This page shows what was measured, who it was measured in, and what that does not settle.
What Pacritinib does in the body
VONJO is indicated for the treatment of adults with intermediate or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis (MF) with a platelet count below 50 × 10 9 /L.
From the FDA-approved label: Pacritinib is an oral kinase inhibitor with activity against wild type Janus associated kinase 2 (JAK2), mutant JAK2V617F, FMS-like tyrosine kinase 3 (FLT3), and interleukin 1 receptor associated kinase-1 (IRAK1) which contribute to signaling of a number of cytokines and growth factors that are important for hematopoiesis and immune function. Pacritinib is also an inhibitor of activin A receptor, type 1/activin receptor like-kinase 2 (ACVR1/ALK2). MF is often associated with dysregulated JAK2 signaling. At clinically relevant concentrations, pacritinib does not inhibit JAK1. Pacritinib has higher inhibitory activity for JAK2 compared to JAK3 and tyrosine kinase 2 (TYK2).
Why people take it. VONJO is indicated for the treatment of adults with intermediate or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis (MF) with a platelet count below 50 × 10 9 /L.
What happened in people
RNAWiki has not yet published a reviewed conclusion for this use.
§ A fixed RNAWiki sentence
Where this came from
Wording RNAWiki always uses, not a finding about this substance.
No reviewed claim names a result for any goal on this record.
No source is stored against this line.
The limit that matters most
Not recorded.
Where it acts
Not recorded.
Kind of result
No result is published, so no kind of result applies yet
Supervision
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
What the registries record it as
The substance registry classes this as chemical.
FDA substance registry · G22N65IL3O · read 2026-08-29
Its recorded molecular formula is C28H32N4O3•C6H8O7, weighing 664.7.
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-30
Where each sentence above came from
The use the label states, quoted from it. No plain-language version of this sentence has been written.
The use the label states, quoted from it. It is written for a clinician, not for a reader without medical training.
No statement of the main limit is recorded.
The four opening statements run to 176 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Stand-in result
A stand-in result is a number measured because the real result takes too long.
A picture of it, and where the picture fails
It is like judging a journey by the speedometer rather than by arriving.
Where that stops being true. Speed does predict arrival. Many stand-in results do not predict the real one.
What people get wrong. A stand-in result is often reported as the result itself.
A surrogate endpoint substituted for a clinical endpoint, valid only where the substitution has been shown to hold.
Enzyme
An enzyme is a protein that speeds up one chemical change.
A picture of it, and where the picture fails
An enzyme is like a machine on a production line doing one cut.
Where that stops being true. A machine is switched on and off by a person. Enzymes are controlled by the cell.
What people get wrong. Enzymes are thought to be used up. They are not; they work again and again.
A catalytic protein that lowers the activation energy of a specific reaction.
Receptor
A receptor is a part of a cell that a signal fits into.
A picture of it, and where the picture fails
A receptor is like a lock waiting for one key.
Where that stops being true. A lock either opens or does not. A receptor can be half-triggered, or worn out.
What people get wrong. Fitting a receptor is read as causing a benefit. It causes a step, and nothing more.
A protein that binds a specific ligand and converts that binding into a cellular response.
Pathway
A pathway is a chain of steps inside a cell, each one setting off the next.
A picture of it, and where the picture fails
A pathway is like a row of dominoes.
Where that stops being true. Dominoes fall one way. Pathways loop back and can switch themselves off.
What people get wrong. Changing one step is read as changing the outcome. Other steps often absorb it.
An ordered series of molecular interactions producing a defined cellular change.
What happened in people◇Read from sources, not yet reviewed
What happened in people
Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.
