Pacritinib For The Reduction Of Bone Marrow Fibrosis In Patients With Myelofibrosis Who Have Thrombocytopenia; A Multicenter, Open-Label, Single Arm, Phase II Exploratory Study
ESTADO CLÍNICO
Reclutando
FASE/S DEL ENSAYO
Fase II
PATOLOGÍA
Mielofibrosis Primaria
CENTRO INVESTIGADOR
H. Fundación Jiménez Díaz
INVESTIGADOR PRINCIPAL
Francisca Ferrer Marín
CENTRO INVESTIGADOR
H.G.U. Gregorio Marañón
INVESTIGADOR PRINCIPAL
Santiago Osorio Prendes
CENTRO INVESTIGADOR
H.U. 12 de Octubre
INVESTIGADOR PRINCIPAL
Rosa Ayala Díaz
CENTRO INVESTIGADOR
H.U. Ramón y Cajal
INVESTIGADOR PRINCIPAL
Valentín García Gutiérrez
FECHA DE APERTURA
Febrero, 2026
FECHA DE CIERRE
,
CRITERIOS DE INCLUSIÓN
Signed written and voluntary informed consent.
Adequate coagulation defined by prothrombin time/international normalized ratio and partial thromboplastin time 1.5 × ULN.
If fertile, willing to use effective birth control methods during the study and up to 30 days after the last dose of pacritinib
Willing to undergo and able to tolerate frequent MRI during the study and BM biopsy
Able to understand and willing to complete symptom assessments.
Age 18 years
Patients with a confirmed diagnosis of myelofibrosis, either primary myelofibrosis (PMF) or post polycythemia vera (PPV-MF) or post essential thrombocythemia (PET-MF)
Patients with thrombocytopenia, delimited by platelets counts between 50 - 120 x10e9/L.
Patients who require JAK-2 inhibitor therapy in the opinion of the investigator and are eligible to start treatment with pacritinib either in the first line (JAK2 inhibitor-naive) or in second line setting (after no response or loss of response or intolerance to one prior JAK2 inhibitor). Note: patients should have recovered to grade 1 from any toxicity from previous treatment.
Have a Eastern Cooperative Oncology Group Performance Status (ECOG-PS) of 0 - 2
Have a dynamic international prognostic scoring system (DIPSS) Intermediate-1, Intermediate-2, or High risk
Peripheral blasts count < 5% and absolute neutrophil count (ANC) of 500/L.
Adequate liver and renal function, defined by: a. liver transaminases, including alanine aminotransferase (ALT or GOT) and aspartate aminotransferase (AST or GOT) 3 x upper limit normal (ULN). AST/ALT 5 × ULN if transaminase elevation is related to MF. b. Total bilirubin and/or direct bilirubin 4 x ULN. c. Estimated glomerular filtration rate (eGFR) > 30 mL/min.
Adequate coagulation defined by prothrombin time/international normalized ratio and partial thromboplastin time 1.5 × ULN.
If fertile, willing to use effective birth control methods during the study and up to 30 days after the last dose of pacritinib
Willing to undergo and able to tolerate frequent MRI during the study and BM biopsy
Able to understand and willing to complete symptom assessments.
Age 18 years
Patients with a confirmed diagnosis of myelofibrosis, either primary myelofibrosis (PMF) or post polycythemia vera (PPV-MF) or post essential thrombocythemia (PET-MF)
Patients with thrombocytopenia, delimited by platelets counts between 50 - 120 x10e9/L.
Patients who require JAK-2 inhibitor therapy in the opinion of the investigator and are eligible to start treatment with pacritinib either in the first line (JAK2 inhibitor-naive) or in second line setting (after no response or loss of response or intolerance to one prior JAK2 inhibitor). Note: patients should have recovered to grade 1 from any toxicity from previous treatment.
Have a Eastern Cooperative Oncology Group Performance Status (ECOG-PS) of 0 - 2
Have a dynamic international prognostic scoring system (DIPSS) Intermediate-1, Intermediate-2, or High risk
Peripheral blasts count < 5% and absolute neutrophil count (ANC) of 500/L.
Adequate liver and renal function, defined by: a. liver transaminases, including alanine aminotransferase (ALT or GOT) and aspartate aminotransferase (AST or GOT) 3 x upper limit normal (ULN). AST/ALT 5 × ULN if transaminase elevation is related to MF. b. Total bilirubin and/or direct bilirubin 4 x ULN. c. Estimated glomerular filtration rate (eGFR) > 30 mL/min.
CRITERIOS DE EXCLUSIÓN
Life expectancy <6 months.
Any active GI or metabolic condition that could interfere with absorption of oral medication.
Splenic irradiation within the last 6 months.
Previously treated with pacritinib.
