UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark one)One)

☒ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31 2020., 2023

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 001-3200File Number 001-32001

APTOSE BIOSCIENCES INC.Aptose Biosciences Inc.

(Exact name of registrantRegistrant as specified in its charter)Charter)

Registrant’s telephone number, including area code: (647) 479-9828

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:
None

Indicate by check mark if the registrantRegistrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YES Yes ☐ NONo☒

Indicate by check mark if the registrantRegistrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. YES Yes ☐ NO No ☒

Indicate by check mark whetherwhether the registrantRegistrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrantRegistrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. YES Yes☒ NO No ☐

Indicate by check mark whether the registrantRegistrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§229.405232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrantRegistrant was required to submit and post such files). YES Yes☒ NO No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b 212b-2 of the Exchange Act). YES Yes ☐ NO No ☒

The aggregate market value of the voting stock and nonvoting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold, or the average bid and asked prices of such common equity, as of June 30, 20202023 was $478,045,833.$29,584,561.

As of March 23, 2021,26, 2024, the registrant had 88,885,238 common shares15,717,701 Common Shares outstanding.

The forward-looking statements contained in this Annual Report on Form 10-K reflect our current views with respect to future events, are subject to significant risks and uncertainties, and are based upon a number of estimates and assumptions that, while considered reasonable by us, are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies. Forward-looking statements contained in this Annual Report on Form 10-K are made as of the date of this Annual Report on Form 10-K.

Except as required under applicable securities legislation, we undertake no obligation to publicly update or revise forward-looking statements, whether as a result of new information, future events or otherwise.

Risk Factor Summary

Many factors could cause our actual results, performance or achievements to be materially different from any future results, performance, or achievements that may be expressed or implied by such forward-looking statements, including, among others:

Should one or more of these risks or uncertainties materialize, or should the assumptions described in the Item 1A. Risk Factors in this Annual Report on Form 10-K underlying those forward-looking statements prove incorrect, actual results may vary materially from those described in the forward-looking statements.

Although we have attempted to identify factors that could cause actual actions, events or results to differ materially from those described in forward-looking statements, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. Forward-looking statements are based upon our beliefs, estimates and opinions at the time they are made and we undertake no obligation to update forward-looking statements if these beliefs, estimates and opinions or circumstances should change, except as required by applicable law. There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.

We qualify all the forward-looking statements contained in this Annual Report on Form 10-K by the foregoing cautionary statements.

ITEM 1A. RISK FACTORS

Risk Factors and Uncertainties

Any of the risks and uncertainties described below could significantly and negatively affect our business, prospects, financial condition, operating results, or credit ratings, which could cause the trading price of our Common Shares to decline. Additional risks and uncertainties not presently known to us, or risks that we currently consider immaterial, could also impair our business operations or financial condition. The following discussion of risk factors contains “forward-looking” statements, as discussed above.

Risks Related to our Business

There is substantial doubt that we can remain a going concern over the next twelve months.

As of the filing date, we have sufficient liquidity to support the Company's operations until August 2024. In order for the Company to meet its capital requirements, and continue to operate, additional financing will be necessary. The Company is evaluating strategies to obtain the required additional funding for future operations. These strategies may include, but are not limited to, obtaining equity financing, and restructuring of operations to decrease expenses. However, given the challenges in the U.S. and global financial markets, and the matter in Note 17 to the Financial Statements, Subsequent events, that may impact the Company's ability to raise financing in the capital markets, the Company may be unable to access further equity or when needed, if at all. As the Company is primarily pursuing one compound that is licensed from a related party with significant licensing payments who will have influence on the Company, other investors may not be willing to invest in the Company. As such, there can be no assurance that the Company will be able to obtain additional liquidity when needed or under acceptable terms, if at all. The consolidated financial statements do not reflect any adjustments to the carrying amounts and classification of assets, liabilities, and reported expenses that may be necessary if the Company were unable to continue as a going concern. Such adjustments may be material. See Note 2(a) to the Financial Statements, Going concern.

We are an early stageearly-stage development company with no revenues from product sales.

We are at an early stage of development. In the past five years, noneNone of our potential products has obtained regulatory approval for commercial use and sale in any country and as such, no revenues have resulted from product sales. Significant additional investment will be necessary to complete the development of any of our product candidates. Preclinical and clinical trial work must be completed before our potential products could be ready for use within the markets that we have identified. We may fail to develop any products, obtain regulatory approvals, enter or complete clinical trials or commercialize any products. We do not know whether any of our potential product development efforts will prove to be effective, meet applicable regulatory standards, obtain the requisite regulatory approvals, be capable of being manufactured at a reasonable cost or be accepted in the marketplace. We also do not know whether sales, license fees or related royalties will allow us to recoup any investment we make in the commercialization of our products.

The product candidates we are currently developing are not expected to be commercially viable for at least the next several years and we may encounter unforeseen difficulties or delays in commercializing our product candidates. In addition, our potential products may not be effective or may cause undesirable side effects.

Our product candidates require significant funding to reach regulatory approval assuming positive clinical results. For example, our product candidate APTO-253 began enrollment in aWe are currently conducting Phase 1a/b1 clinical trial in patients with relapsed or refractory AML and high risk MDS and was placed on clinical hold by the FDA following a voluntary suspension of dosing by us. That hold has been lifted, but significant additional funding will be necessary to complete the restarted Phase 1a/b clinical and, if required, Phase 2 or Phase 3 clinical trials. Similarly, we have received FDA approval to initiate a Phase 1a/b clinical trialtrials with our product candidate luxeptinib for patients with B-cell malignancies.candidates tuspetinib and luxeptinib. Significant additional capital will be necessary to complete the Phase 1 clinical trial,trials, and if required, Phase 2 or Phase 3 clinical trials. Such funding for our product candidates may be difficult, or impossible to raise in the public or private markets or through partnerships. If funding or partnerships are not readily attainable, the development of our product candidates may be significantly delayed or stopped altogether. The announcement of a delay or discontinuation of development would likelyof any of our product candidates could have a negative impact on our share price.

We need to raise additional capital.

We have an ongoing need to raise additional capital. As of the filing date, we have sufficient liquidity to support the Company's operations until August 2024. To obtain the necessary capital, we must rely on some or all of the following: additional share issues, debt issuances (including promissory notes), collaboration agreements or corporate partnerships and grants and tax credits to provide full or partial funding for our activities. Additional funding may not be available on terms that are acceptable to us or in amounts that will enable us to carry out our business plan. Although, as of the date of this report, the COVID-19 pandemic did not have and we do not expect that it will have a significant impact on our liquidity and capital resources, the extent to which COVID-19 impacts our business will depend on future developments, which are highly uncertain and cannot be predicted, including the scope, severity and duration of the pandemic, the actions taken to contain the pandemic or mitigate its impact, and the direct and indirect economic effects of the pandemic and containment measures, among other future developments. As such, our ability to raise additional funds could be affected by adverse market conditions resulting from the COVID-19 pandemic and delays related to COVID-19 in enrollment in our trial.

Our need for capital may require us to:

In addition, sales of a substantial number of our Common Shares in the public markets, or the perception that such sales could occur, could depress the market price of our Common Shares and impair our ability to raise capital through the sale of additional equity securities.

Our operations could be adversely affected by events outside of our control, such as natural disasters, wars or health crises such as the COVID-19 pandemic.crises.

We may be impacted by business interruptions resulting from pandemics and public health emergencies, including those related to COVID-19, geopolitical actions, including war and terrorism or natural disasters including earthquakes, typhoons, floods and fires. An outbreak of infectious disease, a pandemicAny such event, or a similar public health threat, such as the COVID-19 pandemic, or a fear of any of the foregoing, could adversely impact us by causing operating, manufacturing, supply chain, clinical trial and project development delays and disruptions, labourlabor shortages, travel and shipping disruption and shutdowns (including as a result of government regulation and prevention measures). Although, as of the date of this report, we do not expect that COVID-19 will have a significant impact on our liquidity and capital resources, the extent to which COVID-19 impacts our business will depend on future developments, which are highly uncertain and cannot be predicted, including the scope, severity and duration of the pandemic, the actions taken to contain the pandemic or mitigate its impact, and the direct and indirect economic effects of the pandemic and containment measures, among other future developments.shutdowns. We may incur expenses or delays relating to such events outside of our control, which could have a material adverse impact on our business, operating results and financial condition.

We have a history of operating losses. We expect to incur net losses and we may never achieve or maintain profitability.

We have not been profitable since our inception in 1986. We reported net losses of $51.2 million in the fiscal year ended December 31, 2023, $41.8 million in the fiscal year ended December 31, 2022, $65.4 million in the fiscal year ended December 31, 2021, $55.2 million in the fiscal year ended December 31, 2020 $26.3 million in the fiscal year ended December 31, 2019 and $28.8 million in the fiscal year ended December 31, 2018,, and as of December 31, 2020,2023, we had an accumulated deficit of $357.2$515.5 million. We had negative shareholder's equity of $2.9 million as of December 31, 2023 (December 31, 2022, positive shareholder's equity of $37.7 million).

We have not generated any significant revenue to date and it is possible that we will never have sufficient product sales revenue (if any) to achieve profitability. We expect to continue to incur losses for at least the next several years as we or our collaborators and licensees pursue clinical trials, and research and development efforts. To become profitable, we, either alone or with our collaborators and licensees, must successfully develop, manufacture and market our current product candidates APTO-253tuspetinib or luxeptinib, as well as continue to identify, develop, manufacture and market new product candidates. It is possible that we will never have significant product sales revenue or receive royalties on our licensed product candidates. If funding is insufficient at any time in the future, we may not be able to develop or commercialize our products, take advantage of business opportunities or respond to competitive pressures.

We currently do not earn any revenues from our drug candidates and are therefore considered to be in the development stage. The continuation of our research and development activities and the commercialization of the targeted therapeutic products are dependent upon our ability to successfully finance and complete our research and development programs through a combination of equity financing and payments from strategic partners. We have no current sources of significant payments from strategic partners. As of the filing date, we have sufficient liquidity to support the Company's operations until August 2024.

We heavily rely on the capabilities and experience of our key executives and scientists and the loss of any of them could affect our ability to develop our products.

The loss of our executive officers could harm our operations and our ability to achieve strategic objectives. While we have employment agreements with our executive officers, such employment agreements do not guarantee their retention. We also depend on our scientific and clinical collaborators and advisors, all of whom have outside commitments that may limit their availability to us. In addition, we believe that our future success will depend in large part upon our ability to attract and retain highly skilled scientific, managerial, medical, clinical and regulatory personnel, particularly as we expand our activities and seek regulatory approvals for clinical trials. We routinely enter into consulting agreements with our scientific and clinical collaborators and advisors, key opinion leaders and academic partners in the ordinary course of our business. We also enter into contractual agreements with physicians and institutions who will recruit patients into our clinical trials on our behalf in the ordinary course of our business. Notwithstanding these arrangements, we face significant competition for these types of personnel from other companies, research and academic institutions, government entities and other organizations. We cannot predict our success in hiring or retaining the personnel we require for continued growth. The loss of the services of any of our executive officers or other key personnel could potentially harm our business, operating results or financial condition.

Our employees may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements, which could have a material adverse effect on our business.

We are exposed to the risk of employee fraud or other misconduct. Misconduct by employees could include failures to comply with FDA/Health Canada regulations, provide accurate information to the FDA/Health Canada, comply with manufacturing standards we have established, comply with federal, state and provincial health-care fraud and abuse laws and regulations, report financial information or data accurately or disclose unauthorized activities to us. In particular, sales, marketing and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Employee misconduct could also involve the improper use of information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our reputation. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a substantial impact on our business and results of operations, including the imposition of substantial fines or other sanctions.

We have no sales, marketing or distribution experience and would have to invest significant financial and management resources to establish these capabilities.

We have no sales, marketing or distribution experience. We currently expect to rely heavily on third parties to launch and market our products, if they are approved. However, if we elect to develop internal sales, distribution and marketing capabilities, we will need to invest significant financial and management resources. For products where we decide to perform sales, marketing and distribution functions ourselves, we could face a number of additional risks, including:

If we are unable to develop our own sales, marketing and distribution capabilities, we will not be able to successfully commercialize our products without reliance on third parties.

We may expand our business through the acquisition of companies or businesses or by entering into collaborations or by in-licensing product candidates, each of which could disrupt our business and harm our financial condition.

We may in the future seek to expand our pipeline and capabilities by acquiring one or more companies or businesses, entering into collaborations or in-licensing one or more product candidates. For example, in June 2016, we entered into a definitive agreement with CG, granting Aptose an exclusive option to research, develop and commercialize CG-806 in all countries of the world except the Republic of Korea, for all fields of use.use, and in November 2021 we entered into the Tuspetinib Licensing Agreement with Hanmi granting Aptose exclusive worldwide rights to develop and commercialize tuspetinib.

Acquisitions, collaborations and in-licenses involve numerous risks, including, but not limited to:

We have experience in entering collaborations and in-licensing product candidates; however, we cannot provide assurance that any acquisition, collaboration or in-license will result in short-term or long-term benefitsany benefit to us. We may incorrectly judge the value or worth of an acquired company or business or in-licensed product candidate. In addition, our future success wouldcould depend in part on our ability to manage the rapid growth associated with some of these acquisitions, collaborations and in-licenses. We cannot assure you that we would be able to successfully combine our business with that of acquired businesses, manage a collaboration or integrate in-licensed product candidates. Furthermore, the development or expansion of our business may require a substantial capital investment by us.

Fluctuations in exchange rates can cause us to incur losses.

We may be exposed to fluctuations of the United StatesU.S. dollar against certain other currencies because we hold most of our cash and cash equivalents in United StatesU.S. dollars, while we incur some of our expenses in foreign currencies, primarily the Canadian dollar. Fluctuations in the value of currencies could cause us to incur currency exchange losses, and we do not currently employ a hedging strategy against exchange rate risk. As a result, changes in the exchange rate between the Canadian dollar and the U.S. dollar could materially impact our reported results of operations and distort period to period comparisons. In particular, to the extent that foreign currency-denominated (i.e., non-U.S. dollar) monetary assets do not equal the amount of our foreign currency denominated monetary liabilities, foreign currency gains or losses could arise and materially impact our financial statements. As a result of such foreign currency fluctuations, it could be more difficult to detect underlying trends in our business and results of operations. In addition, to the extent that fluctuations in currency exchange rates cause our results of operations to differ from our expectations or the expectations of our investors, the trading price of our Common Shares could be adversely affected.

Risks Related to Development, Clinical Testing and Regulatory Approval of Our Product Candidates

Fast Track Designation by the FDA may not lead to a faster development or regulatory review or approval process.

We have obtained Fast Track Designation for tuspetinib for the treatment of patients with R/R AML and FLT3 mutation. We may seek Fast Track Designation for one or more of our other product candidates. If a drug is intended for the treatment of a serious or life-threatening condition and the drug demonstrates the potential to address unmet medical needs for this condition, the product sponsor may apply for FDA Fast Track Designation. The FDA has broad discretion whether or not to grant this designation, so even if we believe a particular product candidate is eligible for this designation, we cannot assure you that the FDA would decide to grant it. Even if we do receive Fast Track Designation, we may not experience a faster development process, review or approval compared to conventional FDA procedures. The FDA may withdraw Fast Track Designation if it believes that the designation is no longer supported by data from our clinical development program.

