UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Quarterly Period Ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number: 1-32001 APTOSE BIOSCIENCES INC. (Exact Name of Registrant as Specified in Its Charter) Canada (State or other jurisdiction of incorporation or ...

EXHIBIT 99.1 Aptose Reports First Quarter 2025 Results Highlights Progress in TUSCANY Clinical Trial of Tuspetinib in AML Triple Frontline Therapy OTC Exchange - Aptose common shares ("the Common Shares") are now listed for trading on the OTC Markets (OTC) under the ticker "APTOF," in addition to the Company's continued listing on the Toronto Stock Exchange (TSX) under the symbol "APS". This significantly expands Aptose accessibility for U.S.-based investors and enhances overall share liquidity by enabling ...

Summary of Aptose Biosciences Conference Call Company Overview - **Company**: Aptose Biosciences - **Focus**: Clinical stage precision oncology company developing Tuspitinib for acute myeloid leukemia (AML) treatment [2][12] Industry Context - **Disease**: Acute Myeloid Leukemia (AML) - **Characteristics**: Aggressive cancer of the bone marrow and blood, primarily affecting patients aged 65 and older [5][6] - **Current Treatment**: Standard of care is a two-drug cocktail (Venaza: Venetoclax and Azacitidine) [6][9] - **Survival Rates**: Five-year survival rate for patients aged 65+ is approximately 9% [6] Core Points and Arguments - **Need for Improved Therapy**: - Current therapies have high rates of refractoriness (one-third of patients do not respond) and limited overall survival (median of 14.7 months for responders) [7][8] - Need for therapies that are broadly active across all genetic subtypes of AML [9][12] - **Tuspitinib's Role**: - Described as a safe, mutation-agnostic third drug to be added to the Venaza backbone [12][48] - Demonstrated excellent safety profile, convenient administration (once daily oral tablets), and broad activity against various AML mutations [13][48] - Potential market opportunity exceeding $1 billion annually [14] - **Clinical Trials**: - **Tuscany Trial**: Focused on newly diagnosed AML patients, aiming to select optimal dosing for pivotal studies [19][38] - Initial dosing started at 40 mg, escalated to 80 mg, with promising results in terms of complete remissions and minimal toxicity [20][22][24] - Patients achieving complete remission (CR) and minimal residual disease (MRD) negativity, indicating potential for durable responses [26][37] - **Regulatory Status**: - Orphan drug designation and fast track status received from the FDA [18] - Required to start trials in relapsed/refractory patients before moving to newly diagnosed patients [16] Important but Overlooked Content - **Patient Case Studies**: - Multiple case studies presented showing diverse mutation profiles and successful outcomes with Tuspitinib [30][34][36] - Highlighted the drug's effectiveness in patients with challenging mutations like TP53, which are often excluded from clinical trials [29][34] - **Upcoming Milestones**: - Data presentation at the European Hematology Association meeting and the American Society of Hematology meeting planned for later in the year [40][42] - Selection of pivotal trial dose expected within the year [38][49] - **Company Structure**: - Small team of 15 full-time employees, with a strong advisory board including key opinion leaders in AML and MDS [43][45] Conclusion - Aptose Biosciences is positioned to address significant unmet needs in AML treatment with its lead drug Tuspitinib, supported by promising clinical data and a strategic focus on broad applicability across genetic subtypes. The company is on track for pivotal trials and has garnered interest from major pharmaceutical companies.

Aptose is developing TUS+VEN+AZA as a one-of-a-kind safe and mutation agnostic frontline triple drug therapy for newly diagnosed AML patients First two dose cohorts of TUS+VEN+AZA triplet demonstrate safety, complete remissions, and MRD negativity across patients with diverse mutations, including TP53-mutated/CK AML and FLT3-wildtype AML patients SAN DIEGO and TORONTO, May 05, 2025 (GLOBE NEWSWIRE) -- Aptose Biosciences Inc. (“Aptose” or the “Company”) (TSX: APS; OTC: APTOF), a clinical-stage precision onco ...

Core Viewpoint - Aptose Biosciences Inc. announced that KPMG LLP will not stand for re-appointment as the independent registered public accounting firm for the 2025 annual audit, while KPMG will continue to review the company's quarterly interim financial results through the first two fiscal quarters of 2025 [1]. Group 1: Company Announcement - KPMG did not seek the company's consent regarding its decision not to stand for re-appointment, and neither the Board of Directors nor the Audit Committee participated in this decision [2]. - KPMG issued unqualified reports on the company's consolidated financial statements for the fiscal years ended December 31, 2024, and 2023 [3]. - There were no disagreements or reportable events between the company and KPMG during the fiscal years ended December 31, 2024, and 2023, except for a communicated material weakness in internal control over financial reporting related to complex financial instruments [4]. Group 2: Company Overview - Aptose Biosciences is a clinical-stage biotechnology company focused on developing precision medicines for oncology, particularly in hematology [6]. - The company's lead compound, tuspetinib (TUS), is an oral kinase inhibitor being developed as a frontline triplet therapy for newly diagnosed acute myeloid leukemia (AML) [6].

