FDA Grants Orphan Drug Designation to Roxadustat for Myelodysplastic Syndromes

The US Food & Drug Administration (FDA) granted roxadustat an Orphan Drug Designation for the treatment of myelodysplastic syndromes (MDS), announced by FibroGen, Inc., on December 15, 2025.1

“The Orphan Drug Designation granted to roxadustat for MDS underscores the significant treatment gap in this indication and highlights patients’ need for additional convenient treatments that can provide [a] durable response,” said FibroGen Chief Executive Officer Thane Wettig, MBA.1 “Roxadustat showed an improvement in transfusion-independence in a subset of patients with high transfusion burden in a post-hoc analysis from the Phase 3 MATTHERHORN trial, which, along with its favorable tolerability profile and oral route of administration, has the ability to set it apart from current second-line treatments.”

An estimated 58,000 people in the United States are living with lower-risk MDS, describing a group of disorders characterized by dysfunctional progenitor blood cells and stem cells. The vast majority, about 85%, develop anemia, a condition associated with elevated cardiovascular risk and increased reliance on blood transfusions.1

For patients who become transfusion dependent, rates of cardiac events, infections, and iron overload rise. Meanwhile, transfusion-dependent patients experience significant fatigue, cognitive dysfunction, and reduced quality of life.

Currently, less than half of patients (35% to 40%) on current first-line treatments, including luspatercept, imetelstat, or lenalidomide, reach transfusion independence. Even if transfusions help, relief is often temporary and may not be worth the trouble to dose-calibrate. At the moment, patients have limited options for second- or third-line treatments.1

A post hoc analysis of the phase 3 MATTERHORN trial showed that roxadustat was associated with greater transfusion independence than placebo among patients with a high baseline transfusion burden. Among patients receiving ≥ 4 units of red blood cells over 8 weeks at baseline, 36% (8/22) treated with roxadustat achieved transfusion independence for at least 56 days, compared with 7% (1/15) of those receiving placebo within 28 weeks (nominal P = .041).2

Roxadustat is an oral hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor that stimulates erythropoiesis by increasing endogenous erythropoietin production, enhancing iron absorption and mobilization, and suppressing hepcidin. The agent is currently approved for the treatment of anemia in patients with chronic kidney disease on dialysis in Europe, Japan, and several other countries.1

“Our team is finalizing the phase 3 protocol in this patient population for submission to the FDA in the fourth quarter of 2025,” Wettig added.1

References

1. FibroGen. Roxadustat Granted Orphan Drug Designation for the Treatment of Myelodysplastic Syndromes by the U.S. Food and Drug Administration. GlobeNewswire. Published December 15, 2025. Accessed December 15, 2025. https://www.globenewswire.com/news-release/2025/12/15/3205285/33525/en/Roxadustat-Granted-Orphan-Drug-Designation-for-the-Treatment-of-Myelodysplastic-Syndromes-by-the-U-S-Food-and-Drug-Administration.html

2. FibroGen Announces Positive Type C Meeting with the FDA for Roxadustat in Patients with Anemia Associated with Lower-Risk Myelodysplastic Syndromes | FibroGen, Inc. FibroGen, Inc. Published 2025. Accessed December 15, 2025. https://investor.fibrogen.com/news-releases/news-release-details/fibrogen-announces-positive-type-c-meeting-fda-roxadustat