Clinical trials are long, expensive and uncertain processes and the FDA or Health Canada may ultimately not approve any of our product candidates. We may never develop any commercial drugs or other products that generate revenues.

In the past five years, noneNone of our product candidates has received regulatory approval for commercial use and sale in North America. We cannot market a pharmaceutical product in any jurisdiction until it has completed thorough preclinical testing and clinical trials in addition to that jurisdiction’s extensive regulatory approval process. Approval in one country does not assure approval in another country. In general, significant research and development and clinical studies are required to demonstrate the safety and effectivenessefficacy of our product candidates before we can submit any applications for regulatory approval.

Clinical trials are long, expensive and uncertain processes. Clinical trials may not start or be on schedule and the FDA, or Health Canada or any other regulatory body may not ultimately approve our product candidates for commercial sale in the relevant territory. The clinical trials of any of our drug candidates could be unsuccessful, which would prevent us from advancing, commercializing or partnering the drug.

Even if the results of our preclinical studies or clinical trials are initially positive, it is possible that we will obtain different results in the later stages of drug development or that results seen in clinical trials will not continue with longer term treatment. Positive results in Phase 1 clinical trials may not necessarily repeat in larger Phase 2 or Phase 3 clinical trials.

Our preclinical studies and clinical trials may not generate positivenegative results that will not allow us to move towards the commercial use and sale of our product candidates. Furthermore, negative preclinical or clinical trial results may cause our business, financial condition, or results of operations to be materially adversely affected. For example, our Phase 1a/b clinical trial of APTO-253 in patients with relapsed or refractory AMLOur tuspetinib and high risk MDS was placed on clinical hold by the FDA in November 2015. Those short comings of the drug product were addressed and the clinical hold was lifted. However, there can be no assurance that the Company will have the resources, or that we will decide, to continue the development of APTO-253. There is a long development path ahead that will take many years to complete the development and is prone to the risks of failure or delays inherent in drug development. Likewise, our luxeptinib product candidate iscandidates are currently being evaluated in a Phase 1a/b study for patients having B-cell malignancies,1 studies, and it isare expected to undergo many years of testing and regulatory examinations prior to any potential regulatory approvals.

Preparing, submitting and advancing applications for regulatory approval of products is complex, expensive and time intensive and entails significant uncertainty. A commitment of substantial resources to conduct time-consuming research, preclinical studies and clinical trials is required if we are to complete development of our products.

Clinical trials of our products require that we identify and enroll a large number of patients with the illness under investigation. We may not be able to enroll a sufficient number of appropriate patients to complete our clinical trials in a timely manner, particularly in smaller indications and indications where there is significant competition for patients. If we experience difficulty in enrolling a sufficient number of patients to conduct our clinical trials, we may need to delay or terminate ongoing clinical trials and will not accomplish objectives material to our success. Delays in planned patient enrollment or lower than anticipated event rates in our current clinical trials or future clinical trials also may result in increased costs, program delays, or both.

In addition, unacceptable toxicities or adverse side effects may occur at any time in the course of preclinical studies or human clinical trials or, if any product candidates are successfully developed and approved for marketing, during commercial use of any approved products. The appearance of any unacceptable toxicities or adverse side effects could interrupt, limit, delay or abort the development of any of our product candidates or, if previously approved, necessitate their withdrawal from the market. Furthermore, disease resistance or other unforeseen factors may limit the effectiveness of our potential products.

Our failure to develop safe and commercially viable drugs would substantially impair our ability to generate revenues and sustain our operations and would materially harm our business and adversely affect our share price.

We may choose to expend our limited resources on programs that do not yield successful product candidates as opposed to indications that may be more profitable or for which there is a greater likelihood of success.

Because we have limited resources and access to capital to fund our operations, our management must make strategic decisions as to which product candidates and indications to pursue and how much of our resources to allocate to each. Our management must also evaluate the benefits of developing in‑licensed or jointly owned technologies, which in some circumstances we may be contractually obligated to pursue, relative to developing other product candidates, indications or programs. Our management has broad discretion to suspend, scale down, or discontinue any or all of these development efforts, or to initiate new programs to treat other diseases. If we select and commit resources to opportunities that we are unable to successfully develop, or we forego more promising opportunities, our business, financial condition and results of operations will be adversely affected.

We may not achieve our projected development goals in the time frames we announce and expect.

We set goals for, and make public statements regarding, the expected timing of the accomplishment of objectives material to our success, such as the commencement and completion of clinical trials, the submission of a drug-regulatory application, and the expected costs to develop our product candidates. The actual timing and costs of these events can vary dramatically due to factors within and beyond our control, such as delays or failures in our IND submissions or clinical trials, issues related to the manufacturing of drug supply, uncertainties inherent in the regulatory approval process, market conditions and interest by partners in our product candidates, among other things. Our clinical trials may not be completed, we may not make regulatory submissions or receive regulatory approvals as planned; or we may not secure partnerships for any of our product candidates. Any failure to achieve one or more of these milestones as planned would have a material adverse effect on our business, financial condition and results of operations.

Although, as of the date of this report, we do not foresee material delays to the enrollment of patients or timelines for our trials due to COVID-19, the extent to which COVID-19 will impact the projected development goals will depend on future developments, which are highly uncertain and cannot be predicted. In the beginning of April 2020 we learned that certain of our larger sites would not be able to enroll new patients on the fourth dose level of luxeptinib due to the current environment caused by COVID-19 and we therefore expect a slowdown in enrollment at these sites. While it is difficult to estimate the duration and impact of COVID-19 on the larger clinical sites and regional cancer care sites, as of the date of this report, we have not experienced and do not foresee material delays to the enrollment of patients or timelines for the luxeptinib Phase 1a/b B-cell malignancy trial due to the variety of clinical sites that we have actively recruited for this trial. While as of the date of this report we have not experienced any material delays in initiating our luxeptinib Phase 1 clinical study in AML due to COVID-19, we are conducting site initiation visits remotely which could result in delays in site activations and negatively impact this trial. Additionally, COVID-19 could negatively impact patient enrolment if our clinical sites are unable to enroll patients due to either a lack of administrative resources at their sites or decisions made at the clinical sites to limit patient exposure to COVID-19.

Future enrollment of patients on the APTO-253 trial is likely to be negatively impacted as a result of the current environment, as it is administered to patients intravenously, which requires the need for hospital / clinical site resources to assist and monitor patients during each infusion.

Delays in clinical testing could result in delays in commercializing our product candidates and our business may be substantially harmed.

We cannot predict whether any clinical trials will begin as planned, will need to be restructured or will be completed on schedule, if at all. Our product development costs will increase if we experience delays in clinical testing. Significant clinical trial delays could shorten any periods during which we may have the exclusive right to commercialize our product candidates or allow our competitors to bring products to market before us, which would impair our ability to successfully commercialize our product candidates and may harm our financial condition, results of operations and prospects. The completion of clinical trials for our products, including the APTO-253 Phase 1a/btuspetinib and luxeptinib clinical trial, the Phase 1a/b clinical trial for the luxeptinib study for the treatment of patients having B-cell malignancies, and the IND acceptance of our planned Phase 1a/b study for the development of luxeptinib for the treatment of patients with R/R AMLtrials may be delayed for a number of reasons, including delays related, but not limited, to:

Our product development costs will increase if we experience delays in testing or approval or if we need to perform more or larger clinical trials than planned. Additionally, changes in regulatory requirements and policies may occur, and we may need to amend study protocols to reflect these changes. Amendments may require us to resubmit our study protocols to regulatory authorities or IRBs or ethics committees or boards for re-examination, which may impact the cost, timing or successful completion of a trial. Delays or increased product development costs may have a material adverse effect on our business, financial condition and prospects.

We rely on contract manufacturers over whom we have limited control. If we are subject to quality, cost or delivery issues with the preclinical and clinical grade materials supplied by contract manufacturers, our business operations could suffer significant harm.

We rely on CMOscontract manufacturing organizations ("CMOs") to manufacture our product candidates for some preclinical studies and clinical trials. We rely on CMOs for manufacturing, filling, packaging, storing and shipping of drug product in compliance with cGMP regulations applicable to our products. The FDA and other regulatory agencies ensure the quality of drug products by carefully monitoring drug manufacturers’ compliance with cGMP regulations. The cGMP regulations for drugs contain minimum requirements for the methods, facilities and controls used in manufacturing, processing and packing of a drug product.

We contracted with multiple CMOs for the manufacture of APTO-253tuspetinib and CG-806luxeptinib to supply the active ingredient and then drug product for our clinical trials. The synthesis of CG-806luxeptinib is challenging from a scale-up synthetic chemistry perspective. The formulation and manufacture of APTO-253 is a complex process with many variables involved. We pre-qualified CMOs to have the capacity, the systems and the experience to supply CG-806tuspetinib and APTO-253luxeptinib for our clinical trials. We have qualified the manufacturing facilities and the FDA has also performed site audits for our selected CMOs. In spite ofDespite the efforts to prequalify CMOs, delays and errors may occur, and any such manufacturing failures, delays or compliance issues could cause delays in the completion of our clinical trial programs.

There can be no assurances that CMOs will be able to meet our timetable and requirements. We have contracted with alternate suppliers in the event our current CMOs are unable to scale up production, or if our current CMOs otherwise experience any other significant problems in the manufacture of CG-806tuspetinib and APTO-253.luxeptinib. However, it is possible that all third-party manufacturing sources may experience failure or delays and may demand commercially unreasonable terms, which may lead to further delays in the development of our product candidates. Further, contract manufacturers must operate in compliance with cGMP and failure to do so could result in, among other things, the disruption of product supplies. Our dependence upon third parties for the manufacture of our products may adversely affect our profit margins and our ability to develop and deliver products on a timely and competitive basis.

Although, as of the date of this report, we have not experienced any material delays in the manufacturing of luxeptinib and APTO-253 due to COVID-19, the extent to which it will impact the manufacturing of our products will depend on future developments, which are highly uncertain and cannot be predicted. Should our suppliers involved in the manufacture of luxeptinib be required to shut down their facilities due to COVID-19 either due to lack of materials or personnel, our trials would be negatively impacted. We are mitigating this risk by continuing to manufacture drug supply, but there is no guarantee that we will have enough drug to supply the trial if any of our manufacturers have a sustained shut down in their operations. COVID-19 may also affect the timing and delivery of labeled and packaged drug product for APTO-253 since it is an intravenous formulation which, compared to orally administered therapies, involves a more complex process. Factors related to COVID-19 caused a delay in the labeling and packaging of the APTO-253 drug product; however, going forward we do not anticipate this to materially affect the patient accrual for the ongoing Phase 1b trial.

Some components of our products are manufactured by third parties outside of the United States, and our business may be harmed by legal, regulatory, economic, political and public health risks associated with international trade and those markets.

We have third-party manufacturing partners in South Korea, Germany and the United Kingdom; in addition, some materials used by our third-party manufacturers are supplied by companies located in other countries, including China. Our reliance on suppliers and manufacturers in foreign markets creates risks inherent in doing business in foreign jurisdictions, including: (a) the burdens of complying with a variety of foreign laws and regulations, including laws relating to the importation and taxation of goods (b) public health crises, such as pandemics and epidemics, in the countries where our suppliers and manufacturers are located; (c) transportation interruptions or increases in transportation costs; and (d) foreign intellectual property infringement risks. For example, the ongoing COVID-19 pandemic has resulted in the extended shutdown of certain businesses and markets in many regions causing reduced availability for certain pharmaceutical ingredients. The current public health crisis or any further political developments or health concerns in markets in which our products are manufactured or from which we obtain necessary pharmaceutical ingredients could adversely affect the supply of our drug products and, in turn, our business, financial condition, and results of operations.

If we have difficulty enrolling patients in clinical trials, the completion of the trials may be delayed or cancelled.canceled.

As our product candidates advance from preclinical testing to clinical testing, and then through progressively larger and more complex clinical trials, we will need to enroll an increasing number of patients that meet our eligibility criteria. There is significant competition for recruiting cancer patients in clinical trials, and we may be unable to enroll the patients we need to complete clinical trials for cancer indications on a timely basis or at all. Certain factors that affect enrollment of patients in our clinical trials are impacted by external forces that may be beyond our control. Such factors include, but are not limited to, the following:

Although, as of the datepatient population;

If we are unable to successfully develop companion diagnostics for our therapeutic product candidates, or experience significant delays in doing so, we may not achieve marketing approval or realize the full commercial potential of our therapeutic product candidates.

We plan to develop companion diagnostics for our therapeutic product candidates. We expect that, at least in some cases, regulatory authorities may require the development and regulatory approval of a companion diagnostic as a condition to approving our therapeutic product candidates. We have limited experience and capabilities in developing or commercializing diagnostics and plan to rely in large part on third parties to perform these functions. We do not currently have any agreement in place with any third party to develop or commercialize companion diagnostics for any of our therapeutic product candidates.

Companion diagnostics are subject to regulation by the FDA, Health Canada and comparable foreign regulatory authorities as medical devices and may require separate regulatory approval or clearance prior to commercialization. If we, or any third parties that we engage to assist us, are unable to successfully develop companion diagnostics for our therapeutic product candidates, or experience delays in doing so, our business may be substantially harmed.

We rely and will continue to rely on third parties to conduct and monitor many of our preclinical studies and our clinical trials, and their failure to perform as required could cause substantial harm to our business.

We rely and will continue to rely on third parties to conduct a significant portion of our preclinical and clinical development activities. Preclinical activities include in vivo studies providing access to specific disease models, pharmacology and toxicology studies, and assay development. Clinical development activities include trial design, regulatory submissions, clinical patient recruitment, clinical trial monitoring, clinical data management and analysis, safety monitoring and project management, contract manufacturing and quality assurance. If there is any dispute or disruption in our relationship with third parties, or if they are unable to provide quality services in a timely manner and at a feasible cost, our active development programs will face delays. Further, if any of these third parties fails to perform as we expect or if their work fails to meet regulatory requirements, our testing could be delayed, cancelledcanceled or rendered ineffective.

Negative results from clinical trials or studies of others and adverse safety events involving the targets of our products may have an adverse impact on our future commercialization efforts.

From time to time, studies or clinical trials on various aspects of biopharmaceutical products are conducted by academic researchers, competitors or others. The results of these studies or trials, when published, may have a significant effect on the market for the biopharmaceutical product that is the subject of the study. The publication of negative results of studies or clinical trials or adverse safety events related to our product candidates, or the therapeutic areas in which our product candidates compete, could adversely affect our share price and our ability to finance future development of our product candidates, and our business and financial results could be materially and adversely affected.

The design or our execution of clinical trials may not support regulatory approval.

The design or execution of a clinical trial can determine whether its results will support regulatory approval and flaws in the design or execution of a clinical trial may not become apparent until the clinical trial is well advanced. In some instances, there can be significant variability in safety or efficacy results between different trials of the same product candidate due to numerous factors, including changes in trial protocols, differences in size and type of the patient populations, adherence to the dosing regimen and other trial protocols and the rate of dropout among clinical trial participants. We do not know whether any Phase 2, Phase 3 or other clinical trials that we may conduct will demonstrate consistent or adequate efficacy and safety to obtain regulatory approval to market our product candidates.

