Constellation Pharmaceuticals Provides an Update from the Ongoing MANIFEST Study of Pelabresib

• Translational data support the disease-modifying potential of pelabresib
• Central pathology review confirmed bone marrow fibrosis improvements observed with pelabresib treatment
• Impact of pelabresib treatment observed across a wide range of myelofibrosis patient subgroups
  

CAMBRIDGE, Mass., June 11, 2021 (GLOBE NEWSWIRE) -- Constellation Pharmaceuticals, Inc. (Nasdaq: CNST), a clinical-stage biopharmaceutical company using its expertise in epigenetics to discover and develop novel therapeutics, today announced that three posters relating to the MANIFEST clinical trial of pelabresib (CPI-0610) in myelofibrosis (MF) were published online in association with the European Hematology Association (EHA) annual meeting. The data in these posters are based on a data cutoff of September 29, 2020 from the MANIFEST Phase 2 clinical trial and reflect an analysis of pelabresib clinical and translational activity.  

“We are particularly enthusiastic about the publication of centrally reviewed translational data, which describe early improvements in bone marrow fibrosis in patients treated with pelabresib, and we believe these results support our thesis of disease-modifying treatment effects that go beyond symptom management,” said Patrick Trojer, chief scientific officer of Constellation Pharmaceuticals. “We are currently enrolling patients in the Phase 3 pivotal study of MANIFEST-2 and our goal is to transform the standard of care for the treatment of myelofibrosis.”

Data Highlights

Translational data, across all three arms of the Phase 2 MANIFEST study, support the disease-modifying potential of pelabresib

• Centrally reviewed bone marrow fibrosis (BMF) pathology conducted in 63 patients showed similar improvements as reported previously for local review of BMF grade. 23 out of 63 patients (37%) achieved at least a 1 grade improvement in BMF. Of these patients, 83% achieved improvements in BMF by 24 weeks.
• 17% of the patients with BMF improvement (4 out of 23), improved by at least 2 grades.
• 31 out of 63 patients (49%) were stabilized or had no change, and only 4 out of 63 patients (6%) worsened.
• An increase in BM erythroid progenitor cells and reduction of the number and cluster formation of megakaryocytes in the BM was observed in 59% and 65%, respectively, of 37 samples from patients treated with pelabresib either as a monotherapy or in combination with ruxolitinib.
• Pelabresib durably reduced inflammatory cytokines such as tumor necrosis factor alpha (TNF alpha) and interleukin 18 (IL18) as early as 2 weeks and maintained through 24 weeks of treatment, based on an analysis of patient samples.