Carlisle Companies Incorporated

Phase 3 study demonstrates benefits of the first influenza vaccine to combine three proven approaches to enhancing protection for older adults in a single vaccine.

MAIDENHEAD, United Kingdom, Sept. 11, 2026 /PRNewswire/ -- CSL Seqirus, a business of CSL (ASX: CSL; USOTC: CSLLY), today announced publication of pivotal Phase 3 study results for its MF59^®-adjuvanted cell-based higher-dose quadrivalent influenza vaccine (aQIVc) in The Lancet Infectious Diseases, marking an important milestone in the evolution of influenza prevention for older adults.¹

The publication follows approval of the trivalent formulation of aQIVc by the Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom earlier this year for adults aged 50 years and older.² The vaccine, marketed as AUJEMFLU^®, has also been approved by the European Commission for adults aged 50 years and above.

The peer-reviewed publication reports findings from a large-scale study of the first influenza vaccine to combine three proven approaches to enhancing protection in older adults: MF59^® adjuvant, cell-based manufacturing, and a higher dose formulation compared to standard influenza vaccines.^1,3

Each of these approaches has been used separately in influenza vaccines for many years and is supported by extensive clinical and real-world evidence. This publication provides the first large-scale evaluation of their combination within a single vaccine.^1,2

Influenza remains a significant public health challenge, causing substantial illness, hospitalisations and deaths each year despite widespread vaccination programmes.⁴ 

Older adults are particularly vulnerable because the immune system becomes less responsive with age, reducing its ability to mount a strong protective response following vaccination.⁵ 

aQIVc combines three proven approaches to enhancing vaccine protection in older adults, with each playing a distinct and complementary role. Cell-based manufacturing helps preserve a closer match to circulating influenza strains, MF59® adjuvant strengthens, broadens and lengthens the immune response and a higher dose formulation further optimises that response.^2,6,7,8

The Phase 3 randomised immunogenicity and safety study enrolled 7,699 adults aged 50 years and older across eight countries and compared aQIVc with two enhanced influenza vaccines. The study met its primary objectives and demonstrated:¹

• Superiority versus the adjuvanted egg-based influenza vaccine comparator across all four influenza strains and age groups assessed.
• Non-inferiority versus a recombinant influenza vaccine for three out of four strains in the 50+ age group and four out of four strains in those aged 65+.
• Immune responses that persisted throughout the influenza season.
• A well-tolerated safety profile. Most reactions were mild or moderate and resolved within three days.¹  

The publication also reported exploratory findings of enhanced neuraminidase antibody responses versus comparators. The role of neuraminidase antibodies is an emerging area of influenza research that may contribute to reduced disease severity and broader protection beyond traditional measures of vaccine response.⁹

The study authors concluded that the findings support further evaluation of the vaccine and provide evidence for National Immunisation Technical Advisory Groups considering enhanced influenza vaccination strategies for older adults.¹

Regulatory submissions for the trivalent formulation of aQIVc have been made in multiple markets, with introductions expected to occur through a phased approach aligned to local regulatory, policy and access pathways.

Gregg Sylvester, Chief Medical Officer and Head of Research & Development, CSL Seqirus, said:

"Publication in The Lancet Infectious Diseases is a significant milestone for CSL Seqirus and reflects decades of investment in influenza vaccine innovation."

"These findings provide important new evidence for healthcare professionals, policy makers and immunisation advisory groups considering future influenza vaccination strategies for older adults."

Professor Colin Russell, Chair of the European Scientific Working Group on Influenza (ESWI) and Professor of Applied Evolutionary Biology at Amsterdam University Medical Center, said:

"Influenza vaccine innovation has historically progressed through incremental advances in technology and manufacturing. What makes this study noteworthy is that it shows the potential benefit of bringing multiple proven approaches together in a single vaccine."

"Given the continued burden of influenza-related illness, hospitalisation and death among older adults despite widespread vaccination, these findings represent an important contribution to ongoing efforts to improve protection in this vulnerable population."

About the Phase 3 Study

The randomised, observer-blind Phase 3 immunogenicity study enrolled 7,699 adults aged 50 years and older across Canada, Denmark, Estonia, Germany, Pakistan, the Philippines, the United Kingdom and the United States. Participants received either the MF59-adjuvanted cell-derived higher dose quadrivalent vaccine, an MF59-adjuvanted egg-based quadrivalent influenza vaccine or a recombinant quadrivalent influenza vaccine. The study evaluated immunogenicity, safety and manufacturing consistency.