Further, the FDA, Health Canada and comparable foreign regulatory authorities will have some discretion in the approval process and in determining when or whether regulatory approval will be obtained for any of our product candidates. Our product candidates may not be approved even if they achieve their primary endpoints in future Phase 3 clinical trials or registration trials. The FDA, Health Canada or other regulatory authorities may disagree with our trial design and our interpretation of data from preclinical studies and clinical trials. In addition, any of these regulatory authorities may change requirements for the approval of a product candidate even after reviewing and providing comments or advice on a protocol for a pivotal Phase 3 clinical trial that has the potential to result in approval by the FDA, Health Canada or another regulatory agency. In addition, any of these regulatory authorities may also approve a product candidate for fewer or more limited indications than we request or may grant approval contingent on the performance of costly post-marketing clinical trials. The FDA, Health Canada or other regulatory authorities may not approve the labeling claims that we believe would be necessary or desirable for the successful commercialization of our product candidates.

As a result of intense competition and technological change in the biotechnical and pharmaceutical industries, the marketplace may not accept our products or product candidates, and we may not be able to compete successfully against other companies in our industry and achieve profitability.

Many of our competitors have:

Consequently, our competitors may obtain FDA, Health Canada and other regulatory approvals for product candidates sooner and may be more successful in manufacturing and marketing their products than we or our collaborators are.

Our competitors’ existing and future products, therapies and technological approaches will compete directly with the products we seek to develop. Current and prospective competing products may be more effective than our existing and future products insofar as they may provide greater therapeutic benefits for a specific problem or may offer easier delivery or comparable performance at a lower cost.

For luxeptinibtuspetinib and APTO-253luxeptinib in AML, examples of potential competitors include companies that have developed approved or are currently developing inhibitors that directly target the wild type include AbbVie (IMBRUVICA) and AstraZeneca (CALQUENCE) and Beigene Co., Ltd. (Zanubrutinib).

Others that are developing inhibitors that target the C481S-mutant BTK include Merck (MK-1026), Roche, and Eli Lilly (LY3527727) among others.

For luxeptinib and APTO-253 in AML, examples of potential competitors include companies that have developed, approved or are currently developing non-targetedpursuing different therapies include Jazz (VYXEOS), Pfizer (MYLOTARG), Novartis (RYDAPT), Astellas (XOSPATA), AbbVie (VENCLEXTA), Daiichi Sankyo (quizartinib), Arog (crenolanib), Agios/Servier (TIBSOVO), Rigel (REZLIDHA), Celgene/BMS (IDHIFA), Kronos Bio (lanraplenib), Curis (emavusertib), Syndax (revumenib, SNDX-5613), and Roche (VENCLEXTA)Kura (KO-539), among others. Others

For luxeptinib in B cell malignancies, examples of companies that have developed or are developing highly targeted therapies such as FLT-3pursuing different approaches to BTK inhibition, both for the wild type and C481S-mutant forms, include Novartis (RYDAPT)AbbVie (IMBRUVICA), Astellas (XOSPATA)AstraZeneca (CALQUENCE), Daiichi Sankyo (QUIZARTINIB)Beigene Co., Arog (CRENOLANIB)Ltd. (Zanubrutinib), Merck (nemtabrutinib), and IDH1 include Agios (TIBSOVO) and Celgene/BMS (IDHIFA)Eli Lilly (pirtobrutinib), among others.

Any product candidate that we develop and that obtains regulatory approval must then compete for market acceptance and market share. Our products may not gain market acceptance among physicians, patients, healthcare payers, insurers, the medical community and other stakeholders. The degree of market acceptance of our product candidates, if approved for commercial sale, will depend on a number of factors, including:

Further, any products we develop may become obsolete or face generic entry before we recover any expenses we incurred in connection with the development of these products. As a result, we may never achieve profitability.

Risks Related to our Intellectual Property

We may be unable to obtain patents to protect our technologies from other companies with competitive products, and patents of other companies could prevent us from manufacturing, developing or marketing our products.

Patent protection

The patent positions of pharmaceutical and biotechnology companies are uncertain and involve complex legal and factual questions. The USPTOUnited States Patent and Trademark Office (“USPTO”) and many other patent offices in the world have not established a consistent policy regarding the breadth of claims that they will allow in biotechnology patents.

Our pending patent applications may not result in issued patents and our issued patents may not be held valid and enforceable if challenged. Competitors may be able to circumvent any such issued patents by adoption of a competitive, though non-infringing product or process. Interpretation and evaluation of pharmaceutical or biotechnology patent claims present complex and often novel legal and factual questions. Our business could be adversely affected by increased competition in the event that any patent granted to it is held to be invalid or unenforceable or is inadequate in scope to protect our operations.

Allowable patentable subject matter and the scope of patent protection obtainable may differ between jurisdictions. If a patent office allows broad claims, the number and cost of patent interference proceedings in the United States, or analogous proceedings in other jurisdictions and the risk of infringement litigation may increase. If it allows narrow claims, the risk of infringement may decrease, but the value of our rights under our patents, licenses and patent applications may also decrease.

The scope of the claims in a patent application can be significantly modified during prosecution before the patent is issued. Consequently, we cannot know whether our pending applications will result in the issuance of patents or, if any patents are issued, whether they will provide us with significant proprietary protection or will be circumvented, invalidated or found to be unenforceable.

Publication of discoveries in scientific or patent literature often lags behind actual discoveries. Patent applications filed in the United States generally will be published 18 months after the filing date unless the applicant certifies that the invention will not be the subject of a foreign patent application. In many other jurisdictions, such as Canada, patent applications are published 18 months from the priority date. We may not be aware of such literature. Accordingly, we cannot be certain that the named inventors of our products and processes were the first to invent that product or process or that we were the first to pursue patent coverage for our inventions.

In addition, United States patent laws may change which could prevent or limit us from filing patent applications or patent claims in the United States to protect our products and technologies or limit the exclusivity periods that are available to patent holders for United States patents. For example, the Leahy-Smith America Invents Act, (the “Leahy-Smith Act”) was signed into law in 2011 and includes a number of significant changes to United States patent law. These include changes to transition from a “first-to-invent” system to a “first-to-file” system and to the way issued patents are challenged. These changes may favor larger and more established companies that have more resources to devote to patent application filing and prosecution. It is not clear what, if any, impact the Leahy-Smith Act will ultimately have on the cost of prosecuting our patent applications in the United States, our ability to obtain patents in the United States based on our discoveries and our ability to enforce or defend our United States issued patents.

Until such time, if ever, that further patents are issued to us, we will rely upon the law of trade secrets to the extent possible given the publication requirements under international patent treaty laws and/or requirements under foreign patent laws to protect our technology and our products incorporating the technology. In this regard, we have adopted certain confidentiality procedures. These include: limiting access to confidential information to certain key personnel; requiring all directors, officers, employees and consultants and others who may have access to our intellectual property to enter into confidentiality agreements which prohibit the use of or disclosure of confidential information to third parties; and implementing physical security measures designed to restrict access to such confidential information and products. Our ability to maintain the confidentiality of our technology is crucial to our ultimate possible commercial success. The procedures adopted by us to protect the confidentiality of our technology may not be effective, third parties may gain access to our trade secrets or our trade secrets or those of our collaborators may be independently discovered by others. Our collaborators, employees and consultants and other parties may not comply with the terms of their agreements with us, and we might be unable to adequately enforce our rights or obtain adequate compensation for the damages caused by unauthorized disclosure or use of our trade secrets or know how. Further, by seeking patent protection in various countries, it is inevitable that a substantial portion of our technology will become available to our competitors, through publication of such patent applications.

Enforcement of intellectual property rights

Protection of the rights revealed in published patent applications can be complex, costly and uncertain. Our commercial success depends in part on our ability to maintain and enforce our proprietary rights. If third parties engage in activities that infringe our proprietary rights, our management’s focus will be diverted and we may incur significant costs in asserting our rights. We may not be successful in asserting our proprietary rights, which could result in our patents being held invalid or a court holding that the third party is not infringing, either of which would harm our competitive position.

Others may design around our patented technology. We may have to participate in interference proceedings declared by the USPTO, European opposition proceedings, or other analogous proceedings in other parts of the world to determine priority of invention and the validity of patent rights granted or applied for, which could result in substantial cost and delay, even if the eventual outcome is favorable to us. Our pending patent applications, even if issued, may not be held valid or enforceable.

Our products and product candidates may infringe the intellectual property rights of others, or others may infringe on our intellectual property rights which could increase our costs.

Our success also depends on avoiding infringement of the proprietary technologies of others. In particular, there may be certain issued patents and patent applications claiming subject matter which we or our collaborators may be required to license in order to research, develop or commercialize APTO-253tuspetinib or luxeptinib. In addition, third parties may assert infringement or other intellectual property claims against us. An adverse outcome in these proceedings could subject us to significant liabilities to third-parties,third parties, require disputed rights to be licensed from third-parties or require us to cease or modify our use of the technology. If we are required to license third-party technology, a license under such patents and patent applications may not be available on acceptable terms or at all. Further, we may incur substantial costs defending ourselves in lawsuits against charges of patent infringement or other unlawful use of another’s proprietary technology. We may also need to bring claims against others who we believe are infringing our rights in order to become or remain competitive and successful. Any such claims can be time consuming and expensive to pursue.

We may incur substantial cost in defending our intellectual property.

While we believe that our products and technology do not infringe proprietary rights of others, third parties may assert infringement claims in the future and such claims could be successful. Even if challenges are unsuccessful, we could incur substantial costs in defending ourselves against patent infringement claims brought by others or in prosecuting suits against others. In addition, others may obtain patents that we would need to license, which may not be available to us on reasonable terms. Whether we are able to obtain a necessary license would depend on the terms offered, the degree of risk of infringement and the need for the patent.

We have licensed important portions of our intellectual property from Hanmi and CG, and are subject to significant obligations under thatthose license agreement.agreements.

The Rightsrights we hold under our license agreementagreements with Hanmi and CG are critical to our business.

Our tuspetinib program is built around patents exclusively in-licensed from Hanmi, which permit us to research, develop and commercialize tuspetinib worldwide. Under the Tuspetinib Licensing Agreement, we are subject to significant obligations, including diligence obligations with respect to development and commercialization activities, payment obligations upon achievement of certain milestones and royalties on product sales, as well as other material obligations. Hanmi is eligible for payments upon the achievement of developmental, regulatory and commercial-based milestones, as well as tiered royalties on product sales.

Our luxeptinib program is built around patents exclusively in-licensed from CG, which permit us to research, develop and commercialize CG-806luxeptinib worldwide except for the Republic of Korea. Under our agreement with CG, we are subject to significant obligations, including diligence obligations with respect to development and commercialization activities, payment obligations upon achievement of certain milestones and royalties on product sales, as well as other material obligations. CG is eligible for payments upon the achievement of developmental, regulatory and commercial-based milestones, as well as low single-digit royalties on product sales in all territories outside of the Republic of Korea.sales.

If there is any conflict, dispute, disagreement or issue of non-performance between us and Hanmi or CG regarding our rights or obligations under the respective license agreements, including any conflict, dispute or disagreement arising from our failure to satisfy diligence or payment obligations under such agreements, Hanmi or CG may have a right to terminate the respective license. The loss of this license agreement could materially and adversely affect our ability to use intellectual property that could be critical to our drug discovery and development efforts, as well as our ability to enter into future collaboration, licensing and/or marketing agreements for one or more affected drug candidates or development programs.

Our business depends, in part, on our ability to use technology that we have licensed or will in the future license from third parties, including CG, and, if these licenses were terminated or if we were unable to license additional technology we may need in the future, our business will be adversely affected.

We currently hold licenses for certain technologies that are or may be critical to our current and subsequent product candidates. These include our exclusive license to research, develop and commercialize luxeptinib worldwide except for the Republic of Korea. TheKorea, and our exclusive license from CG isto develop and commercialize tuspetinib worldwide. Both licenses are subject to termination in the event of a breach by us of the license, if we fail to cure the breach following notice and the passage of a cure period. We may need to acquire additional licenses in the future to technologies developed by others. Furthermore, future license agreements may require us to make substantial milestone payments. We may also be obligated to make royalty payments on the sales, if any, of products resulting from the license. The termination of a license or the inability to license future technologies on acceptable terms may adversely affect our ability to develop or sell our products.

Legal and Regulatory Risk

Our ability to develop, produce and market our products is subject to extensive government regulation.

Government regulation is a significant factor in the development, production and marketing of our products. Research and development, testing, manufacture, marketing and sales of pharmaceutical products or related products are subject to extensive regulatory oversight, often in multiple jurisdictions, which may cause significant additional costs and/or delays in bringing products to market, and in turn, may cause significant losses to investors. The regulations applicable to our product candidates in a given jurisdiction may change. Even if granted, regulatory approvals may include significant limitations on the uses for which products can be marketed or may be conditioned on the conduct of post-marketing surveillance studies. Failure to comply with applicable regulatory requirements can, among other things, result in delay in approving or refusal to approve a product candidate, interruptions of clinical trials or manufacturing, suspension or withdrawal of regulatory approval, warning letters, the imposition of civil penalties or other monetary payments, product recall or seizure, operating restrictions, injunctions or criminal prosecution. In addition, regulatory agencies many not approve the labeling claims that are necessary or desirable for the successful commercialization of our product candidates.

Requirements for regulatory approval vary widely from country to country. Whether or not approved in Canada or the United States, regulatoryRegulatory authorities in other countries must approve a product prior to the commencement of marketing the product in those countries.product. The time required to obtain any such approval may be longer or shorter than in Canada or the United States. Approved drugs, as well as their manufacturers, are subject to continuing and ongoing review, and discovery of problems with these products or the failure to adhere to manufacturing or quality control requirements may result in regulatory restrictions being imposed.

Current and future legislation may increase the difficulty and cost for us to obtain marketing approval of and commercialize our product candidates and may adversely affect the prices we may obtain.

In the United States and some foreign jurisdictions, there have been a number of legislative and regulatory changes and proposed changes regarding the healthcare system that could, among other things, prevent or delay marketing approval of our product candidates, restrict or regulate post approval activities and affect our ability to profitably sell any products for which we obtain marketing approval.

For example, in March 2010, the Patient Protection and Affordable Care Act, as amended by the Health Care Education Reconciliation Act, or collectively the Affordable Care Act, was enacted to broaden access to health insurance, reduce or constrain the growth of healthcare spending, enhance remedies against fraud and abuse, add new transparency requirements for health care and health insurance industries, impose new taxes and fees on the health industry and impose additional health policy reforms. Additionally, the Drug Supply Chain Security Act, enacted in 2013, imposed new obligations on manufacturers of pharmaceutical products related to product tracking and tracing.