Spleen volume
✗ The study did not show it
Who was studied
NCT03165734
How many people
407
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Spleen Volume Reduction
✗ The study did not show it
Who was studied
NCT01773187
How many people
327
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Spleen Volume Reduction
✗ The study did not show it
Who was studied
NCT02055781
How many people
311
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Percentage of Participants With Progression to IMV and/or ECMO or Death
✗ The study did not show it
Who was studied
NCT04404361
How many people
200
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Spleen Volume Reduction Response (≥ 35%)
✗ The study did not show it
Who was studied
NCT04884191
How many people
165
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Recommended phase 2 dose of pacritinib in participants 12-17 years of age
✗ The study did not show it
Who was studied
NCT06303193
How many people
160
Study design
Phase 1/Phase 2
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
What we know
RNAWiki holds 6 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What happened in people◇Read from sources, not yet reviewed
How close this is to real life
The top step is something a person would feel or care about. The bottom is a guess from software. Filled steps are where evidence exists for this substance.
■Living longer, or avoiding a major eventEvidence recorded. Death, a heart attack, a stroke, a hospital stay.2 registered measures of this kind. 1 written-up study measured this and did not show a benefit.
□What a body can do day to dayNo evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
□Measured performanceNo evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
■Symptoms and quality of lifeEvidence recorded. Pain, tiredness, mood, sleep, as the person rated it.1 registered measure of this kind.
■A number that stands in for healthEvidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.2 registered measures of this kind.
■A step measured inside a personEvidence recorded. Something measured in human tissue or human cells.A human record sits on the stored organism ladder.
■AnimalsEvidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in Mouse. A result in animals says what to test next. It does not say what happens in people.
■Cells in a dishEvidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
□A guess from softwareNo evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.
Higher on these steps means closer to something a person would feel. It does not mean better done.
What it would be like to take◇Read from sources, not yet reviewed
Felt, measured, or meaningful
Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.
Felt
Things a person could notice without a test.
total symptom
Measured
Things only a test, a scale or a device shows.
maximum plasma concentration
time to reach maximum plasma concentration
Meaningful
Things that change how a life goes, not only a number.
progression free survival
complete remission rate
A registered study says what someone planned to measure. It does not say what they found. A number moving is not the same as a life going better. The two are shown apart here.
Felt, but not shown to help. A person notices a change. No study showed it leads anywhere good.
Measured, but not felt. A number moves. The person notices nothing. Both can be true.
Measured, but not shown to matter. A number moves in the good direction. Nobody showed that lives went better.
Matters, but takes years. The result that counts may take longer than anyone would keep watching.
Names that fit none of the three (17)
overall response
clinical activity
overall response rate
complete response
apparent volume of distribution
stat activity
spleen volume
rate of dose limiting toxicities
enrolled who receive hematopoietic stem cell transplantation
phase ii overall response rate
spleen volume reduction 35 at week 24
clinical benefit
maximum tolerated dose
dose limiting toxicities
recommended phase ii dose
incidence of adverse events
objective response rate
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What it would be like to take◇Read from sources, not yet reviewed
How long anything takes
Nine different lengths of time that get confused with each other. None of them is worked out from another.
Before anything is noticed.RNAWiki does not store this separately, and never works it out from another figure on this page.
Before a test result moves.RNAWiki does not store this separately, and never works it out from another figure on this page.
Before performance moves.RNAWiki does not store this separately, and never works it out from another figure on this page.
How long the result was watched.No finished study window is recorded for a study that tested this substance.
How long people took it.How long people actually took it is not stored. The study window is not the same thing.
How long people were followed.Follow-up length is not stored separately. It is never read off the study window, which would be a different thing.
How fast the body clears it. 27.7 hours hours
Read from the label, which states: “Elimination The mean apparent clearance at steady-state (CV%) of pacritinib is 2.09 L/h (33.1%), and mean effective half-life (CV%) is 27.7 hours (17.0%).”
How long effects linger.RNAWiki does not store this separately, and never works it out from another figure on this page.
Beyond the studies. Nothing is recorded about the long term.
The longest finished study sets the edge of what anyone measured.
A study window is not how long people took it, and neither is how long they were followed. Where RNAWiki holds only one of the three, it shows one.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
VONJO is indicated for the treatment of adults with intermediate or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis (MF) with a platelet count below 50 × 10 9 /L. This indication is approved under accelerated approval based on spleen volume reduction [see Clinical Studies ( 14 )].
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What the label states about particular groups
On pediatric, the label states: “Safety and effectiveness in pediatric patients have not been established.”
