Chiesi Global Rare Diseases and Protalix BioTherapeutics Receive Positive CHMP Opinion for an Additional Dosing Regimen of Every Four Weeks for Elfabrio (pegunigalsidase alfa) in the EU Committee for Medicinal Products f

Chiesi Global Rare Diseases and Protalix BioTherapeutics

Receive Positive CHMP Opinion for an Additional Dosing Regimen of Every Four Weeks for Elfabrio (pegunigalsidase alfa)

Committee for Medicinal

Products for Human Use (CHMP) issues a positive opinion following re-examination, which will be reviewed by the European Commission (EC),

with a decision anticipated by March 2026

EC, this dosing regimen would reduce the burden to eligible patients, their families, and the broader healthcare system due to the current

requirement to visit infusion centres every two weeks for treatment

This dosing regimen for Elfabrio is not approved

in the U.S. In the U.S., the approved dosing regimen remains 1 mg/kg every 2 weeks. Please consult with your healthcare provider

PARMA, Italy and CARMIEL, Israel - Jan. 30,

2026 - Chiesi Global Rare Diseases, a business unit of the Chiesi Group established to deliver innovative therapies and solutions

for people living with rare diseases, and Protalix BioTherapeutics, Inc. (NYSE American: PLX), a biopharmaceutical company focused

on the discovery, development, production and commercialization of innovative therapeutics for rare diseases with significant unmet needs,

today announced an update on Elfabrio (pegunigalsidase alfa). The Committee for Medicinal Products for Human Use (CHMP)

of the European Medicines Agency (EMA) has issued a positive opinion recommending approval of the 2mg/kg every-4-weeks (E4W) dosing regimen

for Elfabrio in Fabry disease adult patients stable with an ERT (Enzyme Replacement Therapy) treatment. This positive opinion follows

the CHMP's re-examination of the company's application for the additional dosing regimen.

"It is our privilege to provide the Fabry community with a safe

and effective option, and we are thrilled that the CHMP positive opinion supporting an every-four-week dosing regimen brings us one step

forward to further reducing treatment burden in this condition," said Giacomo Chiesi, Executive Vice President, Chiesi Global

Rare Diseases. "We're focused on evolving treatments based on real-world needs, so that people have not just the right

care, but care that fits naturally into their lives. By extending the time between infusions, our aim is that people living with this

condition can focus on what truly matters, living their lives."

"Expanding the range of treatment

options is critical to better meet the needs of people with Fabry disease," said Prof. Ale

Linhart, DrSc, FESC. "Beyond managing the condition effectively, this extended administration

protocol acknowledges the importance of meeting patient preferences in order to reduce disruptions to their daily lives."

"The CHMP's positive opinion is another

testament to Protalix's commitment to advancing treatments for people living with Fabry disease and, together with Chiesi, we are

grateful to all of the patients and investigators and their staff members who participated in our clinical trial programs," said

Dror Bashan, President and Chief Executive Officer of Protalix. "The CHMP's positive opinion is a powerful validation

of Protalix's innovative pipeline and our proprietary ProCellEx manufacturing platform, built on years of rigorous

research and clinical progress."

"The CHMP positive opinion

on the every-four-week regimen recognizes the importance of reducing treatment burden for people living with Fabry and their families,"

said Mary Pavlou, President, Fabry International Network (FIN). "Extending infusion intervals allows therapy to better fit

into everyday life, supporting work, study, and family commitments. This step reflects care that adapts to real life and respects the

priorities of those who live with the disease."

The CHMP opinion is based on results from an open-label, switch-over

study, BRIGHT (formally PB-102-F50), designed to assess the safety, efficacy, and pharmacokinetics (PK) of the new dosing regimen of pegunigalsidase

alfa 2 mg/kg E4W for 52 weeks, and its ongoing open-label extension study CLI-06657AA1-03 (formerly PB-102-F51, with a median exposure

of almost 6 years). Further support is provided by an updated Population Pharmacokinetics (PopPK) model and exposure-response analysis,

which leverage data from multiple clinical studies.

Protalix will be eligible to receive a regulatory milestone payment

of $25 million from Chiesi if the E4W dosing regimen is approved by the EC.

This dosing regimen for Elfabrio is not approved in the U.S.

In the U.S., the approved dosing regimen remains 1 mg/kg every 2 weeks. Please consult with your healthcare provider.

