An Open-label, Parallel, Phase 3, Two-arm Study to Investigate the Efficacy and Safety of Fitusiran Prophylaxis in Male Participants Aged 1 to Less Than 12 Years With Hemophilia A or B With or Without Inhibitory Antibodies to Factors VIII or IX

This is a parallel, Phase 3, two-arm, open-label study to evaluate the efficacy and safety of treatment with fitusiran prophylaxis administered to male pediatric participants (aged 1 to <12 years) who have severe hemophilia A or B, with or without inhibitory antibodies to FVIII or FIX.
Number of participants:
Approximately 85 participants will be enrolled into the study:
* Approximately 60 fitusiran-naïve participants with severe hemophilia A or B, with or without inhibitors (fitusiran-naïve arm), and
* Approximately 25 participants with severe hemophilia A or B with inhibitors rolling over from the EFC15467* dose confirmation study (roll-over arm).
* Fitusiran has been investigated in the pediatric population in study EFC15467, which enrolled male participants aged 1 to <12 years with hemophilia A or B with inhibitors to examine the safety and tolerability of fitusiran in the pediatric population.
Participants will be enrolled into 1 of 2 arms:
* Fitusiran-naïve: these participants have not previously received fitusiran, and they will undergo screening and study eligibility assessments. Once enrolled, they will go through a 24-week standard of care (SOC) period before starting fitusiran prophylaxis.
* Roll-over participants from the EFC15467 study: only participants who are still on active treatment in study EFC15467 and consenting to study EFC17905 will be eligible to roll over. They will not need to undergo screening or further eligibility assessments. They will directly enroll into the fitusiran treatment period and continue treatment on their current fitusiran dose.
The duration of fitusiran treatment will be up to 160 weeks for the fitusiran-naïve arm and up to 60 weeks for the roll-over arm.

Start Date18 Dec 2025

Sponsor / Collaborator

Sanofi

NCT06145373

/ RecruitingPhase 4

An Open-label, Single-arm Treatment Study to Investigate the Safety and Tolerability of Switching From Emicizumab to Fitusiran Prophylaxis in Male Participants Aged ≥12 Years of Age With Severe Hemophilia A, With or Without Inhibitors

This is an exploratory, single group, Phase 4, study to assess treatment with fitusiran prophylaxis after switching from emicizumab prophylaxis.
This study aims to evaluate the safety and tolerability of switching to fitusiran after a transition period from the last dose of emicizumab. The study will be conducted in male participants with severe hemophilia A, with or without inhibitors, aged ≥12 years, who were previously receiving emicizumab prophylaxis.
Study details include:
* The study duration will be up to approximately 28 months:
* There will be an approximately 2-month screening period.
* There will be an approximately 2-month period before fitusiran treatment starts (pre-fitusiran treatment period)
* The fitusiran treatment duration will be up to 18-months (fitusiran treatment period)
* The antithrombin (AT) follow-up (FU) period will be approximately 6 months after the last dose of fitusiran (during which the AT activity level will be monitored at approximately monthly intervals following the final fitusiran dose until AT activity levels return to at least 60%).
* The study site visits are scheduled at monthly/ every 2 months intervals of 28 days (4 weeks) / 56 days (8 weeks), respectively, during the fitusiran treatment period.

Start Date01 Mar 2024

Sponsor / Collaborator

Sanofi

NCT05662319

/ Active, not recruitingPhase 3

A Phase 3, Single-arm, Multicenter, Multinational, Open-label, One-way Crossover Study to Investigate the Efficacy and Safety of Fitusiran Prophylaxis in Male Participants Aged ≥ 12 Years With Severe Hemophilia A or B With or Without Inhibitory Antibodies to Factor VIII or IX

This is a multicenter, multinational, open-label, one-way cross-over, Phase 3, single-arm study for treatment of hemophilia.
The purpose of this study is to measure the frequency of treated bleeding episodes with fitusiran in male adult and adolescent (≥12 years old) participants with hemophilia A or B, with or without inhibitory antibodies to factor VIII or IX who have switched from their prior standard of care treatment.
The total study duration will be up to approximately 50 months (200 weeks, 1 study month is equivalent to 4 weeks) and will include:
* A screening period up to approximately 60 days,
* A standard of care (SOC) period of approximately 6 study months (24 weeks),
* A fitusiran treatment period of approximately 36 study months (144 weeks),
* An antithrombin (AT) follow-up period of approximately 6 study months (24 weeks) but may be shorter or longer depending on individual participants AT recovery.
The frequency for telephone visits will be approximately every 2 weeks. For site visits the frequency will be approximately every 8 weeks during the SOC period and approximately every 4 weeks during the fitusiran treatment period. If applicable and if allowed by local regulation, home and/or remote visits may be conducted during the study

