AstraZeneca plc (LON:AZN) supplemental Biologics License Application (sBLA) for Imfinzi (durvalumab), in combination with standard-of-care chemotherapy, has been accepted and granted Priority Review in the US for patients with locally advanced or metastatic biliary tract cancer (BTC).
The Food and Drug Administration (FDA) grants Priority Review to applications for medicines that, if approved, would offer significant improvements over available options by demonstrating safety or efficacy improvements, preventing serious conditions, or enhancing patient compliance.1 The Prescription Drug User Fee Act date, the FDA action date for their regulatory decision, is during the third quarter of 2022.
BTC is a group of rare and aggressive cancers that occur in the bile ducts and gallbladder. 2,3 Approximately 23,000 people in the US are diagnosed with BTC each year.2 These patients have a poor prognosis, with approximately 5% to 15% of patients with BTC surviving five years.4
Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said: “People with advanced biliary tract cancer have faced poor outcomes and limited treatment options for too long, and today’s news for the TOPAZ-1 trial underscores the urgency to deliver new, effective therapies in this setting. We are working closely with the FDA to bring the first immunotherapy-based option to patients with this devastating cancer and potentially set a new standard of care with Imfinzi plus chemotherapy.”
The sBLA was based on results from an interim analysis of the TOPAZ-1 Phase III trial presented during the 2022 American Society of Clinical Oncology Gastrointestinal Cancers (ASCO GI) Symposium. The data showed Imfinzi plus chemotherapy (gemcitabine plus cisplatin) reduced the risk of death by 20% versus chemotherapy alone (based on a hazard ratio [HR] of 0.80; 95% confidence interval [CI], 0.66-0.97; 2-sided p=0.021). An estimated one in four (25%) patients treated with Imfinzi plus chemotherapy were alive at two years compared to one in 10 (10%) treated with chemotherapy alone.
Results also showed a statistically significant 25% reduction in the risk of disease progression or death with Imfinzi plus chemotherapy (HR, 0.75; 95% CI, 0.64-0.89; 2-sided p=0.001). The Imfinzi combination was generally well tolerated and did not increase the discontinuation rate due to adverse events compared to chemotherapy alone.
In December 2020, Imfinzi was granted Orphan Drug Designation in the US for the treatment of BTC.
Biliary tract cancer
Biliary tract cancer (BTC) is a group of rare and aggressive gastrointestinal (GI) cancers that form in the cells of the bile ducts (cholangiocarcinoma), gallbladder or ampulla of Vater (where the bile duct and pancreatic duct connect to the small intestine).2,3
Cholangiocarcinoma is more common in China and South-East Asia and is on the rise in Western countries.2,4 Gallbladder cancer is more common in certain regions of South America, India and Japan.5
Early-stage BTC affecting the bile ducts and gallbladder often presents without clear symptoms and most new cases of BTC are therefore diagnosed at an advanced stage, when treatment options are limited and the prognosis is poor.4-6
TOPAZ-1 is a randomised, double-blind, placebo controlled, multicentre, global Phase III trial of Imfinzi in combination with chemotherapy (gemcitabine plus cisplatin) versus placebo in combination with chemotherapy as a 1st-line treatment in 685 patients with unresectable advanced or metastatic BTC including intrahepatic and extrahepatic cholangiocarcinoma, and gallbladder cancer. Patients with ampullary carcinoma were excluded.
The primary endpoint is overall survival and key secondary endpoints included progression-free survival, objective response rate and safety. The trial was conducted in 105 centres across 17 countries including in the US, Europe, South America and several countries in Asia including South Korea, Thailand, Japan and China.
Imfinzi (durvalumab) is a human monoclonal antibody that binds to the PD-L1 protein and blocks the interaction of PD-L1 with the PD-1 and CD80 proteins, countering the tumour’s immune-evading tactics and releasing the inhibition of immune responses.
Imfinzi is the only approved immunotherapy in the curative-intent setting of unresectable, Stage III non-small cell lung cancer (NSCLC) in patients whose disease has not progressed after chemoradiotherapy, and is the global standard of care in this setting based on the PACIFIC Phase III trial.
Imfinzi is also approved in the US, EU, Japan, China and many other countries around the world for the treatment of extensive-stage small cell lung cancer (ES-SCLC) based on the CASPIAN Phase III trial. In 2021, updated results from the CASPIAN trial showed Imfinzi plus chemotherapy tripled patient survival at three years versus chemotherapy alone.
Imfinzi is also approved for previously treated patients with advanced bladder cancer in several countries.
Since the first approval in May 2017, more than 100,000 patients have been treated with Imfinzi.
As part of a broad development programme, Imfinzi is being tested as a single treatment and in combinations with other anti-cancer treatments for patients with small cell lung cancer (SCLC), NSCLC, bladder cancer, several GI cancers, ovarian cancer, endometrial cancer, and other solid tumours.
In the past year, Imfinzi combinations have demonstrated clinical benefit in multiple additional cancer settings with positive Phase III trials in unresectable advanced liver cancer (HIMALAYA) and metastatic NSCLC (POSEIDON).
AstraZeneca in GI cancers
AstraZeneca has a broad development programme for the treatment of GI cancers across several medicines and a variety of tumour types and stages of disease. In 2020, GI cancers collectively represented approximately 5.1 million new cancer cases leading to approximately 3.6 million deaths.6
Within this programme, the Company is committed to improving outcomes in gastric, liver, BTC, oesophageal, pancreatic, and colorectal cancers.
Imfinzi is being assessed in combinations in liver, BTC, oesophageal and gastric cancers in an extensive development programme spanning early to late-stage disease.
The Company aims to understand the potential of Enhertu (trastuzumab deruxtecan), a HER2-directed antibody drug conjugate, in the two most common GI cancers, colorectal and gastric cancers. Enhertu is jointly developed and commercialised by AstraZeneca and Daiichi Sankyo.
Lynparza (olaparib) is a first-in-class PARP inhibitor with a broad and advanced clinical trial programme across multiple GI tumour types including pancreatic and colorectal cancers. Lynparza is developed and commercialised in collaboration with MSD (Merck & Co., Inc. inside the US and Canada).