Updated exploratory results from the TOPAZ-1 Phase III trial showed AstraZeneca's Imfinzi (durvalumab) in combination with standard-of-care chemotherapy demonstrated a clinically meaningful long-term overall survival (OS) benefit at three years for patients with advanced biliary tract cancer (BTC).

These results from TOPAZ-1, which are the longest survival follow-up ever reported for a global, randomised Phase III trial in this setting, will be presented on 18 April at the 2024 Cholangiocarcinoma Foundation Conference in Salt Lake City, Utah.

At more than three years (median follow-up of 41.3 months), results showed Imfinzi plus chemotherapy reduced the risk of death by 26% versus chemotherapy alone (based on a hazard ratio [HR] of 0.74; 95% confidence interval [CI], 0.63-0.87). The median OS was 12.9 months for Imfinzi plus chemotherapy versus 11.3 months for chemotherapy alone. More than twice as many patients on the Imfinzi-based regimen were alive at three years versus chemotherapy alone (14.6% versus 6.9%).

The TOPAZ-1 trial met the primary endpoint of OS in October 2021 (https://www.astrazeneca.com/media-centre/press-releases/2021/imfinzi-improved-survival-in-biliary-tract-cancer.html) at a planned interim analysis, showing that the combination reduced the risk of death by 20% versus chemotherapy alone (based on a HR of 0.80; 95% CI, 0.66-0.97; 2-sided p=0.021 at a statistical significance threshold of 0.03).

Do-Youn Oh, MD, PhD, Professor, Division of Medical Oncology, Department of Internal Medicine at Seoul National University Hospital and Seoul National University College of Medicine, and principal investigator in the trial, said: "The latest data from TOPAZ-1 show that twice as many patients with advanced biliary tract cancer were still alive at three years with durvalumab and chemotherapy, an especially meaningful advance in a setting where historically the prognosis has been poor. These results reinforce the long-term benefit of this immunotherapy-based combination as a standard of care for patients with this devastating disease."

Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said: "TOPAZ-1 raised the bar for the treatment of advanced biliary tract cancer, showing a remarkable survival benefit for Imfinzi added to chemotherapy with a well-tolerated regimen. These data represent the longest survival follow-up reported for immunotherapy in this setting, and the three-year landmark survival improvement underscores our commitment to improving long-term outcomes in gastrointestinal cancers."

Stacie Lindsey, CEO, Cholangiocarcinoma Foundation said: "AstraZeneca's longer survival data in advanced biliary tract cancer represents a meaningful milestone in that we are seeing three-year survival data for the first time for these patients. The data spurs hope that research will continue to improve outcomes for patients living with these challenging and rare cancers."

Summary of updated survival results: TOPAZ-1[i]

[][][]
OS[i,ii] Imfinzi + Chemotherapy(n=344)
chemotherapy(n=341)
Median OS (95% CI 12.9(11.6-14.1) 11.3(10.1-12.5)
in months)
HR (95% CI)[ iii] 0.74 (0.63-0.87)
OS rate at 36 14.6 (11.0-18.6) 6.9 (4.5-10.0)
months (95% CI)
(%)[iv]
i. 26 months of
additional follow
-up (data cut-off:
23 October 2023)
after the primary
analysis, with 89%
overall OS event
maturity
ii. At data cut
-off for this
analysis, median
(95% CI) follow-up
time in all
patients
calculated using
reverse Kaplan
-Meier technique
was 42.9 (39.8
-44.3) months for
Imfinzi plus
chemotherapy and
41.8 (36.7-46.2)
months for
chemotherapy
iii. HR and 95% CI
calculated using
Cox proportional
hazards model
iv. OS rates
calculated using
Kaplan-Meier
technique

Imfinzi plus chemotherapy continued to be well-tolerated, with no new safety signals observed with longer follow-up. Results showed 15.4% of patients experienced treatment-related serious adverse events with Imfinzi  plus chemotherapy versus 17.3% with chemotherapy alone.

Notes

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).[1,2] Approximately 50,000 people in the US, Europe and Japan and about 210,000 people worldwide are diagnosed with BTC each year.[3-5] These patients historically have a poor prognosis, with approximately 5% to 15% of patients with BTC surviving five years. For patients with metastatic disease, the five-year survival rate drops to less than 5%.[7]

Cholangiocarcinoma is more common in China and Thailand and is on the rise in Western countries.[1,6] Gallbladder cancer is more common in certain regions of South America, India and Japan.[8]

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.[6,8,9]

TOPAZ-1
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 adult patients with unresectable, locally 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
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.

In addition to its indications in unresectable, Stage III NSCLC and ES-SCLC, Imfinzi is currently approved in a number of countries in combination with a short course of Imjudo and chemotherapy for the treatment of metastatic NSCLC.

Imfinzi is also approved in a number of countries in combination with chemotherapy in locally advanced or metastatic biliary tract cancer and in combination with Imjudo in unresectable hepatocellular carcinoma (HCC). Imfinzi is also approved as a monotherapy in unresectable HCC in Japan and the EU and in previously treated patients with advanced bladder cancer in a small number of countries.

