Phase 1/ Phase 2 Study to Assess Safety and Efficacy of Orally Administered JBI-802 in Subjects With Myeloproliferative Neoplasms (MPN) and Myelodysplastic/Myeloproliferative Neoplasms (MDS/MPN) With Thrombocytosis

NCT07612280 | Recruiting Phase 1

• 2 other identifiers: JBI-802-102ACTRN12624000478516
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 7

Brief Summary

This study aims to assess the safety and efficacy of orally administered JBI-802 in subjects with Myeloproliferative Neoplasms (MPN) and Myelodysplastic/ Myeloproliferative Neoplasms (MDS/MPN) with Thrombocytosis. Who is it for? You may be eligible to join this study if you are aged 18 years and over have been diagnosed with Essential Thrombocythemia and either a Morphologically confirmed diagnosis of Myeloproliferative Neoplasms (MPN) or Myelodysplastic/Myeloproliferative Neoplasms (MDS/MPN). Study details: Participants in this study will receive JBI-802 administered orally daily for a 28 day treatment cycle for up to 2-years as long as the participant experiences clinical benefit in the opinion of the Investigator and shows no signs or symptoms of unequivocal progression of disease, unacceptable toxicity, or other reasons for study discontinuation. The starting dose of the study drug is 5 mg/day, a total dose of 35 mg. Dose escalation will occur as per the 3+3 design after an internal Safety Review Committee (SRC) review of each dose stage. Dose expansion to other subtypes of MPN and MDS/MPN will occur after Recommended Phase 2 Dose is determined from the dose escalation phase. Eligibility/Screening for this study will occur within 21 days prior to starting treatment. If the study is suitable for you, you will enter the treatment period. The dose level selected for evaluation in Phase 2 will only be selected if it was safe and well tolerated during Phase 1. The treatment cycles will continue until you wish to stop, or you do not tolerate JBI-802 treatment, Some of the study procedures that include during your treatment period are :Medical, surgical, and cancer history, Height and weight, Physical examination, Vital signs, Eastern Cooperative Oncology Group (ECOG) evaluation, Electrocardiogram, Myeloproliferative neoplasm symptom assessment questionnaire,CT/MRI scan, Bone marrow biopsy, medication usage, Side effects assessment, blood and urine Sampling , liver and thyroid function tests, haematology and coagulation tests, Participants will be followed-up at the start and end of each 28-day cycle to assess safety and tolerability Blood samples will be collected to assess safety and tolerability during the study. After the end of study, subjects will be treated in accordance with local practice. Compassionate use of JBI-802 may be allowed in subjects after study completion, based on the Investigator's judgment in consultation with the Sponsor and on a case-by-case basis. Compassionate use will be controlled by a separate protocol or process as defined by the local regulatory authorities. Continuation of study therapy beyond 2 years may be approved by the Sponsor based on the safety profile and will be contingent on the continued availability of product.

Conditions

Essential Thrombocythemia (ET); Myelodysplastic/Myeloproliferative Neoplasms (MDS/MPN); Myeloproliferative Neoplasms (MPN)

Outcome Measures

Primary Outcomes (6)

• Dose Escalation - Incidence of Dose-Limiting Toxicities (DLTs)

  Number of participants with dose-limiting toxicity (DLT) events during the DLT monitoring period. DLTs are defined per protocol criteria and graded using NCI CTCAE Version 5.0. Units: Number of participants

  At the end of Cycle 1 (each cycle is 28 days)

• Dose Expansion - Overall Response Rate (ORR)

  Percentage of participants with best overall response of complete response or partial response according to MPN IWG-MRT or MDS/MPN IWG criteria. Units: Percentage of participants

  Up to 2 years

• Dose Expansion - Complete Remission (CR) Rate

  Percentage of participants achieving complete remission per IWG criteria. Units: Percentage of participants

  Up to 2 years

• Dose Expansion - Progression-Free Survival (PFS)

  Time from first dose to disease progression or death from any cause. Units: Months

  At 6 months and up to approximately 2 years

• Dose Expansion - Overall Survival (OS)

  Time from first dose to death from any cause. Units: Months

  Up to 2 years

• Dose Expansion - Platelet Count ≤400 ×10⁹/L Without Thromboembolic Events

  Number of participants achieving platelet count ≤400 ×10⁹/L in absence of thromboembolic events. Units: Number of participants

