Is Imfinzi Effective for Biliary Tract Cancer? (TOPAZ-1 Trial)

On January 18, 2022, AstraZeneca announced the results of the TOPAZ-1 Phase 3 clinical trial. The study evaluated the efficacy and safety of Imfinzi (durvalumab), an anti-PD-L1 antibody, in combination with standard chemotherapy as a first-line treatment for patients with unresectable advanced or metastatic biliary tract cancer (BTC).

Study Design: TOPAZ-1 Phase 3 Trial

TOPAZ-1 is an international, multi-center, double-blind, randomized Phase 3 trial. It included 685 patients with unresectable advanced or metastatic BTC (including intrahepatic and extrahepatic cholangiocarcinoma and gallbladder cancer). Patients were randomized into two groups:

1. Imfinzi Group: Imfinzi + Standard Chemotherapy (Gemcitabine and Cisplatin) (N=341)
2. Placebo Group: Placebo + Standard Chemotherapy (N=344)

The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and safety.

Key Survival Results

Overall Survival (OS)

• Median OS: 12.8 months for the Imfinzi group vs. 11.5 months for the placebo group.
• The Imfinzi combination reduced the risk of death by 20% (Hazard Ratio [HR] = 0.80).
• 18-Month OS Rate: 35.1% (Imfinzi) vs. 25.6% (Placebo).
• 24-Month OS Rate: 24.9% (Imfinzi) vs. 10.4% (Placebo).

Progression-Free Survival (PFS)

• Median PFS: 7.2 months (Imfinzi) vs. 5.7 months (Placebo).
• The risk of disease progression or death was reduced by 20% in the Imfinzi group.

Objective Response Rate (ORR)

• ORR: 26.7% for the Imfinzi group vs. 18.7% for the placebo group.

Safety Profile

The incidence of Grade 3 or 4 adverse events was similar between the two groups: 62.7% in the Imfinzi group and 64.9% in the placebo group. Discontinuation of treatment due to adverse events occurred in 8.9% of patients in the Imfinzi group and 11.4% in the placebo group.

Conclusion

Dr. Do-Youn Oh from Seoul National University Hospital noted that there had been no significant progress in treating advanced biliary tract cancer for over a decade. The TOPAZ-1 trial demonstrates that Imfinzi plus chemotherapy significantly improves overall survival with a favorable safety profile, establishing this combination as a potential new standard of care for advanced BTC.

Source: AstraZeneca Press Release - TOPAZ-1 Results

#BiliaryTractCancer #Cholangiocarcinoma #Imfinzi #Durvalumab #TOPAZ1 #CancerResearch

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