Suzhou Zelgen Biopharmaceuticals Co., Ltd (SHA: 688266) has announced that the results of three clinical studies for its Category 1 drug jacktinib in myelofibrosis have been shortlisted for the European Hematology Association (EHA) annual meeting this year.
Phase III Study: Jacktinib vs. Hydroxyurea in Myelofibrosis
A randomized, double-blind Phase III study compared jacktinib with hydroxyurea in moderate-2 or high-risk myelofibrosis patients. The study aimed to assess the efficacy and safety of the drug in this patient population. As of April 28, 2022, the interim analysis included 47 patients receiving jacktinib and 23 patients receiving hydroxyurea treatment. At 24 weeks, the SVR35 rate was significantly higher in the jacktinib group (72.3%) compared to the hydroxyurea group (17.4%), with optimal splenic response rates of 80.9% and 26.1%, respectively. The TSS50 rates were 63.8% for the jacktinib group and 43.5% for the hydroxyurea group. In terms of safety, the incidence of AE ≥ grade 3 in the jacktinib group was lower than that in the hydroxyurea group.
Phase IIb Study: Jacktinib in Myelofibrosis Intolerant of Ruxolitinib
An open, single-center Phase IIb study assessed the safety and efficacy of jacktinib in myelofibrosis patients intolerant of ruxolitinib, consisting of dosage exploration and expansion phases. Subjects received 100 mg bid of jacktinib for at least 24 weeks. A total of 44 patients were included in the Full Analysis Set (FAS). At the 24th week, the SVR35 rate was 43.2%, with an optimal remission rate of the spleen at 54.5%. The median time to reach SVR35 was 12.1 weeks, and 80.4% of patients maintained spleen reactions for at least 24 weeks. At week 24, 61.8% of evaluable patients showed a ≥ 50% improvement in TSS compared to baseline.
Phase II Study: Jacktinib in Refractory or Recurrent Myelofibrosis
A single-arm, open, multi-center Phase II study assessed the safety and efficacy of jacktinib in refractory or recurrent myelofibrosis previously treated with ruxolitinib. Subjects received 100 mg bid of jacktinib for at least 24 weeks, with a total of 34 patients enrolled. At week 24, 11 patients (32.4%) achieved SVR35, and the optimal remission rate of the spleen was 38.2%. The median time to reach SVR35 was 8.1 weeks, and 46.4% of patients showed a ≥ 50% improvement in TSS compared to baseline.-Fineline Info & Tech
