IMFINZI® (durvalumab) regimen reduced risk of progression, recurrence or death by 29% in early-stage gastric cancer vs. chemotherapy alone in MATTERHORN Phase III trial

Associated Press

2 days ago

WILMINGTON, Del.--(BUSINESS WIRE)--Jun 1, 2025--
Positive results from the MATTERHORN Phase III trial showed perioperative treatment with AstraZeneca's IMFINZI ® (durvalumab) in combination with standard-of-care FLOT (fluorouracil, leucovorin, oxaliplatin, and docetaxel) chemotherapy demonstrated a statistically significant and clinically meaningful improvement in the primary endpoint of event-free survival (EFS) versus chemotherapy alone. Patients were treated with neoadjuvant IMFINZI in combination with chemotherapy before surgery, followed by adjuvant IMFINZI in combination with chemotherapy, then IMFINZI monotherapy. The trial evaluated this regimen versus perioperative chemotherapy alone for patients with resectable, early-stage and locally advanced (Stages II, III, IVA) gastric and gastroesophageal junction (GEJ) cancers.
These results will be presented today during the Plenary Session at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, IL (abstract #LBA5) and simultaneously published in The New England Journal of Medicine.
In a planned interim analysis, patients treated with the IMFINZI-based perioperative regimen showed a 29% reduction in the risk of disease progression, recurrence or death versus chemotherapy alone (based on an EFS hazard ratio [HR] of 0.71; 95% confidence interval [CI] 0.58-0.86; p<0.001). Estimated median EFS was not yet reached for the IMFINZI arm versus 32.8 months for the comparator arm. An estimated 78.2% of patients treated with the IMFINZI-based perioperative regimen were event-free at one year compared to 74.0% in the comparator arm; the estimated 24-month EFS rate was 67.4% versus 58.5%, respectively, signaling a greater magnitude of benefit over time for the IMFINZI-based regimen.
For the secondary endpoint of overall survival (OS), a strong trend was observed in favor of the IMFINZI-based perioperative regimen (HR=0.78; 95% CI 0.62-0.97; p=0.025). The trial will continue to follow OS, which will be formally assessed at the final analysis.
Yelena Y. Janjigian, MD, Chief Attending Physician of the Gastrointestinal Medical Oncology Service, Memorial Sloan Kettering Cancer Center, New York, and principal investigator for the trial, said: 'Despite receiving curative-intent surgery and chemotherapy, patients with gastric and gastroesophageal cancers frequently develop recurrent disease. Results from the MATTERHORN trial showed that more than two-thirds of patients treated with a durvalumab-based perioperative regimen had not experienced a recurrence or were progression-free after two years. This new treatment approach should become the new standard of care in this setting based on these results.'
Cristian Massacesi, Chief Medical Officer and Oncology Chief Development Officer, AstraZeneca, said: 'This immunotherapy-based perioperative regimen has the potential to change the clinical paradigm in early gastric and gastroesophageal junction cancers based on the reduction in risk of progression, recurrence or death by nearly a third and the strong trend towards improved survival. As the third positive trial of perioperative treatment with IMFINZI across multiple tumor types, the MATTERHORN trial further validates this approach and highlights our commitment to bringing novel therapies to early stages of disease where there is the greatest chance for cure.'
Summary of results: MATTERHORN
The safety profile for IMFINZI and FLOT chemotherapy was consistent with the known profiles of each medicine, and the percentage of patients that completed surgery was similar compared to chemotherapy alone. Grade 3 or higher adverse events due to any cause were similar between the two arms.
In a previously reported interim analysis for the key secondary endpoint of pathologic complete response (pCR), the IMFINZI - based regimen more than doubled the pCR rate compared to neoadjuvant chemotherapy alone (19% versus 7%, odds ratio 3.08; p<0.001).
IMPORTANT SAFETY INFORMATION
There are no contraindications for IMFINZI ® (durvalumab) or IMJUDO ® (tremelimumab-actl).
Severe and Fatal Immune-Mediated Adverse Reactions
Important immune-mediated adverse reactions listed under Warnings and Precautions may not include all possible severe and fatal immune-mediated reactions. Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue. Immune-mediated adverse reactions can occur at any time after starting treatment or after discontinuation. Monitor patients closely for symptoms and signs that may be clinical manifestations of underlying immune-mediated adverse reactions. Evaluate clinical chemistries including liver enzymes, creatinine, adrenocorticotropic hormone (ACTH) level, and thyroid function at baseline and before each dose. In cases of suspected immune-mediated adverse reactions, initiate appropriate workup to exclude alternative etiologies, including infection. Institute medical management promptly, including specialty consultation as appropriate. Withhold or permanently discontinue IMFINZI and IMJUDO depending on severity. See USPI Dosing and Administration for specific details. In general, if IMFINZI and IMJUDO requires interruption or discontinuation, administer systemic corticosteroid therapy (1 mg to 2 mg/kg/day prednisone or equivalent) until improvement to Grade 1 or less. Upon improvement to Grade 1 or less, initiate corticosteroid taper and continue to taper over at least 1 month. Consider administration of other systemic immunosuppressants in patients whose immune-mediated adverse reactions are not controlled with corticosteroid therapy.