Members of CongressSince its enactment, there have been judicial, executive and the Trump Administration have considered legislationCongressional challenges to fundamentally change or repeal the Affordable Care Act. While Congress has not passed repeal legislation to date, the Tax Cuts and Jobs Act (“TCJA”) includes a provision repealing the individual insurance coverage mandate included in the Affordable Care Act, effective January 1, 2019. Further, President Trump signed an Executive Order directing federal agencies with authorities and responsibilities under the Affordable Care Act to waive, defer, grant exemptions from, or delay the implementation of any provisioncertain aspects of the Affordable Care Act, that would impose a fiscal or regulatory burden on states, individuals, healthcare providers, health insurers, or manufacturers of pharmaceuticals or medical devices. On October 13, 2017, the President signed an Executive Order terminating the cost-sharing subsidies that reimburse insurers under the Affordable Care Act. Several state Attorneys General filed suitand we expect there will be additional challenges and amendments to stop the administration from terminating the subsidies, but their request for a restraining order was denied by a federal judge in California on October 25, 2017. In addition, the Centers for Medicare and Medicaid Services has recently proposed regulations that would give states greater flexibility in setting benchmarks for insurers in the individual and small group marketplaces, which may have the effect of relaxing the essential health benefits required under the Affordable Care Act for plans sold through such marketplaces. Congress may consider other legislationin the future. On June 17, 2021, the United States Supreme Court dismissed the most recent judicial challenge to replace elementsthe Affordable Care Act without specifically ruling on the constitutionality of the Affordable Care Act. The implicationsPrior to the Supreme Court’s decision, President Biden issued an executive order initiating a special enrollment period from February 15, 2021 through August 15, 2021 for purposes of obtaining health insurance coverage through the Affordable Care Act itsmarketplace. The executive order also instructed certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, including among others, reexamining Medicaid demonstration projects and waiver programs that include work requirements, and policies that create unnecessary barriers to obtaining access to health insurance coverage through Medicaid or the Affordable Care Act. It is possible repeal, any legislation that may be proposed to replace the Affordable Care Act will be subject to judicial or Congressional challenges in the political uncertainty surroundingfuture. It is unclear how any repeal or replacement legislation forsuch challenges and the healthcare reform measures of the Biden administration will impact the Affordable Care Act and our business and financial condition, if any, are not yet clear.business.

We expect ongoing initiatives in the United States and internationally to increase pressure on drug pricing. Regulations that mandate price controls and limitations on patient access to products or establish prices paid by government entities or programs may impact product candidates that we may successfully develop. Pharmaceutical product pricing is subject to enhanced government and public scrutiny and calls for reform. Some U.S. states have implemented, and other U.S. states are considering, pharmaceutical price controls or patient access constraints under the Medicaid program, and some U.S. states are considering price-control regimes that would apply to broader segments of their populations that are not Medicaid eligible. Efforts by government officials or legislators to implement measures to regulate prices or payments for pharmaceutical products, including legislation on drug importation, could have an adverse effect on anticipated revenues from product candidates that we may successfully develop and for which we may obtain regulatory approval and may affect our overall financial condition and ability to develop drug candidates.

Legislative and regulatory proposals have also been made to expand post approval requirements and restrict sales and promotional activities for pharmaceutical products in the US. Any healthcare reforms enacted in the future may, like the Affordable Care Act, be phased in over a number of years but, if enacted, could reduce our revenue, increase our costs, or require us to revise the ways in which we conduct business or put us at risk for loss of business. We areIt is not sureclear whether additional legislative changes will be enacted, or whether the current regulations, guidance or interpretations will be changed, or what the impact of such changes on our business, if any, may be.

In Canada, the Patented Medicine Prices Review Board (“PMPRB”(the “PMPRB”) has jurisdiction to control prices of patented medicines that are considered excessive. Recent changes to the regulations governing the PMPRB are intended to lower the prices of patented medicines even further. The PMPRB’s jurisdiction could extend to any of our drug products that are approved in Canada and protected under Canadian patents, with an adverse effect on the prices that we would otherwise obtain for these drugs in the relevant market.

Coverage and adequate reimbursement may not be available for our product candidates, which could make it difficult for us to sell our products profitably.

Market acceptance and sales of any drug candidates that we develop will depend in part on the extent to which reimbursement for these products and related treatments will be available from third party payors, including government health administration authorities and private health insurers. Third party payors decide which drugs they will pay for and establish reimbursement levels. Third party payors often rely upon Medicare coverage policy and payment limitations in setting their own reimbursement policies. However, decisions regarding the extent of coverage and amount of reimbursement to be provided for each of our drug candidates will be made on a plan by planplan-by-plan basis. One payor’s determination to provide coverage for a product does not assure that other payors will also provide coverage, and adequate reimbursement, for the product. Additionally, a third partythird-party payor’s decision to provide coverage for a drug does not imply that an adequate reimbursement rate will be approved. Each plan determines whether or not it will provide coverage for a drug, what amount it will pay the manufacturer for the drug, and on what tier of its formulary the drug will be placed. The position of a drug on a formulary generally determines the copayment that a patient will need to make to obtain the drug and can strongly influence the adoption of a drug by patients and physicians. Patients who are prescribed treatments for their conditions and providers performing the prescribed services generally rely on third party payors to reimburse all or part of the associated healthcare costs. Patients are unlikely to use our products unless coverage is provided and reimbursement is adequate to cover a significant portion of the cost of our products.

A primary trend in the U.S. healthcare industry and elsewhere is cost containment. Third party payors have attempted to control costs by limiting coverage and the amount of reimbursement for particular medications. We cannot be sure that coverage and reimbursement will be available for any product that we commercialize and, if reimbursement is available, what the level of reimbursement will be. Inadequate coverage and reimbursement may impact the demand for, or the price of, any product for which we obtain marketing approval. If coverage and adequate reimbursement is not available, or is available only to limited levels, we may not be able to successfully commercialize any drug candidates that we develop.

Additionally, there have been a number of legislative and regulatory proposals to change the healthcare system in the United States and in some foreign jurisdictions, including Canada, that could affect our ability to sell any future drugs profitably. These legislative and regulatory changes may negatively impact the reimbursement for any future drugs, following approval.

We are subject to U.S. and Canadian healthcare laws and regulations, which could expose us to criminal sanctions, civil penalties, contractual damages, reputational harm, fines, disgorgement, exclusion from participation in government healthcare programs, curtailment or restricting of our operations and diminished profits and future earnings.

Healthcare providers, physicians and others will play a primary role in the recommendation and prescription of any products for which we obtain marketing approval. Our future arrangements with healthcare providers, patients and third partythird-party payors could expose us to broadly applicable U.S. and Canadian laws and regulations relating to fraud abuse and healthcare more generally that may constrain the business or financial arrangements and collaborative partners through which we market, sell and distribute any products for which we obtain marketing approval.

Efforts to ensure that our collaborations with third parties, and our business generally, will comply with applicable U.S. and Canadian healthcare laws and regulations will involve substantial costs. It is possible that governmental authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of these laws or any other governmental laws and regulations that may apply to us, we may be subject to significant civil, criminal and administrative penalties, damages, fines, imprisonment, exclusion of products from government funded healthcare programs, contractual damages, reputational harm, disgorgement, curtailment or restricting of our operations, any of which could substantially disrupt our operations and diminish our profits and future earnings. If any of the physicians or other providers or entities with whom we expect to do business isare found not to be in compliance with applicable laws, they may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs. The risk of ourthe Company being found in violation of these laws is increased by the fact that many of them have not been fully interpreted by the regulatory authorities or the courts, and their provisions are open to a variety of interpretations.

If product liability, clinical trial liability or environmental liability claims are brought against us or we are unable to obtain or maintain product liability, clinical trial or environmental liability insurance, we may incur substantial liabilities that could reduce our financial resources.

The clinical testing and commercial use of pharmaceutical products involves significant exposure to product liability, clinical trial liability, environmental liability and other risks that are inherent in the testing, manufacturing and marketing of our products. These liabilities, if realized, could have a material adverse effect on our business, results of operations and financial condition.

We have obtained limited product liability insurance coverage for our clinical trials on humans; however, our insurance coverage may be insufficient to protect us against all product liability damages. Regardless of merit or eventual outcome, liability claims may result in decreased demand for a future product, injury to reputation, withdrawal of clinical trial volunteers, loss of revenue, costs of litigation, distraction of management and substantial monetary awards to plaintiffs. Additionally, if we are required to pay a product liability claim, we may not have sufficient financial resources to complete development or commercialization of any of our product candidates and our business and results of operations will be adversely affected. In general, insurance will not protect us against some of our own actions, such as negligence.

As our development activities progress towards the commercialization of product candidates, our liability coverage may not be adequate, and we may not be able to obtain adequate product liability insurance coverage at a reasonable cost, if at all. Even if we obtain product liability insurance, our financial position may be materially adversely affected by a product liability claim. A product liability claim could also significantly harm our reputation and delay market acceptance of our product candidates. Additionally, product recalls may be issued at the direction of the FDA, other government agencies or other companies having regulatory control for pharmaceutical sales. If a product recall occurs in the future, such a recall could adversely affect our business, financial condition or reputation.

If we fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.

We are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes. Our operations involve the use of hazardous and flammable materials, including chemicals and radioactive and biological materials. Our operations also produce hazardous waste products. We generally contract with third parties for the disposal of these materials and wastes. We cannot eliminate the risk of contamination or injury from these materials. In the event of contamination or injury resulting from our use of hazardous materials, we could be held liable for any resulting damages, and any liability could exceed our resources. We also could incur significant costs associated with civil or criminal fines and penalties.

Although we maintain workers’ compensation insurance to cover us for costs and expenses we may incur due to injuries to our employees resulting from the use of hazardous materials, this insurance may not provide adequate coverage against potential liabilities. We do not maintain insurance for environmental liability or toxic tort claims that may be asserted against us in connection with our storage or disposal of biological, hazardous or radioactive materials.

In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair our research, development or production efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions.

We may be unable to obtain partnerships for our product candidates, which could curtail future development and negatively affect our share price. In addition, our partners might not satisfy their contractual responsibilities or devote sufficient resources to our partnership.

Our strategy for the research, development and commercialization of our products requires entering into various arrangements with corporate collaborators, licensors, licensees and others, and our commercial success is dependent upon these outside parties performing their respective contractual responsibilities. The amount and timing of resources that such third parties will devote to these activities may not be within our control. These third parties may not perform their obligations as expected and our collaborators may not devote adequate resources to our programs. In addition, we could become involved in disputes with our collaborators, which could result in a delay or termination of the related development programs or result in litigation. We intend to seek additional collaborative arrangements to develop and commercialize some of our products. We may not be able to negotiate collaborative arrangements on favorable terms, or at all, in the future, and our current or future collaborative arrangements may not be successful.

If we cannot negotiate collaboration, license or partnering agreements, we may never achieve profitability and we may not be able to continue to develop our product candidates. Continuing Phase 1a/b,1, and commencing Phase 2 and Phase 3 clinical trials for luxeptinibtuspetinib and APTO-253luxeptinib would require significant amounts of funding and such funding may not be available to us.

Risks Related to Our Common Shares

Our share price has been and is likely to continue to be volatile and an investment in our Common Shares could suffer a decline in value.

You should consider an investment in our Common Shares as risky and invest only if you can withstand a significant loss and wide fluctuations in the market value of your investment. The market price of our Common Shares has been highly volatile and is likely to continue to be volatile. This leads to a heightened risk of securities litigation pertaining to such volatility. Factors affecting our Common Share price include but are not limited to:

Future sales of our Common Shares by us or by our existing shareholders could cause our share price to fall.

The issuance of Common Shares by usthe Company could result in significant dilution in the equity interest of existing shareholders and adversely affect the market price of our Common Shares. Sales by existing shareholders of a large number of our Common Shares in the public market and the issuance of Common Shares in connection with strategic alliances, or the perception that such additional sales could occur, could cause the market price of our Common Shares to decline and have an undesirable impact on our ability to raise capital.

We are susceptible to stress in the global economy and therefore, our business may be affected by the current and future global financial conditions.

If the increased level of volatility and market turmoil that have marked recent years continue, our operations, business, financial condition and the trading price of our Common Shares could be materially adversely affected. Furthermore, general economic conditions may have a great impact on us, including our ability to raise capital, our commercialization opportunities and our ability to establish and maintain arrangements with others for research, manufacturing, product development and sales.

An active trading marketFailure to meet the TSX's and the Nasdaq’s continued listing requirements could result in the delisting of our Common Shares, may not be sustained.

Ournegatively impact the price of our Common Shares are listed for trading onand negatively impact our ability to raise additional capital.

If we fail to satisfy the continued listing requirements of the Nasdaq Capital Market, andsuch as the Toronto Stock Exchange. However, an active trading market incorporate governance requirements or the minimum closing bid price requirement, the exchange may take steps to delist our Common Shares. A delisting would likely have a negative effect on the price of our Common Shares and would impair your ability to sell or purchase our Common Shares when you wish to do so. In the event of a delisting notification, we anticipate that we would take actions to restore our compliance with applicable exchange requirements, such as stabilize our market price, improve the liquidity of our Common Shares, prevent our Common Shares from dropping below such exchange’s minimum bid price requirement, or prevent future non-compliance with such exchange’s listing requirements.

On February 29, 2024, the Company received a deficiency letter (the “2024 Deficiency Letter”) from the Nasdaq Listing Qualifications Department of The Nasdaq Stock Market LLC (“Nasdaq”) notifying the Company that the Company’s January 2024 private placement (the "Private Placement") of securities to Hanmi violated rule 5635(d) because the Company did not obtain shareholder approval prior to such issuance. Nasdaq stated that the Private Placement involved the issuance of greater than 20% of the issued and outstanding Common Shares of the Company at a discount to the Nasdaq official closing price on January 25, 2024, the date of the subscription agreement between the Company and Hanmi. The 2024 Deficiency Letter has no immediate effect on the stock exchanges may notlisting of the Company’s Common Shares. In accordance with the Nasdaq Listing Rules, the Company has been given forty-five (45) calendar days, or until April 14, 2024, to submit a plan to regain compliance. If Nasdaq accepts the Company’s plan to regain compliance, Nasdaq can grant an extension of up to 180 calendar days from the date of the Deficiency Letter to evidence compliance. Although the Company believes that the Private Placement was completed in accordance with the Nasdaq Listing Rules, the Company respects Nasdaq’s query and intends to work with Nasdaq to resolve Nasdaq’s concerns and will consider available options to regain compliance. However, there can be sustained and we may notno assurance that the Company will be able to maintainregain compliance with the applicable Nasdaq Listing Rules.

Compliance with changing regulation of corporate governance and public disclosure may result in additional expenses.

Changing laws, regulations and standards relating to corporate governance and public disclosure, including the Dodd-Frank Wall Street Reform and Consumer Protection Act, new SEC regulations and Nasdaq rules, are creating uncertainty for companies such as ours. These laws, regulations and standards are subject to varying interpretations in some cases due to their lack of specificity, and as a result, their application in practice may evolve over time as new guidance is provided by regulatory and governing bodies, which could result in continuing uncertainty regarding compliance matters and higher costs necessitated by ongoing revisions to disclosure and governance practices. We are committed to maintaining high standards of corporate governance and public disclosure. As a result, our listings.efforts to comply with evolving laws, regulations and standards have resulted in, and are likely to continue to result in, increased general and administrative expenses and management time related to compliance

activities. If we fail to comply with these laws, regulations and standards, our reputation may be harmed and we might be subject to sanctions or investigation by regulatory authorities, such as the SEC. Any such action could adversely affect our financial results and the market price of our common stock.

Certain Canadian laws could delay or deter a change of control.

