Manifest: Pelabresib in Combination With Ruxolitinib for Janus Kinase Inhibitor Treatment-Naïve Myelofibrosis

John Mascarenhas, Marina Kremyanskaya, Andrea Patriarca, Francesca Palandri, Timothy Devos, Francesco Passamonti, Raajit K Rampal, Adam J Mead, Gabriella Hobbs, Joseph M Scandura, Moshe Talpaz, Nikki Granacher, Tim C P Somervaille, Ronald Hoffman, Marielle J Wondergem, Mohamed E Salama, Gozde Colak, Jike Cui, Jean-Jacques Kiladjian, Alessandro M VannucchiSrdan Verstovsek, Natalia Curto-García, Claire Harrison, Vikas Gupta

Research output: Contribution to journalArticlepeer-review

Abstract

PURPOSE: Standard therapy for myelofibrosis comprises Janus kinase inhibitors (JAKis), yet spleen response rates of 30%-40%, high discontinuation rates, and a lack of disease modification highlight an unmet need. Pelabresib (CPI-0610) is an investigational, selective oral bromodomain and extraterminal domain inhibitor (BETi).

METHODS: MANIFEST (ClinicalTrails.gov identifier: NCT02158858), a global, open-label, nonrandomized, multicohort, phase II study, includes a cohort of JAKi-naïve patients with myelofibrosis treated with pelabresib and ruxolitinib. The primary end point is a spleen volume reduction of ≥ 35% (SVR35) at 24 weeks.

RESULTS: Eighty-four patients received ≥ 1 dose of pelabresib and ruxolitinib. The median age was 68 (range, 37-85) years; 24% of patients were intermediate-1 risk, 61% were intermediate-2 risk, and 16% were high risk as per the Dynamic International Prognostic Scoring System; 66% (55 of 84) of patients had a hemoglobin level of < 10 g/dL at baseline. At 24 weeks, 68% (57 of 84) achieved SVR35, and 56% (46 of 82) achieved a total symptom score reduction of ≥ 50% (TSS50). Additional benefits at week 24 included 36% (29 of 84) of patients with improved hemoglobin levels (mean, 1.3 g/dL; median, 0.8 g/dL), 28% (16 of 57) with ≥ 1 grade improvement in fibrosis, and 29.5% (13 of 44) with > 25% reduction in JAK2V617F-mutant allele fraction, which was associated with SVR35 response (P = .018, Fisher's exact test). At 48 weeks, 60% (47 of 79) of patients had SVR35 response. Grade 3 or 4 toxicities seen in ≥ 10% patients were thrombocytopenia (12%) and anemia (35%), leading to treatment discontinuation in three patients. 95% (80 of 84) of the study participants continued combination therapy beyond 24 weeks.

CONCLUSION: The rational combination of the BETi pelabresib and ruxolitinib in JAKi-naïve patients with myelofibrosis was well tolerated and showed durable improvements in spleen and symptom burden, with associated biomarker findings of potential disease-modifying activity.

Original languageEnglish
Pages (from-to)4993-5004
Number of pages12
JournalJournal of clinical oncology : official journal of the American Society of Clinical Oncology
Volume41
Issue number32
Early online date7 Mar 2023
DOIs
Publication statusPublished - 10 Nov 2023

Keywords

  • Humans
  • Aged
  • Janus Kinase Inhibitors/adverse effects
  • Primary Myelofibrosis/drug therapy
  • Protein Kinase Inhibitors/adverse effects
  • Nitriles/therapeutic use
  • Hemoglobins/therapeutic use
  • Janus Kinase 2/genetics
  • Treatment Outcome

Fingerprint

Dive into the research topics of 'Manifest: Pelabresib in Combination With Ruxolitinib for Janus Kinase Inhibitor Treatment-Naïve Myelofibrosis'. Together they form a unique fingerprint.

Cite this