A novel drug for myelofibrosis (MF) could become part of the first-line therapeutic scheme in combination with current drugs or by itself, according to a study recently published in Haematologica.
“Overall, zinpentraxin alfa showed evidence of clinical activity and tolerable safety as monotherapy and in combination with ruxolitinib in this open-label, non-randomized trial,” the authors wrote.
This interventional study consisted of an open-label phase 2 clinical trial that aimed to determine the safety and efficacy of zinpentraxin alfa for patients with MF. The intervention consisted of a screening stage of 4 weeks, followed by 24 weeks of treatment according to a scheme of 6 x 4-week cycles, and finally, a follow-up of 4 weeks.
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The trial included a total of 27 patients previously diagnosed with MF. The age ranged from 51 to 85 years, with a median of 67.0 years. About half of the samples had grade 3, and around a third grade 2 bone marrow fibrosis. Also, most of the participants showcased anemia, and about half had thrombocytopenia.
Although all patients received zinpentraxin 10 mg/kg, they formed part of 1 of 4 treatment groups according to the therapeutic scheme. Cohort 1 had 8 patients who received the treatment weekly, while cohort 2 had 7 patients who received it every 4 weeks. Cohorts 3 and 4 had 6 patients each who received zinpentraxin in combination with ruxolitinib, weekly or every 4 weeks, respectively.
Only 9 individuals showcased overall response at the 24-week follow-up, with an overall response rate (ORR) of 33%. Cohort 4 had the highest ORR of 50%, followed by cohort 1 with 38%, cohort 3 with 33%, and lastly, cohort 2 with only 14%.
Importantly, 28% of the cases exhibited a reduction of the Myeloproliferative Neoplasm-Symptom Assessment Form Total Symptom Score of 50% or more, and 35% improved bone marrow fibrosis of at least 1 grade.
“Moreover, prolonged administration of zinpentraxin alfa may alleviate the progressive anemia and thrombocytopenia resulting from the BM-associated fibrosis, as well as from the myelosuppressive activity of ruxolitinib and other JAK inhibitors,” the authors highlighted.
Regarding safety, most adverse events were tolerable, with fatigue as the most frequent. Abnormalities in the complete blood cell count, such as anemia and thrombocytopenia, occurred only in 3 and 1 patient, respectively. Serious adverse events manifested in 15% of the participants.
Reference
Verstovsek S, Foltz L, Gupta V, et al. Safety and efficacy of zinpentraxin alfa as monotherapy or in combination with ruxolitinib in myelofibrosis: stage I of a phase II trial. Haematologica. Published online May 11, 2023. doi:10.3324/haematol.2022.282411
