Encouraging Preliminary Results in Myelofibrosis Trial Lead to Enhancements in Phase 2

After seeing encouraging phase 1 results, the phase 2 portion of a clinical trial currently evaluating the efficacy of the BET inhibitor CPI-0610 in patients with myelofibrosis has been enhanced and expanded, according to Constellation Pharmaceuticals, the drug’s manufacturer.

Initially, The MANIFEST study set out to examine anti-tumor activity and safety in 35 patients treated with monotherapy and 35 patients with refractory disease or those who have relapsed or do not respond to standard of care who received a combination with Jakafi (ruxolitinib). With treatment, patients saw a decrease in spleen swelling and symptom improvement. Additionally, one patient who had previously been dependent on red-blood-cell transfusions no longer needed them after treatment.

Based on this positive preliminary phase 1 data, researchers announced the amendment of the second phase of the trial’s design to stratify patients based on their transfusion dependence status. Each cohort is expected to enroll up to 25 non-transfusion-dependent patients and 16 transfusion-dependent patients.

In addition, the study’s design is also being amended to include a third cohort to determine if CPI-0610 can be used in combination with Jakafi as a first-line therapy in patients with JAK 1/2-inhibitor-naïve myelofibrosis. In this cohort, up to 43 anemic patients will be enrolled.

The expansion of the MANIFEST study is a result of the unmet medical need for myelofibrosis therapies that modify the disease, according to the drug’s manufacturer. These enhancements are meant to provide “additional measures of potential clinical benefit and to expand the potential addressable patient population for CPI-0610.”

In a statement on the trial updates, Adrian Senderowicz, senior vice president and chief medical officer of Constellation Pharmaceuticals, explained, “We are enhancing the study’s design to better measure these potential effects.”

“We continue to look forward to determining proof of concept for CPI-0610 in myelofibrosis by mid-2019,” he added.