Imfinzi Approved in US as First Perioperative Immunotherapy for Muscle-Invasive Bladder Cancer

AstraZeneca's innovative cancer treatment, Imfinzi (durvalumab), combined with gemcitabine and cisplatin as a neoadjuvant therapy, has gained approval from the US Food and Drug Administration (FDA) for treating adult patients with muscle-invasive bladder cancer (MIBC). This approval follows the promising results of the NIAGARA Phase III trial, presented at the 2024 European Society for Medical Oncology (ESMO) Congress and published in The New England Journal of Medicine.

MIBC is a serious form of bladder cancer where the tumor invades the muscle wall of the bladder but hasn't spread to distant body parts. The standard treatment approach includes neoadjuvant chemotherapy followed by radical cystectomy, which involves the surgical removal of the bladder. Despite this aggressive treatment, many patients experience high recurrence rates, and the overall prognosis remains poor.

The NIAGARA Phase III trial highlighted the effectiveness of Imfinzi when used in a perioperative setting—a combination of treatments before and after surgery. Patients received four cycles of Imfinzi along with neoadjuvant chemotherapy before undergoing radical cystectomy. This was followed by eight cycles of Imfinzi as an adjuvant monotherapy. The trial's results were encouraging, showing a 32% reduction in disease progression, recurrence, lack of surgery, or death compared to the control group. The hazard ratio for event-free survival (EFS) was 0.68, with an estimated 67.8% of patients in the Imfinzi group being event-free at two years versus 59.8% in the comparator group.

Additionally, the study revealed a 25% reduction in the risk of death with the Imfinzi regimen compared to the control group. Two-year survival rates were also higher in the Imfinzi group, with 82.2% of patients alive versus 75.2% in the standard treatment group. The therapy was generally well tolerated, with no surprising safety concerns, and adverse events were manageable and mostly low-grade.

In February 2025, this new regimen was incorporated into the National Comprehensive Cancer Network (NCCN) Clinical Practical Guidelines in Oncology as a recommended treatment for MIBC, reflecting the robust evidence from the NIAGARA trial. Beyond the US, Imfinzi has received approval in Brazil for this indication, and regulatory reviews are underway in the European Union, Japan, and several other countries.

Bladder cancer ranks as the ninth most common cancer globally, with over 614,000 new cases annually. Urothelial carcinoma is the predominant type, originating in the urinary tract's urothelial cells. Approximately half of the patients undergoing bladder removal experience disease recurrence, underscoring the urgent need for effective post-surgery treatment options.

The NIAGARA trial is a significant milestone as it is the largest global Phase III trial for MIBC, involving 1,063 patients across 192 centers in 22 countries. It evaluated the dual primary endpoints of EFS and pathologic complete response at cystectomy, along with secondary endpoints such as overall survival and safety.

Imfinzi works as a human monoclonal antibody targeting the PD-L1 protein, disrupting its interaction with PD-1 and CD80 proteins. This mechanism helps counteract the tumor's immune evasion strategies and stimulates a stronger immune response against cancer. Imfinzi's approval for MIBC adds to its list of indications across various cancers, including non-small cell lung cancer, small cell lung cancer, biliary tract cancer, and hepatocellular carcinoma.

AstraZeneca continues to push the boundaries of cancer treatment through its commitment to immuno-oncology, aiming to transform patient outcomes and redefine the standard of care.