This phase II trial studies selinexor in treating patients with prostate cancer that has spread to other parts of the body (metastatic), keeps growing even when the amount of testosterone in the body is reduced to very low levels (castration-resistant), and did not respond to treatment (refractory) with abiraterone acetate and/or enzalutamide. Selinexor may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth.
PRIMARY OBJECTIVES: I. To describe radiographic progression free survival (rPFS) associated with selinexor in patients with abiraterone (abiraterone acetate) refractory metastatic castration-resistant prostate cancer (mCRPC). SECONDARY OBJECTIVES: I. To measure prostate-specific antigen (PSA) changes at 12 weeks post-selinexor initiation. II. To assess time to PSA progression. III. To measure time to development of \>= 2 new bone lesions. IV. To compare the relationship of abiraterone-resistance status (primary vs acquired) and treatment outcome. V. To determine the effect of selinexor on persistent pain associated with bone metastasis using the brief pain inventory (BPI) short form. VI. To describe the safety profile of selinexor in patients with metastatic castration-resistant prostate cancer. VII. To determine the effect of selinexor on circulating leukocyte exportin 1 (XPO-1) expression, leukocyte gene expression profile and macrophage inhibitory cytokine-1 (MIC-1) messenger ribonucleic acid (mRNA) expression. VIII. To assess serum selinexor trough levels as a function of dose and time since last dose. TERTIARY OBJECTIVES: I. To describe the relationship of XPO-1 expression to PSA decline. II. To describe the expression profile of metastatic tumor and outcome. III. To describe the type of progression (e.g. pain, bone etc). IV. To define XPO-1 expression in patients for whom pre- and post-treatment biopsy is obtained. OUTLINE: Patients receive selinexor orally (PO) on days 1 and 3 of weeks 1-3. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up for 30 days and then every 6 months thereafter.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
14
Given PO
University of California, San Francisco
San Francisco, California, United States
Radiographic Progression Free Survival (rPFS)
Defined as the time from study start until one of the following events occurs: \>= 2 new bone lesions on technetium bone scan; Response Evaluation Criteria in Solid Tumors (RECIST)-defined tumor progression; clinical deterioration requiring a change in prostate cancer therapy, or at clinician discretion; surgery or radiation to treat a prostate cancer related indication; or death from any cause.
Time frame: From study start up to 3 years
Abiraterone Resistance Status (Primary Versus Acquired)
Comparison of radiographic progression free survival between patients with primary abiraterone resistance and acquired abiraterone resistance using a Cox proportional hazards model.
Time frame: At baseline
Time to PSA Progression
Time between the first evaluation at which the response criteria are met and the first documentation of PSA (Prostate-Specific Antigen) progression or death. Progression is defined as a rise in PSA of 50% above nadir value or 25% above baseline if there is no decline.
Time frame: Time between the first evaluation at which the response criteria are met and the first documentation of PSA progression or death or up to 3 years
Incidence of Non-serious Adverse Events
Incidence of non-serious adverse events, graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0
Time frame: Up to 3 years after treatment start
Comparison of Leukocyte Exportin 1 (XPO-1) and Macrophage Inhibitory Cytokine-1 (MIC-1) Gene Expression Levels Pre- and Post-Selinexor Treatment
Total RNA isolated from leukocytes of patients will be used for quantitative polymerase chain reaction analysis (qPCR) in order to compare expression levels of XPO-1 and MIC-1 as a function of selinexor dose and total time on treatment.
Time frame: On days 1 and 15 of course 1 and on day 1 of courses 2 and 3
PSA Decline of ≥50% at 12 Weeks Post Therapy Initiation
The number of patients experiencing a PSA decline from baseline of at least 50% in PSA at 12 weeks following the initiation of study therapy.
Time frame: At 12 weeks post therapy initiation
Reduction in Pain for Symptomatic Patients, Measured Using the Brief Pain Inventory (BPI), Short Form
The effect of selinexor on persistent pain associated with bone metastasis, measured using the Brief Pain Inventory (BPI), Short Form. 0 denotes ''no pain'' and 10, ''pain as bad as you can imagine".
Time frame: At baseline and day 1 of every following cycle until end of treatment or 3 years after study start
Serum Selinexor Levels
Serum selinexor trough levels as a function of dose and time since last dose
Time frame: At day 1 of course 1, each treatment day until end of treatment up to 3 years
Time to Confirmed Development of >= 2 New Bone Lesions That Cannot be Attributable to Bone Scan Flare
Defined as time interval between the date of treatment initiation and the date of documented new lesions. Evaluation criteria is defined by the PSAWG2 (Prostate-Specific Antigen Working Group 2) criteria for bone scan evaluation. The time will be 'backdated' to when the \>= 2 new lesions were detected if a second scan is done to confirm progression.
Time frame: At week 8, 16, 24, and every 12 weeks thereafter up to 3 years after treatment start
Incidence of Serious Adverse Events
Incidence of serious adverse events, graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0
Time frame: Up to 3 years after treatment start
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