Pacritinib

VONJO

Open Pacritinib in the interactive console ↗

Pacritinib ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Pacritinib ballicule

Pacritinib VONJO mascot mnemonic cartoon — Visual mnemonic: Pacritinib mascot
**“Pac-nibblin’ Banjo”**

What it isJAK-family inhibitor that spares JAK1; myelofibrosis with severe thrombocytopenia.

Why this oneJAK1 sparing permits use when thrombocytopenia makes ruxolitinib untenable.

What limits itDiarrhea and bleeding commonly limit treatment; QT prolongation and limited long-term data require caution.

Pacritinib molecular structure (skeletal formula) — Molecular structure: Pacritinib

FDA-approved for

Myelofibrosis with severe thrombocytopenia (2022)

FDA label

Read the full label on DailyMed ↗

FDA dosing	Population	Start	Target	Max
Myelofibrosis, intermediate/high-risk, primary or secondary (post-PV / post-ET) — see flags	Adults	200 mg BID	200 mg BID	200 mg BID

Renal Avoid if eGFR <30 mL/min

Hepatic Mild–moderate (Child-Pugh A/B): no adjustment; severe (Child-Pugh C): 100 mg BID, may increase to 200 mg BID after 12 weeks if ineffective and no safety concerns

Instructions

Swallow capsules whole — do not open, break, or chew; with or without food
Taper or discontinue prior kinase inhibitors per their labels before starting
Baseline CBC (with differential and platelets), coagulation testing (PT, PTT, TT, INR), and ECG before starting; monitor as clinically indicated
Hold 7 days before elective surgery/invasive procedures (hemorrhage risk); restart only after hemostasis assured
Toxicity dose reductions: 200 mg BID → 100 mg BID → 100 mg QD; discontinue if 100 mg QD not tolerated
Missed dose: skip; do not take extra capsules

Available strengths

cap 100 mg

Contraindications

Concomitant strong CYP3A4 inhibitors or inducers

Cautions

Hemorrhage — serious (11–13%) and fatal (2%) bleeds; avoid with active bleeding; hold 7 days pre-procedure
Diarrhea (~48%) — control pre-existing diarrhea first; manage with antidiarrheals, fluids, dose modification; postmarketing severe diarrhea with AKI
Worsening thrombocytopenia — dose reduce/interrupt
QT prolongation — avoid if baseline QTc >480 ms; hold for QTc >500 ms or >60 ms rise; correct hypokalemia before and during
JAK-inhibitor class risks: MACE (esp. smokers/CV risk), thrombosis (DVT/PE/arterial), secondary malignancies (lymphoma)
Infection — delay start until active serious infections resolve
Symptom exacerbation after interruption/discontinuation

Adverse reactions

≥20%: diarrhea, thrombocytopenia, nausea, anemia, peripheral edema

Pregnancy No human data; animal embryonic/fetal loss and maternal toxicity at exposures below the human dose; advise of potential fetal risk

Lactation Breastfeeding not recommended during treatment and for 2 weeks after the last dose

Cost

Pacritinib (VONJO)

Strength		#/mo	generic $/mo	CostPlus
100 mg	cap	60 BID		not offered

NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Pacritinib is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.

NO BOXED WARNINGS

Principal riskDiarrhea and bleeding; QT prolongation

Classes and tags

Clinical profile

Therapeutic safety burden4 / 4

Overdose danger2 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades4 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk2 / 4

Legacy pregnancy categoryN/A (post-2015 labeling)

Defining liabilityHemorrhage, myelosuppression, severe diarrhea and QT prolongation

Open Pacritinib in the interactive console ↗