Treating myelofibrosis (MF): Safety, dosing, and administration

In PERSIST-2, VONJO was generally well tolerated1,2

Most common adverse reactions1

The most common adverse reactions in ≥20% of patients (n=106) were diarrhea, thrombocytopenia, nausea, anemia, and peripheral edema.

Drug interruptions1

The most frequent reasons for drug interruption in ≥2% of patients receiving VONJO (200 mg BID) were anemia (5%), thrombocytopenia (4%), diarrhea (3%), nausea (3%), cardiac failure (3%), neutropenia (2%), and pneumonia (2%).

Drug discontinuation1

Among patients on VONJO, 15% discontinued treatment due to an adverse reaction, with the most frequent reasons being anemia (3%) and thrombocytopenia (2%).

Dosage reductions1

Adverse reactions requiring dosage reduction in ≥2% of patients who received VONJO (200 mg BID) included thrombocytopenia (2%), neutropenia (2%), conjunctival hemorrhage (2%), and epistaxis (2%).

Important Baseline Hematologic Characteristics to Consider1

HEMATOLOGIC PARAMETERS

Median baseline platelet count (plt): 55 x 109/L

  • 45% of patients had plt <50 x 109/L;
    55% had plt 50-100 (x 109/L)

Median baseline hemoglobin level (Hgb): 9.5 g/dL

  • 59% of patients on VONJO were anemic (Hgb <10 g/dL) vs 57% on BAT3
  • 23% of patients were RBC transfusion dependent

Adverse Reactions Reported in ≥10% of Patients With Platelet Counts ≤100 x 109/L Receiving VONJO or BAT1

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Table: Adverse reactions in PERSIST-2 study of VONJO (pacritinib) vs best available therapy
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Table: Adverse reactions in PERSIST-2 study of VONJO (pacritinib) vs best available therapy
  • *Grade by CTCAE Version 4.03.

Incidence of diarrhea1

Most cases of diarrhea with VONJO were low grade and rarely led to treatment interruption (3%).1,2

  • VONJO caused diarrhea in ~48% of patients vs 15% of patients treated with BAT
    • Of the 48% that experienced diarrhea (any grade), most were Grade 1 (29%) and Grade 2 (15%)1,4
  • No patients on VONJO reported diarrhea that resulted in treatment discontinuation
  • Diarrhea decreased over time with most cases (41%) occurring in the first 8 weeks, 15% in Weeks 8-16, and 8% in Weeks 16-24
  • Median time to resolution of diarrhea was 2 weeks
  • Serious diarrhea occurred in 2% of patients treated with VONJO vs no such adverse reactions with BAT

Management of diarrhea1

  • Control preexisting diarrhea before starting VONJO
  • In patients with Grade 3 or 4 diarrhea:
    • Hold VONJO until it resolves to Grade ≤1 or baseline, and restart VONJO at the last given dose
    • Intensify antidiarrheal regimen and provide fluid replacement
    • For recurrent diarrhea, hold VONJO until the diarrhea resolves to Grade ≤1 or baseline, and restart VONJO at 50% of the last given dose once the toxicity has resolved
    • Concomitant antidiarrheal treatment is required for patients restarting VONJO

Start and stay with full dose intensity from day one (200 mg BID)

The majority of patients with MF were able to start and stay on full-dose VONJO. In the pivotal trial (n=106)1:

  • Average daily dose was 380 mg (95% mean relative dose intensity)
  • Median daily dose was 400 mg (100% median relative dose intensity)
  • Dosage reductions due to an adverse reaction occurred in 12% of patients on VONJO 200 mg BID 
(vs 7% of patients treated with BAT)
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200mg Twice Per Day
  • Swallow capsules whole. Do not open, break, or chew capsules
  • Patients who are on other kinase inhibitors must taper or discontinue treatment before starting VONJO (according to the Prescribing Information for that drug)

Dose modifications for diarrhea, thrombocytopenia, hemorrhage, and prolonged QT interval may be required (see Warnings and Precautions below).

  • BAT=best available therapy; BID=twice daily; CTCAE=Common Terminology Criteria for Adverse Events; MOA=mechanism of action; NCCN=National Comprehensive Cancer Network® (NCCN®); RBC=red blood cell.
  • References: 1. VONJO. Prescribing information. CTI BioPharma Corp.; 2023. 2. Mascarenhas J, et al. JAMA Oncol. 2018;4(5):652-659. 3. Mascarenhas J, et al. JAMA Oncol. 2018. Accessed December 21, 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5885169/bin/jamaoncol-e175818-s001.pdf 4. Data on File. Sobi, Inc. 2023.