Recently, Dr. Huang Haowen, Deputy Director of our Comprehensive Internal Medicine Department, successfully prescribed Gucacitinib hydrochloride tablets (Zepan®) for a patient with myelofibrosis. Gucacitinib hydrochloride has broken the deadlock of limited targeted therapy options for myelofibrosis in China, and its clinical value has gained widespread recognition within the global hematology community.

About Myelofibrosis

Myelofibrosis is a BCR::ABL1-negative myeloproliferative neoplasm (MPN). Its main clinical features include anemia, progressive splenomegaly, constitutional symptoms, and a high risk of leukemic transformation. The prognosis for this disease is poor, with a 5-year survival rate of only 38.9% for patients, highlighting an urgent need to improve long-term survival. With in-depth research into the pathogenic mechanisms of myelofibrosis, inhibition of the JAK-STAT pathway has become the main clinical treatment strategy.

Key Clinical Study Data

The approval of Gucacitinib hydrochloride was primarily based on the results of the Phase III ZGJAK016 study. The ZGJAK016 study was a randomized, double-blind, double-dummy, parallel-controlled, multicenter study comparing the efficacy and safety of Gucacitinib hydrochloride versus hydroxyurea as a first-line treatment. The primary efficacy endpoint results showed that the proportion of subjects treated with Gucacitinib hydrochloride achieving a ≥35% reduction in spleen volume from baseline at 24 weeks (SVR35) was 64.8%. Other endpoint measures, including clinical improvement, anemia response, hemoglobin improvement, and disease symptom scores, also demonstrated favorable benefits.

Successful Inclusion in National Reimbursement Drug List

As China's first novel JAK/activin receptor (ACVR)1 dual inhibitor with independent intellectual property rights, the approval of Gucacitinib hydrochloride has ended the era of limited treatment options for myelofibrosis in China, marking a new stage in its treatment.

On December 7, 2025, the *National Reimbursement Drug List for Basic Medical Insurance, Work-Related Injury Insurance, and Maternity Insurance* was officially released, and Gucacitinib hydrochloride tablets (Zepan®) were successfully included. This not only fills the gap for a domestic JAK inhibitor in the field of myelofibrosis but also significantly reduces the treatment burden for patients and improves the accessibility of clinical medication. Furthermore, it will enable more patients to benefit from this innovative therapy.