Limitations on the ability to acquire and hold our Common Shares may be imposed by the Competition Act in Canada. This legislation permits the Commissioner of Competition of Canada to review any acquisition of a significant interest in us.the Company. This legislation grants the Commissioner jurisdiction to challenge such an acquisition before the Canadian Competition Tribunal if the Commissioner believes that it would, or would be likely to, result in a substantial lessening or prevention of competition in any market in Canada. The Investment Canada Act subjects an acquisition of control of a company by a non-Canadian to government review if the value of our assets, as calculated pursuant to the legislation, exceeds a threshold amount. A reviewable acquisition may not proceed unless the relevant minister is satisfied that the investment is likely to result in a net benefit to Canada. Any of the foregoing could prevent or delay a change of control and may deprive or limit strategic opportunities for our shareholders to sell their shares.

The exercise of all or any number of outstanding stock options, the award of any additional options, restricted stock units or other stock-based awards or any issuance of shares to raise funds or acquire a business may dilute your Common Shares.

We have in the past and may in the future grant to some or all of our directors, officers and employees options to purchase our Common Shares and other stock-based awards as non-cash incentives to those persons. The issuance of any equity securities could, and the issuance of any additional shares will, cause our existing shareholders to experience dilution of their ownership interests.

Any additional issuance of shares or a decision to acquire other businesses through the sale of equity securities may dilute our investors’ interests, and investors may suffer dilution in their net book value per share depending on the price at which such securities are sold. Such issuance may cause a reduction inreduce the proportionate ownership and voting power of all other shareholders. The dilution may result in a decline in the price of our Common Shares or a change in control.

We do not expect to pay dividends for the foreseeable future.

We have not paid any cash dividends to date and we do not intend to declare dividends for the foreseeable future, as we anticipate that we will reinvest future earnings, if any, in the development and growth of our business. Therefore, investors will not receive any funds unless they sell their Common Shares, and shareholders may be unable to sell their shares on favorable terms or at all. We cannot assure you of a positive return on investment or that you will not lose the entire amount of your investment in our Common Shares. Prospective investors seeking or needing dividend income or liquidity should not purchase our Common Shares.

General Risks

It may be difficult for non-Canadian investors to obtain and enforce judgments against us because of our Canadian incorporation and presence.

We are a corporation existing under the laws of Canada. Some of our directors and officers, and manysome of the experts named or unnamed in this Annual Report on Form 10-K, are residents of Canada, and all or a substantial portion of their assets, and a substantial portion of our assets, are located outside the United States. Consequently, although we have appointed an agent for service of process in the United States, it may be difficult for holders of our shares who reside in the United States to effect service within the United States upon our directors and officers and experts who are not residents of the United States. It may also be difficult for holders of our shares who reside in the United States to realize in the United States upon judgments of courts of the United States predicated upon our civil liability and the civil liability of our directors, officers and experts under the United States federal securities laws. Investors should not assume that Canadian courts (i) would enforce judgments of United States courts obtained in actions against us or our directors, officers or experts predicated upon the civil liability provisions of the United States federal securities laws or the securities or “blue sky” laws of any state within the United States or (ii) would enforce, in original actions, liabilities against us or our directors, officers or experts predicated upon the United States federal securities laws or any such state securities or “blue sky” laws. In addition, we have been advised by our Canadian counsel that in normal circumstances, only civil judgments and not other rights arising from United States securities legislation are enforceable in Canada and that the protections afforded by Canadian securities laws may not be available to investors in the United States.

We are likely a “passive foreign investment company” which may have adverse United States federal income tax consequences for United States shareholders.

United States investors in our Common Shares should be aware that we believe we are classified as a passive foreign investment company (“PFIC”) during the tax year ended December 31, 2020,2022, and based on the nature of our business, the projected composition of our gross income and the projected composition and estimated fair market value of our assets, we expect to be a PFIC for the year endingended December 31, 2021,2023, and may be a PFIC in subsequent tax years. If the Company is a PFIC for any year during a United States shareholder’s holding period, then such United States shareholder generally will be required to treat any gain realized upon a disposition of Common Shares, or any so-called “excess distribution” received on its Common Shares, as ordinary income, and to pay an interest charge on a portion of such gain or distributions, unless the shareholder makes a timely and effective “qualified electing fund” election (“QEF election”) or a “mark-to-market” election with respect to the Common Shares. A United States shareholder who makes a QEF election generally must report on a current basis its share of the Company’s net capital gain and ordinary earnings for any year in which the Company is a PFIC, whether or not the Company distributes any amounts to its shareholders. However, United States shareholders should be aware that we do not intend to satisfy record keeping requirements that apply to a qualified electing fund, and we do not intend to supply United States shareholders with information that such United States shareholders require to report under the QEF election rules, in the event that we are a PFIC and a United States shareholder wishes to make a QEF election. Thus, United States shareholders should assume that they will not be able to make a QEF election with respect to their Common Shares. A United States shareholder who makes the mark-to-market election generally must include as ordinary income each year the excess of the fair market value of the Common Shares over the taxpayer’s basis therein. Each United States shareholder should consult its own tax advisor regarding the United States federal, United States local, and foreign tax consequences of the PFIC rules and the acquisition, ownership, and disposition of our Common Shares.

Any failure to maintain an effective system of internal controls may result in material misstatements of our consolidated financial statements or cause us to fail to meet our reporting obligations or fail to prevent fraud; and in that case, our shareholders could lose confidence in our financial reporting, which would harm our business and could negatively impact the price of our Common Shares.

Section 404(a) of the Sarbanes-Oxley Act of 2002 requires that our management assess and report annually on the effectiveness of our internal control over financial reporting and identify any material weaknesses in our internal control over financial reporting.

Effective internal controls are necessary for us to provide reliable financial reports and prevent fraud. If we fail to maintain an effective system of internal controls, we might not be able to report our financial results accurately or prevent fraud; and in that case, our shareholders could lose confidence in our financial reporting, which would harm our business and could negatively impact the price of our Common Shares. While we believe that we have sufficient personnel and review procedures to allow us to maintain an effective system of internal controls, we cannot assure you that we will not experience potential material weaknesses in our internal control. Even if we conclude that our internal control over financial reporting provides reasonable assurance regarding the reliability of financial reporting and the preparation of consolidated financial statements for external purposes in accordance with US GAAP, because of its inherent limitations, internal control over financial reporting may not prevent or detect fraud or misstatements. Failure to implement required new or improved controls, or difficulties encountered in their implementation, could harm our results of operations or cause us to fail to meet our future reporting obligations.

If we fail to timely achieve and maintain the adequacy of our internal control over financial reporting, we may not be able to produce reliable financial reports or help prevent fraud. Our failure to achieve and maintain effective internal control over financial reporting could prevent us from complying with our reporting obligations on a timely basis, which could result in the loss of investor confidence in the reliability of our consolidated financial statements, harm our business and negatively impact the trading price of our Common Shares.

Prior to December 31, 2018, we were a foreign private issuer and were therefore not subject to certain United States securities law disclosure requirements that apply to a domestic United States issuer, which may limit the historical information publicly available to our shareholders.

As a foreign private issuer prior to December 31, 2018, we were exempt from certain rules under the Exchange Act that impose disclosure requirements as well as procedural requirements for proxy solicitations under Section 14 of the Exchange Act. In addition, our officers, directors and principal shareholders were exempt from the reporting and “short-swing” profit recovery provisions of Section 16 of the Exchange Act. Moreover, we were not required to file periodic reports and financial statements with the SEC as frequently or as promptly as a company that files as a domestic issuer whose securities are registered under the Exchange Act, nor were we generally required to comply with the SEC’s Regulation Fair Disclosure, which restricts the selective disclosure of material non-public information. For as long as we were a “foreign private issuer” or an eligible Canadian issuer under the Multijurisdictional Disclosure System, we filed our annual financial statements on Form 20-F, or on Form 40-F, respectively, and furnished our quarterly updates on Form 6-K to the SEC. However, the information we filed or furnished was not the same as the information required in annual and quarterly reports on Form 10-K or Form 10-Q for United States domestic issuers. Accordingly, there may be less historical information publicly available concerning us than there is for a company that has filed as a domestic issuer for longer.

Data security incidents and privacy breaches could result in important remediation costs, increased cyber security costs, litigation and reputational harm.

Cyber security incidents can result from deliberate attacks or unintentional events. Cyber-attacks and security breaches could include unauthorized attempts to access, disable, improperly modify or degrade the Company’s information, systems and networks, the introduction of computer viruses and other malicious codes and fraudulent “phishing” emails that seek to misappropriate data and information or install malware onto users’ computers. Cyber-attacks in particular vary in technique and sources, are persistent, frequently change and are increasingly more targeted and difficult to detect and prevent against. Our network security and data recovery measures and those of third parties with which we contract, may not be adequate to protect against cyber-attacks.

Disruptions due to cyber security incidents could adversely affect our business. In particular, a cyber security incident could result in the loss or corruption of data from our research and development activities, including clinical trials, which may cause significant delays to some or all of our clinical programs. Also, our trade secrets, including unpatented know how, technology and other proprietary information could be disclosed to competitors further to a breach, which would harm our business and competitive position. We expect that risks and exposures related to cyber security attacks will remain high for the foreseeable future due to the rapidly evolving nature and sophistication of these threats. While we have invested in the protection of data and information technology, there can be no assurance that our efforts to implement adequate security measures would be sufficient to protect us against cyber-attacks.

We must successfully upgrade and maintain our information technology systems.

We rely on various information technology systems to manage our operations. There are inherent costs and risks associated with maintaining, modifying and/or changing these systems and implementing new systems, including potential disruption of our internal control structure, substantial capital expenditures, additional administration and operating expenses, retention of sufficiently skilled personnel to implement and operate its systems, demands on management time and other risks and costs of delays or difficulties in transitioning to new systems or of integrating new systems into our current systems. In addition, our information technology system implementations may not result in productivity improvements at a level that outweighs the costs of implementation, or at all. The implementation of new information technology systems may also cause disruptions in our business operations and have an adverse effect on our business, prospects, financial condition and operating results.

ITEM 1B. UNRESOLVED STAFF COMMENTS

None.

ITEM 1C. CYBERSECURITY

None.Cybersecurity Risk Management and Strategy

We have developed and maintain a cybersecurity program designed to assess, identify, and manage risks from cybersecurity threats. As part of this program, we conduct periodic assessments of our IT Systems to evaluate the effectiveness of applicable security controls. These assessments follow industry-standard frameworks and include a review of our information security controls to assess cybersecurity capabilities and maturity. The results of these assessments are reported to the Audit Committee of the Board of Directors..

In general, we seek to address cybersecurity risks through a cross-functional approach that is focused on preserving the confidentiality, integrity, and availability of the information that we collect and store by identifying, preventing, and mitigating cybersecurity threats and effectively responding to cybersecurity incidents when they occur.

We have established a cybersecurity policy that outlines the governance processes for identifying and managing material risks to privacy and cybersecurity. In addition, our cybersecurity policy describes our capabilities and processes for the detection, response, analysis, mitigation, recovery, and reporting of cybersecurity incidents. We also manage and maintain business continuity and disaster recovery capabilities to help ensure the availability of business-critical technology resources.

Governance Related to Cybersecurity Risks

Management is responsible for the day-to-day management of risks we face, while our board of directors, as a whole and through committees, has responsibility for the oversight of risk management. Our Audit Committee oversees the management of risks from cybersecurity threats. In addition, the full board reviews our major risk exposures, their potential impact on us, and the steps we take to manage them.

Our Chief Information Officer ("CIO") is responsible for developing, implementing, and maintaining our cybersecurity risk management policies and procedures. The individual currently serving in the role of CIO has over thirty-five years of experience in cybersecurity, information security, data protection, regulatory compliance, and risk management within complex and international business verticals such as pharmaceutical/biotech, technology, and logistics. The CIO provides regular cybersecurity updates to our board of directors.

Our Information Technology Steering Committee ("ITSC") oversees matters regarding the Company’s Information Technology strategy, priorities, and governance, including cybersecurity threats and risk assessments, through periodic meetings and frequent communications. ITSC members include representatives from the Finance, Regulatory Affairs, Operations, and Information Technology departments. The ITSC has a charter that is reviewed internally to ensure it is aligned with our business strategy. As outlined in its charter, and relative to cybersecurity, the ITSC is responsible for identifying and assessing material cybersecurity risks across the Company, including escalating to our Audit Committee and Executive Management where appropriate.

ITEM 2. PROPERTIES

We lease approximately 7,3097,556 square feet of office space and 2,168 square feet of lab space in San Diego, California. The lease for the office space expires on March 31, 2023,California and can be extended for an additional 5 year period. The lease for our lab space expires on February 28, 2022. We lease approximately 2,078 square feet of office space in Toronto, Ontario, Canada. The lease for the San Diego office space is scheduled to expire on May 31, 2026. Aptose previously leased 2,618 square feet of laboratory space in San Diego. We exited this location expireslaboratory space prior to the expiration of the lease on February 28, 2023. The lease for the Toronto office space is scheduled to expire on June 30, 2023, with an option to renew for another five-year period.2024. We believe that our facilities are sufficient to meet our needs and that suitable additional space will be available as and when needed.

ITEM 3. LEGAL PROCEEDINGS

We know of no material pending legal proceedings to which our company or subsidiaries is a party or of which any of our properties, or the properties of our subsidiaries, is the subject. However, from time to time, we may be subject to various pending or threatened legal actions and proceedings, including those that arise in the ordinary course of our business. Such matters are subject to many uncertainties and to outcomes that are not predictable with assurance and that may not be known for extended periods of time.

ITEM 4. MINE SAFETY DISCLOSURES

None.

PART II.

ITEM 5. MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND ISSUER PURCHASES OF EQUITY SECURITIES

Our Common Shares are currently traded on The Nasdaq Capital Market under the symbol “APTO” and the Toronto Stock Exchange under the symbol “APS”.“APS.”

As of March 23, 2021,26, 2024, there were approximately 3230 shareholders of record of our Common Shares, which included Cede & Co., a nominee for Depository Trust Company, or DTC, and CDS & Co., a nominee for The Canadian Depository for Securities Ltd., or CDS.("CDS"). Common shares that are held by financial institutions as nominees for beneficial owners are deposited into participant accounts at either DTC or CDS, and are considered to be held of record by Cede & Co. or CDS & Co., each as one shareholder.

We currently intend to retain all future earnings, if any, for the operation and expansion of our business and, therefore, do not anticipate declaring or paying cash dividends on our Common Shares in the foreseeable future.

Repurchases of Equity Securities

There were no repurchases of equity securities during the fourth quarter of 2020.2023.

ITEM 6. SELECTED financial dataRESERVED

ITEM 7 - MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

This discussion contains forward-looking statements that involve risks and uncertainties. When reviewing the discussion below, you should keep in mind the substantial risks and uncertainties that impact our business. In particular, we encourage you to review the risks and uncertainties described in “Risk Factors” in Part I, Item 1A in this Annual Report on Form 10-K. These risks and uncertainties could cause actual results to differ materially from those projected or implied by our forward-looking statements contained in this report. These forward-looking statements are made as of the date of this management’s discussion and analysis, and we do not intend, and do not assume any obligation, to update these forward-looking statements, except as required by law.