Start Date01 Feb 2023

Sponsor / Collaborator

Sanofi

100 Clinical Results associated with Fitusiran

100 Translational Medicine associated with Fitusiran

100 Patents (Medical) associated with Fitusiran

Literatures (Medical) associated with Fitusiran

01 Feb 2026·AMERICAN JOURNAL OF MANAGED CARE

Redefining hemophilia management: treatment goals, nonfactor replacement therapies, and the role of fitusiran

Article

Author: Pipe, Steven W

Hemophilia is a rare, but debilitating congenital bleeding disorder. Current therapeutic guidelines, last updated in 2020, recommend recombinant clotting factor concentrates as the standard replacement therapy, with emicizumab offered as an alternative nonfactor standard of care. Since the publication of those guidelines, approvals of new gene-based and nonfactor therapies have reshaped the therapeutic landscape. This supplement describes the safety and efficacy of those therapies approved after the 2020 guidelines were published. It also presents managed care considerations describing how opportunities for resource optimization, therapeutic efficiency, and alternative administration approaches may advance progress toward aspirational treatment goals. A main focus is on fitusiran, the most recently approved nonfactor therapy, which introduced a novel mechanism of action and dosing strategy to the hemophilia therapeutic landscape in addition to its broad patient applicability. As this and other therapeutic advancements redefine the standard of care for patients with hemophilia, managed care and policy frameworks must adapt to ensure timely access and affordability. Likewise, updates to clinical guidelines and care pathways are essential to capture the rapidly evolving therapeutic landscape.

01 Nov 2025·HAEMOPHILIA

Utilising Thrombin Generation Assay to Guide Co‐Administration of Factor Therapies With Fitusiran

Letter

Author: Dericquebourg, Amy ; Rezigue, Hamdi ; Jourdy, Yohann ; Lienhart, Anne ; Nougier, Christophe ; Leuci, Alexandre ; Dargaud, Yesim ; Desage, Stephanie

01 Aug 2025·DRUGS

Fitusiran: First Approval

Review

Author: Lee, Arnold

Haemophilia A and B are inherited bleeding disorders caused by mutations in clotting factors. Small interfering RNA therapies may be utilised to restore coagulation by preventing the synthesis of antithrombin. Fitusiran (QFITLIA™) is a small interfering RNA therapy that targets antithrombin, which is being developed by Sanofi for the prophylactic management of haemophilia A and B with or without inhibitors. Fitusiran has the potential to be administered less frequently than other prophylactic treatments for haemophilia. This article summarizes the milestones in the development of fitusiran leading to this first approval for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and paediatric patients aged 12 years and older with haemophilia A or B with or without factor VIII or IX inhibitors.

News (Medical) associated with Fitusiran

02 Mar 2026

·www.pharmaceutical-technology.com

Sanofi receives CHMP recommendation for Dupixent approval in Europe

CSU is a chronic skin disease driven partly by type 2 inflammation, leading to severe itching and hives. Credit: Pormezz / Shutterstock.com. The Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has issued a positive opinion recommending the approval of Sanofi and Regeneron’s Dupixent (dupilumab) in the European Union (EU) for paediatric patients with chronic spontaneous urticaria (CSU). The recommendation applies to children aged two to 11 years experiencing moderate-to-severe CSU who do not respond adequately to histamine-1 antihistamines and are naïve to anti-immunoglobulin E (IgE) therapy. It is based on results from the LIBERTY-CUPID clinical programme, including two Phase III trials (Study A and Study C) involving children aged six to 11 years, and the single-arm CUPIDKids Phase III study for children aged two to 11 years with CSU. A final decision is anticipated in the coming months. Dupixent is already approved for use in certain adults and adolescents with CSU in regions including the EU, Japan, and the US. In the US, a supplemental biologics licence application is under review to extend approval of Dupixent for children aged two to 11 years, with a decision from the US Food and Drug Administration (FDA) anticipated by April 2026. GlobalData Strategic Intelligence US Tariffs are shifting - will you react or anticipate? Don’t let policy changes catch you off guard. Stay proactive with real-time data and expert analysis. By GlobalData Learn more about Strategic Intelligence CSU is a chronic skin disease driven partly by type 2 inflammation, leading to severe itching and hives. Dupixent is a human monoclonal antibody targeting interleukin-4 and interleukin-13 pathways without serving as an immunosuppressant. It is being jointly developed by Sanofi and Regeneron and studied across over 60 clinical trials involving more than 12,000 patients with type 2 inflammation-driven diseases. Ongoing Phase III studies are evaluating further potential indications. In December 2025, China’s National Medical Products Administration (NMPA) granted approval for Sanofi’s rare haematologic disease treatments, Qfitlia (fitusiran) and Cablivi (caplacizumab), for patients with haemophilia and acquired thrombotic thrombocytopenic purpura (aTTP), respectively.

