Aptose Reports Second Quarter 2025 Results
Tuspetinib Continues to Demonstrate Excellent Safety and Complete Responses in the TUSCANY Clinical Trial of Tuspetinib in AML Triple Drug Frontline Therapy at 120 mg Dose
Cohort Safety Review Committee (CSRC) Recommends Tuspetinib Dose Escalation to 160 mg Dose
Hanmi Continues to Support Development of Tuspetinib
SAN DIEGO and TORONTO, Aug. 13, 2025 (GLOBE NEWSWIRE) -- Aptose Biosciences Inc. ("Aptose" or the "Company") (TSX:APS, OTC:APTOF), a clinical-stage precision oncology company developing a tuspetinib (TUS)-based triple drug frontline therapy to treat patients with newly diagnosed acute myeloid leukemia (AML), today announced financial results for the second quarter ended June 30, 2025, and provided a corporate update.
"During the second quarter, the TUSCANY triplet trial continued to progress well. Our investigators are eager to improve outcomes for patients with mutations that are especially difficult to treat in AML, and we continue to observe exciting safety and activity with the addition of TUS to the VEN+AZA standard treatment," said William G. Rice, Ph.D., Chairman, President and Chief Executive Officer of Aptose. "We look forward to providing updates to the data we presented at EHA in June."
Key Corporate Highlights
Tuspetinib Data Reported at the European Hematology Association (EHA) 2025 Congress in Oral Presentation, Tuspetinib based TUS+VEN+AZA triplet therapy is being advanced in the TUSCANY Phase 1/2 trial with the goal of creating a one-of-a-kind frontline therapy for newly diagnosed AML patients that is safe and active across diverse AML populations (mutation agnostic triplet frontline therapy), including patients without FLT3 mutations (wildtype FLT3). Data from the first two cohorts, with a 40 mg or 80 mg dose of tuspetinib in the TUS+VEN+AZA combination, reveal promising clinical safety and antileukemic activity and were presented in an oral presentation at EHA 2025 in June (press release here) by Dr. Gabriel Mannis, Associate Professor of Medicine, Stanford University School of Medicine, and an investigator in the TUSCANY study. Dr. Mannis also noted three patients were rapidly enrolled on the third dose cohort of 120 mg TUS in the TUS+VEN+AZA triplet, and that no DLTs were observed. Among the key findings: Multiple CRs were achieved, at the initial dose of 40 mg (3 of 4 CRs and minimal residual disease (MRD)-negative) and at the 80 mg dose (3 of 3 CR/CRi). Regardless of FLT3, TP53, NPM1, or myelodysplasia related mutation status, TUS demonstrated activity in newly diagnosed AML patients. MRD-negative responses were achieved across diverse genetic populations, including in subjects with biallelic TP53 mutations and complex karyotypes. In addition, TUS can be administered safely with standard-of-care dosing of VEN/AZA, and TUS PK properties are not significantly altered by VEN, AZA, antifungals or food. No prolonged myelosuppression was noted in Cycle 1 in the absence of AML and there were no treatment-related deaths with 9 out of 10 enrolled subjects remaining on study treatment.
TUS Continues to Demonstrate Safety and CRs at 120 mg Dose in the TUSCANY Triplet Trial; 160 mg Dose Cohort Now Open After Dose Escalation Decision by CSRC, The fourth dosing cohort of 160 mg of TUS in the TUS+VEN+AZA TUSCANY trial is now open for enrollment after the CSRC reviewed the current data from the 120 mg TUS dose cohort. All patients treated in the 120 mg dose cohort remain on study while enrollment is open for the 160 mg dose cohort.
Aptose Clinical Data Accepted for Poster Presentation at European School of Haematology (ESH) 7th International Conference, Aptose recently was notified that its abstract "TUSCANY Study of Safety and Efficacy of Tuspetinib plus Standard of Care Venetoclax and Azacitidine in Study Participants with Newly Diagnosed AML Ineligible for Induction Chemotherapy" was accepted for a poster presentation at the ESH 7th International Conference on Acute Myeloid Leukemia "Molecular and Translational": Advances in Biology and Treatment, being held October 16-18, 2025 in Estoril, Portugal.
Aptose and Hanmi Enter Loan Agreement to Advance Development of Tuspetinib in Triplet Therapy for AML, During the quarter, Aptose announced that it entered into a loan agreement with Hanmi Pharmaceutical Co. Ltd. ("Hanmi"). The Loan Agreement is an uncommitted facility for up to US$8.5million, administered through multiple advances for the purpose of continued clinical development of TUS (press release here). To date, Aptose has received an aggregate of US$5.6M under the Loan Agreement.
Aptose Trading on OTCQB Market, On July 1st, Aptose announced that it had been upgraded to list for trading on the OTCQB Market under the ticker symbol "APTOF," in addition to the Company's continued listing on the Toronto Stock Exchange (TSX) under the symbol "APS." The OTCQB Market is for early stage and developing U.S. and international companies. Companies listed on the OTCQB Market are current in their reporting and undergo an annual verification and management certification process. Investors can find Real-Time quotes and market information for the company on www.otcmarkets.com.
Aptose Selects Ernst & Young as its New Independent Auditor and will Hold a Reconvened Meeting of its Shareholders on August 22, 2025, Earlier this month, Aptose announced that its Board of Directors unanimously approved the selection of Ernst & Young LLP ("EY") as the Company's independent registered public accounting firm to serve as the Company's independent auditor. The Company had adjourned its Annual and Special Meeting of shareholders held on May 27, 2025 (the "Meeting"), for the purposes of completing its search for a successor independent auditor, and will reconvene the Meeting of shareholders on August 22, 2025 at 10:00 a.m. (Eastern Time) (the"Reconvened Meeting") to vote on the appointment of EY. Shareholders are invited to attend the Reconvened Meeting by using the live webcast link here: https://meetings.lumiconnect.com/400-935-182-032. Only registered shareholders and duly appointed proxyholders as of the record date on April 22, 2025, will be entitled to vote and ask questions at the Reconvened Meeting.
Completed and Planned Value-Creating Milestones
2025: 1H
Reported safety and efficacy with 40mg TUS+VEN+AZA
Reported safety and efficacy with 80mg TUS+VEN+AZA
2025: European Hematology Association (EHA)
Report maturing data from TUS+VEN+AZA triplet study
2025: 2H
Reported safety and efficacy with 120 mg TUS+VEN+AZA
CSRC review of data; decision to dose escalate to 160 mg TUS+VEN+AZA
Report evolving data from 120 mg TUS+VEN+AZA triplet
2025: American Society of Hematology (ASH)
Report response rate and durability of TUS+VEN+AZA triplet
Select TUS dose for TUS+VEN+HMA triplet Ph 2/3 PIVOTAL trials
Prepare for initiation of Ph 2/3 PIVOTAL program
FINANCIAL RESULTS OF OPERATIONSAptose Biosciences Inc.Statements of Operations Data(unaudited)($ in thousands, except for share and per share data)
Three months endedJune 30,
Six months endedJune 30,
2025
2024
2025
2024
Expenses:
Research and development
$
3,298
$
4,413
$
5,662
$
10,858
General and administrative
3,623
2,932
6,720
6,247
Operating expenses