All amounts are expressed in United States dollars unless otherwise stated.

OVERVIEW

Aptose Biosciences Inc. is a science-driven clinical stage biotechnology company committed to precision medicines addressing the unmet clinical 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’s executive office is in San Diego, California, and our head office is in Toronto, Canada.

Aptose Programs

We are advancing first-in-classoral targeted agents to treat life-threatening hematologic cancers such as AML, high-risk MDS, CLL and other hematologic malignancies. Based on insights intothat require immediate treatment. We have two clinical-stage oral kinase inhibitors under active development for the genetic and epigenetic profiles of certain cancers and patient populations, Aptose is building a pipeline of novel oncology therapies directed at dysregulated processes and signaling pathways. Aptose is developing targeted medicines for precision treatment of these diseases to optimize efficacyhematologic malignancies: tuspetinib ("HM43239" or "TUS") and quality of life by minimizing the side effects associated with conventional therapies. We currently have in development two molecules: luxeptinib (CG-806)("CG-806" or "LUX"). Tuspetinib and APTO-253, bothluxeptinib are being evaluated for safety, tolerability, pharmacokinetics and signals of efficacy in Phase 11/2 clinical trials. Eachtrials, and each molecule is described below. A third molecule (APTO-253) is not under clinical development and will not be discussed further.

Tuspetinib, Aptose’s lead asset, is being developed for frontline combination therapy in newly diagnosed AML patients to unlock the most significant patient impact and greatest commercial opportunity. Tuspetinib is a once-daily oral kinase inhibitor, targeting a select group of kinases operative in myeloid malignancies, such as acute myeloid leukemia ("AML") and the higher risk myelodysplastic syndromes ("hr-MDS"), and known to be involved in tumor proliferation, resistance to therapy, and differentiation. However, tuspetinib avoids kinases that typically cause toxicities associated with other kinase inhibitors and is consequently a well-tolerated antileukemic agent. The clinical development path for triplet combination therapy in newly diagnosed AML patients with tuspetinib-based triplet combination therapy (TUS + VEN + hypomethylating agent; (TUS+VEN+HMA), the TUS+VEN doublet in relapsed or refractory R/R AML patients.

Tuspetinib has completed the dose escalation and dose exploration stages of an international Phase 1/2 clinical trial designed to assess the safety, tolerability, pharmacokinetics, pharmacodynamic responses, and efficacy as a single agent in patients with R/R AML. Complete responses (“CRs”) without dose limiting toxicities were achieved at four dose levels across a broad diversity of mutationally-defined AML populations and with a highly favorable safety profile. Tuspetinib to date has demonstrated a favorable safety profile and has caused no drug-related QTc prolongations, liver or kidney toxicities, muscle damage, differentiation syndrome, and no myelosuppression with continuous dosing of patients in remission. A recommended phase 2 dose (RP2D) of 80 mg tuspetinib once daily as an oral tablet was selected and approved by the U.S. FDA for use as a single agent in patients with R/R AML. At the RP2D, tuspetinib demonstrated notable response rates in R/R AML patients that had never been treated with venetoclax (VEN-naive AML): CR/CRh=36% among all-comers, CR/CRh=50% among patients with mutated FLT3, and CR/CRh=25% in patients with wildtype FLT3.

Following completion of the single agent dose escalation and exploration trial, tuspetinib advanced into the APTIVATE expansion trial of the Phase 1/2 program in R/R AML patient populations treated with the TUS+VEN doublet, with the intent to position tuspetinib for triple combination studies in frontline therapy. The TUS+VEN doublet combination therapy maintained a favorable safety profile: no new or unexpected safety signals were observed, and there were no reported drug-related adverse events of QTc prolongation, differentiation syndrome, or deaths. The TUS+VEN doublet combination also achieved responses in heavily pretreated R/R AML patients, including those with wildtype or mutated FLT3, and those who failed prior therapy with venetoclax ("Prior-VEN") or FLT3 inhibitors ("Prior-FLT3i"). Based on the safety and efficacy profile of tuspetinib, we believe that tuspetinib, if

approved, can reach annual sales greater than $3 billion by 2035 because we believe tuspetinib could 1) become the preferred kinase inhibitor for inclusion in triplet combination for front line AML patients with FLT3 mutations and for patients with wild type FLT3, 2) become the preferred kinase inhibitor for inclusion in combination with venetoclax for second line AML patients, 3) serve as an effective agent for maintenance therapy to prevent relapse in patients who achieved a complete remission through a stem cell transplant or through drug-based therapy, 4) serve as an effective agent for the treatment of third line FLT3 mutated patients failed by prior therapy with other FLT3 inhibitors and 5) serve in front line triplet combinations, second line doublet combinations, and maintenance therapy for hr-MDS patients. These beliefs related to the potential commercial opportunity are based on management’s current assumptions and estimates, which are subject to change, and there can be no assurance that tuspetinib will ever be approved or successfully commercialized and, if approved and commercialized, that it will ever generate significant revenues. See our “Risk Factors – “We are an early-stage development company with no revenues from product sales.” and “We have a history of operating losses. We expect to incur net losses and we may never achieve or maintain profitability.” in this Annual Report on Form 10-K.

Luxeptinib is an orally administered,oral, highly potent first-in-class FLT3/BTKkinase inhibitor that selectively targets defined clusters of kinases that are operative in myeloid and lymphoid hematologic malignancies. This mutationally agnostic small molecule anticancer agent is currently beinghas been evaluated in a Phase 1a/b study for the treatment of patients having B-cell malignancies including classic CLL, SLL and certain NHL that are resistant/refractory/intolerant to other therapies. In addition, Aptose received IND allowance and initiated patient dosing in a Phase 1a/b study to develop luxeptinib for the treatment of patients with R/R AML, including the emerging populations resistant to FLT3 inhibitors. In this trial of patients with R/R AML, the luxeptinib starting dose of 450 mg BID was selected because the plasma from B-cell cancer patients at that dose completely inhibited phospho-FLT3, suggesting that this starting dose might be active in the AML patient population,leukemias and that dose escalation is planned to identify an optimal dose for treating a breadth of AML patients. It is important to note that luxeptinib now is undergoing formal clinical development in both lymphoidlymphomas and myeloid hematologic malignancies.

APTO-253 is a first-in-class small molecule therapeutic agent that clinically inhibits expression of the MYC oncogene without causing, to date, general myelosuppression of the bone marrow. The MYC oncogene is overexpressed across many hematologic cancers, including AML and certain B cell malignancies, as well as certain solid tumor indications. MYC acts as a transcription factor that regulates cell growth, proliferation, differentiation and apoptosis, and overexpression of MYC amplifies new sets of genes to promote survival of cancer cells. APTO-253 suppresses expression of the MYC oncogene in AML cells and depletes those cells of the MYC oncoprotein, leading to apoptotic cell death. APTO-253 is currently being evaluated in a Phase 1a/b study for the treatment of patients with R/R AML and high-risk MDS. APTO-253 may serve asor hr-MDS. These clinical studies demonstrated tumor shrinkage among B-cell cancer patients, including a safe and effective MYC inhibitor for AML/MDS patientsCR in a diffuse large B-cell lymphoma patient that combines wellwas determined via biopsy analysis at the end of Cycle 22 with other agents and does not significantly impact900mg BID dosing of the normal bone marrow.

Impactoriginal G1 formulation. Likewise, an MRD-negative CR in one R/R AML patient occurred with 450mg BID dosing of COVID 19 on our Research Programs:

We are advancing first-in-class targeted agents to treat life-threatening cancers that, in most cases, are not elective for patients and require immediate treatment. However, COVID-19 has caused global economic and social disruptions that could adversely affect our ongoing or planned research and development and clinical trial activities including enrollmentthe original G1 formulation. Because absorption of the original G1 formulation hampered effectiveness of luxeptinib, a new G3 formulation was developed. Enrollment of patients in our ongoing clinical trials, collection and analysis of patient data and eventually, the reporting of top-line results from our trials.

Our team proactively addressed these new challenges swiftly and appropriately, implementing safeguards and procedures to ensure both the safety of our employees and stakeholders, and accommodate the potential challenges due to COVID-19. Aptose was early in directing its employees to work-from-home and provided the tools to minimize productivity disruptions. Our clinical operations team reached out to active and future clinical sites to determine their needs and challenges and assist where possible, including virtual monitoring of patients, which reduces patients’ visits. We also have contacted our drug manufacturers to identify any potential supply chain disruptions and are adjusting accordingly. During the early part of the first quarter of 2020, we began to carefully monitor the potential impact of COVID-19, and on a regular basis, we communicated with investigators at our clinical sites to gain an evolving understanding of competing COVID-19 related activities and clinical trial related activities.

In the beginning of April 2020, we learned that some of our larger clinical sites that are impacted by COVID-19 may either postpone or face delays in the enrollment of patients on all on-going clinical trials due to a number of factors, including the re-allocation of resources and to avoid clinical trial patients being exposed to COVID-19. Such measures taken at the clinical sites could lead to a slowdown in the enrollment of patients on our trials at these sites. To minimize the impact of COVID-19, we focused efforts on our other larger clinical sites and regional cancer care sites that are not/less impacted by COVID-19 to recruit patients into the fourth cohort. While it is difficult to estimate the duration and impact of COVID-19 on the larger clinical sites and regional cancer care sites, as of the date of this report, we have not experienced and do not foresee material delays to the enrollment of patients or timelines for the luxeptinib Phase 1a/b B-cell malignancy trial dueand the AML trial have been completed, and clinical evaluation of the G3 formulation has been completed. The G3 formulation was determined to deliver superior plasma exposure levels relative to the varietyoriginal G1 formulation, and any future trial with luxeptinib should use the G3 formulation. Regarding potential next steps with luxeptinib, recent therapeutic strategies with CLL B-cell cancer patients typically involve therapy with certain BTK inhibitors in combination with venetoclax (VEN). Drug resistance has begun to emerge in a molecularly defined subgroup of clinical sites that we have actively recruited forthese patients, and the drug resistance has been correlated with mutations in the FLT3 receptor. Although FLT3 mutations are typically associated with AML patients, these R/R CLL prior-BTKi/Prior-VEN/FLT3-mutated patients are difficult to treat and represent a potential commercial market of approximately $200 million by 2039. The Dana Farber Cancer Institute identified this trial. APTO-253, which is administered intravenously, requiresemerging patient population and has requested luxeptinib be tested as part of an investigator sponsored trial in combination with VEN in the need for hospital / clinical site resourcesR/R CLL prior-BTKi/Prior-VEN/FLT3-mutated patients. Non-clinical studies are underway to assist and monitor patients during each infusion and based on the current conditions caused by COVID-19, future enrollment of patients on this trial is likely to be negatively impacted.

PROGRAM UPDATES

Luxeptinib (CG-806)

Indication and Clinical Trials:

Luxeptinib is being developed with the intent to deliver the agent as an oral therapeuticposition LUX+VEN for the treatment of R/R AMLthese patients, and efforts are underway to identify sources of capital to support such a trial to develop LUX for the treatmenta molecularly defined CLL subpopulation with a high unmet medical need.

PROGRAM UPDATES

Tuspetinib

Tuspetinib is an oral, highly potent, small molecule inhibitor of a spectrum of B cellkinases operative in myeloid malignancies (including but not limitedand known to CLL, SLLbe involved in tumor proliferation, resistance to therapy and NHL).

On March 25, 2019, we announceddifferentiation. Preclinical in vitro and in vivo studies suggest that the FDA granted Aptose IND allowance to initiate its Phase 1a/b clinical trial for luxeptinib. The clinical trial is a multicenter, open label, dose-escalation study with additional optional expansion cohorts to assess the safety, tolerability, pharmacokineticsTuspetinib may be an effective monotherapy and pharmacodynamic effects, and prelimnary efficacy of luxeptinibcombination therapy in patients with CLL, SLL or NHL. In this study, luxeptinib is administered in gelatin capsules twice daily (BID during a 28-day cycle.

As of the date of this report, we have initiated thirtyhematologic malignancies including AML. An international Phase 1/2 clinical sites for the Phase 1a/b trial in patients with CLL/SLLrelapsed or NHL which include specialty regional cancer care centers as well as large hospitals and key academic institutions. As of the daterefractory AML is ongoing. The dose escalation portion of this report, we have completed the first, second, third and fourth dose levels (150 mg, 300 mg, 450 mg and 600 mg BID, respectively). Cohort 5 (750mg) enrollment is ongoing. Under an FDA-approved accelerated titration protocol, only one patient was required at eachstudy to date has observed evidence of the first two dose levels, followed by three patients at each dose level thereafter. Intra-patient dose escalation is allowed if the higher dose is safe in three or more patients, and additional patients may be enrolled at dose levels previously declared safe. To date, we have reported that among enrolled patients with an array of B-cell malignancies, three classic CLL patients have received luxeptinib and all three demonstrated inhibition of phospho-BTK and “on-target” lymphocytosis and modest tumor reductions in different tumor types, indicating target engagement and pharmacologicrobust clinical activity, of luxeptinib. As luxeptinib moves from low/intermediate dose levels and into the higher dose levels, it is hoped that an optimal dose can be selected that demonstrates formal clinicalincluding multiple complete responses without excessive toxicity.

We are also advancing luxeptinib into myeloid malignancies, with an initial focus on AML, in a separate Phase 1a/b trial. On June 29, 2020, we announced that we had received allowance from the FDA to proceed into a study in R/R AML with a starting dose of 450 mg BID, and subsequently on October 19, 2020, announced that we had initiated dosing of the first patient with AML. As of the date of this report we have initiated six clinical sites for the Phase 1a/b trial and dosing continues at the 600 mg dose cohort.

The clinical trial is a multicenter, open label, dose-escalation study with additional optional expansion cohorts to assess the safety, tolerability, pharmacokinetics and pharmacodynamic effects, and preliminary efficacy of luxeptinib in patients with R/R AML. In this study, luxeptinib is administered in gelatin capsules BID during a 28-day cycle. Our strategy was to identify a startingvarious disease genotypes, and no toxicity trends that should prevent further dose of luxeptinib that we believe could be therapeutically active in critically ill patients with R/R AML. In our ongoing Phase 1a/b study in patients with CLL and other B-cell malignancies, 450 mg BID luxeptinib delivered plasma levels potently inhibited phospho-FLT3 in a plasma inhibitory activity (PIA) reporter cell assay, suggesting that the 450 mg BID dose may be active in patients with AML. Aptose plans to dose escalate beyond the 450 mg BID dose level, provided the 450 mg BID dose level is safe and well tolerated in R/R AML patients. Based on strong preclinical evidence of luxeptinib’s activity against AML – including demonstration of mutation-agnostic and genotype-agnostic potency, particularly compared against other FLT3 inhibitors, and its ability to safely cure AML in murine leukemia models – we believe that luxeptinib may offer hope to the fragile and difficult-to-treat AML patient population. escalation.

The FDA has granted orphan drug designation to luxeptinibtuspetinib for the treatment of patients with AML.AML in October 2018. Orphan drug designation is granted by the FDA to encourage companies to develop therapies for the treatment of diseases that affect fewer than 200,000 individuals in the United States. Orphan drug status provides research and development tax credits, an opportunity to obtain grant funding, exemption from FDA application fees and other benefits. The orphan drug designation also provides us with seven additional years of marketing exclusivity in this indication.

