Clinical and Biological Interest of Taxanes in Advanced Squamous Cell Anal Carcinoma

Overview

Squamous cell carcinoma of the anal canal (SCCA) is a rare disease and mostly diagnosed at an early stage. After standard concurrent chemoradiation (CRT) with mitomycin (MMC) and 5-fluorouracil (5FU), the disease will recur in 20% of patients. After treatment failure (including salvage surgery), cisplatin-5FU combination is the standard option but complete response is a rare event and the prognosis remains poor with most patients' death occurring in the first 12 months. Decision making for physicians in this setting is only based on retrospective studies or small phase II clinical trials including less than 20 patients. Hence, no efficient standard of care is currently available for relapsing SCCA patients who are currently treated with a palliative intent. Between 2007 and 2013, 8 consecutive patients with advanced recurrent SCCA after CRT were treated with DCF regimen (docetaxel, cisplatin and 5-fluorouracil) in the Regional Cancer Institute of Franche Comté. After a median follow-up of 41 months, 4 patients (50%) achieved a complete response. Three patients underwent surgery of all involved metastatic sites. A pathological complete response was observed for all of them including in metastases occurring in irradiated fields, suggesting that taxane-based chemotherapy might be an effective strategy to circumvent resistance to radiotherapy (a preliminary cohort of 8 patients was published (Kim S et al Annals of oncology 2013). Furthermore, all complete responders were HPV 16, and high levels of specific T cell responses against Human Papillomavirus (HPV) HPV16-derived E6/E7 and telomerase were detected in 50% of complete responders suggesting the potential restoration of cancer immunosurveillance by this regimen. Then, the Epitopes-HPV02 multicenter phase II study will aim to confirm the new role of taxane-based chemotherapy in SCCA patients.

Epitopes-HPV02 study is a national multicenter open label phase II trial including 66 patients. Patients will receive 6 cycles of DCF regimen (docetaxel 75 mg/m2 day, CDDP 75 mg/m2 and 5FU at 750 mg/m2/day for 5 days) every 3 weeks or 8 cycles of modified-DCF regimen (docetaxel 40 mg/m2 day, CDDP 40 mg/m2 day and 5-FU at 1200 mg/m2/day for 2 days) every 2 weeks, according to their clinical status. CT scan will be planned at baseline, after 3 and after 6 cycles of DCF regimen (or after 4 and 8 cycles of modified-DCF regimen) and then every three months until disease progression or death. A Pet-scan will be performed before and after 6 cycles of DCF. Tumor assessment will be carried out according to RECIST V1.1 criteria. This study is carried out by the University Hospital of Besançon and were approved by the independent Est-II French Committee for Protection of Persons (CPP) and by the French Health Products Safety Agency (ANSM). This study will be conducted in 17 clinical centers in France.