Core Viewpoint - Aptose Biosciences Inc. is participating in the 2025 Bloom Burton & Co. Healthcare Investor Conference to present its developments in precision oncology, specifically focusing on its lead compound tuspetinib for treating acute myeloid leukemia [1][4]. Company Overview - Aptose Biosciences is a clinical-stage biotechnology company focused on developing precision medicines for oncology, with an emphasis on hematology [5]. - The company's lead product, tuspetinib (TUS), is an oral kinase inhibitor that has shown efficacy as both a monotherapy and in combination therapy for relapsed or refractory acute myeloid leukemia (AML) [5]. - Tuspetinib is being developed as a frontline triplet therapy for newly diagnosed AML patients [5]. Conference Details - The 2025 Bloom Burton & Co. Healthcare Investor Conference will take place on May 5-6, 2025, in Toronto [1][4]. - Dr. William G. Rice, Chairman, President, and CEO of Aptose, will present on May 5, 2025, at 3:00 p.m. EDT [2][3]. - The presentation will be available via webcast, and further details can be found on the Aptose website [3]. Investor Engagement - The conference provides an opportunity for investors to receive corporate updates from various Canadian healthcare companies through presentations and one-on-one meetings [4]. - Aptose is open to scheduling one-on-one meetings with interested investors during the conference [2].

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][5] - The company will participate in the 2025 Bloom Burton & Co. Healthcare Investor Conference in Toronto on May 5-6, 2025, where Dr. William G. Rice will present and host one-on-one meetings [1][2][4] Company Overview - Aptose is committed to developing precision medicines to address unmet medical needs in oncology, with a focus on hematology [5] - The company's pipeline includes small molecule cancer therapeutics designed for single-agent efficacy and to enhance the efficacy of other anti-cancer therapies without overlapping toxicities [5] - Tuspetinib (TUS) is an oral kinase inhibitor that has shown activity as both a monotherapy and in combination therapy for patients with relapsed or refractory AML, and is being developed as a triplet therapy for newly diagnosed AML [5] Conference Details - The 2025 Bloom Burton & Co. Healthcare Investor Conference will feature corporate updates from various Canadian healthcare companies, providing opportunities for investors to engage with company representatives [4] - Dr. William G. Rice's corporate presentation is scheduled for May 5, 2025, at 3:00 p.m. EDT, and will be available via webcast [3]

Core Viewpoint - Aptose Biosciences Inc. has been determined by the Nasdaq Hearings Panel to delist its common shares from Nasdaq due to non-compliance with the Exchange's equity requirement by the deadline of March 31, 2025 [1] Company Overview - Aptose Biosciences is a clinical-stage biotechnology company focused on developing precision medicines for oncology, particularly in hematology [3] - The company's lead compound, tuspetinib (TUS), is an oral kinase inhibitor aimed at treating acute myeloid leukemia (AML) and is being developed as a frontline triplet therapy for newly diagnosed AML patients [3] Delisting Details - The Nasdaq Hearings Panel's decision was based on Aptose's failure to demonstrate compliance with the equity requirement outlined in Listing Rule 5550(b)(1) by the specified date [1] - Trading of Aptose's common shares will be suspended effective April 2, 2025, following the Panel's determination [1] Future Plans - The company and its board are considering all available options, including an appeal against the delisting decision, while continuing to execute its business plan [2] - Aptose intends to seek a listing on a U.S. national Securities Exchange at an appropriate time [2]