Phase 3Drug ApprovalImmunotherapy

12 Feb 2026

·endpoints.news

Sanofi’s new CEO Belén Garijo gets frosty reception as Dupixent challenge awaits

The negative reaction to the impending departure of Sanofi CEO Paul Hudson, and Merck KGaA leader Belén Garijo as his replacement, is perhaps surprising given the French company’s muted performance under Hudson’s leadership. Sanofi’s shares fell about 3% in Paris and 4% in New York, a cold shoulder that may simply reflect the scale of the challenge that Garijo faces when she takes the reins in late April. She’ll have less than five years before the company’s immunological juggernaut Dupixent goes generic. Investors are concerned Garijo doesn’t have a track record of delivering R&D productivity at Merck KGaA, Jefferies managing director Michael Leuchten told Endpoints News in an interview. He considers that criticism “a little unfair” because the German conglomerate focused its capital allocation on areas other than pharma. “We thought the negative reaction on share price was harsh and kind of misses some of the nuances of what may be going on here,” Leuchten said. The company’s shares have lost about a quarter of their value in the past year. Garijo and her team will have to find pragmatic ways to extend Dupixent’s exclusivity, which could be possible through patent settlements and building on its joint venture with Regeneron, because there isn’t time to “rebuild an R&D organization from scratch” before Dupixent’s patent expires, Leuchten said. “One scenario that I think is possible is for Sanofi to go and acquire some assets that they fully fund and put those assets into the joint venture,” Leuchten said. Sanofi’s strategic priorities will remain unchanged under Garijo, a company spokesperson told Endpoints in an email. At Merck KGaA, Garijo’s history of dealmaking wasn’t scintillating. The biggest deal the company closed under her leadership was the $3.9 billion SpringWorks acquisition , and the rare cancer drugs Merck KGaA obtained haven’t been particularly lucrative so far. Another aspect driving some of the skepticism is that Garijo has had trouble delivering on promises in the past. In a letter in early 2022, she set out a goal for Merck KGaA known as “25 by 25” — achieving €25 billion ($27 billion) in total sales by 2025. The group won’t report its 2025 earnings until next month, but last October it guided to 2025 net sales between €20.8 billion and €21.4 billion. This missed goal is undeniably partly due to pipeline misfires. The failure of Merck KGaA’s evobrutinib in multiple sclerosis in late 2023 was followed by the cancellation of the pivotal trial of the head and neck cancer drug xevinapant in June 2024, after an interim analysis concluded the study was headed for failure. But Sanofi’s efforts to improve its drug development under Hudson didn’t always go as planned either. In 2019, at the beginning of his tenure as CEO, Hudson highlighted six programs as priorities. Two made it to market, Qfitlia (for hemophilia) and Beyfortus (for respiratory syncytial virus), but the others have either disappointed or failed entirely. Hudson also stopped developing a GLP-1 program for diabetes called efpeglenatide, just as other drugmakers were stepping up development efforts of this mechanism in obesity. There is no guarantee that asset would have gone on to do well, but the decision looks poor in retrospect. Sanofi’s current strategy involves going big on vaccines and investing in deals with a budget of up to €15 billion to spend across four key therapeutic areas: immunology, vaccines, neurology and rare diseases. This seems unlikely to compensate for Dupixent’s loss of exclusivity, since the drug accounted for 36% of Sanofi’s 2025 revenues. It was perhaps Sanofi’s eagerness on immunology that led things to go wrong at the French drugmaker under Hudson in the first place, Leuchten said. Sanofi assumed that immunology can be approached rationally and with acceptable risk, but time has shown that the space is “a lot more complicated than we thought,” Leuchten said. “The placebo response rates are all over the shop, you get intratrial variability, so the rational approach doesn’t work as well as anybody thought.” Sanofi’s change at the top seems to have happened fast; CEO transitions can be planned around a year in advance in the normal run of things. But Sanofi has ousted leaders with unceremonious haste before. In 2014 it sacked then-CEO Chris Viehbacher after a boardroom clash over Viehbacher’s management style.