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-30
On older people, the label states: “Clinical studies of VONJO did not include sufficient numbers of subjects aged 65 years and over to determine whether they respond differently from younger subjects.”
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary There are no available data on VONJO use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes.”
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary There are no data on the presence of pacritinib in either human or animal milk, the effects on the breastfed child, or the effects on milk production.”
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-30
On people with reduced liver function, the label states: “In patients with severe hepatic impairment [Child-Pugh C], the recommended dosage of VONJO is 100 mg twice daily.”
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-30
On people with reduced kidney function, the label states: “Administration of a single dose of VONJO 400 mg to subjects with renal impairment resulted in approximately 30% increase in C max and AUC of pacritinib in subjects with eGFR 15 to 29 mL/min and eGFR <15 mL/min on hemodialysis compared to subjects with normal renal function (eGFR ≥90 mL/min).”
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-30
Where the result stopped carrying
This is a scope explorer, not a diagnosis engine.
It shows who was studied so you can see whether people similar to you were included.
RNAWiki cannot tell whether a study fits you. It can show who was in it.
What it would be like to take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied for a different goal
The studies measured something else entirely.
On this record: Some registered studies measured things that match no goal on this page.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (10)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Prescription only
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Oral
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form and route recorded on this substance.
No source is stored against this line.
Who oversees it
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Suppression classes recorded: S1, S4.
No source is stored against this line.
What is in the pack
Sold as capsule, given by the oral route.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold and what that means for what is in the pack.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take∅Nothing found in the sources checked
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
∅Nothing found in the sources checked
No harm is recorded against this substance in the sources RNAWiki checked. Finding nothing is not the same as showing there is nothing.
The sources listed were searched and held nothing. That is not the same as nothing existing.
Reports sent to a regulator
These are reports people sent to a regulator. They do not show the medicine caused the reaction.
Nobody counted how many people took the medicine and reported nothing.
The same event can be reported more than once, and many reports are incomplete.
News coverage, lawsuits and new warnings change how often people report.
A count is not a rate and not a risk.
Pacritinib appears in spontaneous reports to regulators. Across the 7 most-reported reaction terms, 86 reaction mentions were counted. One report can name several reactions.
The recorded terms (7)
diarrhoea — 22 reaction mentions
platelet count decreased — 17 reaction mentions
platelet count abnormal — 15 reaction mentions
haemoglobin abnormal — 13 reaction mentions
haemoglobin decreased — 11 reaction mentions
myelofibrosis — 5 reaction mentions
myeloproliferative neoplasm — 3 reaction mentions
open-targets-adr · recorded 2026-06-24 · a recorded source, not a stored snapshot
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear◇Read from sources, not yet reviewed
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Oral
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form used in the studies cited on this page.
No source is stored against this line.
What is sold
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
Nothing further is recorded about which forms are sold.
No source is stored against this line.
What is recorded as being sold
2 products list this as an active ingredient in the United States drug directory. 2 of them contain it and nothing else.
FDA National Drug Code directory · 72482-100 · read 2026-08-29
They are sold as capsule and powder, taken oral.
FDA National Drug Code directory · 72482-100 · read 2026-08-29
The regulator's established pharmacologic class for it is breast cancer resistance protein inhibitors [moa], cytochrome p450 1a2 inhibitors [moa] and cytochrome p450 3a4 inhibitors [moa].
FDA National Drug Code directory · 72482-100 · read 2026-08-29
1 published label names it as an active ingredient. 1 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-29
Vonjo is oral at 3 DOSAGE FORMS AND STRENGTHS Capsule: 100 mg, oblong, size 0 hard gelatin capsule with an opaque scarlet cap printed with “Pacritinib 100 mg” and opaque gray body printed with “C78837”., recorded as fda label in effect 2026-07-30 in the United States.
US prescribing information · 4b5ab444-0e1a-4984-99db-76ad11a298ee · read 2026-08-30
Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.
What it would be like to take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
Self-experiment planning is not offered for a prescription or clinician-supervised medicine. The questions below are for a clinician or pharmacist.