About aQIVc

aQIVc is an MF59-adjuvanted, cell-based higher-dose quadrivalent influenza vaccine developed for adults aged 50 years and older.  The trivalent formulation has been licensed for use in people aged 50 and above in the UK and by the European Medicines Agency where it is marketed as AUJEMFLU.^®

The vaccine combines three proven approaches designed to enhance protection in older adults:

• MF59 adjuvant technology
• Cell-based manufacturing
• A higher dose formulation versus standard dose influenza vaccines
• Each dose contains 45 micrograms of haemagglutinin per influenza strain and 19.5 mg of MF59 adjuvant²

About CSL Seqirus

CSL Seqirus is part of CSL (ASX: CSL). As one of the largest influenza vaccine providers in the world, CSL Seqirus is a major contributor to the prevention of influenza globally and a transcontinental partner in pandemic preparedness and response. With state-of-the-art production facilities in the US, the UK and Australia, CSL Seqirus utilises egg, cell and adjuvant technologies to offer a broad portfolio of differentiated influenza vaccines in more than 20 countries around the world. For more information about CSL Seqirus, visit www.CSL.com.

Intended Audience

This press release is issued by CSL Seqirus and is intended to provide information about our global business. Information relating to the approval status, product labels, recommendations and availability of CSL Seqirus products may vary from country to country. Please consult your local regulatory authority for information on approval status and local prescribing information.

Forward-Looking Statements

This press release may contain forward-looking statements, including statements regarding future results, performance, regulatory milestones, product availability or achievements. These statements involve known and unknown risks, uncertainties and other factors which may cause actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Given these uncertainties, you should not place undue reliance on forward-looking statements.

For more information, please contact:

MEDIA CONTACT 

Alex Kiefer

Alex.Kiefer@Seqirus.com

Director International & Pandemic Communications, CSL Seqirus 

GL-aTIVc-26-0011

References

¹ Essink BJ, Vermeulen W, Andrade C, Mazur M, de Rooij R, Heijnen E, et al. Immunogenicity and safety of an MF59-adjuvanted cell-derived higher-dose quadrivalent influenza vaccine (aQIVc) in adults aged 50 years or older: a phase 3 randomised controlled trial. Lancet Infect Dis. In press 2026. Volume 26. September 2026.  THELANCETID-D-26-00167R3.

² Aujemflu suspension for injection in pre-filled syringe: summary of product characteristics [Internet]. Maidenhead: Seqirus UK Limited; 4 June 2026 (PL 47991/0020). Available from: https://www.medicines.org.uk/emc/product/102343/smpc cited 2026 Aug 2.

³ Ashraf M, Boivin W, Nguyen-Van-Tam JS, Nolan T, Stein AN, Russell CA. Development of an adjuvanted, higher-dose, cell-based influenza vaccine: combining advanced technologies to improve vaccine effectiveness. Expert Rev Vaccines. 2026;25(1):2667732. doi:10.1080/14760584.2026.2667732.

⁴ World Health Organization. Influenza (seasonal): fact sheet [Internet]. Geneva: WHO; 28 February 2025. Available from: https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)  cited 2026 Aug 28.

⁵ Cadar AN, Martin DE, Bartley JM. Targeting the hallmarks of aging to improve influenza vaccine responses in older adults. Immun Ageing. 2023;20:23. doi:10.1186/s12979-023-00348-6.

⁶ Essink BJ, Vermeulen W, Andrade C, de Rooij R, Isakov L, Casula D, et al. A randomised phase 2 immunogenicity and safety study of a MF59-adjuvanted quadrivalent subunit inactivated cell-derived influenza vaccine (aQIVc) in adults aged 50 years and older. Vaccine. 2025;51:126791. doi:10.1016/j.vaccine.2025.126791.

⁷ de Looze F, Essink BJ, van Boxmeer J, Andrade C, de Rooij R, Casula D, et al. Immunogenicity and safety of higher-dose cell-based adjuvanted quadrivalent influenza vaccines: combined results of randomised, controlled dose-finding and dose-confirmation studies. Vaccine. 2026;79:128436. doi:10.1016/j.vaccine.2026.128436.

