A Safety and Efficacy Study of Pracinostat and Azacitidine in Patients With High Risk Myelodysplastic Syndromes
This is a Phase 2, two-stage study of the safety and efficacy of pracinostat in combination with azacitidine in patients with IPSS-R high and very high risk myelodysplastic syndrome (MDS) who are previously untreated with hypomethylating agents (HMAs). Enrollment in this study will be limited to high/very high risk MDS because this group represents the highest unmet need, with median survival of less than 18 months. Stage 1a will be conducted as an open-label single arm in up to 40 subjects to assess if this regimen with a lower pracinostat dose results in a discontinuation rate that meets a predefined threshold and in efficacy that justifies expansion of enrollment into Stage 1b. A discontinuation rate of approximately ≤10% in Stage 1a, a rate comparable to that observed with azacitidine alone in study MEI-003 (NCT01873703), supports expansion into Stage 1b. Stage 1b will be conducted as expansion of stage 1a. Approximately 20 additional subjects will be enrolled. Study drugs should be continued until disease progression or intolerable toxicity. It is important to note that the median time to achieving a response with azacitidine alone is 4 to 5 months. Furthermore, the median time to achieving a Complete Response (CR) in study MEI-003 (NCT01873703) was 4 cycles. Therefore, early (<6 months) discontinuation of trial therapy for 'no response' should be avoided. The Medical Monitor should be contacted prior to discontinuing a subject from the study to discuss the rationale for discontinuation.