Executive Change

29 Jan 2026

·www.globenewswire.com

Press release: 2025: strong sales and EPS growth. Continued profitable growth expected in 2026

2025: strong sales and EPS growth.Continued profitable growth expected in 2026 Paris, January 29, 2026 Q4 sales growth of 13.3% at CER1 and business earnings per share (EPS)2 of €1.53 Pharma launches increased sales by 49.4%, reaching €1.1 billion, primarily driven by Ayvakit and ALTUVIIIODupixent sales increased by 32.2% to €4.2 billion, a strong end to the yearVaccines sales decreased by 2.5% to €2.0 billion, with influenza performing better than anticipatedResearch and Development expenses reached €2.3 billion, up by 6.6%Selling, general and administrative expenses reached €2.7 billion, up by 9.6%, supporting launchesBusiness EPS was €1.53, up by 26.7% at CER; 16.8% at actual exchange rates, delivering profitable growth; IFRS EPS -€0.66 Pipeline progress Ten regulatory approvals across immunology, rare diseases, and otherPositive phase 3 readouts: amlitelimab program in AD (COAST 2, SHORE) and Dupixent in AFRSTolebrutinib in PPMS did not meet the primary endpointFour regulatory submission acceptances, five phase 3 study starts, three regulatory designations (orphan, priority reviews) Capital allocation Announcement of the Dynavax acquisition3 and completion of the Vicebio acquisitionCompletion of the €5 billion share buyback programProposed dividend of €4.12; up by 5.1% Other major developments Sanofi reached agreement with the US government to lower medicine costs while strengthening innovationSanofi leads an industry working group on biopharma life cycle assessment Guidance In 2026, sales are expected to grow by a high single-digit percentage at CER. Business EPS at CER is expected to grow slightly faster than sales (before share buyback), delivering profitable growth.4 Sanofi intends to execute a share buyback program in 2026 of €1 billion. Paul Hudson, Chief Executive Officer: “In the fourth quarter, sales growth accelerated to 13.3%, delivering another strong performance. Growth was supported by new medicines and Dupixent, reaching a new quarterly high. Business EPS was up by 26.7% with the benefit of cost discipline and growth leverage. We obtained ten regulatory approvals across immunology, rare diseases, and other, and had several positive phase 3 readouts. In 2025, we achieved a strong year of profitable growth. Sales increased by 9.9% at constant exchange rates, while business EPS improved significantly faster by 15.0%. We launched three new medicines and vaccines: Qfitlia, Wayrilz, and Nuvaxovid, providing innovative options to patients with rare diseases and COVID-19 prevention. All this was made possible by the dedicated effort of all Sanofi colleagues worldwide. In 2026, we expect sales to grow by a high single-digit percentage and business EPS to grow slightly faster than sales. We anticipate profitable growth to continue over at least five years.” Q4 2025ChangeChange at CERFY 2025ChangeChange at CERNet sales €11,303m +7.0% +13.3% €43,626m +6.2% +9.9%IFRS net income€(801)m -260.5% — €7,813m +40.5% — IFRS EPS€(0.66) -265.0% — €6.40 +44.1% — Free cash flow5 €2,637m +12.7% — €8,089m +35.8% — Business operating income €2,341m +12.7% +21.7 % €12,149m +7.1% +11.9%Business net income €1,856m +13.0% +22.3 % €9,555m +7.2% +12.1%Business EPS €1.53 +16.8% +26.7% €7.83 +10.0% +15.0% 1 Changes in net sales are at constant exchange rates (CER) unless stated otherwise (definition in Appendix 9).2 To facilitate an understanding of operational performance, Sanofi comments on the business net income, a non-IFRS financial measure (definition in Appendix 9). The income statement is in Appendix 3 and a reconciliation of IFRS net income to business net income is in Appendix 4.3 The acquisition of Dynavax is currently pending; it is expected to close in Q1 2026 subject to the satisfaction of customary closing conditions.4 Applying January 2026 average currency exchange rates, the currency impacts are estimated at c.-2% on sales and at c.-3% on business EPS.5 Free cash flow is a non-IFRS financial measure (definition in Appendix 9). Attachment Press release

Phase 3AcquisitionClinical ResultDrug ApprovalOrphan Drug

100 Deals associated with Fitusiran

External Link

KEGG	Wiki	ATC	Drug Bank
-	-	-	DB15002

R&D Status

Approved

10 top approved records.

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Indication	Country/Location	Organization	Date
Hemophilia A	United States	Genzyme Corp.	28 Mar 2025
Hemophilia B	United States	Genzyme Corp.	28 Mar 2025

Developing

10 top R&D records.

