Pacritinib for Prostate Cancer

(POSTPONE Trial)

Overseen By Medical College of Wisconsin Cancer Center Clinical Trials Office

Age: 18+

Sex: Male

Trial Phase: Phase 2

Sponsor: Medical College of Wisconsin

Must be taking: Androgen deprivation therapy

Must not be taking: CYP3A4 inhibitors, Anticoagulants, others

Disqualifiers: Uncontrolled hypertension, Severe hepatic impairment, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 1

Duration: 24 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to test the effectiveness of pacritinib, an oral drug, in treating prostate cancer that has spread and no longer responds to standard hormone therapies. Researchers seek to determine if pacritinib can benefit patients whose cancer has progressed after other treatments. Eligible patients should have prostate cancer with signs of spreading, despite previous treatments, and a biopsy showing specific protein activity called STAT5. As a Phase 2 trial, this research focuses on measuring the treatment's effectiveness in an initial, smaller group, offering a chance to benefit from a potentially effective new therapy.

Will I have to stop taking my current medications?

The trial requires stopping certain medications before starting treatment. You must not use investigational agents within 28 days before starting, and you need to stop using strong CYP3A4 inhibitors or inducers, medications that increase bleeding risk, and those that prolong the QT interval at least 14 days before treatment.

Is there any evidence suggesting that pacritinib is likely to be safe for humans?

Research shows that patients generally tolerate pacritinib well. A study comparing pacritinib with other treatments found its safety to be similar or even better. Patients taking pacritinib experienced manageable side effects comparable to those of other treatments.

Additionally, a real-world study reviewed reports of side effects from people using pacritinib. This thorough review confirmed that serious side effects were uncommon, and most patients managed the treatment without major problems.

This evidence suggests that pacritinib is safe for many patients. However, individual experiences can vary, so it is important to discuss potential risks with a healthcare provider before starting a new medication. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for prostate cancer?

Unlike the standard treatments for prostate cancer, which often include hormone therapy, chemotherapy, or radiation, pacritinib is an oral drug that targets specific pathways involved in cancer cell growth. Researchers are excited about pacritinib because it inhibits JAK2, a protein that plays a crucial role in the proliferation of cancer cells. This targeted approach could potentially lead to fewer side effects and improved outcomes compared to traditional therapies. Additionally, being an oral medication, pacritinib offers a more convenient administration method, which may enhance patient compliance and quality of life.

What evidence suggests that pacritinib might be an effective treatment for prostate cancer?

Research has shown that pacritinib, a type of medication, has promising effects against tumors, particularly in prostate cancer. Studies have found that this drug can block a protein called JAK2, which aids cancer cell growth. In this trial, participants will receive pacritinib. Previous research suggests that patients with prostate cancer who used pacritinib experienced a slower increase in prostate-specific antigen (PSA) levels, indicating reduced cancer activity. This suggests that pacritinib might effectively slow the growth of prostate cancer in patients whose cancer persists despite other treatments. ^{5 6 7 8 9}

Who Is on the Research Team?

Deepak Kilari, MD

Principal Investigator

Medical College of Wisconsin

Are You a Good Fit for This Trial?

This trial is for individuals with metastatic castrate-resistant prostate cancer who have previously progressed on ARSI treatments. Participants must have a recent biopsy showing positive STAT5 activation.

Inclusion Criteria

Screening serum testosterone < 50 ng/dL

Ability to understand and sign informed consent document

I am 18 years old or older.

Exclusion Criteria

I have a long-term bowel condition like Crohn's or ulcerative colitis.

Use of investigational agents within 28 days prior to randomization

Seropositivity for human immunodeficiency virus

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

4 weeks

1 visit (in-person)

Treatment

Participants receive pacritinib 200 mg twice daily

24 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Pacritinib

Trial Overview The study is testing the effectiveness of pacritinib, taken at 200 mg twice daily, in treating metastatic castrate-resistant prostate cancer that's worsened after prior ARSI therapy.

How Is the Trial Designed?

Group I: Pacritinib Experimental Treatment 1 Intervention

Pacritinib is an oral drug.

Who Is Running the Clinical Trial?

Medical College of Wisconsin

Lead Sponsor

Trials

645

Recruited

1,180,000+

Citations

1. ascopubs.org ascopubs.org/doi/10.1200/JCO.2022.40.6_suppl.TPS220

A single-arm, open-label, phase 2 study evaluating ... Pacritinib (PAC) is a novel JAK2 inhibitor that suppresses wild-type Jak2 in cell-based assays and has demonstrated promising antitumor activity ...

2. clinicaltrials.gov clinicaltrials.gov/study/NCT07226713?rank=9

Pacritinib in Participants With Metastatic Castrate-Resistant ... This is a single-arm, open-label phase 2 study to evaluate the role of pacritinib for patients with metastatic castrate-resistant prostate ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8209752/

Pacritinib versus best available therapy for the treatment of ... Achievement of SVR greater than 10% at week 24 correlated with improved overall survival relative to achievement of SVR of less than 10% in ...

4. clinicaltrials.gov clinicaltrials.gov/study/NCT04635059

Study Details | NCT04635059 | Pacritinib for Biochemical ... The primary objective of this study is to determine the effect of pacritinib on the time to prostate-specific antigen (PSA) progression in patients with ...

5. mcw.edu mcw.edu/mcwknowledge/mcw-stories/when-prostate-cancer-returns

When Prostate Cancer Returns | Featured Stories Physicians track the levels of PSA circulating in a patient's blood to determine the effect of pacritinib on prostate cancer growth. The study ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT07226713

Pacritinib in Participants With Metastatic Castrate-Resistant ... A tumor sample must be obtained within 30 days of treatment. STAT5 activation levels need to be high, with positive STATA5 activation status ...

7. frontiersin.org frontiersin.org/journals/oncology/articles/10.3389/fonc.2025.1618267/full

a real-world study based on FDA Adverse Event Reporting ... The aim of study is provided a comprehensive profile of pacritinib's safety by evaluating the adverse events (AEs) using a real-world pharmacovigilance ...

8. ascopubs.org ascopubs.org/doi/10.1200/JCO.2022.40.16_suppl.7058

Risk-adjusted safety analysis of pacritinib (PAC) in patients ... Risk-adjusted analysis demonstrates that the safety profile of PAC 200 mg BID is comparable or superior to BAT, including RUX.

9. accessdata.fda.gov accessdata.fda.gov/drugsatfda_docs/nda/2022/208712Orig1s000IntegratedR.pdf

208712Orig1s000 INTEGRATED REVIEW - accessdata.fda.gov An Independent Data Monitoring Committee monitored the safety of pacritinib. No interim efficacy analysis was performed. For subjects who ...