Trial Information

A Phase II Study of Docetaxel and S-1 as First-line Chemotherapy in Patients With Advanced Esophageal Cancer

Esophageal cancer is the ninth most common cancer in male population in Korea. It was
estimated that 1,864 new cases of esophageal cancer were reported and 1,434 deaths occurred
in Korea in 2005.

Although half of the patients with esophageal cancer initially present with locoregional
disease amenable to radical surgery or radiation-based therapy, most patients eventually
develop metastatic disease with or without local recurrence.

Chemotherapy plays a major role in palliative therapy and remains to be the primary mode of
treatment for the recurrent or metastatic esophageal cancer. Although various chemotherapy
regimens are available, esophageal cancer carries a very poor prognosis, with a mean
survival time of less than 8.1 months with current chemotherapies used singly or in
combination with 5-fluorouracil (5-FU), vindesine, mitomycin, docetaxel, paclitaxel,
cisplatin, irinotecan, vinorelbine, or capecitabine. The majority of the trials performed
were in small numbers of patients with reported response rates from 15 to 40%.

The response was usually of short duration and there was no survival benefit with single
agent chemotherapy. Combination chemotherapy has slightly improved the results in terms of
duration of response (3-6 months), but still there was little improvement in overall
survival. Therefore, the identification of new active agents is essential to prolong the
survival.

Clinical trials of single agent docetaxel have been reported in patients with esophageal
cancer and the response rate is about 18-25%.

S-1, a new biochemical modulator of 5-FU, is an oral dihydropyrimidine dehydrogenase(DPD)
inhibitory fluoropyrimidine. The advantages of S-1 compared with 5-FU are greater
convenience because of its oral formulation and continuous delivery, without intravenous
infusion. S-1 is frequently used as a substitute for 5-FU in gastric cancer, but limited
data is available for esophageal cancer.

The combination of docetaxel and S-1 is highly active and well tolerated in advanced or
recurrent gastric cancer, and the synergistic antitumor activity has been fully elucidated.

Therefore, we will evaluate the efficacy of docetaxel and S-1 combination chemotherapy in
Korean patients with esophageal cancer.