Manufacturing:

Following the Tuspetinib licensing agreement between Aptose and Hanmi on November 4, 2021 (the "Tuspetinib Licensing Agreement"), Aptose received from Hanmi an existing inventory of drug product expected to support continuation of the current Phase 1/2 study. The Company and Hanmi also entered into a separate supply agreement in 2022 for additional production of new drug substance and drug product to support further clinical development. Additional batches of API and drug product have been produced by other companies during 2022 and 2023.

Manufacturing:Program Updates at Recent Scientific Forums:

On December 9, 2023, Aptose featured tuspetinib in an oral presentation at the 65th American Society of Hematology (ASH) Annual Meeting and Exposition and announced that a growing body of clinical data for Aptose’s lead compound tuspetinib, demonstrates significant benefit as a single agent and in combination with venetoclax in patients with R/R AML in the ongoing APTIVATE Phase 1/2 study. Data were presented in an oral presentation by lead investigator Naval G. Daver, M.D., Professor, Director Leukemia Research Alliance Program, Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX.

Dr. Daver reported data from more than 100 relapsed/refractory patients from multiple international clinical sites, who had failed prior therapy and then were treated with TUS as a single agent or TUS+VEN. Both TUS and TUS+VEN delivered multiple composite complete remissions (CRc) in this very ill AML population, while maintaining a favorable safety profile across all treated patients. The data demonstrated tuspetinib is active and well tolerated in one of the most challenging and heterogeneous disease settings in oncology – relapsed and refractory AML. Tuspetinib demonstrated broad activity, including activity in patients with FLT3 wild-type AML (accounting for more than 70% of the AML population), FLT3 mutated AML, NPM1 mutated AML, as well as in patients with mutations historically associated with resistance to targeted therapy. Most notably, TUS targets VEN resistance mechanisms, enabling TUS+VEN uniquely to treat the very ill prior-VEN AML population, including both FLT3 mutant and FLT3 wildtype disease. From a broader perspective, the growing body of antileukemic activity, and continued favorable safety profile, support advancement of tuspetinib in a TUS+VEN+HMA triplet for the treatment of frontline newly diagnosed AML patients.”

Dr. Daver also pointed out that while patients on the TUS+VEN therapy are early in their treatment cycles, most achieving a response remained on treatment and that responses have begun to mature as dosing continues. Highlights of Dr. Daver’s ASH oral presentation include:

On October 29, 2023, Aptose presented two posters related to the clinical and preclinical activity of tuspetinib at the European School of Haematology 6th International Conference: Acute Myeloid Leukemia "Molecular and Translational": Advances in Biology and Treatment, held October 29-31, 2023, in Estoril, Portugal. Clinical findings included 1) data from the APTO-TUS-HV01 clinical trial (the "Food Effect Study") evaluating the pharmacokinetic (PK) properties of tuspetinib in healthy human volunteers in which tuspetinib was administered with our without food, and 2) from an international Phase 1/2 study of tuspetinib as a single agent (TUS) and in combination with venetoclax in patients with R/R AML from across clinical centers in the United States, South Korea, Spain, Australia and other sites. Data from the Food Effect Study in healthy human volunteers demonstrated tuspetinib can be administered with or without food and foresee no clinically meaningful difference in exposure. This is an important finding for patient convenience, as venetoclax is dosed with food and tuspetinib can now be co-administered with venetoclax rather than in staggered dosing. Findings from the Phase 1/2 clinical trial demonstrated tuspetinib as a single agent was well-tolerated and highly active among R/R AML patients with a diversity of adverse genotypes and delivered a 42% CR/CRh cross-evaluable venetoclax (VEN) naive patients at the 80mg daily RP2D. The TUS+VEN doublet has been well tolerated in the APTIVATE international Phase 1/2 expansion trial in R/R AML patients and achieved multiple responses in patients who previously failed venetoclax ("Prior-VEN failure AML"), including Prior-VEN failure patients who also previously failed FLT3 inhibitors, all of whom represent emerging populations of high unmet medical need. Notably, tuspetinib targets venetoclax resistance mechanisms that may re-sensitize Prior-VEN failure patients to venetoclax.

Separate from the clinical studies, the preclinical study (entitled: “Tuspetinib Oral Myeloid Kinase Inhibitor Creates Synthetic Lethal Vulnerability to Venetoclax”) presented by Aptose during the ESH Conference investigated the effects of tuspetinib on key elements of the phosphokinome and apoptotic proteome in both parental and TUS-resistant AML cells. In parental cells, tuspetinib inhibits key oncogenic signaling pathways and shifts the balance of pro- and anti-apoptotic proteins in favor of apoptosis, suggesting that it may generate vulnerability to venetoclax. In addition, acquired resistance in the AML cells to tuspetinib generated a synthetic lethal vulnerability to venetoclax of unusually high magnitude. Concurrent administration of TUS+VEN therefore may discourage the emergence of resistance to tuspetinib during treatment.

In conjunction with poster presentations at the ESH Conference, on October 30, 2023, Aptose held a “Clinical Update and KOL Data Review of AML Drug Tuspetinib” that was webcast and featured Dr. Naval Daver, MD, Professor, Director Leukemia Research Alliance Program, Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas. Dr. Daver is the lead investigator on Aptose’s APTIVATE trial and is recognized for significant achievements in the development of novel AML treatments, including several combination therapies. Aptose presented data in 49 patients who received the TUS+VEN doublet, showing an overall response rate ("ORR") of 48% among all patients that had achieved an evaluable stage, as well as a 44% ORR among Prior-VEN failure AML patients, including FLT3-unmutated ("wildtype") patients (43% ORR) and FLT3-mutated patients (60% ORR), some of whom also had failed prior therapy with FLT3 inhibitors. The TUS+VEN doublet was well tolerated with no unexpected safety signals. The TUS+VEN doublet may serve the Prior-VEN failure R/R AML patients that represent a rapidly growing population that is highly refractory to any salvage therapy. The compelling data with the TUS+VEN doublet in R/R AML patients suggest a TUS+VEN+HMA triplet may also serve the needs of frontline (1L) newly diagnosed AML patients.

Concurrent with the European Hematology Association (EHA) Annual Congress held June 8-11, 2023, Aptose held an interim clinical update webcast on June 10, 2023, to present highlights from the ongoing clinical development of tuspetinib. Aptose reported completion of the tuspetinib dose escalation and dose exploration Phase 1/2 trial in 77 R/R AML patients, tuspetinib demonstrated a favorable safety profile, and tuspetinib delivered monotherapy responses across four dose levels with no dose-limiting toxicity in mutationally diverse and difficult to treat R/R AML populations, including patients with highly adverse mutations that typically do not respond to monotherapy or combination therapy: TP53-mutated patients with a CR/CRh = 20% and RAS-mutated patients with a CR/CRh = 22%. Aptose also reported completion of a successful End of Phase 1 Meeting with the US FDA for tuspetinib, that a monotherapy RP2D was selected as 80mg daily, and that all development paths remain open, including the single arm accelerated path. Following completion of the dose escalation and dose exploration phases of the Phase 1/2 clinical program, Aptose focused attention on the tuspetinib APTIVATE expansion trial. The APTIVATE trial is designed to identify patient populations sensitive to tuspetinib monotherapy that may serve as development paths for single arm accelerated approval and to use the TUS+VEN doublet in R/R AML patients and identify patient populations of unmet need that are sensitive to the TUS+VEN doublet and can serve as development paths for accelerated and full approvals.

We reported that patient enrollment in the APTIVATE expansion trial has been brisk and preliminary CR activity had already been reported in patients receiving the TUS+VEN doublet who previously failed therapy with venetoclax. During the interim clinical update webcast Aptose also reviewed clinical findings with the new G3 formulation of luxeptinib. Aptose disclosed that continuous dosing with 50mg of the G3 formulation achieves roughly an equivalent pharmacokinetic profile as 900mg original G1 formulation, and that dose escalation with the G3 formulation was anticipated.

On March 23, 2023, Aptose announced the APTIVATE Phase 1/2 expansion trial with tuspetinib had been initiated and already had treated several R/R AML patients in the monotherapy arm, and that patient enrollment had been initiated in the doublet combination treatment arm of the APTIVATE trial with the TUS+VEN doublet. Since then, patients have continued to enroll and receive tuspetinib on the monotherapy arm. Plus, enrollment and dosing of patients on the TUS+VEN doublet arm have been brisk. Clinical investigator interest for tuspetinib is evident, and early signs of antileukemic activity during the APTIVATE trial have fueled the level of excitement for the trial.

Clinical responses to monotherapy with tuspetinib have been observed in a broad range of mutationally defined populations, including those with mutated forms of NPM1, MLL, TP53, DNMT3A, RUNX1, wild-type FLT3, ITD or TKD mutated FLT3, various splicing factors, and other genes. In the March 23, 2023, announcement, Aptose also highlighted an unexpected observation of a 29% CR/CRh response rate with tuspetinib monotherapy in R/R AML patients having mutations in the RAS gene or other genes in the RAS pathway. Responses in RAS-mutated patients are important because the RAS pathway is often mutated in response to therapy by other agents as the AML cells mutate toward resistance to those other agents. Collectively, these observations of broad clinical activity of tuspetinib, along with its favorable safety profile, position tuspetinib for potential accelerated development paths, as well as for doublet, triplet and maintenance therapy indications.

On January 30, 2023, Aptose announced dosing of patients in the APTIVATE Phase 1/2 clinical trial of tuspetinib, and that another clinical response has been achieved by a R/R AML patient receiving 40 mg tuspetinib once daily orally in the original dose exploration trial, the second response at the recently launched low-dose 40 mg cohort. In addition, Aptose elucidated a rationale for the superior safety profile of tuspetinib. While several kinase inhibitors require high exposures that exert near complete suppression of a single target to elicit responses, those agents often cause additional toxicity because they also cause extensive inhibition of that target in normal cells. In contrast, tuspetinib simultaneously suppresses a small suite of kinase-driven pathways critical for leukemogenesis. Consequently, tuspetinib achieves clinical responses at lower exposures with less overall suppression of each pathway, thereby avoiding many of the toxicities observed with competing agents.

Tuspetinib has completed the dose escalation and dose exploration phases of an international Phase 1/2 study in patients with relapsed or refractory AML across clinical centers in the United States and South Korea. Clinical data from tuspetinib in AML were presented at the ASH Annual Meeting in December 2022 and presented during a Corporate Comprehensive Clinical Update Call held December 11, 2022. Data presented demonstrated that tuspetinib delivers single agent responses without prolonged myelosuppression or life-threatening toxicities in these very ill and heavily pretreated relapsed or refractory AML patients. Responses were observed in a broad range of mutationally-defined populations, including those with mutated forms of NPM1, MLL, TP53, NRAS, KRAS, DNMT3A, RUNX1, wild-type FLT3, ITD or TKD mutated FLT3, various splicing factors, and other genes As of October 6, 2022, 60 heavily pretreated R/R AML patients were enrolled at multiple centers and treated at doses escalating from 20 mg to 200 mg, with further dose exploration at the 40 mg, 80 mg, 120 mg and 160 mg dose levels. Tuspetinib delivered multiple CRs at 40 mg, 80 mg, 120 mg and 160 mg dose levels in which no DLTs were observed. Tuspetinib demonstrated clinically meaningful benefit in all responders, by either bridging successfully to HSCT or leading to a durable response, as well as a favorable safety profile. In addition to 5 CRc and 1 PR reported at ASH 2021, 4 new CRc and 3 new PR had been generated during 2022. New responses during 2022 were achieved with 160 mg,120 mg, 80 mg, and 40 mg. Among efficacy-evaluable patients treated with 80 mg, 120 mg, or 160mg, the following response rates ranging from 19% to 75% were achieved in specific genotypic subpopulations of r/r AML patients. Significant bone marrow leukemic blast reductions were observed broadly in FLT3+ and FLT3 wildtype patients across multiple dose levels, comparable to reported gilteritinib data, but in more heavily pre-treated relapsed and refractory AML patients. Vignettes of patient experiences highlight the potency and breadth of tuspetinib to deliver complete remissions among several mutationally-defined populations with a diversity of adverse mutations. Tuspetinib continued to show a favorable safety profile with only mild AEs and no DLTs up to 160 mg per day, and no drug discontinuations from drug-related toxicity. No drug-related SAE, drug-related deaths, differentiation syndrome, AE of QT prolongation or DLT were observed through the 160 mg level. Tuspetinib avoids many of the typical toxicities observed with other tyrosine kinase inhibitors. Aptose identified a safe therapeutic range with a broad therapeutic window, spanning the dose levels of 40, 80, 120 and 160 milligrams. Aptose also announced that enrollment had been initiated in the APTIVATE expansion trial for monotherapy and drug combination therapy with tuspetinib. For the APTIVATE expansion trial, Aptose selected 120 mg as the initiating single agent expansion dose and 80 mg as the initiating dose selected for combination with venetoclax.

At the European Hematology Association Annual Congress 2022 held June 9-12, 2022, Aptose presented preclinical data from tuspetinib in a poster entitled “Myeloid Kinome Inhibitor HM43239 Overcomes Acquired Resistance in Acute Myeloid Leukemia Models.” Oral HM43239 potently inhibits kinases that drive AML, including SYK, diverse forms of the FLT3, JAK1 and JAK2, and mutant forms of the c-KIT kinases. The SYK and JAK1/2 intracellular kinases and the FLT3 (mutated and wildtype) and cKIT (mutated) receptor kinases mediate oncogenic signaling pathways in AML that can drive malignant proliferation and promote drug resistance to certain drugs. Tuspetinib was developed to overcome shortcomings of other drugs, such as simple SYK inhibitors and approved inhibitors of FLT3. These preclinical findings support the continued clinical development of tuspetinib for the treatment of multiple AML populations, particularly those who have failed other therapies.

Major conclusions include

Luxeptinib

Indication and Clinical Trials:

Luxeptinib is currently being evaluated 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 MDS. During 2022, a new G3 formulation was tested as a single dose in 20 patients during the ongoing Phase 1 a/b clinical program. Modeling of the PK properties of G3 predicted steady-state plasma exposure from continuous dosing with 50 mg of G3 (every 12 hours, Q12h) should be comparable to that of 900 mg of the original G1 formulation Q12h, representing a significant improvement in bioavailability with G3. On November 14, 2022, Aptose announced dosing of the first AML patient to receive a continuous dosing regimen of the G3 formulation (50 mg G3 Q12h), with the protocol allowing for further dose escalation of G3 in subsequent patients. Clinical data from both studies were presented during a Corporate Comprehensive Clinical Update Call held December 11, 2022. During the Corporate Update Call, Aptose announced a CR was achieved with a DLBCL patient at the end of Cycle 22 with 900mg BID of the original G1 formulation. Previously, an MRD-negative CR was reported with a R/R AML patient receiving 450mg BID of the original G1 formulation. Aptose expects that 9-15 patients will determine if G3 is safe and achieves desired exposures to deliver clinical responses.