Questions worth asking
Which of the trials of Pacritinib studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Pacritinib are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Where else this substance is registered
FDA substance identifier (UNII)
G22N65IL3O
RxNorm concept
2595248
Checks this page had to pass
✓ Passed
Identity resolved
no open identity hold
✓ Passed
No unresolved merge across substance families
no quarantine open
✓ Passed
Every public sentence names a source
The opening statement carries the origin: Quoted from a stored source.
✗ Not passed
Trial roles classified for highlighted evidence
No registered study is classified as testing this substance.
✓ Passed
No internal keys in reader text
enforced by the copy-contract test over the rendered page
✓ Passed
Safety mode resolved
Suppression classes recorded: S1, S4.
✓ Passed
Canonical metadata present
slug and display name present
What is missing or unclear◇Read from sources, not yet reviewed
How this medicine reached us
Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.
What the approval register records
1 approved application covers products containing this substance. The earliest was NDA208712, approved 20220228 to SOBI.
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What is not here
6 questions this page could not answer
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Recorded evidence blocks (13)
Q2
What did Pacritinib's largest trial (407 people) and its longest (11 years) measure?
407 people in Pacritinib's largest registered study, 11 years in its longest registered window, measuring The maximum plasma concentration (Cmax). ClinicalTrials.gov · 2026-09-01
33 phase2, 26 phase1, 3 phase3, 1 early phase1; NCT03165734; 2028-10-13; no ageing endpoint recorded. Last human test completed 2023, NCT05657613.
Interpretation These counts include studies where Pacritinib was a comparison treatment, a background treatment or an exposure in an observational study, and the longest window may be a planned end date. Trial roles have not yet been classified for this record.
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phase2
33
phase1
26
phase3
3
early phase1
1
Last recorded human testNCT05657613
2023-06-08
recorded 2026-09-01 · last checked 2026-09-04
Q3
From mouse to human: where has Pacritinib shown lifespan?
6 recorded entries; human; capsule; also "Pacritinib 400mg capsule", "Pacritinib 100mg", "Pacritinib 100mg and Clarithromycin 500mg"
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human
NCT02765724
capsule; Pacritinib 400mg capsule
NCT02807051
Pacritinib 100mg
NCT02807051
Pacritinib 100mg and Clarithromycin 500mg
NCT02808455
Pacritinib 400 mg Capsule
NCT02808455
Pacritinib 80 mg Solution
NCT05657613
Part 2 -Group A Bosentan 125 mg (CYP450 3A4 inducer) with Pacritinib
recorded 2026-09-01 · last checked 2026-09-04
Q6
Pacritinib's half-life is 27.7 hours — which schedules were studied?
27.7 hours, the half-life Pacritinib's label states. openfda-label · 4b5ab444-0e1a-4984-99db-76ad11a298ee · 2026-08-30
Show the evidence
half life
27.7 hours hours; Elimination The mean apparent clearance at steady-state (CV%) of pacritinib is 2.09 L/h (33.1%), and mean effective half-life (CV%) is 27.7 hours (17.0%).
metabolism
Metabolism Pacritinib is predominantly metabolized by the CYP3A4 isozyme.
recorded 2026-08-30 · last checked 2026-09-04
Q7
Which of apparent volume of distribution, clinical activity and clinical benefit did Pacritinib's trials measure?
apparent volume of distribution, clinical activity and clinical benefit lead 22 outcome terms across Pacritinib's trials. ClinicalTrials.gov · 2026-09-01
Interpretation overall response rate, complete remission rate, complete response, maximum plasma concentration, time to reach maximum plasma concentration and apparent volume of distribution follow.
Show the evidence
overall response
1
clinical activity
1
progression free survival
1
overall response rate
1
complete remission rate
1
complete response
1
14 more recorded rows
maximum plasma concentration
1
time to reach maximum plasma concentration
1
apparent volume of distribution
1
stat activity
1
spleen volume
1
total symptom
1
rate of dose limiting toxicities
1
enrolled who receive hematopoietic stem cell transplantation
1
phase ii overall response rate
1
spleen volume reduction 35 at week 24
1
clinical benefit
1
maximum tolerated dose
1
dose limiting toxicities
1
recommended phase ii dose
1
recorded 2026-09-01 · last checked 2026-09-04
Q8
Which of Pacritinib's 22 ongoing trials reports first?