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Indication	Highest Phase	Country/Location	Organization	Date
Hemophilia	Phase 3	China	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	France	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	Germany	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	Greece	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	Italy	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	Mexico	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	Saudi Arabia	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	South Africa	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	South Korea	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023
Hemophilia	Phase 3	Taiwan Province	Sanofi-Aventis Recherche & Développement SA	28 Jul 2023

Clinical Result

Indication

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Study	Phase	Population	Analyzed Enrollment	Group	Results	Evaluation	Publication Date


NCT02554773 (OLE, ASH2025)	Phase 2/3	Hemophilia B \| Hemophilia A	71	Fitusiran	yzzfaxlene(wzxtfyalef) = cqvutrxnbj xwxxyaqtqq (uxkuurgmwf ) View more	Positive	06 Dec 2025
NCT03417245 \| NCT03417102 \| NCT03754790 (ATLAS-OLE, FDA_CDER) Manual	Phase 3	Hemophilia B \| Hemophilia A	-	QFITLIA AT-DR (prior bypassing agent)	vgyywdjymu(jamymxkrts) = atrfgdgjas fnepdyvvkj (jpnynhhryz, 2.8 - 9.5) View more	Positive	28 Mar 2025
				On-Demand BPA (prior bypassing agent)	vgyywdjymu(jamymxkrts) = lmkteygmkw fnepdyvvkj (jpnynhhryz, 11.8 - 31.0) View more
NCT02554773 (Pubmed) Manual	Phase 2	Hemophilia B \| Hemophilia A	34	fitusiran (AT-based dose regimen)	eqjhobdwvr(netogmlmba) = yvrnnnmiko amxifolplp (mnqxrjvexm )	Positive	06 Dec 2024
				fitusiran (the original dose regimen)	eqjhobdwvr(netogmlmba) = qrgcgptwha amxifolplp (mnqxrjvexm )
NCT02554773 (OLE, CTgov)	Phase 1/2	Hemophilia B \| Hemophilia A	34	fitusiran (Original Dose Regimen (SAS 1))	sreeqcakcn = uorotrttpg lapeaymfcq (jrflcrwuff, ihloxnixwn - hczzearwzp) View more	-	05 Jun 2024
				fitusiran (AT-Based Dose Regimen (SAS 2))	sreeqcakcn = yqzfuubrpl lapeaymfcq (jrflcrwuff, qooyqjjbfm - hpgcmeqeeu) View more
NCT03417102 (ATLAS-INH, Pubmed) Manual	Phase 3	Hemophilia B \| Hemophilia A	57	fitusiran	kbuezjbota(itxqpuhvtj) = tpgsztcpuj fdsdfpyjkd (zjzizyyhhx, 1.0 - 2.7) View more	Positive	29 Apr 2023
				bypassing agents	kbuezjbota(itxqpuhvtj) = ulhykinjsb fdsdfpyjkd (zjzizyyhhx, 10.6 - 30.8) View more
NCT03549871 (ATLAS-PPX, GlobeNewswire) Manual	Phase 3	Hemorrhage \| Hemophilia B	80	Fitusiran	wgegsvkqzi(wyntrmcoaz) = rbmstjmxgy xdqeqnnxns (micitpakhq ) View more	Positive	10 Jul 2022
NCT03549871 (ATLAS-PPX, ISTH2022)	Phase 3	Hemophilia	217	fitusiran	rjtpwqgzjq(dvxbwgdspu) = okehoipwva zapbrjewnb (wrvinyctra )	-	09 Jul 2022
NCT03417245 \| NCT03417102 (ATLAS-INH, ISTH2022)	Phase 3	Hemophilia inhibitors	118	Fitusiran prophylaxis	hldmlzkwfk(giciescrxn) = hugzlwzflh wunbyevmeh (mhovphbwig ) View more	-	09 Jul 2022
NCT03417102 (ISTH2022)	Phase 3	Hemophilia A	-	Fitusiran prophylaxis	ewoujljkyy(eohvouianw) = mkovzuwoej nurbrqmswx (jqdoycsxlp ) View more	-	09 Jul 2022
NCT03417245 (ATLAS-A/B, CTgov)	Phase 3	Hemophilia B \| Hemophilia A	120	factor concentrates (Factor On-demand)	aihaygwabp = otjlwtsmgc rnljbiwakm (oqdlmjiqsv, yrtlorttsw - cyeojaspnn) View more	-	04 Feb 2022
				factor concentrates+fitusiran (Fitusiran 80 mg Prophylaxis)	aihaygwabp = sanuyxbyhz rnljbiwakm (oqdlmjiqsv, oaoezgaony - fyuytywyfe) View more

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