bonretinib (OB756) / Biosun Pharma - LARVOL DELTA

A PHASE 2, OPEN-LABEL, MULTICENTER STUDY EVALUATING THE SAFETY AND EFFICACY OF OB756, A NOVEL JAK2 INHIBITOR, IN JAK INHIBITOR-NAÏVE PATIENTS WITH ESSENTIAL THROMBOCYTHEMIA (EHA 2025) - P1/2 | "Essential thrombocythemia (ET) has a relatively favorable prognosis among MPNs, but it still carries a heavy disease burden, and many patients are intolerant to hydroxyurea or interferon therapy. OB756 shows good tolerability and efficacy in ET patients, rapidly achieving hematologic remission, reducing spleen size, and lowering JAK2V617F allele burden, with durable responses and low non-hematologic toxicity, emerging as a promising new treatment option."

Clinical • P2 data • Anemia • Essential Thrombocythemia • Gene Therapies • Leukopenia • Myeloproliferative Neoplasm • Thrombocytopenia • Thrombocytosis

A NOVEL JAK2 INHIBITOR OB756 INHIBITS MEGAKARYOPOIESIS DIFFERENTIATION AND PROPLATELET BIOGENESIS VIA PI3K-AKT SIGNALING PATHWAY IN PATIENTS WITH PH-NEGATIVE MYELOPROLIFERATIVE NEOPLASMS (EHA 2025) - "The novel JAK2 inhibitor OB756 inhibits MKs differentiation, ploidy, and platelet biogenesis via PI3K-AKT signaling pathway in Ph- MPNs, highlighting its potential clinical benefits for MPN patients."

Clinical • Essential Thrombocythemia • Hematological Disorders • Myeloproliferative Neoplasm • Oncology • Polycythemia Vera • Thrombocytopenia • Thrombocytosis • CD34 • ITGA2B • ITGB3

OB756 Showcases Favorable Tolerability in JAK Inhibitor–Naive Myelofibrosis (OncLive) - P1b/2 | N=85 | CTR20201950 | "The investigative JAK2 inhibitor OB756 was found to be well tolerated and to elicit meaningful clinical activity in the form of rapid and durable spleen reduction in Chinese patients with myelofibrosis who did not have prior exposure to JAK inhibition, according to data from a phase 1/2 study (CTR20201950) presented during the 2024 ASH Annual Meeting. In the phase 1 portion of the research, no dose-limiting toxicities were reported when the agent was administered at twice daily doses ranging from 8 mg to 32 mg. Investigators ultimately identified 16 mg and 20 mg twice daily as the recommended phase 2 dose (RP2D) according to p-STAT3 inhibited percentage in an Imax model. Of 66 evaluable patients, 54.5% achieved a spleen volume reduction (SVR) of at least 35% (SVR35) at the end of cycle 6. Moreover, 59.1% of patients achieved SVR35 at the time of the last follow-up; at the end of cycle 12, 50.0% had achieved SVR35."

P1/2 data • Myelofibrosis

First in-Class JAK2 Inhibitor OB756 Therapy for Patients with Polycythemia Vera : A Phase 2, Open-Label, Multicenter Study (ASH 2024) - "OB756 also showed durable CHR and few non-hematological TEAEs, and may be a new treatment option for PV patients. Furthermore, a randomized double-blind phase 3 study is ongoing, aiming to assess the efficacy and safety of OB756 compared to hydroxyurea in patients with PV in China (CTR20240873)."

Clinical • P2 data • Anemia • Cardiovascular • Myeloproliferative Neoplasm • Polycythemia Vera • Thrombocytopenia • Thrombosis

A Novel JAK2 Inhibitor OB756 in Treatment of Janus Kinase Inhibitor-Naive Patients with Myelofibrosis: A Phase 1/2, Open-Label, Multicenter Study (ASH 2024) - "Conclusion : OB756 is well tolerated and showed meaningful clinical activity in patients with MF, especially for quick and durable spleen reduction. OB756 also showed few non-hematological TEAEs, and may be a new treatment option for MF patients."

Clinical • P1/2 data • Anemia • Myelofibrosis • Thrombocytopenia • CALR

A Novel JAK2 Inhibitor OB756 Inhibits Megakaryopoiesis Differentiation and Proplatelet Biogenesis in Thrombocythemia and Polycythemia Vera (ASH 2024) - "2022ZYC-D09). *Correspondence to : Prof Jian Huang, E-mail : househuang@zju.edu.cn."

Hematological Disorders • Myeloproliferative Neoplasm • Oncology • Polycythemia Vera • Thrombocytopenia • Thrombocytosis • CD34 • ITGA2B • ITGB3

Phase Ib/II clinical study to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and initial efficacy of OB756 tablets in moderate to high-risk patients with primary myelofibrosis, postcytoplasmic myelofibrosis, and postthrombocythemia primary myelofibrosis (ChiCTR) - P1/2 | N=120 | Completed | Sponsor: The First Affiliated Hospital of Zhejiang University School of Medicine; Hangzhou Biosun Pharmaceutical Co., LTD

New P1/2 trial • Hematological Disorders • Myelofibrosis • Polycythemia Vera • Thrombocytosis