  Up to 2 years

Secondary Outcomes (8)

• Dose Escalation - Incidence of Treatment-Emergent Adverse Events (TEAEs)

  From first dose up to 2 years

• Maximum Plasma Concentration (Cmax) of JBI-802

  From Cycle 1 Day 1 up to Cycle 3 Day 1 (each cycle is 28 days)

• Area Under the Plasma Concentration-Time Curve (AUC0-t) of JBI-802

  From Cycle 1 Day 1 up to Cycle 3 Day 1 (each cycle is 28 days)

• Time to Maximum Plasma Concentration (Tmax) of JBI-802

  From Cycle 1 Day 1 up to Cycle 3 Day 1 (each cycle is 28 days)

• Overall Response Rate (ORR)

  Up to 2 years

Study Arms (2)

Dose Escalation: Escalating oral dose of JBI-802

EXPERIMENTAL

JBI-802 - CoREST inhibitor (Dual LSD1 and HDAC6 inhibitor)

Drug: JBI-802

Dose Expansion: Expansion arm at the RP2D of oral JBI-802

EXPERIMENTAL

Drug: JBI-802

Interventions

JBI-802 DRUG

CoREST inhibitor dual targeting LSD1 and HDAC6

Dose Escalation: Escalating oral dose of JBI-802; Dose Expansion: Expansion arm at the RP2D of oral JBI-802

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• \- Male or female subjects aged ≥18 years at the time of screening visit.
• For Dose Escalation Phase:
• Subjects diagnosed with any one of the following:
• Subject with diagnosis of Essential Thrombocythemia (ET) per World Health Organization (WHO) diagnostic criteria for myeloproliferative neoplasms .
• Subject requires treatment in order to lower platelet count based on subject age over 60 or history of thrombosis.
• Subject with Morphologically confirmed diagnosis of MDS/MPN neoplasms, excluding Juvenile Myelomonocytic Leukaemia (JMML), CMML and aCML (Atypical Chronic Myeloid Leukaemia), in accordance with WHO 2016 revised criteria, that is relapsed and/or refractory or intolerant to standard of care and that, in the opinion of the Investigator, subjects who have no available therapies known to provide clinical benefits.
• Subject with Myelodysplastic/myeloproliferative neoplasm, (unclassifiable (MDS/MPN-UC) and MDS/MPN-RS-T).
• For Dose Expansion Phase
• Subjects diagnosed with any one of the following:
• Subject with diagnosis of Essential Thrombocythemia (ET) per WHO diagnostic criteria for myeloproliferative neoplasms which requires treatment in order to lower platelet count based on subject age over 60 or history of thrombosis.
• Subject with diagnosis of Polycythemia Vera (PV) per WHO diagnostic criteria that is relapsed and/or refractory or intolerant to standard of care and that, in the opinion of the Investigator, subjects who have no available therapies known to provide clinical benefits Subject with morphologically confirmed diagnosis of pre-fibrotic myelofibrosis (MF) subject in accordance with the WHO 2016 revised criteria, that is relapsed, intolerant, and/or refractory and that, in the opinion of the Investigator, subjects who have no available therapies known to provide clinical benefits. (Refer Appendix II)
• MDS/MPN (MDS/MPN-RS-T, MDS/MPN unclassifiable and CMML subjects providing the marrow blast count is ≤5%.). 2. Subject must have disease that failed at least one standard therapy or being intolerant to standard of care. 3. Subject must have discontinued immediate prior therapy at least 1 week (4 weeks for interferon) prior to study drug administration. 4. Subject with screening laboratory values:
• Hb ≥ 9 g/dL, if subject is transfused to meet this criterion, transfusion must be completed ≥ 14 days prior to first dose.
• Absolute neutrophil count ≥ 1500 × 109/L
• Absolute neutrophil count ≥ 1000 × 109/L, if significant marrow infiltration

You may not qualify if:

