11 Hematology Headlines You Missed in December 2025

December saw significant progress in the hematology space, marked by key trial results at the 67th American Society of Hematology (ASH) Annual Meeting and Exposition, as well as a number of US Food and Drug Administration (FDA) approvals. Mitapivat and narsoplimab received approvals for anemia in alpha- or beta-thalassemia and hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA), respectively. At the same time, roxadustat was granted Orphan Drug Designation for myelodysplastic syndromes. Meanwhile, new data from the XTEND-ed trial and the LUNA 3 long-term extension provided key insights into the efficacy of efanesoctocog alfa and rilzabrutinib.

In light of this sudden influx of news, the editorial team at HCPLive has collected 11 of the most impactful headlines from December to make catching up a bit easier. Check them out below.

FDA Decisions

FDA Approves Fibrinogen, Human-chmt (Fesilty) for Congenital Fibrinogen Deficiency

On December 19, 2025, the FDA approved fibrinogen, human-chmt under the brand name Fesilty for the treatment of acute bleeding episodes in pediatric and adult patients with congenital fibrinogen deficiency (CFD), including hypo- or afibrinogenemia. The human blood coagulation factor has now received regulatory approval in 2 countries and is expected to receive approval across European markets in 2026. Additionally, parent company Grifols expects Fesilty to be available during the first half of 2026.

FDA Approves Omidubicel-onlv (Omisirge) As First Cellular Severe Aplastic Anemia Therapy

On December 8, 2025, the FDA approved omidubicel-onlv, making it the first approved hematopoietic stem cell transplant therapy for severe aplastic anemia and addressing a patient population with critically unmet medical need. Omidubicel-onlv functions via donated cord blood stem cells chemically enhanced with nicotinamide, which are given to a patient to restore the blood and immune system. It addresses limitations of umbilical cord blood as a source, including delayed hematopoietic recovery and increased infections. It also provides additional graft options for patients who need hematopoietic stem cell transplant.

FDA Grants Orphan Drug Designation to Roxadustat for Myelodysplastic Syndromes

On December 15, 2025, the FDA granted Orphan Drug Designation to FibroGen’s roxadustat for the treatment of myelodysplastic syndromes. The oral hypoxia-inducible factor prolyl hydroxylase inhibitor stimulates erythropoiesis by increasing endogenous erythropoietin production, enhancing iron absorption and mobilization and suppressing hepcidin. The decision was based on a post-hoc analysis of the phase 3 MATTERHORN trial, which displayed roxadustat’s association with greater transfusion independence compared to placebo in patients with high baseline transfusion burdens.

FDA Approves Narsoplimab (Yartemlea) As First TA-TMA Therapy

On December 24, 2025, the FDA approved Omeros Corporation’s narsoplimab-wuug – under the brand name Yartemlea – for the treatment of hematopoietic stem cell TA-TMA. This decision makes narsoplimab the first and only approved lectin pathway inhibitor in TA-TMA care. Results from a single-arm, open-label study and additional data from an expanded access program formed the backbone of the application; during these trials, narsoplimab treatment resulted in a 3- to 4-fold reductions in mortality risk compared with an external control cohort. Particularly of note, narsoplimab has no Boxed Warning and no Risk Evaluation and Mitigation Strategy, and vaccinations are not required before treatment.

FDA Approves Mitapivat (AQVESME) for Non-Transfusion-Dependent Alpha- and Beta-Thalassemia

On December 24, 2025, the FDA approved mitapivat, an oral activator of pyruvate kinase R, developed by Agios for the treatment of anemia in adults with alpha- or beta-thalassemia, a disease with historically few treatment options. The decision was based on the phase 3 ENERGIZE and ENERGIZE-T trials, both of which saw mitapivat recipients exhibit substantial hemoglobin response after treatment compared to placebo.

Trial Results

SUMMIT: Bezuclastinib Outperforms Placebo in Nonadvanced Systemic Mastocytosis

Data from the registration-directed part 2 of the phase 2 SUMMIT trial, presented at the 67th ASH meeting, showcased bezuclastinib’s benefits on patient-reported symptoms and objective measures of mast cell burden in patients with nonadvanced systemic mastocytosis (NonAdvSM). The trial enrolled a total of 179 patients; among these, 119 received bezuclastinib and 60 received placebo. By week 24, patients receiving bezuclastinib saw a substantial reduction of serum tryptase, while placebo recipients saw none.

Ianalumab Improves Stable Response, Reduces Fatigue in ITP, With Hanny Al-Samkari, MD

A presentation of the VAYHIT2 trial at ASH 2025 by Hanny Al-Samkari, MD, the Peggy S. Blitz Endowed Chair in hematology and oncology at the Massachusetts General Hospital, has shown ianalumab’s efficacy in prolonging time to treatment failure in patients with primary immune thrombocytopenia when combined with eltrombopag. Additionally, ianalumab improved stable response at 6 months, reduced fatigue, facilitated tapering off eltrombopag, and delayed the need for subsequent therapy.

VAYHIT3: Ianalumab Reduces Bleeding, Depletes B Cells in Immune Thrombocytopenia, With Philip Choi, MBBS, PhD

A secondary analysis of the VAYHIT3 trial, presented at ASH 2025 by Philip Choi, MBBS, PhD, an associate professor at the Australian National University College of Science and Medicine, highlighted ianalumab’s rapid reduction in bleeding events and B-cell depletion in patients with primary immune thrombocytopenia in heavily pretreated adults. A series of biomarker analyses are expected over the next 12-18 months.

Conference Coverage

HOPE-B: 5-Year Etranacogene Dezaparvovec Maintains Durable Efficacy and Safety in Hemophilia B, With Steven Pipe, MD

Presented by Steven Pipe, MD, professor of pediatrics and pathology at the University of Michigan, at ASH 2025, an analysis from the HOPE-B trial has shown that a single dose of etranacogene dezaparvovec maintains durable endogenous factor IX Padua expression and produces sustained reductions in bleeding rates in adult patients with moderately severe or severe hemophilia B, with ≤90% reduction by year 5. The adeno-associated virus vector-based one-time gene therapy received FDA approval in 2022 as the first gene therapy for adults with hemophilia B who use factor IX prophylaxis with current or prior life-threatening bleeding. Participants from the HOPE-B trial who have given consent will continue long-term monitoring for up to 15 years in the IX-TEND 3003 study.

Rilzabrutinib Preserves Platelet Response in ITP Through Extension Study, With David Kuter, MD

Data from the LUNA 3 trial, presented by David Kuter, MD, the director of clinical hematology at Massachusetts General Hospital, at ASH 2025, have shown rilzabrutinib’s capacity for sustained platelet responses and symptom improvement in patients with immune thrombocytopenia. This allowed patients enrolled in the trial to wean off of concomitant corticosteroids while maintaining platelet counts within a safe range. Additionally, median platelet counts stayed relatively consistent through an extension period of 33 months.

Efanesoctocog Alfa Improves Bleeding Regardless of Age in Hemophilia A, With Lynn Malec, MD, MSc

The XTEND-ed study, presented by Lynn Malec, MD, MSc, an associate professor in the division of hematology and oncology at the Medical College of Wisconsin, at ASH 2025, displayed efanesoctocog alfa’s tolerability and efficacy in providing bleed protection to adult, adolescent, and child patients with severe hemophilia A. This first-in-class high-sustained factor VIII replacement therapy decouples recombinant FVIII from endogenous von Willebrand factor, resulting in substantially reduced risk of spontaneous and traumatic bleeds.