SAN DIEGO and TORONTO, Dec. 19, 2025 (GLOBE NEWSWIRE) -- Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX: APS; OTC: APTOF) announced today that it will be rescheduling its upcoming special meeting of shareholders, originally scheduled to be held on January 16, 2026 (the “Meeting”), to a later date to be announced. Aptose will hold the rescheduled Meeting as soon as practicable in January 2026. No changes are expected to be made to the record date of the Meeting, being the close of business on Decem ...

Core Insights - Aptose Biosciences Inc. presented clinical data for its lead compound tuspetinib (TUS) in combination with venetoclax (VEN) and azacitidine (AZA) at the 67th American Society of Hematology Annual Meeting, highlighting promising safety and antileukemic activity in treating acute myeloid leukemia (AML) [1][2][3] Group 1: Clinical Data and Efficacy - The TUSCANY trial showed a 100% clinical response rate (CR/CRh) at the higher doses of 80 mg and 120 mg TUS [5][6] - High-quality clinical responses were observed across various genetic subgroups, including FLT3 wildtype and those with adverse mutations such as TP53 and RAS [6][7] - Minimal residual disease (MRD) negativity was achieved in 78% of responding subjects, indicating effective treatment outcomes [6][7] Group 2: Safety and Tolerability - TUS+VEN+AZA therapy demonstrated a favorable safety profile with no dose-limiting toxicities reported across all evaluated TUS dose levels [6][7] - No drug-related deaths or significant adverse events such as differentiation syndrome or QTc prolongation were reported [6][7] - The therapy was well tolerated, with 8 out of 10 evaluable subjects achieving red cell and platelet transfusion independence for over 8 weeks after their best response [6][7] Group 3: Future Directions - The company has commenced treating patients at the highest dose level of 160 mg TUS, with early responses already observed [3][6] - The ongoing TUSCANY Phase 1/2 study aims to further evaluate the efficacy and safety of TUS in combination with standard therapies for newly diagnosed AML patients ineligible for induction chemotherapy [7][8]

Core Viewpoint - Aptose Biosciences Inc. has entered into a definitive arrangement agreement with Hanmi Pharmaceutical Co. Ltd. for a "go private" transaction, where minority shareholders will receive C$2.41 in cash per share, representing a 28% premium over the 30-day volume-weighted average price (VWAP) of C$1.88 [1][2] Company Overview - Aptose is a clinical-stage biotechnology company focused on developing precision medicines for oncology, particularly in hematology, with its lead compound being tuspetinib (TUS) [19] - The company has been supported by Hanmi, which owns 19.93% of Aptose's outstanding shares and has provided over US$30 million in debt facilities for the development of TUS [2][19] Transaction Details - Under the arrangement agreement, Hanmi Purchaser will acquire all common shares not owned by Hanmi or its affiliates through a plan of arrangement [4] - Each common share will be exchanged for C$2.41 in cash, and options, restricted share units, and warrants will also be converted into cash based on the same valuation [5][6] - The transaction is subject to customary closing conditions, including court approval and shareholder approval [8][9] Shareholder Approval - The transaction requires approval from at least two-thirds of the votes cast by Aptose shareholders at a special meeting, which must occur by January 16, 2026 [9] - Voting support agreements have been established with Aptose's directors and officers to vote in favor of the transaction [10] Financial Valuation - Locust Walk Securities, LLC provided a formal valuation indicating that the fair market value of Aptose's common shares ranges from C$1.00 to C$5.23, affirming that the cash consideration is fair from a financial perspective [12][15] Strategic Implications - The transaction allows Aptose to continue developing TUS in combination with other treatments for acute myeloid leukemia (AML), with promising early clinical data reported [3][17] - This marks Hanmi's entry into the North American market, establishing a strategic foothold for future partnerships and clinical expansion [3][18]

Core Insights - Aptose Biosciences Inc. is developing a triple drug frontline therapy using tuspetinib (TUS) for newly diagnosed acute myeloid leukemia (AML) patients [1][4] - The TUSCANY study's abstract has been selected for poster presentation at the 67th American Society of Hematology (ASH) Annual Meeting scheduled for December 6-9, 2025 [1][2] Presentation Details - The poster presentation will focus on the safety and efficacy of tuspetinib combined with standard care venetoclax and azacitidine for AML patients ineligible for induction chemotherapy [2] - The session will take place on December 6, 2025, from 5:30 PM to 7:30 PM at the OCCC - West Halls B3-B4 [2] Company Overview - Aptose is a clinical-stage biotechnology company focused on precision medicines for oncology, particularly in hematology [4] - Tuspetinib has shown activity as both a monotherapy and in combination therapy for relapsed or refractory AML and is being developed as a frontline triplet therapy for newly diagnosed AML [4]