⁸ Ashraf M, Stein AN, Youhanna J, Rockman S, McMahon M, McGovern I, et al. The impact of egg adaptation and immune imprinting on influenza vaccine effectiveness. Vaccine. 2025;62:127393. doi:10.1016/j.vaccine.2025.127393.

⁹ Monto AS, Petrie JG, Cross RT, Johnson E, Liu M, Zhong W, et al. Antibody to influenza virus neuraminidase: an independent correlate of protection. J Infect Dis. 2015;212(8):1191-99. doi:10.1093/infdis/jiv195.

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SOURCE CSL Seqirus

• CSL Canada is proud to recognize this important milestone of the first Canadian patient to receive HEMGENIX^® (etranacogene dezaparvovec), the one-time gene therapy treatment for eligible patients living with hemophilia B, at London Health Sciences Centre in London, Ontario.
• Following a successful pan-Canadian Pharmaceutical Alliance (pCPA) agreement, HEMGENIX^® is now publicly reimbursed in Ontario and British Columbia via the Exceptional Access Program, with additional provinces under consideration.
• It is indicated for the treatment of adults (aged 18 years of age or older) with severe to moderately severe hemophilia B (congenital Factor IX deficiency) who require routine prophylaxis to prevent or reduce the frequency of bleeding episodes.¹ There is no clinical experience of HEMGENIX^® use in patients with mild or moderate hemophilia B (FIX activity > 2%).
• This milestone marks the first HEMGENIX^® treatment administered to a Canadian patient outside of a clinical trial, demonstrating real‑world access to gene therapy in Canada.   

OTTAWA, ON, May 20, 2026 /CNW/ - CSL Canada is proud to announce the first Canadian patient has received HEMGENIX^® (etranacogene dezaparvovec), a one-time hemophilia B gene therapy, at London Health Sciences Centre (LHSC). This milestone marks a significant advancement in hemophilia B care, reflecting how clinical innovation and health system collaboration are enabling real-world access to gene therapy for eligible patients in Canada.

Hemophilia B is a rare genetic bleeding disorder caused by a deficiency of clotting Factor IX, which prevents blood from clotting properly, often resulting in a lifelong dependence on medication to manage bleeding.² People living with hemophilia B may experience spontaneous or prolonged bleeding episodes that can lead to joint damage, chronic pain, reduced mobility, and other long-term complications that affect quality of life.³

For many patients and families, hemophilia B often means navigating constant vigilance around physical activity, injury risk, and disease management affecting all facets of everyday life. In Canada, hemophilia B affects approximately one in 50,000 people,⁴ typically requiring lifelong management through medical monitoring, specialized multidisciplinary care and sustained healthcare system resources through hemophilia treatment centres.⁵

HEMGENIX^® is a gene therapy addressing the underlying cause of hemophilia B by enabling the body to produce Factor IX on its own. This one-time treatment option, for patients who otherwise require ongoing replacement therapy, offers eligible adults the potential to reduce the routine burden of care and improve long-term disease management. Following a successful pan-Canadian Pharmaceutical Alliance (pCPA) agreement, HEMGENIX^® is now publicly reimbursed in Ontario and British Columbia.

"The first treatment with HEMGENIX^® in Canada reflects the tremendous importance of expanding treatment options and access to hemophilia B patients," said Marie-Ève Jacques, General Manager, CSL Canada.    

"This is a meaningful moment for the bleeding disorders community in Canada," said Emil Wijnker, President of the Canadian Hemophilia Society. "For many, hemophilia B is a constant consideration in everyday life. Advances like gene therapy signal real progress, with the potential to ease that burden and meaningfully change how people manage their condition over time."

"The first HEMGENIX^® treatment in Canada marks an important step forward in how we care for people living with hemophilia B," said Dr. Chai Phua, MD, FRCPC, Medical Director of the Adult Bleeding Disorders Program at London Health Sciences Centre. "Gene therapy introduces a new approach to treatment, and delivering it requires close coordination across clinical teams and systems. It's encouraging to see this level of readiness translating into real-world care for eligible patients."

CSL Canada continues to advance innovation and is working to help ensure all eligible Canadians can access and benefit from advances in hemophilia care and innovation.