Spleen volume; Proportion of patients receiving allo-SCT, with failure within or at day 180 post-transplant.; latest 2035-01-01
Show the evidence
Trial
NCT03165734
"A Phase 3 Study of Pacritinib in Patients With Primary Myelofibrosis, Post Polycythemia Vera Myelofibrosis, or Post-Essential Thrombocythemia Myelofibrosis"; n 407; "Spleen volume"; 2028-10-13
NCT03645824
"Myelofibrosis Treated With Pacritinib Before aSCT. (HOVON134MF)"; n 61; "Proportion of patients receiving allo-SCT, with failure within or at day 180 post-transplant."; 2027-02
NCT04282187
"Decitabine With Ruxolitinib, Fedratinib or Pacritinib for the Treatment of Accelerated/Blast Phase Myeloproliferative Neoplasms"; n 25; "Proportion of patients enrolled who receive hematopoietic stem cell transplantation (HCT)"; 2026-11-11
NCT04520269
"A Single Arm, Phase Ib/II Trial of Single Agent Pacritinib in Patients With 1q21.3 Amplified Solid Tumors Enriching for Interleukin-1 Receptor-associated Kinase 1 Pathway Activation (PAIR)"; n 74; "Overall radiological response rate"; 2026-07
NCT04858256
"Pacritinib in Relapsed/Refractory T-cell Lymphoproliferative Neoplasms"; n 100; "Overall response rate (ORR)"; 2028-11
NCT05531786
"Phase I/II Study of Pacritinib, A JAK2/IRAK1/CSF1R Inhibitor, in Refractory Chronic Graft-Versus-Host Disease (cGVHD) After Allogeneic Hematopoietic Stem Cell Transplantation (HSCT)"; n 50; "Phase I: Safety of pacritinib in refractory cGVHD."; 2027-07-22
14 further recorded trials
NCT05980806
"A Study of Selinexor Monotherapy in Subjects With JAK Inhibitor-naïve Myelofibrosis and Moderate Thrombocytopenia"; n 58; "Proportion of Participants with Spleen Volume Reduction ≥35% (SVR35) at Week 24"; 2028-10
NCT06052618
"Phase II Study of Pacritinib in Kaposi Sarcoma Herpesvirus (KSHV)-Associated Multicentric Castleman Disease and KSHV-Associated Inflammatory Cytokine Syndrome (KICS)"; n 75; "Clinical benefit"; 2034-01-01
NCT06159491
"Pacritinib in CMML"; n 26; "Dose-limiting toxicity of Pacritinib in combination with Azacitidine"; 2028-01
NCT06218628
"Pacritinib w/ Talazoparib in Pts w/ Myeloproliferative Neoplasms Unresponsive to JAK2 Inhibition"; n 24; "Maximum Tolerated Dose (MTD)"; 2030-08-27
NCT06303193
"Pacritinib, a Kinase Inhibitor of CSF1R, IRAK1, JAK2, and FLT3, in Adults and Pediatric Participants 12 Years of Age or Older With Myelodysplastic Syndromes or Myelodysplastic/Myeloproliferative Neoplasms"; n 160; "Recommended phase 2 dose of pacritinib in participants 12-17 years of age"; 2035-01-01
NCT06414681
"Combination of Tagraxofusp With Pacritinib in Patients With Intermediate-1 or Higher Myelofibrosis, Who Have Had Prior Therapy With the Approved JAK Inhibitors or in Which Therapy With the Approved JAK Inhibitors is Not Appropriate, Contraindicated or Declined"; n 20; "Spleen volume reduction by MRI or CT imaging, achieving ≥ 35% reduction in spleen volume imaging from baseline to week 24."; 2026-12
NCT06538181
"Pacritinib in Vacuoles, E1 Ubiqutin-activating Enzyme, X-linked, Autoinflammatory, Somatic (VEXAS) Syndrome"; n 15; "Number of participants with dose-limiting toxicities (DLTs)"; 2029-02-28
NCT06675123
"Pacritinib in Combination With a BTK Inhibitor for the Treatment of Patients With Relapsed or Refractory Mantle Cell Lymphoma"; n 10; "Incidence of adverse events (AEs)"; 2028-03-08
NCT06782373