Core Insights - Aptose Biosciences is presenting promising data from the TUSCANY trial, which evaluates the safety and efficacy of the tuspetinib-based triplet therapy (TUS+VEN+AZA) for newly diagnosed AML patients ineligible for induction chemotherapy [1][2][3] Group 1: Clinical Trial Data - The TUSCANY trial has shown that the addition of tuspetinib to the standard treatment of venetoclax and azacitidine has resulted in complete remission (CR) or complete remission with incomplete hematologic recovery (CRh) in 100% of patients treated at higher doses of 80 mg and 120 mg [5][6] - Overall, 90% of patients in the trial have achieved CR/CRh responses, with 88% of FLT3 wildtype AML patients responding positively [6][8] - The therapy has demonstrated activity across diverse genetic subtypes, including those with unmutated FLT3, FLT3-ITD, NPM1c, biallelic TP53, RAS, and myelodysplasia-related mutations [3][14] Group 2: Safety Profile - The TUS+VEN+AZA combination has been well tolerated, with no significant safety concerns or dose-limiting toxicities reported, including no prolonged myelosuppression, differentiation syndrome, QTc prolongation, or treatment-related deaths [2][6] - Dosing has commenced at the 160 mg level, indicating ongoing escalation in the trial [5][14] Group 3: Trial Design and Objectives - The TUSCANY trial is a Phase 1/2 study being conducted at 10 leading U.S. clinical sites, aiming to establish a safe and effective frontline therapy for a broad range of newly diagnosed AML patients [9][11] - The trial is designed to test various doses and schedules of tuspetinib in combination with standard dosing of azacitidine and venetoclax, with an anticipated enrollment of 18-24 patients by the end of 2025 [9][10]

Core Insights - The TUSCANY trial is evaluating the safety and efficacy of a triplet therapy combining tuspetinib (TUS) with venetoclax (VEN) and azacitidine (AZA) for newly diagnosed acute myeloid leukemia (AML) patients who are ineligible for induction chemotherapy [1][8] - Initial results from 10 patients show promising clinical safety and antileukemic activity, with a high rate of complete remissions (CR) and minimal safety concerns [2][3] Summary by Sections Trial Overview - The TUSCANY Phase 1/2 trial is designed to test various doses of TUS in combination with standard dosing of AZA and VEN for AML patients [9] - The trial is being conducted at 10 leading U.S. clinical sites, with an expected enrollment of 18-24 patients by the end of 2025 [9] Safety and Efficacy - No significant safety concerns or dose-limiting toxicities (DLTs) have been observed in the TUSCANY trial, including no prolonged myelosuppression or treatment-related deaths [2][6] - The addition of TUS to VEN+AZA achieved CR/CRh responses in 100% of patients treated at higher dose levels of 80 mg and 120 mg, exceeding the expected 66% response rate from VEN+AZA alone [5][6] Patient Responses - Out of 10 patients, 9 achieved complete remissions, with 7 demonstrating minimal residual disease (MRD) negativity [3][14] - The therapy has shown effectiveness across diverse genetic subtypes, including those with unmutated FLT3, FLT3-ITD, and TP53 mutations [3][14] Current Developments - Dosing has progressed to the 160 mg TUS level, with ongoing assessments of safety and efficacy [2][5][14] - The triplet therapy is being developed as a mutation-agnostic frontline treatment for AML, targeting a broad range of patient populations [2][8]

Core Insights - Aptose Biosciences Inc. is a clinical-stage precision oncology company focused on developing tuspetinib (TUS) as a frontline therapy for newly diagnosed acute myeloid leukemia (AML) [1][4] Group 1: Shareholder Meeting Outcomes - Shareholders voted to appoint Ernst & Young LLP as the independent registered public accounting firm for the Company [2] - The appointment of EY is expected to enhance the Company's growth and commitment to transparency due to their expertise in the life sciences sector [2] Group 2: Funding and Financial Updates - Aptose has received an additional US$1.5 million in funding from Hanmi Pharmaceutical Co. Ltd. as part of an US$8.5 million loan facility agreement [3] - To date, the Company has received a total of US$7.1 million under the Loan Agreement to support the clinical development of tuspetinib [3]

