AstraZeneca (AZ) has shared positive post-hoc results from late-stage study of its Imfinzi (durvalumab) perioperative regimen in muscle-invasive bladder cancer (MIBC).
The phase 3 NIAGARA trial randomised 1,063 MIBC patients to receive Imfinzi plus neoadjuvant chemotherapy prior to bladder removal surgery (cystectomy) followed by Imfinzi, or neoadjuvant chemotherapy alone prior to cystectomy with no further treatment after surgery.
More than 614,000 people are diagnosed with bladder cancer globally every year, with MIBC, named for its growth into the muscle wall of the bladder, accounting for about one in four cases. Despite standard-of-care cystectomy, approximately half of MIBC patients experience disease recurrence.
AZ previously reported that the Imfinzi/chemotherapy combination demonstrated a statistically significant and clinically meaningful improvement in NIAGARA’s primary endpoint of event-free survival (EFS) and its key secondary endpoint of overall survival (OS) versus neoadjuvant chemotherapy.
The new data from an exploratory subgroup analysis of the trial presented at this year’s American Society of Clinical Oncology Genitourinary Cancers Symposium showed that AZ’s regimen reduced the risk of disease progression, recurrence, not undergoing surgery, or death by 42% in patients who achieved pathologic complete response (pCR) and by 23% in those who did not, and lowered the risk of death by 28% in patients who achieved pCR and by 16% in those who did not.
The Imfinzi combination also reduced the risk of developing distant metastases or death by 33% and the risk of death specifically due to bladder cancer by 31%, two secondary endpoints, compared to the comparator arm.
Imfinzi already holds approvals in lung cancer, biliary tract cancer, endometrial cancer and hepatocellular carcinoma.
Perioperative Imfinzi plus neoadjuvant chemotherapy was recently accepted for priority review by the US Food and Drug Administration to treat MIBC, and regulatory applications are also currently under review in the EU and several other countries based on data from NIAGARA.
Cristian Massacesi, chief medical officer and oncology chief development officer at AZ, said: “NIAGARA was the first phase 3 trial of a perioperative immunotherapy regimen in MIBC to show statistically significant and clinically meaningful improvements in EFS and OS.
“The 33% reduction in the risk of distant metastases, which are associated with a poorer prognosis, further reinforces the potential of perioperative Imfinzi to become a new standard of care in this setting.”