Immune-Mediated Pneumonitis
IMFINZI and IMJUDO can cause immune-mediated pneumonitis, which may be fatal. The incidence of pneumonitis is higher in patients who have received prior thoracic radiation.
Immune-Mediated Colitis
IMFINZI with IMJUDO and platinum-based chemotherapy can cause immune-mediated colitis, which may be fatal.
IMFINZI and IMJUDO can cause immune-mediated colitis that is frequently associated with diarrhea. Cytomegalovirus (CMV) infection/reactivation has been reported in patients with corticosteroid-refractory immune-mediated colitis. In cases of corticosteroid-refractory colitis, consider repeating infectious workup to exclude alternative etiologies.
Immune-Mediated Hepatitis
IMFINZI and IMJUDO can cause immune-mediated hepatitis, which may be fatal.
Immune-Mediated Endocrinopathies
Immune-Mediated Nephritis with Renal Dysfunction
IMFINZI and IMJUDO can cause immune-mediated nephritis.
Immune-Mediated Dermatology Reactions
IMFINZI and IMJUDO can cause immune-mediated rash or dermatitis. Exfoliative dermatitis, including Stevens-Johnson Syndrome (SJS), drug rash with eosinophilia and systemic symptoms (DRESS), and toxic epidermal necrolysis (TEN), has occurred with PD-1/L-1 and CTLA-4 blocking antibodies. Topical emollients and/or topical corticosteroids may be adequate to treat mild to moderate non-exfoliative rashes.
Immune-Mediated Pancreatitis
IMFINZI in combination with IMJUDO can cause immune-mediated pancreatitis. Immune-mediated pancreatitis occurred in 2.3% (9/388) of patients receiving IMFINZI and IMJUDO, including Grade 4 (0.3%) and Grade 3 (1.5%) adverse reactions.
Other Immune-Mediated Adverse Reactions
The following clinically significant, immune-mediated adverse reactions occurred at an incidence of less than 1% each in patients who received IMFINZI and IMJUDO or were reported with the use of other immune-checkpoint inhibitors.
Infusion-Related Reactions
IMFINZI and IMJUDO can cause severe or life-threatening infusion-related reactions. Monitor for signs and symptoms of infusion-related reactions. Interrupt, slow the rate of, or permanently discontinue IMFINZI and IMJUDO based on the severity. See USPI Dosing and Administration for specific details. For Grade 1 or 2 infusion-related reactions, consider using pre-medications with subsequent doses.
Complications of Allogeneic HSCT after IMFINZI
Fatal and other serious complications can occur in patients who receive allogeneic hematopoietic stem cell transplantation (HSCT) before or after being treated with a PD-1/L-1 blocking antibody. Transplant-related complications include hyperacute graft-versus-host disease (GVHD), acute GVHD, chronic GVHD, hepatic veno-occlusive disease (VOD) after reduced intensity conditioning, and steroid-requiring febrile syndrome (without an identified infectious cause). These complications may occur despite intervening therapy between PD-1/L-1 blockade and allogeneic HSCT. Follow patients closely for evidence of transplant-related complications and intervene promptly. Consider the benefit versus risks of treatment with a PD-1/L-1 blocking antibody prior to or after an allogeneic HSCT.
Embryo-Fetal Toxicity
Based on their mechanism of action and data from animal studies, IMFINZI and IMJUDO can cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. In females of reproductive potential, verify pregnancy status prior to initiating IMFINZI and IMJUDO and advise them to use effective contraception during treatment with IMFINZI and IMJUDO and for 3 months after the last dose of IMFINZI and IMJUDO.
Lactation
There is no information regarding the presence of IMFINZI and IMJUDO in human milk; however, because of the potential for serious adverse reactions in breastfed infants from IMFINZI and IMJUDO, advise women not to breastfeed during treatment and for 3 months after the last dose.
Adverse Reactions
Unresectable Stage III NSCLC
Resectable NSCLC
Metastatic NSCLC
Limited-stage Small Cell Lung Cancer
Extensive-stage Small Cell Lung Cancer
Locally Advanced or Metastatic Biliary Tract Cancers
Unresectable Hepatocellular Carcinoma
Primary advanced or Recurrent dMMR Endometrial Cancer
Muscle-Invasive Bladder Cancer (MIBC)
The safety and effectiveness of IMFINZI and IMJUDO have not been established in pediatric patients.
