)
Dysphagia	31 (58)	14 (26)	0 (0)
Stomatitis	12 (23)	6 (11)	0 (0)
Hypokalemia	10 (19)	4 (8)	0 (0)
Dehydration	7 (13)	4 (8)	0 (0)
Infection	5 (9)	5 (9)	0 (0)
1There was one grade 5 treatment-related AE of syncope; 2Any skin toxicities determined to be caused by radiation therapy.