Concurrent enrollment in another interventional trial.
Treatment with an experimental therapy within 28 days prior to the first dose of study treatment.
Systemic treatment with a strong CYP3A4 inhibitor or inducer and the treatment cannot be either discontinued or switched to a different medication within 5 half-lifes prior to study entry.
Severe (Child-Pugh C) liver impairment.
Significant recent bleeding history defined as NCI CTCAE grade 2 within 3 months prior to first dose of study treatment, or with active bleeding, unless precipitated by an inciting event (e.g., surgery, trauma, or injury).
Conditions or medications that increase the risk of bleeding, except for aspirin (dosages of 100 mg per day). Patients treated with "direct-acting oral anticoagulants (DOACs), could be considered for inclusion (may be consulted with the Sponsor, GEMFIN).
Patients with rheumatoid arthritis for whom therapy with an alternative JAK inhibitor is required
Any history of CTCAE grade 2 dysrhythmias or non-dysrhythmia cardiac conditions within 6 months prior to the first dose of study treatment. Patients with non-dysrhythmia or non-QTc grade 2 cardiovascular conditions , may be considered for inclusion, if stable , asymptomatic and unlikely to affect patient safety.
QT corrected by the Fridericia method (QTcF) prolongation >480 ms or other factors that increase the risk for QTcF interval prolongation (e.g., heart failure, hypokalemia or history of long QT interval syndrome).
New York Heart Association Class II, III, or IV congestive heart failure.
Active or uncontrolled inflammatory or chronic functional bowel disorder such as Crohns disease, inflammatory bowel disease, chronic diarrhea or constipation
Other malignancy within 3 years prior to treatment Day 1, other than curatively treated basal cell or squamous cell skin or corneal cancer; curatively treated carcinoma in situ of the cervix. The exception is if patients have been disease-free for at least 5 years, and are deemed by the investigator to be at low risk for recurrence of that malignancy.
Known seropositivity for human immunodeficiency virus. Known active hepatitis B, or C virus infection.
Women who are pregnant or lactating
Uncontrolled intercurrent illness, including, but not limited to, ongoing active infection, psychiatric illness, or social situation that, in the judgment of the treating physician, would limit compliance with study requirements.
Any active GI or metabolic condition that could interfere with absorption of oral medication.
Splenic irradiation within the last 6 months.
Previously treated with pacritinib.
Concurrent enrollment in another interventional trial.
Treatment with an experimental therapy within 28 days prior to the first dose of study treatment.
Systemic treatment with a strong CYP3A4 inhibitor or inducer and the treatment cannot be either discontinued or switched to a different medication within 5 half-lifes prior to study entry.
Severe (Child-Pugh C) liver impairment.
Significant recent bleeding history defined as NCI CTCAE grade 2 within 3 months prior to first dose of study treatment, or with active bleeding, unless precipitated by an inciting event (e.g., surgery, trauma, or injury).
Conditions or medications that increase the risk of bleeding, except for aspirin (dosages of 100 mg per day). Patients treated with "direct-acting oral anticoagulants (DOACs), could be considered for inclusion (may be consulted with the Sponsor, GEMFIN).
Patients with rheumatoid arthritis for whom therapy with an alternative JAK inhibitor is required
Any history of CTCAE grade 2 dysrhythmias or non-dysrhythmia cardiac conditions within 6 months prior to the first dose of study treatment. Patients with non-dysrhythmia or non-QTc grade 2 cardiovascular conditions , may be considered for inclusion, if stable , asymptomatic and unlikely to affect patient safety.
QT corrected by the Fridericia method (QTcF) prolongation >480 ms or other factors that increase the risk for QTcF interval prolongation (e.g., heart failure, hypokalemia or history of long QT interval syndrome).
New York Heart Association Class II, III, or IV congestive heart failure.
Active or uncontrolled inflammatory or chronic functional bowel disorder such as Crohns disease, inflammatory bowel disease, chronic diarrhea or constipation
Other malignancy within 3 years prior to treatment Day 1, other than curatively treated basal cell or squamous cell skin or corneal cancer; curatively treated carcinoma in situ of the cervix. The exception is if patients have been disease-free for at least 5 years, and are deemed by the investigator to be at low risk for recurrence of that malignancy.
Known seropositivity for human immunodeficiency virus. Known active hepatitis B, or C virus infection.
Women who are pregnant or lactating
Uncontrolled intercurrent illness, including, but not limited to, ongoing active infection, psychiatric illness, or social situation that, in the judgment of the treating physician, would limit compliance with study requirements.
DESCRIPCIÓN
The primary objective of this study is to evaluate the effect of pacritinib on the bone marrow fibrosis.
PALABRAS CLAVE
myelofibrosis