Core Insights - Aptose Biosciences Inc. is advancing its clinical-stage precision oncology drug, tuspetinib (TUS), in a Phase 1/2 trial named TUSCANY for newly diagnosed acute myeloid leukemia (AML) patients [1][9] Group 1: Trial Overview - The TUSCANY trial began in December 2024 and has shown positive data from three cohorts with varying doses of TUS (40 mg, 80 mg, and 120 mg) combined with venetoclax (VEN) and azacitidine (AZA) [1][2] - The trial aims to provide a safe, mutation-agnostic frontline therapy for AML patients who cannot receive induction chemotherapy [2][9] Group 2: Efficacy Data - The combination therapy of TUS+VEN+AZA has demonstrated a complete response (CR) or complete response with partial hematological recovery (CRh) rate of 90% (9 out of 10 patients) compared to 65% for VEN+AZA [4] - In specific subpopulations, such as those with NPM1, FLT3-ITD, and TP53 mutations, the CR/CRh rates reached 100% [4][5] - The minimal residual disease (MRD) negativity rate among all subjects treated with TUS+VEN+AZA was 70% (7 out of 10), significantly higher than the 23.4% rate for VEN+AZA [4][5] Group 3: Safety Profile - The TUSCANY trial reported no significant safety concerns or dose-limiting toxicities (DLTs) at the 120 mg TUS dose level, with no treatment-related deaths or prolonged myelosuppression observed [2][5] - Nine out of ten patients remain on study, indicating a favorable safety and tolerability profile [2][6] Group 4: Future Directions - Following a safety review, the trial is advancing to a 160 mg TUS dose level, with expectations of continued positive outcomes [2][3] - The company anticipates that the ongoing data collection will further support the efficacy and safety of the TUS+VEN+AZA combination therapy [6][10]

Core Insights - Aptose Biosciences Inc. reported financial results for Q2 2025, highlighting progress in the TUSCANY triplet trial for treating newly diagnosed acute myeloid leukemia (AML) with tuspetinib-based therapy [1][2] Financial Performance - The net loss for Q2 2025 was $7.0 million, a decrease from $7.3 million in Q2 2024. For the first half of 2025, the net loss was $12.6 million, down from $16.9 million in the same period of 2024 [11][12] - Research and development expenses for Q2 2025 were $3.3 million, down from $4.4 million in Q2 2024. For the first half of 2025, these expenses totaled $5.7 million, compared to $10.9 million in the first half of 2024 [14][17] Clinical Development - The TUSCANY trial is advancing with promising safety and efficacy results for the tuspetinib (TUS) combination therapy, showing complete responses (CRs) across various genetic backgrounds in AML patients [4][5] - The Cohort Safety Review Committee (CSRC) recommended escalating the tuspetinib dose from 120 mg to 160 mg based on positive safety data [4][5] - Data from the TUSCANY trial was presented at the European Hematology Association (EHA) 2025 Congress, indicating that TUS can be safely combined with standard treatments [5][6] Corporate Developments - Aptose entered a loan agreement with Hanmi Pharmaceutical for up to $8.5 million to support the development of tuspetinib [6][9] - The company has been upgraded to trade on the OTCQB Market, enhancing its visibility among investors [9] - Aptose selected Ernst & Young as its new independent auditor and will hold a reconvened shareholder meeting on August 22, 2025 [9][10] Research and Development Focus - The company is focusing on the development of precision oncology therapies, particularly for hematological malignancies, with tuspetinib as a lead candidate [17][19] - Program costs for tuspetinib were $2.2 million for Q2 2025, down from $2.7 million in Q2 2024, attributed to reduced clinical trial activities [18]

Core Insights - Aptose Biosciences is advancing its clinical-stage precision oncology drug, tuspetinib (TUS), in a Phase 1/2 trial called TUSCANY, focusing on a triplet therapy for newly diagnosed acute myeloid leukemia (AML) patients [1][6][10] - The Cohort Safety Review Committee has approved an increase in the TUS dosage from 120 mg to 160 mg based on positive safety and efficacy data [1][9] - The triplet therapy (TUS+VEN+AZA) aims to provide a safe and effective treatment for a diverse population of AML patients who cannot undergo induction chemotherapy [3][6] Financial Updates - Aptose has received an additional advance of US$1.1 million from Hanmi Pharmaceutical as part of an US$8.5 million loan facility agreement, totaling US$5.6 million received to date [2][9] Clinical Trial Details - The TUSCANY trial is designed to evaluate the safety and efficacy of TUS in combination with standard doses of venetoclax (VEN) and azacitidine (AZA) [7][9] - The trial is being conducted at 10 leading U.S. clinical sites, with an expected enrollment of 18-24 patients by late 2025 [7][9] - Initial cohorts at 40 mg, 80 mg, and 120 mg doses have shown no significant safety concerns or dose-limiting toxicities, with patients achieving complete remissions and minimal residual disease negativity [3][4][5] Therapeutic Potential - The TUS+VEN+AZA triplet therapy is positioned as a unique, mutation-agnostic frontline treatment for newly diagnosed AML patients, particularly those with adverse mutations [5][6] - Data from the trial indicate that patients with challenging mutations, such as biallelic TP53 or FLT3-ITD, have achieved complete remissions safely [5][9]