The withdrawal comes after the confirmatory phase 3 DANUBE trial missed its primary end points.
AstraZeneca has voluntarily withdrawn the FDA indication for the PD-L1 inhibitor durvalumab (Imfinzi) for use in previously treated patients with locally advanced or metastatic bladder cancer.1
Durvalumab received an accelerated approval from the FDA for this indication in May 2017 based on the single-arm phase 1/2 Study 1108.2 However, an FDA accelerated approval is contingent upon the results of a confirmatory trial, and in November 2020, AstraZeneca reported that the phase 3 DANUBE trial exploring durvalumab in frontline urothelial cancer missed its primary end points.3
“The science of immunotherapy has moved swiftly over the past few years, bringing new options to patients at an unprecedented pace. While the withdrawal in previously treated metastatic bladder cancer is disappointing, we respect the principles FDA set out when the accelerated approval pathway was founded and remain committed to bringing new and innovative options to patients. In the last three years, Imfinzi has become an important standard of care in multiple lung cancer settings, an area of considerable focus for AstraZeneca,” Dave Fredrickson, executive vice president, Oncology Business Unit, AstraZeneca, stated in a press release.
DANUBE was an open-label, multicenter, international, phase 3 trial that assessed durvalumab alone or in combination with the CTLA-4 inhibitor tremelimumab compared with cisplatin/gemcitabine or gemcitabine/carboplatin in the frontline setting for patients with either cisplatin-eligible or -ineligible, unresectable, metastatic urothelial cancer. Patients who were eligible for enrollment included those with transitional cell carcinoma of the urothelium, including renal pelvis, ureters, urinary bladder, and urethra.
Overall, 1126 patients were randomized in a 1:1:1 ratio to receive durvalumab monotherapy, durvalumab plus tremelimumab, or chemotherapy. Patients were treated until disease progression, unacceptable toxicity, or withdrawal of consent. The study was conducted at 220 centers across 24 countries, including those in the United States, Canada, Europe, South America, Asia, Australia, and the Middle East. The primary end points were overall survival (OS) in PD-L1-high patients who received single-agent durvalumab, as well as OS in patients treated with the combination of durvalumab plus tremelimumab, regardless of PD-L1 status.
The phase 1/2 Study 1108, on which durvalumab’s accelerated approval was based, included 182 patients with locally advanced or metastatic urothelial carcinoma who experienced disease progression following platinum-containing chemotherapy. Data reported at the time of the approval showed that the objective response rate (ORR) per blinded independent central review was 17.0%. At the data cutoff, the median duration of response was not reached (range, 0.9+ to 19.9+ months). Among 95 patients with high PD-L1 expression, the ORR was 26.3%. In the cohort of 73 patients with low or no PD-L1 expression, the ORR was 4.1%.
Durvalumab currently has FDA-approved indications for non–small cell lung cancer and small cell lung cancer.
1. Voluntary withdrawal of Imfinzi indication in advanced bladder cancer in the US. Posted online February 22, 2021. Accessed February 22, 2021. https://bit.ly/2ZGXCDw
2. Durvalumab (Imfinzi). FDA. Posted May 1, 2017. https://bit.ly/3nG6MKp. Accessed February 22, 2021.
3. Update on Phase III DANUBE trial for Imfinzi and tremelimumab in unresectable, Stage IV bladder cancer [news release]: AstraZeneca. Published March 6, 2020. https://bit.ly/3cFFeAu. Accessed February 22, 2021.