Aptose Biosciences Inc., a clinical-stage company, announced dosing of the first patient in its phase 1b clinical study of APTO-253 in patients with relapsed or refractory hematologic malignancies.  APTO-253 is a first-in-class inducer of the Krüppel-like factor 4 (KLF4) tumor suppressor gene, and the only clinical-stage compound targeted for patients with suppressed KLF4 levels.

"Epigenetic suppression of the KLF4 gene has been reported as a key transforming event in acute myeloid leukemia and high-risk myelodysplastic syndromes, and Aptose is a pioneer in advancing KLF4 induction as a new therapeutic approach for the treatment of these patient populations," commented William G. Rice, Ph.D., chairman, president and CEO.

The phase 1b, multicenter, open-label, dose-escalation clinical trial of APTO-253 is designed to assess the safety, tolerability, pharmacokinetics and pharmacodynamic responses and efficacy of APTO-253 as a single agent.  APTO-253 will be administered twice weekly, over a 28-day cycle.  The study is expected to enroll up to 30 patients with relapsed or refractory hematologic malignancies across two separate dose-escalation arms: (a) up to 15 patients with acute myeloid leukemia (AML) and high-risk myelodysplastic syndromes (MDS) patients, and (b) up to 15 patients with lymphomas (Hodgkin and non-Hodgkin lymphoma) and multiple myeloma. The study is designed to then transition to single-agent expansion cohorts in AML and MDS, followed by combination studies. More information can be found at www.clinicaltrials.gov.

Aptose Biosciences is a clinical-stage biotechnology company committed to discovering and developing personalized therapies addressing unmet medical needs in oncology.