About Hemophilia B

Hemophilia B is a life-threatening rare disease. People with the condition are particularly vulnerable to bleeds in their joints, muscles, and internal organs, leading to pain, swelling, and joint damage.⁶ The constant worry of a bleed means that their daily activities can be restricted, even for things as simple as going up and down stairs.^6-8 Current treatments for moderate to severe hemophilia B include life-long prophylactic infusions of Factor IX to temporarily replace or supplement low levels of the blood-clotting factor.⁶ Many people with hemophilia find themselves continually confronted with the mental and emotional impact of managing their condition, and rarely have their minds free of hemophilia.⁷

About HEMGENIX^®

HEMGENIX^® (etranacogene dezaparvovec) is an in vivo gene therapy that reduces the rate of abnormal bleeding in eligible people with hemophilia B by enabling the body to continuously produce Factor IX, the protein that is deficient in people with the disease.⁹ It uses a non-infectious viral vector derived from an adeno-associated virus (AAV5).⁹ The AAV5 vector carries the Padua gene variant of Factor IX to the target cells in the liver, generating Factor IX proteins that are 5x–8x more active than normal.¹⁰ These genetic instructions remain in the target cells, but generally do not become a part of a person's own DNA.⁹ Once delivered, the new genetic instructions allow the cellular machinery to produce stable levels of Factor IX.¹¹

About the Pivotal HOPE-B Trial

The pivotal Phase III HOPE-B trial was a multinational, open-label, single-arm study to evaluate the safety and efficacy of HEMGENIX^®.¹² A total of 54 adult patients with hemophilia B, classified as having moderately severe to severe hemophilia B and requiring prophylactic Factor IX replacement therapy, were enrolled in a prospective, 6-month or longer observational period. During this period, patients continued to use their current standard of care therapy to establish a baseline annual bleeding rate (ABR). ¹² After the 6-month lead-in period, patients received a single intravenous administration of HEMGENIX^® at the 2x10¹³ gc/kg dose. Patients were not excluded from the trial based on pre-existing neutralizing antibodies (NAbs) to AAV5. ¹²

Additionally, new HOPE-B five-year data published in the New England Journal of Medicine and presented simultaneously at the American Society of Hematology (ASH) Annual Meeting 2025, confirmed the five-year durability and safety of HEMGENIX^®.^13,14

HEMGENIX^® was generally well-tolerated, with a total of 100 treatment-related adverse events (TRAEs) 5 years post-infusion, most of which occurred in the first six months post-treatment. ^13,14 No serious treatment-related adverse reactions were reported. ^9,15 Two deaths occurred during the trial due to non-treatment-related AEs: one at approximately 15 months post-dose due to cardiogenic shock and urosepsis, and another at approximately 54 months post-dose due to cardiac amyloidosis. Three previously reported serious adverse events (hepatocellular carcinoma, schwannoma and myelodysplastic syndrome) were determined to be unrelated to treatment with HEMGENIX^® by independent molecular tumour characterization and vector integration analysis.^14,16 No inhibitors to Factor IX were reported.^9,14

The five-year data marks the final analysis for the HOPE-B study, but participants who consent will continue to be monitored in the IX-TEND 222-3003 extended follow-up study (NCT05962398), which will track patients for up to 15 years post-treatment.^13,14

Important Information for Canada

HEMGENIX® is indicated for the treatment of adults (aged 18 years of age or older) with hemophilia B (congenital Factor IX deficiency) who require routine prophylaxis to prevent or reduce the frequency of bleeding episodes.

There is no clinical experience of HEMGENIX® use in patients with mild or moderate hemophilia B (FIX activity > 2%).

Consult the product monograph available here for contraindications, warnings, precautions, adverse reactions, interactions, dosing, and conditions of clinical use. The product monograph is also available through our medical department. Call us at 1-866-773-7721.

About CSL

CSL (ASX:CSL; USOTC:CSLLY) is a leading global biopharma company with a dynamic portfolio of lifesaving medicines, including those that treat hemophilia and immune deficiencies, vaccines to prevent influenza, and therapies in iron deficiency, dialysis and nephrology. Since our start in 1916, we have been driven by our promise to save lives using the latest technologies. Today, CSL – including our three businesses, CSL Behring, CSL Seqirus and CSL Vifor – provides lifesaving products to patients in more than 100 countries and employs 29,000+ people. Our unique combination of commercial strength, R&D focus and operational excellence enables us to identify, develop and deliver innovations so our patients can live life to the fullest. For inspiring stories about the promise of biotechnology, visit CSL.com/Vita.

For more information about CSL, visit https://www.cslbehring.ca/

References

SOURCE CSL Canada