Utidelone Injection; capecitabine
Drug8 patients will be assigned to utidelone plus capecitabine arm receiving utidelone plus capecitabine. Utidelone injection 30mg/m2/day, intravenously administered once a day for 5 consecutive days; capecitabine tablets, 1000mg/m2, orally, 2 times a day for 14 consecutive days. 21 days is a cycle