• \. Subject who is treated with systemic anticancer therapy or biological therapy or an investigational agent within 2 weeks or 5 half-lives, whichever is shorter, prior to start of study drug treatment.
• For MF subject who come off JAK2 antagonists or hydroxyurea, shorter washout is permitted as these subject progress quickly after treatment discontinuation and remain eligible (steroids must be stop at least 7 day before start of study drug treatment)
• Subject who is in need of immediate cytoreduction should be excluded 2. Subject who has undergone autologous/allogeneic Haematopoietic Stem Cell Transplantation (HSCT) therapy within 60 days of the first dose of study drug, or subject on immunosuppressive therapy post-HSCT at the time of screening, or currently with clinically significant Graft-Versus- Host Disease (GVHD) as per treating physician (subjects in relapse after allogeneic transplantation must be off treatment with systemic immunosuppressive agents for at least 4 weeks prior to screening.
• \. Subject with major surgery less than or equal to 21 days prior to starting study drug or has not recovered from adverse effects of such procedure.
• \. Subject who underwent surgery (e.g., stomach bypass) or medical condition that might significantly affect absorption of medicines.
• \. Subject who underwent radiotherapy within 2 weeks prior to start of study drug treatment (palliative radiation or stereotactic radiosurgery within 7 days prior to start of study treatment). Subjects must have recovered from all radiotherapy-related toxicities.
• \. Subject with known malignant central nervous system disease other than neurologically stable, treated brain metastases- defined as metastasis having no evidence of progression or hemorrhage for at least 4 weeks after treatment (including brain radiotherapy). Must be off any systemic corticosteroids for the treatment of symptomatic brain metastases for at least 14 days prior to enrollment.
• \. Subject with severe or unstable medical condition, such as congestive heart failure ischemic heart disease, uncontrolled hypertension, uncontrolled diabetes mellitus, psychiatric condition, as well as an uncontrolled cardiac arrhythmia requiring medication ( less than or equal to Grade 2, according to NCI CTCAE Version 5), myocardial infarction within 6 months prior to starting study treatment, or any other significant or unstable concurrent cardiac illness.
• \. Subject with congenital long QT syndrome or corrected QT interval by Fridericia (QTcF interval) greater than 450 msec for males and greater than 470 msec for females at screening.
• \. Subject with history of other previous or concurrent cancer that would interfere with the determination of safety or efficacy assessments with the exception:
• Patient with previous cancers can be included to the study provided they are in remission at the time of screening and enrolment.
• Patient with localized skin cancer can also be included for screening and enrollment.
• \. Subject with live vaccines within 30 days prior to the first dose of JBI-802.
• \. Subjects who receive Glucocorticoids for any purpose other than to modulate symptoms from an event of clinical interest or for use as a premedication in participants with a known history of an IV contrast allergy administered as part of CT radiography.
• \. Bisphosphonates and/or receptor activator of nuclear factor kappa-B ligand inhibitor therapies cannot be initiated after the Informed Consent Document(s) has been signed. These therapies may be continued if treatment with an agent from 1 of these 2 classes was initiated prior to signing the Informed Consent Document(s).

Sponsors & Collaborators

• Jubilant Therapeutics Inc.: lead

Study Sites (7)

St. Vincent's Hospital Sydney Limited

Sydney, New South Wales, 2010, Australia

RECRUITING

Macquarie University

Sydney, New South Wales, 2109, Australia

RECRUITING

Royal Adelaide Hospital

Adelaide, South Australia, 5000, Australia

RECRUITING

St Vincent's Hospital (Melbourne)

Melbourne, Victoria, 3065, Australia

RECRUITING

Monash Medical Centre

Melbourne, Victoria, 3168, Australia

RECRUITING

The Perth Blood Institute Limited

Perth, Western Australia, 6000, Australia

RECRUITING

Hollywood Private Hospital

Nedlands, 6009, Australia

RECRUITING

MeSH Terms

Conditions

Thrombocythemia, Essential; Myeloproliferative Disorders

Condition Hierarchy (Ancestors)

Blood Coagulation Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Thrombocytosis; Blood Platelet Disorders; Bone Marrow Diseases; Hemorrhagic Disorders

Central Study Contacts

Melda Dolan

CONTACT

+1 267 888 4319; melda.dolan@jubl.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 11, 2025
• First Posted: May 28, 2026
• Study Start: October 21, 2024
• Primary Completion (Estimated): June 15, 2028
• Study Completion (Estimated): September 15, 2028
• Last Updated: June 3, 2026

Record last verified: 2026-06

Locations

AU (7)