Aptose to Hold Corporate Update Monday, December 13th

HM43239 clinical update in AML after oral presentation at 2021 ASH Annual Meeting
Luxeptinib clinical update in AML and B-cell cancers

Aptose Biosciences Inc. ("Aptose") (NASDAQ: APTO, TSX: APS), a clinical-stage company developing highly differentiated therapeutics targeting the underlying mechanisms of cancer, today announced that the company management team will provide a corporate update on Monday, December 13, 2021 at 5:30 PM ET, in conjunction with participation at the 2021 ASH Annual Meeting. The event will include a review of HM43239 data highlighted in an oral presentation at ASH, as well as the up-to-date clinical status of luxeptinib. HM43239 is an oral, myeloid kinome inhibitor in an international Phase 12 trial in patients with relapsed or refractory acute myeloid leukemia (AML). Luxeptinib is an oral, dual lymphoid and myeloid kinome inhibitor in a Phase 1 ab trial in patients with relapsed or refractory B cell malignancies who have failed or are intolerant to standard therapies, and in a separate Phase 1 ab trial in patients with relapsed or refractory AML or high risk myelodysplastic syndrome (MDS)

Aptose Corporate Update Details

Date & Time: Monday, December 13, 2021, 5:30 PM ET

Participant Webcast Link : Link

Participant Dial-in:

The slides will be available on Aptose's website here and a recording of the presentation will be archived shortly after the conclusion of the event.

As announced previously, the abstracts accepted for presentation at ASH are listed below and can be viewed online at the ASH conference website. Note that the poster presentations will include additional data not found in the abstracts.

Oral Presentation Details

Publication #702: First in Human FLT3 and SYK Inhibitor HM43239 Shows Single Agent Activity in Patients with Relapsed or Refractory FLT3 Mutated and Wild-Type Acute Myeloid Leukemia (AML)
Oral Presentation Session Date & Time: Monday, December 13, 2021, 4:00 PM ET
Session Name: 616. Acute Myeloid Leukemias: Investigational Therapies, Excluding Transplantation and Cellular Immunotherapies: Targeted Therapies and Novel Therapies
Location: Georgia World Congress Center, Georgia Ballroom 1-3

Poster Presentation Details

Publication #1355: A Phase 1 a/b Dose Escalation Study of the Mutation Agnostic BTK/FLT3 Inhibitor Luxeptinib (CG-806) in Patients with Relapsed or Refractory B-Cell Malignancies
Poster Session Date & Time: Saturday, December 11, 2021, 5:30 – 7:30 PM ET
Session Name: 623. Mantle Cell, Follicular, and other Indolent B Cell Lymphomas: Clinical and Epidemiological: Poster I
Location: Georgia World Congress Center, Hall B5

Publication #1272: A Phase 1 a/b Dose Escalation Study of the Mutation Agnostic FLT3/BTK Inhibitor Luxeptinib (CG-806) in Patients with Relapsed or Refractory Acute Myeloid Leukemia
Poster Session Date & Time: Saturday, December 11, 2021, 5:30 – 7:30 PM ET
Session Name: 616. Acute Myeloid Leukemias: Investigational Therapies, Excluding Transplantation and Cellular Immunotherapies: Poster I
Location : Georgia World Congress Center, Hall B5

Publication #3411: A Phase 1 a/b Dose Escalation Study of the MYC Repressor Apto-253 in Patients with Relapsed or Refractory AML or High-Risk MDS
Poster Session Date & Time: Monday, December 13, 2021, 6:00 – 8:00 PM ET
Session Name: 616. Acute Myeloid Leukemias: Investigational Therapies, Excluding Transplantation and Cellular Immunotherapies: Poster III
Location: Georgia World Congress Center, Hall B5

The poster abstracts also are published in the November supplemental issue of Blood , an ASH journal, available online.

About Aptose

Aptose Biosciences is a clinical-stage biotechnology company committed to developing personalized therapies addressing unmet medical needs in oncology, with an initial focus on hematology. The Company's small molecule cancer therapeutics pipeline includes products designed to provide single agent efficacy and to enhance the efficacy of other anti-cancer therapies and regimens without overlapping toxicities. The Company has three clinical-stage investigational products for hematologic malignancies: HM43239, an oral, myeloid kinome inhibitor in an international Phase 1/2 trial in patients with relapsed or refractory acute myeloid leukemia (AML); luxeptinib, an oral, dual lymphoid and myeloid kinome inhibitor in a Phase 1 a/b trial in patients with relapsed or refractory B cell malignancies who have failed or are intolerant to standard therapies, and in a separate Phase 1 a/b trial in patients with relapsed or refractory AML or high risk myelodysplastic syndrome (MDS); and APTO-253, a MYC oncogene repressor, in a Phase 1 a/b clinical trial in patients with relapsed or refractory AML or high risk MDS. For more information, please visit www.aptose.com .

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