Clinical Trials and Drug Development - Aptose is conducting a Phase 1/2 clinical trial for Tuspetinib (TUS) in combination with Venetoclax (VEN) and a hypomethylating agent (HMA) for newly diagnosed acute myeloid leukemia (AML) patients[258]. - In a completed trial, Tuspetinib as a single agent achieved a complete response (CR) rate of 36% among all patients and 50% among those with mutated FLT3[259]. - The TUS+VEN doublet combination maintained a favorable safety profile with no new safety signals and significant clinical responses in heavily pretreated relapsed/refractory AML patients[260]. - The TUS+VEN+HMA triplet therapy is expected to establish a new standard of care for newly diagnosed AML patients, particularly those who are VEN-naïve and FLT3i-naïve[261]. - The myeloMATCH precision medicine trials, launched in May 2024, aim to expedite tailored drug combination treatments for newly diagnosed AML and myelodysplastic syndromes (MDS) patients[266]. - The APTIVATE clinical trial demonstrated that TUS+VEN is active across diverse R/R AML populations, including those with adverse genetic mutations[272]. - At the 66th Annual ASH Meeting, Aptose presented findings supporting the advancement of TUS as a third agent in combination therapies for newly diagnosed AML[269]. - Aptose plans to initiate the TUS+VEN+AZA triplet study with a starting dose of 40 mg of Tuspetinib, escalating to 80 mg based on safety and activity[268]. - The ongoing APTIVATE Phase 1/2 trial has treated over 170 patients with TUS alone or in combination with VEN, showing a favorable safety profile and significant response rates[277]. - The APTIVATE trial aims to identify patient populations sensitive to TUS monotherapy and the TUS+VEN doublet, with brisk enrollment and early signs of antileukemic activity reported[287]. - Tuspetinib targets known VEN resistance mechanisms, potentially re-sensitizing prior-VEN failure patients to treatment[282][283]. Financial Performance and Compliance - Nasdaq notified the company of a deficiency regarding a private placement that violated shareholder approval rules[301]. - The company received a deficiency letter for not meeting the minimum bid price requirement, with a deadline to regain compliance by January 13, 2025[303]. - A reverse stock split of 1-for-30 was approved to regain compliance with Nasdaq listing requirements[305]. - As of December 31, 2024, the Company reported negative shareholders' equity of $4.5 million, compared to negative shareholders' equity of $2.9 million as of December 31, 2023[313]. - The Company has not regained compliance with Nasdaq's minimum equity requirement of $2.5 million as of March 28, 2025[308]. - The Company had cash, cash equivalents, and restricted cash of $6.7 million as of December 31, 2024, down from $9.3 million as of December 31, 2023[311]. - The Company has sufficient liquidity to support operations until April 2025, relying on equity financing and strategic partner payments[309]. - The Company raised approximately $9.7 million from a public offering on January 30, 2024, with cash transaction costs of $1.6 million[323]. - The Company completed a public offering on November 25, 2024, raising gross proceeds of $8.0 million before deducting placement agent fees and other expenses[332]. - The Company plans to raise additional funds through equity financing or other financing activities to meet capital requirements[313]. - The Company submitted a compliance plan to Nasdaq on May 17, 2024, and received an extension until September 30, 2024, to regain compliance[307]. - The company filed a short form base shelf prospectus allowing the distribution of up to $200 million of Common Shares, warrants, or units, effective until October 7, 2025[333]. Research and Development Expenses - Cash used in operating activities decreased from $44.6 million in 2023 to $36.0 million in 2024, a reduction of $8.6 million[336]. - The net loss for the year ended December 31, 2024, was $25.4 million, a decrease of approximately $25.8 million compared to a net loss of $51.2 million in 2023[346]. - Research and development expenses decreased by $21.7 million to $15.1 million in 2024 from $36.8 million in 2023, primarily due to reduced program costs for tuspetinib[350]. - General and administrative expenses decreased to $11.2 million in 2024 from $15.6 million in 2023, a reduction of $4.4 million[352]. - The company expects research and development expenses to be lower in 2025 than in 2024, contingent on successful financing activities[347]. Drug Formulation and Market Potential - The G3 formulation of Luxeptinib (LUX) achieved approximately 10-fold better absorption compared to the original formulation, but development has been paused in favor of prioritizing Tuspetinib[262]. - The G3 formulation of luxeptinib demonstrated an 18-fold improvement in plasma steady-state exposure compared to the original G1 formulation[295]. - Continuous dosing of the 50 mg G3 formulation showed plasma exposure levels equivalent to the 900 mg G1 formulation[296]. - The G3 formulation achieved 2-3 µM steady-state plasma levels at 200 mg BID, with approximately 10-fold better absorption than G1[300]. - The potential market for luxeptinib in R/R CLL patients with FLT3 mutations is estimated at $200 million by 2039[291].

Financial Performance - For the year ended December 31, 2024, Aptose reported a net loss of $25.4 million, a decrease of $25.8 million compared to a net loss of $51.2 million in 2023[10]. - Research and development expenses decreased by $21.7 million to $15.1 million for the year ended December 31, 2024, compared to $36.8 million in 2023[13]. - As of December 31, 2024, cash, cash equivalents, and restricted cash equivalents totaled $6.7 million, down from $9.3 million in 2023[12]. - The program costs for tuspetinib were $9.6 million for the year ended December 31, 2024, compared to $24.9 million in 2023, reflecting reduced clinical trial activity[18]. Financing Activities - The company completed several financings totaling approximately $37 million in 2024, including a $10 million loan facility agreement with Hanmi Pharmaceutical[3]. - The company is negotiating a new co-development collaboration agreement with Hanmi to provide additional funding for tuspetinib's clinical development[3]. Clinical Development - The TUS+VEN+AZA triplet therapy achieved complete remissions in difficult-to-treat TP53-mutated AML and FLT3-wildtype AML patients during the ongoing TUSCANY trial[2]. - The company initiated dosing of the TUS+VEN+AZA triplet therapy in newly diagnosed AML patients in the TUSCANY trial, with a starting dose of 40 mg TUS[3]. - Aptose entered into a Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute (NCI) to collaborate on the clinical development of tuspetinib[4]. Compliance and Governance - Aptose regained compliance with Nasdaq's minimum bid price requirement, with the closing bid price of its common shares being $1.00 or greater for ten consecutive business days[4].