The U.S. Food and Drug Administration (FDA) has approved AstraZeneca's immuno-cancer drug Imfinzi (Durvalumab) as a treatment for advanced biliary tract cancer. In other words, it opens the way for immuno-cancer drugs to be administered by adding immuno-cancer drugs to general anticancer drugs such as gemcitabin and cisplatin, which are used as the first standard treatment for advanced biliary tract cancer patients.
 

The background of this approval was the Phase 3 clinical trial of TOPAZ-1 . The TOPAZ-1 study compared the effectiveness of standard chemotherapy (gemsitabin and cisplatin) and a combination therapy with impinge added to standard chemotherapy in 685 patients with advanced biliary tract cancer, and the mean age of enrolled patients was 64 years and 56% of all patients were Asian. The study found that the median survival time of the combined therapy group with impinge was 12.8 months, and that of the group with only standard chemotherapy was 11.5 months. Statistically, the addition of impinge to standard chemotherapy has been shown to reduce the risk of death by about 20% in patients with advanced biliary tract cancer. Characteristically, the improvement in survival becomes apparent over time by adding impinge. The difference in the one-year survival rate of the study subjects was only 6.1% in the two groups, but the two-year survival rate was a significant difference of 14.5%. Even in the actual survival analysis, the difference in survival rates between the two groups was identified in earnest after 6 months of administration.
 

In terms of the tumor size reduction effect, the combination therapy with impinge added to standard chemotherapy was more effective than conventional treatment. Among patients who received combination therapy with impinge added to standard chemotherapy, 26.7% showed decreased tumor size (18.7% in standard treatment group). The duration of inhibiting tumor progression was also 7.2 months versus 5.7 months, showing a significant difference between the two groups. 12.7% of patients who added impinge to standard chemotherapy suffered immune anticancer drug-related side effects, but only 2.4% had severe side effects of grade 3 or higher.
 

The TOPAZ-1 study is meaningful as a global clinical study that has shown that the addition of immuno-cancer drugs to existing chemotherapy can extend the survival of biliary tract cancer patients. Based on the results of this study and the approval of the U.S. Food and Drug Administration, the combination therapy of dervalumab, gemcitabin, and cisplatin has become a new standard treatment for advanced biliary tract cancer.