A Study of Selinexor Monotherapy in Subjects With JAK Inhibitor-naïve Myelofibrosis and Moderate Thrombocytopenia (SENTRY-2)

Karyopharm Therapeutics

Status and phase: Enrolling; Phase 2

Conditions: Moderate Thrombocytopenia; Myelofibrosis; Mild Thrombocytopenia

Treatments: Drug: Selinexor 40 mg; Drug: Selinexor 60 mg; Drug: Momelotinib; Drug: Ruxolitinib; Drug: Pacritinib

Study type: Interventional

Funder types: Industry

Identifiers

NCT05980806

XPORT-MF-044

Details and patient eligibility

About

The main purpose of this study is to evaluate the efficacy of selinexor in JAKi-naïve participants with myelofibrosis (MF) and with normal platelet counts or with mild to moderate thrombocytopenia based on spleen volume reduction (SVR). Additional efficacy and safety parameters will also be assessed during the study.

Enrollment: 58 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Key Inclusion Criteria:

• A diagnosis of MF or post-ET or post-PV MF according to the 2016 World Health Organization (WHO) classification of MPN, confirmed by the most recent local pathology report
• Measurable splenomegaly during the screening period as demonstrated by spleen volume of greater than or equal to (>=) 450 cubic square centimeter (cm^3) by MRI or CT scan (results from MRI or CT imaging performed within 28 days prior to C1D1 are acceptable)
• DIPSS risk category of intermediate-1 with symptoms, or intermediate-2, or high-risk
• ECOG Performance Status less than or equal to (<=) 2
• Platelet count of greater than or equal to (>=) 50 x 10^9/L without platelet transfusion within 7 days prior to the first dose of selinexor
• Absolute neutrophil count (ANC) >=1.0 × 10^9/L without need for growth factors within 7 days prior to the first dose of selinexor
• Adequate liver function as defined by the following: aspartate transaminase (AST) and alanine transaminase (ALT) <= 2.5 × upper limit normal (ULN) and serum total bilirubin <= 3×ULN
• Calculated creatinine clearance (CrCl) greater than (>) 15 milliliter per minute (mL/min) based on the Cockcroft and Gault formula
• Active symptoms of MF as determined by presence of at least 2 symptoms with an average score >= 5 or total score of >= 12 at screening (at least 5 of 7 consecutive days immediately preceding C1D1) using the MFSAF V4.0
• Must provide bone marrow biopsy samples (samples obtained up to 3 months prior to C1D1 are permitted) at screening and during the study
• Currently not eligible for stem cell transplantation
• Must be willing to complete the MFSAF V4.0 daily during the study for evaluating the symptom response (i.e., TSS50)

Key Exclusion Criteria:

• More than 10% blasts in peripheral blood or bone marrow (accelerated or blast phase)
• Previous treatment with JAK inhibitors for MF
• Previous treatment with selinexor or other XPO1 inhibitors
• Females who are pregnant or lactating
• Prior splenectomy, splenic radiation, or a splenic embolization within 6 months prior to C1D1
• History of myocardial infarction, unstable angina, percutaneous transluminal coronary angioplasty (PTCA), coronary artery bypass graft (CABG), cerebrovascular accident (transient ischemic attack [TIA]), ventricular arrhythmias, congestive heart failure class > 2 per New York Heart Association (NYHA) within 6 months of C1D1
• Unable to tolerate two forms of antiemetics prior to each dose for the first two cycles

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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58 participants in 2 patient groups

Selinexor 60 mg (Arm 1)

Experimental group

Description:

Participants will receive selinexor 60 milligrams (mg) oral tablets once weekly (QW) (Days 1, 8, 15, and 22 of each 28-day cycle) until PD, intolerable toxicity, or until they meet the criteria for discontinuation of study treatment. Optional add-on medication dosing may be initiated based on Spleen Volume Reduction (SVR) values at Week 12 or Week 24 of treatment.

Treatment:

Drug: Pacritinib

Drug: Ruxolitinib

Drug: Momelotinib

Drug: Selinexor 60 mg

Selinexor 40 mg (Arm 2)

Experimental group

Description:

Participants will receive selinexor 40 mg oral tablets QW (Days 1, 8, 15, and 22 of each 28-day cycle) until PD, intolerable toxicity, or until they meet the criteria for discontinuation of study treatment. Optional add-on medication dosing may be initiated based on Spleen Volume Reduction (SVR) values at Week 12 or Week 24 of treatment.

Treatment:

Drug: Pacritinib

Drug: Ruxolitinib

Drug: Momelotinib

Drug: Selinexor 40 mg