Combining Pacritinib and Talazoparib for Patients with Myeloproliferative Neoplasms Not Responding to JAK2 Therapy

Phase I Study Accessing the Safety of Pacritinib in Combination With Talazoparib in Patients With Myeloproliferative Neoplasms Unresponsive to Frontline JAK2 (Janus Kinase 2) Inhibition

Phase 1 Interventional Fox Chase Cancer Center · NCT06218628

This study is testing a combination of two medications, pacritinib and talazoparib, to see if they can help patients with certain blood cancers who haven't responded to other treatments.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment24 (estimated)
Ages18 Years and up
SexAll
SponsorFox Chase Cancer Center Academic / other
Drugs / interventionspacritinib, ruxolitinib
Locations1 site (Philadelphia, Pennsylvania)
Trial IDNCT06218628 on ClinicalTrials.gov

What this trial studies

This phase I dose-escalation study aims to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of talazoparib when combined with standard dosing of pacritinib in patients with myeloproliferative neoplasms who have not responded to or cannot tolerate JAK2 inhibitors. Patients will undergo a lead-in phase with pacritinib before starting talazoparib, and the study will utilize a Bayesian Optimal Interval Design to assess dose-limiting toxicities. Eligibility requires a confirmed diagnosis of specific myeloproliferative neoplasms and a history of JAK2 therapy. Bone marrow biopsies will be performed to monitor treatment effects.

Who should consider this trial

Good fit: Ideal candidates include adults over 18 with specific types of myeloproliferative neoplasms who have progressed on or are intolerant to JAK2 inhibitors.

Not a fit: Patients who have not received prior JAK2 therapy or those with low-risk myelofibrosis may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment combination could provide a new therapeutic option for patients with myeloproliferative neoplasms who have limited treatment options.

How similar studies have performed: While there have been studies on JAK2 inhibitors, this specific combination of pacritinib and talazoparib is novel and has not been extensively tested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients must have histologically or cytologically confirmed primary myelofibrosis (PMF), post-polycythemia vera-myelofibrosis (PPV-MF), post-essential thrombocythemia-myelofibrosis (PET-MF), chronic myelomonocytic leukemia, polycythemia vera, or essential thrombocytosis according to the 2008 World Health Organization criteria
* Subject has at least 2 symptoms with a score ≥ 3 or a total score of ≥ 12, as measured by the MFSAF(Myelofibrosis Symptom Assessment Form) v4.0
* Subject classified as intermediate-2 or high-risk MF, as defined by the Dynamic International Prognostic Scoring System Plus (DIPSS+70).
* Age \> 18 years.
* ECOG (Eastern Cooperative Oncology Group) performance status 0-2
* Subject must have received prior treatment with a single JAK2 inhibitor 4.1.6 for at least 12 weeks with documented disease progression OR subject must have appearance of new splenomegaly that is palpable to at least 5 cm below the left costal margin (LCM) in subjects with no evidence of splenomegaly prior to the initiation of any first line JAK2 inhibitor
* Baseline QTc (corrected QT interval) \<0.47 seconds (Bazett formula)
* Patients must have normal organ function as defined in protocol.
* Ability to understand and willingness to sign a written informed consent and HIPAA consent document

Exclusion Criteria:

* Patients may not be receiving any other investigational agents
* Subjects must not be experiencing toxicity due to prior therapy that has not resolved to ≤Grade 1 by study registration, with the exception of sensory neuropathy related to previous systemic therapy exposure, alopecia and fatigue.
* Patients that have transformed to Acute Myeloid Leukemia defined by \>20% blasts count on peripheral blood smear or bone marrow biopsy evaluation
* Uncontrolled inter-current illness including, but not limited to, any other malignancy (with the exception of hormonal therapy for breast cancer/prostate cancer in remission \>1 year and for non-hormonal therapies for other cancers in remission for \>3 years), other ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, uncontrolled cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
* Patients with history of hemorrhagic stroke and evidence of uncontrolled bleeding as well as bleeding disorder
* Known HIV positive patients on combination antiretroviral therapy are ineligible because these patients are at increased risk of lethal infections when treated with marrow-suppressive therapy.
* Pregnant or breast-feeding.

Where this trial is running

Philadelphia, Pennsylvania

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Primary MyelofibrosisPost-polycythemia Vera MyelofibrosisPost-essential Thrombocythemia MyelofibrosisChronic Myelomonocytic LeukemiaPolycythemia VeraEssential ThrombocytosisTalazoparibPacritinib
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.