CSL Behring Announces the First Patient has Received FDA ApprovedHEMGENIX® (etranacogene dezaparvovec-drlb) for Hemophilia B

HEMGENIX®, the first and only FDA approved gene therapy for hemophilia B,
has been proven to elevate and sustain factor IX levels for years, significantly
reduce the rate of annual bleeds versus standard of care, and reduce or
eliminate the need for prophylactic treatment in 94% of patients (51 out of 54)
after a one-time infusion.

Global biotechnology leader CSL Behring today announced that the first patient has received U.S. Food and Drug Administration (FDA) approved HEMGENIX® (etranacogene dezaparvovec-drlb) for hemophilia B in the United States. HEMGENIX is the first and only gene therapy for the treatment of adults with hemophilia B who currently use factor IX prophylaxis therapy, or have current or historical life-threatening bleeding, or have repeated, serious spontaneous bleeding. “As part of our longtime promise to patients, CSL Behring is thrilled to mark this latest milestone of the first commercial patient having received HEMGENIX and look forward to continuing to deliver this paradigm-shifting treatment to the hemophilia B community,” said Bob Lojewski, Senior Vice President and General Manager, North America, CSL Behring. “To the advocacy organizations, medical experts, healthcare professionals, payers, channel partners, and the entire hemophilia community who have collaborated with us to establish access for this innovative therapy, we thank you and look forward to many more patients benefiting from this therapy.”

While prophylactic hemophilia B treatments have significantly advanced over the past
several decades and are effective, treatments are typically administered on a strict infusion
schedule and breakthrough bleeds into joints are still possible. HEMGENIX has the potential
to fundamentally transform the treatment paradigm through a single, one-time infusion in
people living with hemophilia B by addressing the genetic cause of the condition.
In clinical trials, HEMGENIX demonstrated the ability to elevate and sustain factor IX levels for
years, significantly reduce the rate of annual bleeds versus standard of care, and reduce or
eliminate the need for prophylactic treatment in 94% of people who received the therapy. In
addition to the potential long-term health benefits from greater bleed protection and
liberation from infusion schedules, HEMGENIX could also generate significant cost savings
for the healthcare system at-large. Healthcare costs can be 25 times higher for a person living
with hemophilia B compared to individuals who do not have a bleeding disorder—
amounting to a total adult lifetime cost of more than $20 million per person.

“Discussions between CSL Behring and the payer community on the value proposition
offered for HEMGENIX have been positive, which is reflected in the policies that have been
written,” added Lojewski. “As of May 2023, payers covering roughly 60 percent of the U.S.
population have established clear medical policies covering HEMGENIX. For those who have
not yet established policies, we anticipate that coverage decisions for HEMGENIX will be
reviewed on a case-by-case basis.”

“HEMGENIX is an important addition to the current treatment paradigm and a long-awaited
advancement for the hemophilia B community,” said Matthew Ryan, MD, Adult Hematologist
and Medical Director at Hemophilia Outreach Center, Green Bay, WI. “This exciting treatment
offers patients a chance to live a life without frequent bleeds or the burden of regular
infusions. The availability of this new one-time treatment also sparks additional conversations
in the community when it comes to treatment options and goals, which is extremely
important when managing a life-long condition, as an individual’s needs can change for a
variety of reasons.”

People living with hemophilia B who have decided with their doctor to move forward with
treatment with HEMGENIX, can enroll in the HEMGENIX ConnectSM program where they will
be assigned a dedicated support team, including a Patient Resource Navigator and CSL Case
Manager, who can assist with questions about gene therapy, the treatment journey and
insurance coverage.

In further demonstration of the company’s commitment to the hemophilia B community,
CSL Behring is providing ongoing training to centers who may administer HEMGENIX and
encouraging long term data collection through the ATHN registry. Registry data will be
informative to all stakeholders and will generate additional evidence on the long-term safety,
efficacy, and durability of gene therapy.

HEMGENIX® was also approved by the European Commission (EC) for the European Union
and European Economic Area and was granted conditional marketing authorization by the
United Kingdom’s Medicines and Healthcare product Regulatory Agency. The multi-year
clinical development of HEMGENIX® was led by uniQure (Nasdaq: QURE) and sponsorship of
the clinical trials transitioned to CSL after it licensed global rights to commercialize the
treatment.

About Hemophilia B
Hemophilia B is a life-threatening rare disease caused by a mutation on the F9 gene,
resulting in low levels of functional clotting factor IX. People with the condition are
particularly vulnerable to bleeds in their joints, muscles, and internal organs, leading to pain,
swelling, and joint damage. 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.

About HEMGENIX®
HEMGENIX® is a 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 deficient
protein in hemophilia B. It uses AAV5, a non-infectious viral vector, called an adenoassociated
virus (AAV). The AAV5 vector carries the Padua gene variant of Factor IX (FIXPadua)
to the target cells in the liver, generating factor IX proteins that are 5x-8x more active
than normal. These genetic instructions remain in the target cells, but generally do not
become a part of a person’s own DNA. Once delivered, the new genetic instructions allow the
cellular machinery to produce stable levels of factor IX.

