SAN DIEGO, CA, USA and TORONTO, Canada I January 13, 2015 I Aptose Biosciences Inc. (NASDAQ: APTO, TSX: APS), a clinical-stage company developing new therapeutics and molecular diagnostics that target the underlying mechanisms of cancer, today 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.

About the Study

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.

About Aptose

Aptose Biosciences is a clinical-stage biotechnology company committed to discovering and developing personalized therapies addressing unmet medical needs in oncology. Aptose is advancing new therapeutics focused on novel cellular targets on the leading edge of cancer research, coupled with companion diagnostics to identify the optimal patient population for our products. Aptose’s small molecule cancer therapeutics pipeline includes products designed to provide enhanced efficacy with existing anti-cancer therapies and regimens without overlapping toxicities. Aptose Biosciences Inc. is listed on NASDAQ under the symbol APTO and on the TSX under the symbol APS. For further information, please visit www.aptosebiosciences.com.

SOURCE: Aptose Biosciences