"A Study to Assess the Effectiveness and Safety of Pacritinib in Patients With VEXAS Syndrome (PAXIS)"; n 78; "Overall Clinical Response (OCR), defined as achieving Clinical Response or better at any time during the double-blind treatment period."; 2028-05-22
NCT06986174
"A Phase 2 Study to Evaluate the Safety and Efficacy of Pacritinib in Relapsed or Refractory Waldenström Macroglobulinemia"; n 30; "Objective Response Rate (ORR)"; 2032-10-01
NCT07033598
"Pacritinib vs. Hydroxyurea in Advanced Proliferative Chronic Myelomonocytic Leukemia"; n 66; "Clinical benefit at Week 24, defined as achieving erythroid response in the absence of leukemic transformation."; 2028-12
NCT07148947
"Pacritinib With Standard of Care Azacitidine or Decitabine as a Bridge to Allogeneic Hematopoietic Stem Cell Transplant for Patients With Accelerated and Blast Phase Myeloproliferative Neoplasms"; n 27; "Number of patients who receive hematopoietic stem cell transplant"; 2028-12-31
NCT07226713
"Pacritinib in Participants With Metastatic Castrate-Resistant Prostate Cancer That Progressed on or After Prior Treatment With Androgen Receptor Signaling Inhibitors"; n 32; "Progression-free Survival"; 2031-03-01
NCT07394153
"Pacritinib For Bone Marrow Fibrosis In Patients With Myelofibrosis Who Have Thrombocytopenia"; n 30; "Decrease in reticulin fibrosis in bone marrow (BM)"; 2028-06
recorded 2026-09-01 · last checked 2026-09-04
Q9
Which running trial of Pacritinib could settle lifespan?
NCT07226713 measures Progression-free Survival, reading out 2031-03-01.
1 open trial; n 32; "Pacritinib in Participants With Metastatic Castrate-Resistant Prostate Cancer That Progressed on or After Prior Treatment With Androgen Receptor Signaling Inhibitors"
Show the evidence
TrialNCT07226713
"Pacritinib in Participants With Metastatic Castrate-Resistant Prostate Cancer That Progressed on or After Prior Treatment With Androgen Receptor Signaling Inhibitors"; n 32; "Progression-free Survival"; 2031-03-01
Q10
Which 12 trials of Pacritinib posted no result?
Posted no result
12 of 12 completed trials
Registrations
NCT00741871, NCT00719836, NCT00745550, NCT01263899, NCT02803762 and NCT02807051, and 6 more
Completion dates
oldest 2011-10; newest 2023-06-08
Show the evidence
Trial
NCT00741871
2011-10
NCT00719836
2012-01
NCT00745550
2012-01
NCT01263899
2012-02
NCT02803762
2014-10
NCT02807051
2014-10
6 further recorded trials
NCT02807116
2015-02
NCT02808455
2015-03
NCT02765724
2015-06
NCT02807077
2015-07
NCT02323607
2018-07-12
NCT05657613
2023-06-08
Q11
At the median, Pacritinib's trials enrolled 26 people — anything larger?
Median enrolment
26
Largest enrolment
407
Registered trials counted
53
Q12
What do 86 spontaneous reports say about Pacritinib — and not say?
These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.
Pacritinib appears in spontaneous reports to regulators. Across the 7 most-reported reaction terms, 86 reaction mentions were counted: diarrhoea 22; platelet count decreased 17; platelet count abnormal 15; haemoglobin abnormal 13. open-targets-adr · CHEMBL2035187 · 2026-06-24
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diarrhoea
22
platelet count decreased
17
platelet count abnormal
15
haemoglobin abnormal
13
haemoglobin decreased
11
myelofibrosis
5
1 more recorded row
myeloproliferative neoplasm
3
recorded 2026-06-24 · last checked 2026-09-04
Q13
Pacritinib and CYP1A2, CYP3A4 and BCRP: shared by which compounds?