Indications:
IMFINZI, as a single agent, is indicated for the treatment of adult patients with unresectable Stage III non-small cell lung cancer (NSCLC) whose disease has not progressed following concurrent platinum-based chemotherapy and radiation therapy (cCRT).
IMFINZI in combination with platinum-containing chemotherapy as neoadjuvant treatment, followed by IMFINZI continued as a single agent as adjuvant treatment after surgery, is indicated for the treatment of adult patients with resectable (tumors ≥4 cm and/or node positive) NSCLC and no known epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) rearrangements.
IMFINZI, in combination with IMJUDO and platinum-based chemotherapy, is indicated for the treatment of adult patients with metastatic NSCLC with no sensitizing EGFR mutations or ALK genomic tumor aberrations.
IMFINZI, as a single agent, is indicated for the treatment of adult patients with limited-stage small cell lung cancer (LS-SCLC) whose disease has not progressed following concurrent platinum-based chemotherapy and radiation therapy (cCRT).
IMFINZI, in combination with etoposide and either carboplatin or cisplatin, is indicated for the first-line treatment of adult patients with extensive-stage small cell lung cancer (ES-SCLC).
IMFINZI, in combination with gemcitabine and cisplatin, is indicated for the treatment of adult patients with locally advanced or metastatic biliary tract cancer (BTC).
IMFINZI in combination with IMJUDO is indicated for the treatment of adult patients with unresectable hepatocellular carcinoma (uHCC).
IMFINZI in combination with carboplatin and paclitaxel followed by IMFINZI as a single agent is indicated for the treatment of adult patients with primary advanced or recurrent endometrial cancer that is mismatch repair deficient (dMMR) as determined by an FDA-approved test.
IMFINZI in combination with gemcitabine and cisplatin as neoadjuvant treatment, followed by single-agent IMFINZI as adjuvant treatment following radical cystectomy, is indicated for the treatment of adult patients with muscle-invasive bladder cancer (MIBC).
Please see additional Important Safety Information throughout and Full Prescribing Information including Medication Guide for IMFINZI and IMJUDO.
You may report side effects related to AstraZeneca products.
Notes
Gastric and gastroesophageal junction cancers
Gastric (stomach) cancer is the fifth most common cancer worldwide and the fifth-highest leading cause of cancer mortality. 1 Nearly one million new patients were diagnosed with gastric cancer in 2022, with approximately 660,000 deaths reported globally. 1 In many regions, its incidence has been increasing in patients younger than 50 years old, along with other gastrointestinal (GI) malignancies. 2 In 2024, there were approximately 43,000 drug-treated patients in the US, European Union (EU) and Japan with early-stage and locally advanced gastric or GEJ cancer. 3 Approximately 62,000 patients in these regions are expected to be newly diagnosed in this setting by 2030. 4
GEJ cancer is a type of gastric cancer that arises from and spans the area where the esophagus connects to the stomach. 5
Disease recurrence is common in patients with resectable gastric cancer despite undergoing surgery with curative intent and treatment with neoadjuvant/adjuvant chemotherapy. Approximately one in four patients with gastric cancer who undergo surgery develop recurrent disease within one year, and one in four patients do not survive beyond two years, reflecting high unmet medical need. 6-7 Additionally, the five-year survival rate remains poor, with less than half of patients alive at five years. 8
MATTERHORN
MATTERHORN is a randomized, double-blind, placebo-controlled, multi-center, global Phase III trial evaluating IMFINZI as perioperative treatment for patients with resectable Stage II-IVA gastric and GEJ cancers. Perioperative therapy includes treatment before and after surgery, also known as neoadjuvant/adjuvant therapy. In the trial, 948 patients were randomized to receive a 1500mg fixed dose of IMFINZI plus FLOT chemotherapy or placebo plus FLOT chemotherapy every four weeks for two cycles prior to surgery. This was followed by IMFINZI or placebo every four weeks for up to 12 cycles after surgery (including two cycles of IMFINZI or placebo plus FLOT chemotherapy and 10 additional cycles of IMFINZI or placebo monotherapy).
In the MATTERHORN trial, the primary endpoint is EFS, defined as time from randomization until the date of one of the following events (whichever occurred first): RECIST (version 1.1, per blinded independent central review assessment) progression that precludes surgery or requires non-protocol therapy during the neoadjuvant period; RECIST progression/recurrence during the adjuvant period; non-RECIST progression that precludes surgery or requires non-protocol therapy during the neoadjuvant period or discovered during surgery; progression/recurrence confirmed by biopsy post-surgery; or death due to any cause. Key secondary endpoints include pCR rate, defined as the proportion of patients who have no detectable cancer cells in resected tumor tissue following neoadjuvant therapy, and OS. The trial enrolled participants in 176 centers in 20 countries, including in the US, Canada, Europe, South America and Asia.