Since the first approval in May 2017, more than 220,000 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 SCLC, NSCLC, bladder cancer, breast cancer, several gastrointestinal cancers and other solid tumours.

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.[10]

Within this programme, the Company is committed to improving outcomes in gastric, liver, biliary tract, oesophageal, pancreatic and colorectal cancers.

In addition to its indications in BTC and HCC, Imfinzi is being assessed in combinations, including with Imjudo, in liver, oesophageal and gastric cancers in an extensive development programme spanning early to late-stage disease across settings.

The Company is also assessing rilvegostomig (AZD2936), a PD-1/TIGIT bispecific antibody, in combination with chemotherapy as an adjuvant therapy in biliary tract cancer.

Enhertu (trastuzumab deruxtecan), a HER2-directed antibody drug conjugate, is approved in the US and several other countries for HER2-positive advanced gastric cancer and is being assessed in colorectal cancer. It also has been assessed in multiple GI settings including biliary tract cancer in the DESTINY-PanTumor02 Phase II trial, and it was recently approved in the US for the treatment of unresectable or metastatic HER2-positive solid tumours who have received prior systemic treatment and have no satisfactory alternative treatment options. Enhertu is jointly developed and commercialised by AstraZeneca and Daiichi Sankyo.

Lynparza (olaparib), a first-in-class PARP inhibitor, is approved in the US and several other countries for the treatment of BRCA-mutated metastatic pancreatic cancer. Lynparza is developed and commercialised in collaboration with MSD (Merck & Co., Inc. inside the US and Canada).

AstraZeneca is advancing multiple modalities that provide complementary mechanisms for targeting Claudin 18.2, a promising therapeutic target in gastric cancer. These include AZD0901, a potential first-in-class antibody drug conjugate licensed from KYM Biosciences Inc., currently in Phase II development, AZD5863, a novel Claudin 18.2/CD3 T-cell engager bispecific antibody licensed from Harbour Biomed in Phase I development, and AZD6422, an armoured autologous chimeric antigen receptor T-cell (CAR-T) therapy, currently being evaluated in an Investigator Initiated Trial (IIT) in collaboration with AbelZeta in China. 

In early development, AstraZeneca is developing two Glypican 3 (GPC3) armoured CAR-Ts in HCC. AZD5851, currently in Phase I development, is being developed globally, and C-CAR031 / AZD7003 is being co-developed with AbelZeta in China where it is under evaluation in an IIT. 

AstraZeneca in immuno-oncology (IO)
AstraZeneca is a pioneer in introducing the concept of immunotherapy into dedicated clinical areas of high unmet medical need. The Company has a comprehensive and diverse IO portfolio and pipeline anchored in immunotherapies designed to overcome evasion of the anti-tumour immune response and stimulate the body's immune system to attack tumours.

AstraZeneca strives to redefine cancer care and help transform outcomes for patients with Imfinzi as a monotherapy and in combination with Imjudo as well as other novel immunotherapies and modalities. The Company is also investigating next-generation immunotherapies like bispecific antibodies and therapeutics that harness different aspects of immunity to target cancer, including cell therapy and T cell engagers.

AstraZeneca is pursuing an innovative clinical strategy to bring IO-based therapies that deliver long-term survival to new settings across a wide range of cancer types. The Company is focused on exploring novel combination approaches to help prevent treatment resistance and drive longer immune responses. With an extensive clinical programme, the Company also champions the use of IO treatment in earlier disease stages, where there is the greatest potential for cure.

AstraZeneca in oncology
AstraZeneca is leading a revolution in oncology with the ambition to provide cures for cancer in every form, following the science to understand cancer and all its complexities to discover, develop and deliver life-changing medicines to patients.

The Company's focus is on some of the most challenging cancers. It is through persistent innovation that AstraZeneca has built one of the most diverse portfolios and pipelines in the industry, with the potential to catalyse changes in the practice of medicine and transform the patient experience.

AstraZeneca has the vision to redefine cancer care and, one day, eliminate cancer as a cause of death.

AstraZeneca
AstraZeneca (LSE/STO/Nasdaq: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development, and commercialisation of prescription medicines in Oncology, Rare Diseases, and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide. Please visit astrazeneca.com (http://www.astrazeneca.com/) and follow the Company on social media @AstraZeneca (https://www.linkedin.com/company/astrazeneca).

Contacts
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References

1. Marcano-Bonilla L, et al. Biliary tract cancers: epidemiology, molecular pathogenesis and genetic risk associations. CCO. 2016;5(5).
2. ESMO. What is Biliary Tract Cancer. Available at: https://www.esmo.org/content/download/266801/5310983/1/EN-Biliary-Tract-Cancer-Guide-for-Patients.pdf. Accessed March 2024.
3. Siegel RL. Cancer statistics, 2020. CA Cancer J Clin. 2020;70:7-30.
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5. Kohei Nakachi, et al. Hepatobiliary and Pancreatic Oncology Group of the Japan Clinical Oncology Group, A randomized Phase III trial of adjuvant S-1 therapy vs. observation alone in resected biliary tract cancer: Japan Clinical Oncology Group Study (JCOG1202, ASCOT), Japanese Journal of Clinical Oncology. 2018,48:392-395.
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