New data from Cohort 3 of the phase 2 REFINE study of investigational Navitoclax in combination with Ruxolitinib in JAK inhibitor naïve patients with myelofibrosis ( MF ), a rare blood cancer, were announced.
These preliminary findings have shown spleen volume and symptomatic improvement in this cohort.
The results presented at EHA 2022 [ 2022 European Hematology Association ( EHA ) Annual Congress ] were from a preliminary analysis of 32 JAK inhibitor naïve MF patients from Cohort 3 of the REFINE trial.
The primary endpoint was spleen volume reduction of 35% or more ( SVR35 ) from baseline at week 24.
Key secondary endpoints included 50% or more reduction in total symptom score ( TSS50 ) at week 24, anemia response and bone marrow fibrosis ( BMF ) reduction.
In the results, SVR35 was achieved by 63% of evaluable patients at week 24 ( 20/32 ) and by 78% at any time on treatment ( 25/32 ).
At week 24, 41% ( 11/27 ) of evaluable patients with measurable baseline symptoms reached TSS50; notably, 67% of patients ( 18/27 ) met this endpoint at any time during the study.
In this cohort, 35% of evaluable patients, with available fibrosis grade at baseline and during the study, ( 9/26 ) has achieved reduction in bone marrow fibrosis by 1 grade or more at any time during the study with three patients experiencing 2 grade or more reductions in bone marrow fibrosis.
Additionally, 40% of patients evaluable for anemia response ( 6/15 ) experienced improvement in anemia, a common clinical feature of myelofibrosis.
Preliminary safety analysis has identified no new safety signals.
Thirty-one ( 97% ) patients reported one or more adverse event. The most common grade 3 or more adverse events were thrombocytopenia ( 47% ), anemia ( 34% ), and neutropenia ( 25% ).
Seven patients ( 22% ) have reported experiencing serious adverse effects. Three patients ( 9% ) experienced an adverse effect leading to Navitoclax discontinuation and three patients ( 9% ) have reported an adverse event leading to Ruxolitinib discontinuation.
Navitoclax is an investigational, oral BCL-XL/BCL-2 inhibitor. The BCL-2 family of proteins are known regulators of the apoptosis pathway.
Myelofibrosis is a rare, difficult-to-treat blood cancer that results in excessive scar tissue formation ( fibrosis ) in the bone marrow.
Patients living with MF experience symptoms such as an enlarged spleen, fatigue, weakness, and severe anemia, that are often debilitating and greatly impact quality of life. Myelofibrosis also carries a risk of transformation to more aggressive disease such as acute myeloid leukemia. ( Xagena )
Source: Abbvie, 2022