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 tumor's immune-evading tactics and releasing the inhibition of immune responses.
IMFINZI is also approved in combination with chemotherapy (gemcitabine plus cisplatin) in locally advanced or metastatic biliary tract cancer and in combination with IMJUDO ® (tremelimumab-actl) in unresectable hepatocellular carcinoma (HCC). IMFINZI is also approved as a monotherapy in unresectable HCC in Japan and the EU.
In addition to its indications in GI cancers, IMFINZI is the global standard of care based on OS in the curative-intent setting of unresectable, Stage III non-small cell lung cancer (NSCLC) in patients whose disease has not progressed after chemoradiotherapy (CRT). Additionally, IMFINZI is approved as a perioperative treatment in combination with neoadjuvant chemotherapy in resectable NSCLC, and in combination with a short course of IMJUDO and chemotherapy for the treatment of metastatic NSCLC. IMFINZI is also approved for limited-stage small cell lung cancer (SCLC) in patients whose disease has not progressed following concurrent platinum-based CRT; and in combination with chemotherapy for the treatment of extensive-stage SCLC.
IMFINZI is approved in the US and other countries as a perioperative treatment in combination with neoadjuvant chemotherapy for muscle-invasive bladder cancer based on the NIAGARA Phase III trial. Additionally, IMFINZI plus standard-of-care Bacillus Calmette-Guérin induction and maintenance therapy demonstrated a statistically significant and clinically meaningful improvement in disease-free survival for patients with high-risk non-muscle-invasive bladder cancer in the POTOMAC Phase III trial.
IMFINZI in combination with chemotherapy followed by IMFINZI monotherapy is approved as a 1st-line treatment for primary advanced or recurrent endometrial cancer (mismatch repair deficient disease only in US and EU). IMFINZI in combination with chemotherapy followed by olaparib and IMFINZI is approved for patients with mismatch repair proficient advanced or recurrent endometrial cancer in EU and Japan.
Since the first approval in May 2017, more than 374,000 patients have been treated with IMFINZI. As part of a broad development program, IMFINZI is being tested as a single treatment and in combinations with other anti-cancer treatments for patients with NSCLC, bladder cancer, breast cancer, ovarian cancer and several gastrointestinal cancers.
AstraZeneca in GI cancers
AstraZeneca has a broad development program for the treatment of GI cancers across several medicines and a variety of tumor types and stages of disease. In 2022, GI cancers collectively represented approximately 5 million new cancer cases leading to approximately 3.3 million deaths. 9
Within this program, the Company is committed to improving outcomes in gastric, liver, biliary tract, esophageal, pancreatic, and colorectal cancers.
In addition to its indications in BTC and HCC, IMFINZI is being assessed in combinations, including with IMJUDO, in liver, esophageal and gastric cancers in an extensive development program spanning early to late-stage disease across settings.
Fam-trastuzumab deruxtecan-nxki, a HER2-directed antibody drug conjugate, is approved in the US and several other countries for HER2-positive advanced gastric cancer. Fam-trastuzumab deruxtecan-nxki is jointly developed and commercialized by AstraZeneca and Daiichi Sankyo.
Olaparib, a first-in-class PARP inhibitor, is approved the US and several other countries for the treatment of BRCA- mutated metastatic pancreatic cancer. Olaparib is developed and commercialized by AstraZeneca and Merck & Co., Inc., known as MSD outside the US and Canada.
The Company is also assessing rilvegostomig (AZD2936), a PD-1/TIGIT bispecific antibody, in combination with chemotherapy as an adjuvant therapy in BTC, in combination with bevacizumab with or without IMJUDO as a 1st-line treatment in patients with advanced HCC, and as a 1st-line treatment in patients with HER2-negative, locally advanced unresectable or metastatic gastric and GEJ cancers. Rilvegostomig is also being evaluated in combination with fam-trastuzumab deruxtecan-nxki in previously untreated, HER2-expressing, locally advanced or metastatic BTC.
AstraZeneca is advancing multiple modalities that provide complementary mechanisms for targeting Claudin 18.2, a promising therapeutic target in gastric cancer. These include sonesitatug vedotin, a potential first-in-class antibody drug conjugate licensed from KYM Biosciences Inc., currently in Phase III development; AZD5863, a novel Claudin 18.2/CD3 T-cell engager bispecific antibody licensed from Harbour Biomed in Phase I development; and AZD6422, an armored 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) armored 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-tumor immune response and stimulate the body's immune system to attack tumors.
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 program, 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 catalyze 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 is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialization of prescription medicines in Oncology, Rare Diseases and BioPharmaceuticals, including Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca's innovative medicines are sold in more than 125 countries and used by millions of patients worldwide. Please visit www.astrazeneca-us.com and follow the Company on social media @AstraZeneca.
References
Dr. Janjigian provides consulting and advisory services to AstraZeneca.
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