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EHA News - Constellation Announces MANIFEST Trial Clinical Updates

Current TAP Partner

CAMBRIDGE, Mass., June 12, 2020 (GLOBE NEWSWIRE) -- Constellation Pharmaceuticals, Inc. (Nasdaq: CNST) announced that three posters relating to the MANIFEST clinical trial of 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 April 17, 2020, and reflect an analysis of clinical activity in 51 first-line (1L) and 73 second-line (2L) patients. 

About MANIFEST

MANIFEST is an open-label Phase 2 clinical trial of CPI-0610 in patients with myelofibrosis (MF), a rare cancer of the bone marrow that disrupts the body’s normal production of blood cells. Constellation is evaluating CPI-0610 in combination with ruxolitinib in JAK-inhibitor-naïve MF patients (Arm 3), with a primary endpoint of the proportion of patients with a ≥35% spleen volume reduction from baseline (SVR35) after 24 weeks of treatment. Constellation is also evaluating CPI-0610, either as a monotherapy in patients who are resistant to, intolerant of, or ineligible for ruxolitinib and no longer on the drug (Arm 1), or as add-on therapy in combination with ruxolitinib in patients with a sub-optimal response to ruxolitinib or MF progression (Arm 2). Patients in Arms 1 and 2 are being stratified based on TD status. The primary endpoint for the patients in cohorts 1A and 2A, who were TD at baseline, is conversion to TI for 12 consecutive weeks. The primary endpoint for the patients in cohorts 1B and 2B, who were not TD at baseline, is the proportion of patients with a ≥35% spleen volume reduction from baseline after 24 weeks of treatment. 

Data Highlights

Arm 3 (1L) – CPI-0610 + ruxolitinib in JAK-inhibitor-naïve patients

  • 37 of 51 evaluable patients (73%) achieved a 35% reduction in spleen volume (SVR35) at 12 weeks and had a median spleen volume reduction of 51%
  • 19 of 30 evaluable patients (63%) achieved SVR35 at 24 weeks (the primary endpoint for Arm 3) and had a median spleen volume reduction of 53%
  • 17 of 29 evaluable patients (59%) achieved a 50% improvement in Total Symptom Score (TSS50) at 24 weeks and had a median TSS improvement of 64%
  • No evidence of correlation between SVR35 response and baseline risk status, platelet count, or spleen volume

Arm 1 (2L) – CPI-0610 monotherapy in JAK-inhibitor-experienced or -ineligible patients

  • 3 of 14 (21%) evaluable transfusion-dependent (TD) patients converted to transfusion independence (TI), the primary endpoint for cohort 1A
  • 5 of 21 (24%) evaluable non-TD patients achieved SVR35 (the primary endpoint for cohort 1B) and 9 of 19 (47%) evaluable non-TD patients achieved TSS50 at 24 weeks
  • 11 of 19 (58%) non-TD patients on treatment for at least 12 weeks without any transfusions achieved a ≥1.5 g/dL mean increase in hemoglobin

Arm 2 (2L) – CPI-0610 + ruxolitinib in ruxolitinib-experienced patients

  • 11 of 32 (34%) evaluable TD patients converted to TI, the primary endpoint for cohort 2A
  • 4 of 18 (22%) evaluable non-TD patients achieved SVR35 (the primary endpoint for cohort 2B) and 7 of 19 (37%) evaluable non-TD patients achieved TSS50 at 24 weeks

http://ir.constellationpharma.com/news-releases/news-release-details/constellation-pharmaceuticals-provides-updates-manifest-study