Weekly Cetuximab/RT Versus Weekly Cisplatin/RT in HPV-Associated Oropharyngeal Squamous Cell Carcinoma

Overview

A standard treatment for patients with head and neck cancer is radiation given with high doses of a chemotherapy drug called cisplatin, given every 3 weeks during the radiation. This treatment is effective but can significantly increase side effects such as difficulty with swallowing, a sore mouth, fatigue, hearing loss, ringing in the ears and kidney failure. In Australia, a commonly used treatment HPV-Associated Oropharyngeal Squamous Cell Carcinoma is a lower dose of cisplatin given weekly during the radiation. The high dose and low dose schedules result in a similar total dose of cisplatin being given during the radiation, but it is thought that the weekly schedule results in fewer side effects while maintaining effectiveness. Another approach widely used around the world for patients with head and neck cancer, is to administer the antibody, cetuximab, weekly during radiation. Cetuximab has a very different side effect profile to cisplatin, and has been reported to result in less exacerbation of radiation related side effects. Both cetuximab and cisplatin can reduce the growth of a cancer and increase the effectiveness of radiation. Both cisplatin and cetuximab appear to be effective treatments in combination with radiation, but have not been directly compared. The purpose of this study is to compare the treatment related side effects (both acute and longer term) between the cisplatin and cetuximab regimens. Both treatments would be given with the same dose of radiation therapy over 7 weeks. The results of this trial will help determine the optimal treatment for patients with HPV-Associated Oropharyngeal Squamous Cell Carcinoma.

Human Papilloma Virus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is increasing in incidence and has an improved prognosis compared to other head and neck malignancies when treated with standard combination chemoradiation. The current standard regimen of high dose cisplatin and Radiation Therapy (RT) for head and neck cancer patients results in significant toxicity and is at the limits of tolerance. The excellent prognosis of patients with HPV-positive OPSCC raises concerns about overtreatment with the current standard of care, resulting in unnecessary acute and late morbidity. Therefore, investigation of chemo-sparing or chemo-modified regimens with RT for HPV-associated OPSCC that do not compromise efficacy is warranted. A number of regimens less intensive than high dose cisplatin are being used in clinical practice for patients with good prognosis HPV OPSCC, but no comparative trials have been performed in this population. The trial population will be restricted to low risk HPV-associated OPSCC. Trial Arms: A- RT (70 Gy in 35 fractions, 5 days a week over 7 weeks) with weekly Cetuximab (400 mg/m2 loading dose IV prior to radiation, followed by weekly cetuximab 250 mg/m2 for the duration of the radiotherapy) B- RT(70 Gy in 35 fractions, 5 days a week over 7 weeks) with weekly Cisplatin (40 mg/m2 IV for the duration of the radiotherapy) Hypothesis: In patients with locally advanced HPV-associated OPSCC, those treated with weekly cetuximab and conventionally fractionated radiotherapy will experience less acute symptom severity than patients receiving weekly cisplatin and conventionally fractionated radiotherapy. Patients will be followed weekly during treatment, then at 1, 3, 5, 9, 13 weeks post-treatment and at months 6, 9, 12, 15, 18, 21, 24, 28, 32, 36, 42, 48, 54, and 60 post-completion of treatment. Follow-up for the trial will cease when the last patient accrued has a minimum of 2 years follow-up i.e. has attended the 24 months post-treatment review.