FDA Approves Qfitlia™ (fitusiran), the First siRNA (RNAi Therapeutic) for the Treatment of Hemophilia A or B

By: Alnylam Pharmaceuticals, Inc. via Business Wire

March 28, 2025 at 16:44 PM EDT

– Qfitlia Becomes the Sixth Alnylam-Discovered RNAi Therapeutic Approved by U.S. FDA and First and Only to Treat Hemophilia A or B With or Without Inhibitors –

Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), the leading RNAi therapeutics company, today highlighted the significance of the U.S. Food and Drug Administration’s (FDA) approval of Qfitlia™ (fitusiran), the sixth Alnylam-discovered RNAi therapeutic approved in the U.S., and the first and only therapeutic to lower antithrombin (AT), a protein that inhibits blood clotting, with the goal of promoting thrombin generation to rebalance hemostasis and prevent bleeds. Qfitlia is indicated in the U.S. for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients 12 years of age and older with hemophilia A or B, with or without factor VIII or IX inhibitors (neutralizing antibodies). Alnylam scientists discovered Qfitlia, published the first clinical data in the New England Journal of Medicine in 2017 showing reduced bleeding rates in hemophilia patients, and initiated the Phase 3 development program. In 2014, Sanofi obtained global rights to co-develop and co-commercialize Qfitlia under a license and collaboration agreement. The agreement was amended in 2018, with Sanofi obtaining global development and commercialization rights to Qfitlia, and Alnylam becoming eligible to receive tiered royalties of 15 to 30 percent on global net sales.

Qfitlia is the sixth Alnylam-discovered medicine using its RNAi therapeutic platform to be approved to date. The approval marks the completion of the “products” goal in Alnylam’s P⁵x25 strategy, a set of corporate goals for 2025. Qfitlia has the potential to benefit the estimated one million people living with hemophilia A and B around the world.

“Today’s approval of Qfitlia is an important moment for Alnylam and our RNAi therapeutics platform, and for the patients living with hemophilia, who now have access to what we believe will be a transformative medicine,” said Yvonne Greenstreet, MBChB, Chief Executive Officer of Alnylam. “Clinical studies showed that by lowering antithrombin, Qfitlia was able to prophylactically reduce annualized bleeding rates by 90%. Importantly, based on its unique mechanism of action, Qfitlia has demonstrated efficacy in patients with hemophilia A or B, with or without inhibitors, with a subcutaneous injection regimen once every two months. We are excited about the potential of Qfitlia to be an important non-factor option for patients with this burdensome disease.”

Qfitlia is indicated in the U.S. to treat hemophilia A or B for adults and pediatric patients 12 years of age and older with or without inhibiting antibodies to factor VIII (hemophilia A) or factor IX (hemophilia B). Regulatory submissions for Qfitlia have also been completed in China and Brazil.

About RNAi Therapeutics

RNAi (RNA interference) is a natural cellular process of gene silencing that represents one of the most promising and rapidly advancing frontiers in biology and drug development today. Its discovery has been heralded as “a major scientific breakthrough that happens once every decade or so,” and was recognized with the award of the 2006 Nobel Prize for Physiology or Medicine. By harnessing the natural biological process of RNAi occurring in our cells, a new class of medicines known as RNAi therapeutics is now a reality. Small interfering RNA (siRNA), the molecules that mediate RNAi and comprise Alnylam’s RNAi therapeutic platform, function upstream of today’s medicines by potently silencing messenger RNA (mRNA) – the genetic precursors that encode for disease-causing or disease pathway proteins – thus preventing them from being made. This is a revolutionary approach with the potential to transform the care of patients with genetic and other diseases.

About Alnylam Pharmaceuticals

Alnylam (Nasdaq: ALNY) has led the translation of RNA interference (RNAi) into a whole new class of innovative medicines with the potential to transform the lives of people afflicted with rare and prevalent diseases with unmet need. Based on Nobel Prize-winning science, RNAi therapeutics represent a powerful, clinically validated approach yielding transformative medicines. Since its founding in 2002, Alnylam has led the RNAi Revolution and continues to deliver on a bold vision to turn scientific possibility into reality. Alnylam’s commercial RNAi therapeutic products include ONPATTRO^® (patisiran), AMVUTTRA^® (vutrisiran), GIVLAARI^® (givosiran), and OXLUMO^® (lumasiran), which are being developed and commercialized by Alnylam, and Leqvio^® (inclisiran) and Qfitlia^™ (fitusiran), which are being developed and commercialized by Alnylam’s partners, Novartis and Sanofi, respectively. Alnylam has a deep pipeline of investigational medicines, including multiple product candidates that are in late-stage development. Alnylam is executing on its “Alnylam P⁵x25” strategy to deliver transformative medicines in both rare and common diseases benefiting patients around the world through sustainable innovation and exceptional financial performance, resulting in a leading biotech profile. Alnylam is headquartered in Cambridge, MA. For more information about our people, science and pipeline, please visit www.alnylam.com and engage with us on X (formerly Twitter) at @Alnylam, or on LinkedIn, Facebook, or Instagram.

Alnylam Forward Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. All statements other than historical statements of fact regarding Alnylam’s expectations, beliefs, goals, plans or prospects including, without limitation, statements regarding Qfitlia’s potential to benefit people living with hemophilia A and B around the world, Qfitlia’s potential to be a transformational medicine, and Qfitlia’s potential to be an important non-factor option for patients with hemophilia; and the potential for Alnylam to receive royalties on global net sales of Qfitlia, should be considered forward-looking statements. Actual results and future plans may differ materially from those indicated by these forward-looking statements as a result of various important risks, uncertainties and other factors, including, without limitation, risks and uncertainties relating to: Sanofi’s ability to obtain marketing authorizations for Qfitlia in countries outside the U.S. and thereafter to launch Qfitlia and to obtain adoption and reimbursement for Qfitlia; Alnylam’s ability to successfully execute on its “Alnylam P⁵x25” strategy; Alnylam’s ability to discover and develop novel drug candidates and delivery approaches and successfully demonstrate the efficacy and safety of its product candidates; the pre-clinical and clinical results for Alnylam’s product candidates; actions or advice of regulatory agencies and Alnylam’s ability to obtain and maintain regulatory approval for its product candidates, as well as favorable pricing and reimbursement; successfully launching, marketing and selling Alnylam’s approved products globally; delays, interruptions or failures in the manufacture and supply of Alnylam’s product candidates or its marketed products; obtaining, maintaining and protecting intellectual property; Alnylam’s ability to manage its growth and operating expenses through disciplined investment in operations and its ability to achieve a self-sustainable financial profile in the future; Alnylam’s ability to maintain strategic business collaborations; Alnylam’s dependence on third parties for the development and commercialization of certain products, including Sanofi; the outcome of litigation; the risk of future government investigations and substantial changes in governmental polices, regulations, funding and enforcement; and unexpected expenditures; as well as those risks and uncertainties more fully discussed in the “Risk Factors” filed with Alnylam’s 2024 Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC), as may be updated from time to time in Alnylam’s subsequent Quarterly Reports on Form 10-Q, and in other filings that Alnylam makes with the SEC. In addition, any forward-looking statements represent Alnylam’s views only as of today and should not be relied upon as representing its views as of any subsequent date. Alnylam explicitly disclaims any obligation, except to the extent required by law, to update any forward-looking statements.