CYP1A2, CYP3A4 and BCRP appear in Pacritinib's recorded interaction sentences, 11 in all. openfda-label+europepmc · 2026-08-30
Interpretation pharmacokinetics
Show the evidence
CYP1A2
pharmacokinetics
Pacritinib is an inducer of CYP1A2 and CYP3A4.
pharmacokinetics
In Vitro Studies Cytochrome P450 (CYP) Enzymes: Pacritinib is a time-dependent inhibitor of CYP1A2 and CYP3A4, and a reversible inhibitor of CYP3A4 and CYP2C19 (Ki ≤10 µM).
pharmacokinetics
Pacritinib shows less direct inhibition towards CYP1A2, CYP2B6, CYP2C8, CYP2C9, and CYP2D6 (Ki >10 µM).
CYP2B6pharmacokinetics
Pacritinib shows less direct inhibition towards CYP1A2, CYP2B6, CYP2C8, CYP2C9, and CYP2D6 (Ki >10 µM).
CYP2C19pharmacokinetics
In Vitro Studies Cytochrome P450 (CYP) Enzymes: Pacritinib is a time-dependent inhibitor of CYP1A2 and CYP3A4, and a reversible inhibitor of CYP3A4 and CYP2C19 (Ki ≤10 µM).
CYP2C8pharmacokinetics
Pacritinib shows less direct inhibition towards CYP1A2, CYP2B6, CYP2C8, CYP2C9, and CYP2D6 (Ki >10 µM).
CYP2C9pharmacokinetics
Pacritinib shows less direct inhibition towards CYP1A2, CYP2B6, CYP2C8, CYP2C9, and CYP2D6 (Ki >10 µM).
CYP2D6pharmacokinetics
Pacritinib shows less direct inhibition towards CYP1A2, CYP2B6, CYP2C8, CYP2C9, and CYP2D6 (Ki >10 µM).
CYP3A4
pharmacokinetics
Metabolism Pacritinib is predominantly metabolized by the CYP3A4 isozyme.
pharmacokinetics
Pacritinib is an inducer of CYP1A2 and CYP3A4.
pharmacokinetics
In Vitro Studies Cytochrome P450 (CYP) Enzymes: Pacritinib is a time-dependent inhibitor of CYP1A2 and CYP3A4, and a reversible inhibitor of CYP3A4 and CYP2C19 (Ki ≤10 µM).
recorded 2026-08-30 · last checked 2026-09-04
Q14
What is recorded about Pacritinib and mTOR?
"In this first-in-human, phase I, GVHD prevention trial (NCT02891603), we combine pacritinib (PAC), a JAK2 inhibitor, with sirolimus to concurrently reduce T-cell costimulation via mTOR and IL6 activity." — where Pacritinib and mTOR appear together. Europe PMC · pathway abstract search · 2021-03-22
mTOR; PMID 33753457, 22227528
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mTOR
PMID 33753457
"In this first-in-human, phase I, GVHD prevention trial (NCT02891603), we combine pacritinib (PAC), a JAK2 inhibitor, with sirolimus to concurrently reduce T-cell costimulation via mTOR and IL6 activity."
PMID 22227528
"Many drugs are now under investigations targeting different pathways critical for MPN development, such as the JAK-STAT (JAK2 inhibitors: INCB018424 or ruxolitinib, TG101348 or SAR302503, CYT387, SB1518, CEP701 and LY2784544) and the PI3K/AKT/mTOR (everolimus) pathways, or act through remodeling of chromatin with a key role in epigenetics (givinostat, panobinostat and vorinostat)."
recorded 2021-03-22 · last checked 2026-09-04
Where it is registeredIdentifiers, relations and other names
ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · Open Targets 26.06 — CC0 · derived from this page's own recorded fields; no external licence · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
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✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 10 source rows
✓ no critical contamination: no quarantine open
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