Full Press Release Details
Rilzabrutinib granted orphan drug designation in the US for two rare diseases with no approved medicines
Paris, April 3, 2025. The US Food and Drug Administration (FDA) has granted orphan drug designation to rilzabrutinib,
an investigational, novel, advanced, oral, reversible Bruton s tyrosine kinase (BTK) inhibitor, for two rare diseases, warm autoimmune hemolytic anemia (wAIHA) and IgG4-related disease (IgG4-RD). There is
still a significant unmet medical need for these two rare diseases, and neither have any currently approved medicine. FDA grants orphan drug designation to investigational therapies addressing rare medical diseases or conditions that affect fewer
than 200,000 people in the US.
Karin Knobe, MD, PhD
Global Head of Development, Rare Diseases
Orphan drug designation for these two rare, immune-mediated conditions validates our ongoing commitment to pursuing potential first- and best-in-class medicines for diseases that affect small populations but persist with unmet medical need. Our continued exploration of rilzabrutinib across multiple indications
speaks to our belief in its potential for multi-immune modulation, as well as our belief in supporting treatment options, no matter how rare a condition.
Rilzabrutinib is currently under regulatory review in the US, the EU, and China for its potential use in immune thrombocytopenia (ITP). The target action date for the
FDA regulatory decision for ITP, which was granted fast track designation, is August 29, 2025. Rilzabrutinib also received orphan drug designation for ITP in the US, EU, and Japan.
wAIHA and IgG4-RD supporting data
Results from a phase 2b study on wAIHA presented at ASH 2024 (clinical study identifier: NCT05002777) demonstrated that treatment with rilzabrutinib showed clinically meaningful outcomes on response rate and disease markers.
In IgG4-RD patients, results from a phase 2a study (clinical study identifier: NCT04520451) showed treatment with
rilzabrutinib for 52 weeks led to reduction in disease flare, other disease markers, and glucocorticoid sparing. More detailed results will be shared at a forthcoming medical meeting.
The safety profile of rilzabrutinib in both studies was consistent with previous studies.
investigational, oral, reversible, BTK inhibitor that has the potential to be a first- and best-in-class treatment of several immune-mediated diseases. BTK, expressed in
B cells, macrophages, and other innate immune cells, plays a critical role in inflammatory pathways and multiple immune-mediated disease processes. With the application of Sanofi s TAILORED
COVALENCY technology, rilzabrutinib can selectively inhibit the BTK target while potentially reducing the risk of off-target side effects. Based on its
ability to drive multi-immune modulation, rilzabrutinib holds great promise in the treatment of multiple clinical indications.
Affecting one to three people out of 100,000 in the US each year, wAIHA is a rare, potentially life-threatening, autoimmune disorder where autoantibodies lead to the
premature destruction of the body s own red blood cells (hemolysis). People living with wAIHA may experience debilitating fatigue, thromboembolism, dizziness, palpitations, and shortness of breath as the rate of production of new red blood
cells in their bone marrow cannot compensate quickly enough for premature destruction of red blood cells.
IgG4-RD affects approximatively eight out of 100,000 adult patients
in the US each year and is a rare, progressive, relapsing, chronic fibro-inflammatory condition which can manifest in almost every organ and can lead to organ damage and irreversible dysfunction with a sometimes-fatal outcome.
ITP is a rare, complex autoimmune
disorder characterized by low platelet counts (less than 100,000/ L) resulting from both increased platelet destruction and decreased platelet production. Beyond bruising and bleeding, which can include potentially life-threatening episodes
like intracranial hemorrhage, people living with ITP may experience arterial or venous thrombosis, which can result from the ITP itself, from other medical comorbidities, or may also be associated with the use of certain other ITP treatments.
Additionally, people living with ITP often experience easily overlooked symptoms that can significantly impair their quality of life, such as unexplained fatigue, anxiety or depression, and cognitive impairment.
We are an innovative global
healthcare company, driven by one purpose: we chase the miracles of science to improve people s lives. Our team, across the world, is dedicated to transforming the practice of medicine by working to turn the impossible into the possible. We
provide potentially life-changing treatment options and life-saving vaccine protection to millions of people globally, while putting sustainability and social responsibility at the center of our ambitions.
Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY
+33 6 25 09 14 25 | sandrine.guendoul@sanofi.com
Evan Berland | +1 215 432 0234 | evan.berland@sanofi.com
Nicolas Obrist | +33 6 77 21 27 55 |
Bourhis | +33 6 75 06 43 81 | leo.lebourhis@sanofi.com
Victor Rouault | +33 6 70 93 71 40 | victor.rouault@sanofi.com
Timothy Gilbert | +1 516 521 2929 |
Thomas Kudsk Larsen |+44 7545 513 693 |
Kaisserian | +33 6 47 04 12 11 | alize.kaisserian@sanofi.com
Felix Lauscher | +1 908 612 7239 | felix.lauscher@sanofi.com
Keita Browne | +1 781 249 1766 |
| +33 7 85 93 30 17 | nathalie.pham@sanofi.com
Tarik Elgoutni | +1 617 710 3587 | tarik.elgoutni@sanofi.com
Thibaud Ch telet | +33 6 80 80 89 90 |
+33 6 84 00 90 72 | yun.li3@sanofi.com
Sanofi forward-looking statements
This press release contains
forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These statements include projections and estimates and their
underlying assumptions, statements regarding plans, objectives, intentions, and expectations with respect to future financial results, events, operations, services, product development and potential, and statements regarding future performance.
Forward-looking statements are generally identified by the words expects , anticipates , believes , intends , estimates , plans and similar expressions. Although Sanofi s
management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are
difficult to predict and generally beyond the control of Sanofi, that could cause actual results and developments to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks
and uncertainties include among other things, the uncertainties inherent in research and development, future clinical data and analysis, including post marketing, decisions by regulatory authorities, such as the FDA or the EMA, regarding whether and
when to approve any drug, device or biological application that may be filed for any such product candidates as well as their decisions regarding labelling and other matters that could affect the availability or commercial potential of such product
candidates, the fact that product candidates if approved may not be commercially successful, the future approval and commercial success of therapeutic alternatives, Sanofi s ability to benefit from external growth opportunities, to complete
related transactions and/or obtain regulatory clearances, risks associated with intellectual property and any related pending or future litigation and the ultimate outcome of such litigation, trends in exchange rates and prevailing interest rates,
volatile economic and market conditions, cost containment initiatives and subsequent changes thereto, and the impact that global crises may have on us, our customers, suppliers, vendors, and other business partners, and the
financial condition of any one of them, as well as on our employees and on the global economy as a whole. The risks and uncertainties also include the uncertainties discussed or identified in the
public filings with the SEC and the AMF made by Sanofi, including those listed under Risk Factors and Cautionary Statement Regarding Forward-Looking Statements in Sanofi s annual report on Form 20-F for the year ended December 31, 2024. Other than as required by applicable law, Sanofi does not undertake any obligation to update or revise any forward-looking information or statements.
All trademarks mentioned in this press release are the property of the Sanofi group.