Long-term response in patient with recurrent oropharyngeal carcinoma treated with cetuximab, docetaxel and cisplatin (TPEx) as first-line treatment followed by cetuximab maintenance

Background: Cetuximab, an anti-EGFR monoclonal antibody in combination with platinum and 5FU is the standard of care in first-line treatment of patients with recurrent head and neck squamous cell carcinoma (HNSCC), with an expected median outcome of 10months. For this population, development of efficacious and safer therapies is still needed.

Case report: A 62-year-old male with a first recurrence of human papillomavirus positive stage IVA (T3N2bM0) adenocarcinoma of the glossotonsillar sulcus not amenable to locoregional curative treatment was offered chemotherapy as part of the TPEx clinical trial. He was treated by cetuximab (loading dose 400mg/m² on day 1 cycle 1, then 250mg/m² weekly), and chemotherapy (cisplatin 75mg/m² and docetaxel 75mg/m², on day 1). Cycles were repeated every 21days for 4 cycles (TPEx regimen) with systematic granulocyte colony-stimulating factor support at each cycle. Bi-monthly maintenance cetuximab 500mg/m² was then administered. The patient showed a clinical complete response according to RECIST 1.1 criteria after 5months maintenance, with progression-free survival of 25months. Relapses that followed were treated with stereotactic irradiation, radiofrequency ablation, cetuximab and paclitaxel. The patient is alive eleven years after cancer diagnosis and remains controlled for his disease, with a cumulative period of 59months of cetuximab administration (equivalence of 121 injections).

Conclusion: This case report demonstrated that TPEx regimen, by synergistic interaction between taxanes and cetuximab, followed by bimonthly cetuximab maintenance may lead to patient complete remission within the first year of treatment. Furthermore, prolonged intermittent treatment with cetuximab seems to participate in the improved survival associated with preserved quality of life. Key favorable prognostic factors may be moderate tumor differentiation, oropharyngeal location, HPV p16 positive tumor status.