About the Pivotal HOPE-B Trial
The pivotal Phase III HOPE-B trial is an ongoing, multinational, open-label, single-arm study
to evaluate the safety and efficacy of HEMGENIX®. Fifty-four adult hemophilia B patients
classified as having moderately severe to severe hemophilia B and requiring prophylactic
factor IX replacement therapy were enrolled in a prospective, six-month or longer
observational period during which time they continued to use their current standard of care
therapy to establish a baseline Annual Bleeding Rate (ABR). After the six-month lead-in
period, patients received a single intravenous administration of HEMGENIX® at the 2×10^13
gc/kg dose. Patients were not excluded from the trial based on pre-existing neutralizing
antibodies (NAbs) to AAV5.

A total of 54 patients received a single dose of HEMGENIX® in the pivotal trial, with 53 patients
completing at least 18 months of follow-up. The primary endpoint in the pivotal HOPE-B
study was ABR 52 weeks after achievement of stable factor IX expression (months 7 to 18)
compared with the six-month lead-in period. For this endpoint, ABR was measured from
month seven to month 18 after infusion, ensuring the observation period represented a
steady-state factor IX transgene expression. Secondary endpoints included assessment of
factor IX activity.

No serious treatment-related adverse reactions were reported. One death resulting from
urosepsis and cardiogenic shock in a 77-year-old patient at 65 weeks following dosing was
considered unrelated to treatment by investigators and the company sponsor. A serious
adverse event of hepatocellular carcinoma was determined to be unrelated to treatment
with HEMGENIX® by independent molecular tumor characterization and vector integration
analysis. No inhibitors to factor IX were reported.

Long-term 24-month data presented at the 54th American Society of Hematology (ASH) 2022
Annual Meeting and Exposition and at The European Association for Haemophilia and Allied
Disorders (EAHAD) 2023 Annual Meeting continue to reinforce the potential long-lasting
efficacy and safety of HEMGENIX® and the ongoing benefit of this treatment for people living
with hemophilia B.

Important Safety Information (ISI)
What is HEMGENIX®?
HEMGENIX®, etranacogene dezaparvovec-drlb, is a one-time gene therapy for the treatment
of adults with hemophilia B who:
 Currently use Factor IX prophylaxis therapy, or
 Have current or historical life-threatening bleeding, or
 Have repeated, serious spontaneous bleeding episodes.

HEMGENIX® is administered as a single intravenous infusion and can be administered only
once.

What medical testing can I expect to be given before and after administration of
HEMGENIX®?
To determine your eligibility to receive HEMGENIX®, you will be tested for Factor IX inhibitors.
If this test result is positive, a retest will be performed 2 weeks later. If both tests are positive
for Factor IX inhibitors, your doctor will not administer HEMGENIX® to you. If, after
administration of HEMGENIX®, increased Factor IX activity is not achieved, or bleeding is not
controlled, a post-dose test for Factor IX inhibitors will be performed.

HEMGENIX® may lead to elevations of liver enzymes in the blood; therefore, ultrasound and
other testing will be performed to check on liver health before HEMGENIX® can be
administered. Following administration of HEMGENIX®, your doctor will monitor your liver
enzyme levels weekly for at least 3 months. If you have preexisting risk factors for liver cancer,
regular liver health testing will continue for 5 years post-administration. Treatment for
elevated liver enzymes could include corticosteroids.

What were the most common side effects of HEMGENIX® in clinical trials?
In clinical trials for HEMGENIX®, the most common side effects reported in more than 5% of
patients were liver enzyme elevations, headache, elevated levels of a certain blood enzyme,
flu-like symptoms, infusion-related reactions, fatigue, nausea, and feeling unwell. These are
not the only side effects possible. Tell your healthcare provider about any side effect you may
experience.

What should I watch for during infusion with HEMGENIX®?
Your doctor will monitor you for infusion-related reactions during administration of
HEMGENIX®, as well as for at least 3 hours after the infusion is complete. Symptoms may
include chest tightness, headaches, abdominal pain, lightheadedness, flu-like symptoms,
shivering, flushing, rash, and elevated blood pressure. If an infusion-related reaction occurs,
the doctor may slow or stop the HEMGENIX® infusion, resuming at a lower infusion rate once
symptoms resolve.

What should I avoid after receiving HEMGENIX®?
Small amounts of HEMGENIX® may be present in your blood, semen, and other
excreted/secreted materials, and it is not known how long this continues. You should not
donate blood, organs, tissues, or cells for transplantation after receiving HEMGENIX®.

Please see full prescribing information for HEMGENIX®. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.
You can also report side effects to CSL Behring’s Pharmacovigilance Department at 1-866-
915-6958.

About CSL Behring
CSL Behring is a global biotherapeutics leader driven by our promise to save lives. Focused
on serving patients’ needs by using the latest technologies, we discover, develop and deliver
innovative therapies for people living with conditions in the immunology, hematology,
cardiovascular and metabolic, respiratory, and transplant therapeutic areas. We use three
strategic scientific platforms of plasma fractionation, recombinant protein technology, and
cell and gene therapy to support continued innovation and continually refine ways in which
products can address unmet medical needs and help patients lead full lives.
CSL Behring operates one of the world’s largest plasma collection networks, CSL Plasma. Our
parent company, CSL (ASX:CSL; USOTC:CSLLY), headquartered in Melbourne, Australia,
employs 32,000 people, and delivers its lifesaving therapies to people in more than 100
countries. For inspiring stories about the promise of biotechnology, visit CSLBehring.com/Vita and follow us on Twitter.com/CSLBehring.

CSL Behring Media Contact
Etanjalie Ayala
Mobile: +1 610 297 1069
Email: etanjalie.ayala@cslbehring.com

Source: CSL Behring, June 2023