ELFABRIO (pegunigalsidase alfa-iwxj), a PEGylated enzyme replacement

therapy (ERT) to treat Fabry disease, is a plant cell culture-expressed, and chemically modified stabilized recombinant version of the

--Galactosidase--A enzyme. Protein sub-units are covalently bound via chemical cross-linking using short PEG moieties, resulting

in a molecule with stable pharmacokinetic parameters. In clinical studies, ELFABRIO has been observed to have an initial half-life of

Important Safety Information

Elfabrio (pegunigalsidase

alfa-iwxj) is indicated for the treatment of adults with confirmed Fabry disease.

Important Safety Information

Prior to Elfabrio administration, consider

pretreating with antihistamines, antipyretics, and/or corticosteroids. Inform patients and caregivers of the signs and symptoms of hypersensitivity

reactions and infusion-associated reactions (IARs), and instruct them to seek medical care immediately if such symptoms occur.

In clinical trials, 20 (14%) Elfabrio-treated

patients experienced hypersensitivity reactions. Four Elfabrio-treated patients (3%) experienced anaphylaxis reactions that occurred within

5 to 40 minutes of the start of the initial infusion. The signs and symptoms of hypersensitivity reactions and anaphylaxis included headache,

nausea, vomiting, throat tightness, facial and oral edema, truncal rash, tachycardia, hypotension, rigors, urticaria, intense pruritus,

moderate upper airway obstructions, macroglossia, and mild lip edema.

In clinical trials, 41 (29%) Elfabrio-treated

patients experienced one or more infusion-associated reactions, including hypersensitivity, nausea, chills, pruritus, rash, chest pain,

dizziness, vomiting, asthenia, pain, sneezing, dyspnea, nasal congestion, throat irritation, abdominal pain, erythema, diarrhea, burning

sensation, neuralgia, headache, paresthesia, tremor, agitation, increased body temperature, flushing, bradycardia, myalgia, hypertension,

A case of membranoproliferative glomerulonephritis

with immune depositions in the kidney was reported during clinical trials. Monitor serum creatinine and urinary protein-to-creatinine

ratio. If glomerulonephritis is suspected, discontinue treatment until a diagnostic evaluation can be conducted.

When switching to Elfabrio from a prior enzyme

replacement therapy, the risk of hypersensitivity reactions and infusion-associated reactions may be increased in certain patients with

pre-existing anti-drug antibodies (ADAs). Consider monitoring IgG and IgE ADAs and clinical or pharmacodynamic response (eg, plasma lyso-Gb3

levels). The most common adverse reactions ( 15%) were infusion-associated reactions, nasopharyngitis, headache, diarrhea, fatigue,

nausea, back pain, pain in extremity, and sinusitis.

Please see Full Prescribing Information

for Elfabrio including Boxed Warning, for Elfabrio (pegunigalsidase alfa)."

Fabry disease is a rare, inherited lysosomal storage disorder caused

by mutations in the GLA gene, which leads to a deficiency of the enzyme alpha-galactosidase A. This deficiency results in an accumulation

of a fatty substance called globotriaosylceramide (GL-3) in the body's cells, affecting the heart, kidneys, skin, nervous system,

and other organs.1 Fabry disease can cause a range of serious signs and symptoms, including fatigue, chronic pain, gastrointestinal

issues, decreased ability to sweat, progressive kidney failure, heart complications, and increased risk of stroke.2

The condition affects both males and females and can present from childhood

through adulthood, often with delayed diagnosis or misdiagnosis. While Fabry disease is rare, early detection and access to appropriate

treatment - such as enzyme replacement therapy or pharmacological chaperones - are critical in managing symptoms and slowing

disease progression.1

Chiesi is a research-oriented international biopharmaceutical group

that develops and markets innovative therapeutic solutions in respiratory health, rare diseases, and specialty care. The company's

mission is to improve people's quality of life and act responsibly towards both the community and the environment.

By changing its legal status to a Benefit Corporation in Italy, the

US, France and Colombia, Chiesi's commitment to creating shared value for society as a whole is legally binding and central to company-wide

decision-making. As a certified B Corp since 2019, Chiesi is part of a global community of businesses that meet high standards of social

and environmental impact. The company aims to reach Net-Zero greenhouse gases (GHG) emissions by 2035.

With 90 years of experience, Chiesi is headquartered in Parma (Italy),

with 31 affiliates worldwide, and counts more than 7,500 employees. The Group's research and development center in Parma works alongside

6 other important R&D hubs in France, the US, Canada, China, the UK, and Sweden.

For more information visit www.chiesi.com.

About Chiesi Global Rare Diseases

Chiesi Global Rare Diseases is a business