Manufacturing:

During fiscal years 2017 and 2018, we created a scalable chemical synthetic route for the manufacture of luxeptinib drug substance and have scaled the manufacture of API (active pharmaceutical ingredient, or drug substance) to multi-kg levels, we completed the manufacture of a multi-kg batch of API under GMP conditions as our API supply for our first-in-human clinical trials, and we manufactured under GMP conditions two dosage strengths of capsules to serve as our clinical supply in those human studies. During fiscal 2019 and 2020, we completed successful manufacture of multiple batches of API and drug product, and planned numerous GMP production campaigns to supply the ongoing trial and planned trials into the future. To date we have been able to manufacture API and capsules to support clinical supplies under GMP conditions. We are continuingIn fiscal 2021 and 2022 we continued our manufacturing campaigns in the current 2021 fiscal period and continue scale-up and tech transfer activities to support additional manufacturing capacity for the ongoing and planned clinical trials of luxeptinib. Additional research and development funds are beingwere utilized to support exploratory formulation studies in an ongoing effort to craft a superior formulation for later stagethe development of the G3 formulation of luxeptinib. Now that the G3 formulation has been successfully manufactured and has demonstrated encouraging PK properties, the manufacture of additional batches of the first and second generation formulation of luxeptinib are discontinued, and the amount of drug substance manufacturing is reduced.

Publication of Peer-Reviewed Research Articles Related to Luxeptinib:

During the first quarter of 2023, Aptose and its scientific collaborators published a peer reviewed research article, entitled “Luxeptinib interferes with LYN-mediated activation of SYK and modulates BCR signaling in lymphoma,” in the online journal PLOS ONE. The article elucidates the mechanism by which luxeptinib suppresses the B-cell receptor and compares it to BTK inhibitor ibrutinib. Results showed that both luxeptinib and ibrutinib are potent inhibitors of recombinant forms of BTK but have different efficacy profiles and effects on BTK activity. Luxeptinib was more effective than ibrutinib at reducing both steady state and anti-IgM-induced phosphorylation of the LYN and SYK kinases upstream of BTK where IB has little or no effect.

During the first quarter of 2022, three separate peer-reviewed research articles were published that presented preclinical data related to the application of luxeptinib to the treatment of AML, certain B-cell lymphomas and inflammation. These publications contribute to the body of preclinical data demonstrating luxeptinib’s activity as a lymphoid and myeloid kinome inhibitor, and now as an inflammation kinome inhibitor, and support its continued clinical development in several therapeutic areas.

Program Updates at Recent Scientific Forums:

On December 11, 2021, we presented clinical updates from luxeptinib in patients with R/R B-cell malignancies and R/R AML in two virtual poster presentations at the 63rd ASH Annual Meeting (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; 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. The presentations highlighted that in both of these Phase 1/2 studies luxeptinib has been generally well tolerated at dose levels of 450, 600 and 750 mg BID over multiple cycles, and that patients already were being dosed at the 900 mg level. Target engagement of BTK and FLT3, and anti-tumor activity, including dose- and exposure-dependent tumor reductions, have been observed in multiple patients collectively between the studies, including in patients with follicular lymphoma, diffuse large B-cell lymphoma, CLL/SLL, and AML.

Preclinical Program Updates:

We have completed several non-clinical and clinical studies that demonstrate the highly differentiated profile of luxeptinib. Key studies that have been presented at scientific forums are as follows:

APTO-253

APTO-253, a small molecule inhibitor of MYC gene expression, is being evaluated by Aptose in a Phase 1a/b clinical trialstudy in patients with R/R hematologic malignancies, particularly R/R AMLsignificant unmet needs including patients with relapsed or refractory CLL, SLL or NHL who had been failed by or been intolerant to two lines of established therapy. We noted that the second patient, treated at the 300 mg BID dose level, represented a classic CLL patient that developed a brisk lymphocytosis (evidence of BTK target engagement and high-risk MDS.evidence of pharmacologic activity), and that enrollment was continuing.

Other corporate matters

Nasdaq Notice and Reverse Stock Split

On July 18, 2022, we received a letter from the Nasdaq Stock Market, LLC (“Nasdaq”) indicating that, for the last 30 consecutive business days, the bid price for our Common Shares had closed below the minimum $1.00 per share required for continued inclusion on the Nasdaq Capital Market under the Nasdaq Listing Rules. The study is designednotice had no effect on the listing of our Common Shares.

On May 23, 2023, our shareholders voted to approve special resolutions providing for an amendment to our articles of incorporation to effect the Reverse Stock Split at a ratio in the range of 1-for-10 to 1-for-20. Our Board of Directors then transition, as appropriate,approved a ratio of 1-for-15 on May 23, 2023. On May 24, 2023, we filed articles of amendment under the CBCA to single-agent expansion cohortsgive effect to the Reverse Stock Split (consolidation) of our Common Shares on the basis of one post-consolidation Common Share for each 15 pre-consolidation Common Shares. The Common Shares commenced trading on a post-Reverse Stock Split basis at market open on Tuesday, June 6, 2023. The Reverse Share Split was primarily intended to bring us into compliance with the minimum bid price requirement for maintaining the listing of the Common Shares on Nasdaq and to make the bid price more attractive to investors. On June 21, 2023, Nasdaq confirmed that we had regained compliance with the minimum bid price requirement. All references in R/R AML and/or high-risk MDS.this report to historical Common Share prices, numbers of Common Shares, and earnings per share calculations have been presented to reflect the effect of the Reverse Stock Split.

AsOn February 29, 2024, we received a deficiency letter (the “2024 Deficiency Letter”) from the Nasdaq Listing Qualifications Department of The Nasdaq Stock Market LLC (“Nasdaq”) notifying the Company that the Company’s January 2024 Private Placement of securities to Hanmi violated 5635(d) because the Company did not obtain shareholder approval prior to such issuance. Nasdaq stated that the Private Placement involved the issuance of greater than 20% of the issued and outstanding Common Shares of the Company at a discount to the Nasdaq official closing price on January 25, 2024, the date of this report, we have multiple active sites recruiting patients in the dose escalation stagesubscription agreement between the Company and Hanmi. The 2024 Deficiency Letter has no immediate effect on the listing of the trial. AsCompany’s Common Shares. In accordance with the Nasdaq Listing Rules, the Company has been given forty-five (45) calendar days, or until April 14, 2024, to submit a plan to regain compliance. If Nasdaq accepts the Company’s plan to regain compliance, Nasdaq can grant an extension of up to 180 calendar days from the date of this report, we havethe Deficiency Letter to evidence compliance. Although the Company believes that the Private Placement was completed enrollmentin accordance with the Nasdaq Listing Rules, the Company respects Nasdaq’s query and treatment of patients onintends to work with Nasdaq to resolve Nasdaq’s concerns and will consider available options to regain compliance. However, there can be no assurance that the first, second, third and fourth dose levels (20, 40, 66, and 100 mg/m², respectively). Under an FDA-approved accelerated titration protocol, only one patient was required at each ofCompany will be able to regain compliance with the first two dose levels, followed by three patients at each dose level thereafter. Aptose is currently enrolling and treating patients in the fifth dose level (150 mg/m²) of APTO-253. During the second quarter of 2020, the FDA allowed an amendment for Aptose to initiate more aggressive dose escalations with APTO-253, provided the tolerability profile remains favorable. The first four dosing cohorts have enrolled a mix of patients with AML and MDS. To date, we have observed meaningful reductions in MYC expression in peripheral blood mononuclear cells (PBMCs) from treated patients with AML and MDS, demonstrating MYC target engagement and mechanistic proof of concept in different indications.applicable Nasdaq Listing Rules.

Manufacturing:

We are continuing to manufacture additional drug substance and drug product for use in the ongoing trial.

We are exploring additional drug delivery methods for APTO-253 and plan to initiate additional non-clinical studies for solid tumor and hematologic cancer development. As preparing, submitting, and advancing applications for regulatory approval, developing drugs and drug product and clinical trials are sometimes complex, costly, and time-consuming processes, an estimate of the future costs is not reasonable at this time.

Preclinical data presented at scientific forums are as follows:

While as of the date of this report we have not experienced any material delays in initiating our luxeptinib Phase 1 clinical study in AML due to COVID-19, we are conducting site initiation visits remotely which could result in delays in site activations and negatively impact this trial. Additionally, COVID-19 could negatively impact patient enrollment if our clinical sites are unable to enroll patients due to either a lack of administrative resources at their sites or decisions made at the clinical sites to limit patient exposure to COVID-19.

As of the date of this report, we have not experienced material delays in the manufacturing of luxeptinib or APTO-253 related to COVID-19. Should our manufacturers experience shortages in staffing or be required to shut down their facilities due to COVID-19 for an extended period of time, our trials may be negatively impacted.

LIQUIDITY AND CAPITAL RESOURCES

We are an early stageearly-stage development company and we currently do not earn any revenues from our drug candidates. The continuation of our research and development activities and the commercialization of the targeted therapeutic products are dependent upon our ability to successfully finance and complete our research and development programs through a combination of equity financing and payments from strategic partners. We have no current sources of significant payments from strategic partners. As of the filing date, we have sufficient liquidity to support the Company's operations until August 2024.

Sources of liquidity:

The following table presents our cash and cash equivalents, investments and working capital as atof December 31, 20202023 and 2019.2022.

Working capital is a non-GAAP measure and represents primarily cash, cash equivalents, investments, prepaid expenses and other current assets less current liabilities.

We believe that our cash, cash equivalents and investments on hand atAs of December 31, 20202023, we reported negative shareholder's equity of $2.9 million (December 31, 2022, positive shareholder's equity of $37.7 million). In order for the Company to meet its capital requirements, and continue to operate, additional financing will be sufficientnecessary. The Company is evaluating strategies to financeobtain the required additional funding for future operations. These strategies may include, but are not limited to, obtaining equity financing, and restructuring of operations to decrease expenses. However, given the challenges in the U.S. and global financial markets, and the matter in Note 17 to the Financial Statements, Subsequent events, that may impact the Company's ability to raise financing in the capital markets, the Company may be unable to access further equity or when needed, if at all. As the Company is primarily pursuing one compound that is licensed from a related party with significant licensing payments who will have influence on the Company, other investors may not be willing to invest in the Company. As such, there can be no assurance that the Company will be able to obtain additional liquidity when needed or under acceptable terms, if at all. The consolidated financial statements do not reflect any adjustments to the carrying amounts and classification of assets, liabilities, and reported expenses that may be necessary if the Company were unable to continue as a going concern. Such adjustments may be material. If necessary funds are not available, we may have to delay, reduce the scope of, or eliminate some of our operationsdevelopment programs, potentially delaying the time to market for at least 12 months from the issuance dateany of these financial statements. our product candidates.

Our cash needs for the next twelve months include estimates of the number of patients and rate of enrollment of our clinical trials, the amount of drug product that we will require to support our clinical trials, and our general corporate overhead costs to support our operations, and our reliance on our manufacturers. We have based these estimates on assumptions and plans which may change and which could impact the magnitude and/or timing of operating expenses and our cash runway.

Since our inception, we have financed our operations and technology acquisitions primarily from equity financing, proceeds from the exercise of warrants and stock options, and interest income on funds held for future investment.

Hanmi Investment September 2023

On July 20, 2020 and August 10, 2020,2023, the Company completedentered into a confidentially marketed public offering (“CMPO”),binding term sheet with Piper Sandler & Co. (“Piper Sandler”) asHanmi whereby Hanmi agreed to invest, at their sole discretion, up to a maximum of $7 million in Aptose up to a total ownership of 19.99 percent of Aptose by Hanmi. On September 6, 2023, the representative ofCompany entered into a subscription agreement with Hanmi, pursuant to which the underwriters, through the issuance of, in the aggregate, 11,854,472Company sold 668,449 Common Shares to Hanmi for gross proceeds of $62.2$3 million. Hanmi held 884,152 Common Shares of Aptose as of December 31, 2023. Hanmi subsequently invested $4 million (approximately $58.2in Aptose as noted below. See below, "January 2024 Public Offering Financing and Concurrent Hanmi Investment." In addition, see Note 17 to the Financial Statements, Subsequent events.

2023 Committed Equity Facility

On May 25, 2023, the Company and Keystone Capital Partners, LLC ("Keystone") entered into a committed equity facility, (the "2023 Committed Equity Facility"), which provides that subject to the terms and conditions set forth therein, we may sell to Keystone up to the lesser of (i) $25.0 million of the Common Shares and (ii) a number of Common Shares equal to 19.99% of the Common Shares outstanding immediately prior to the execution of the 2023 Committed Equity Facility Agreement with Keystone which respect to the 2023 Committed Equity Facility (subject to certain exceptions) (the “Total Commitment”), from time to time during the 24-month term of the 2023 Committed Equity Facility. Additionally, on May 25, 2023, the Company entered into a Registration Rights Agreement with Keystone, pursuant to which the Company agreed to file a registration statement with the SEC covering the resale of Common Shares that are issued to Keystone under the 2023 Committed Equity Facility. This registration statement became effective on June 30, 2023 and the 2023 Committed Equity Facility commencement date was July 12, 2023 (the "Commencement Date").

Upon entering into the 2023 Committed Equity Facility, the Company agreed to issue to Keystone an aggregate of 25,156 Common Shares (the “Commitment Shares”) as consideration for Keystone’s commitment to purchase Common Shares upon the Company’s direction under the 2023 Committed Equity Facility. The Company issued 7,547 Common Shares, or 30% of the Commitment Shares, on the date of the 2023 Committed Equity Facility Agreement (the “Initial Commitment Shares”). An additional 7,547 Common Shares, or 30% of the Commitment Shares, were issued to Keystone 90 days following the Commencement Date (the “First Back-End Commitment Shares”). The remaining 10,062 Common Shares, or 40% of the Commitment Shares, were issued to Keystone subsequent to December 31, 2023 (the “Second Back-End Commitment Shares”). See Note 17 to the Financial Statements, Subsequent events.

In the year ended December 31, 2023, the Company's sales of Common Shares to Keystone comprised 720,494 Common shares sold to Keystone at an average price of $2.91 per Common share for gross cash proceeds of $2.1 million. In addition, 15,094 Commitment Shares were issued in 2023 and the remaining 10,062 Commitment Shares were issued in January 2024.

January 2024 Public Offering Financing and Concurrent Hanmi Investment

On January 31, 2024, the Company announced the closing of a $9.7 million public offering (the “Public Offering”) and a $4 million private placement (the “Private Placement”) with Hanmi Pharmaceutical. The Public Offering comprised 5,649,122 Common Shares and warrants at a combined offering price of US $1.71 per share. This included 736,842 Common Shares and warrants pursuant to a full exercise by the underwriter of its over-allotment option (the “Over-Allotment Option”). The Private Placement with Hanmi comprised 2,105,263 Common Shares of the Company sold at a price of $1.90, representing an 11% premium over the price of the Common Shares issued as part of the Public Offering. Financing costs included underwriting costs of 7% and approximately $400,000 in professional fees. The Company also issued Hanmi warrants to purchase Common Shares at an exercise price of $1.71 per Warrant Share. The total number of Common Shares outstanding after the closing of the Public Offering, including the Over-Allotment Option, and Private Placement was 15,706,810 and warrants outstanding were 8,332,163. As of the filing date, the total Common Share ownership by Hanmi was 2,989,414, representing ownership of 19.03% of the outstanding Common Shares of the Company. Hanmi also owns 2,339,181 warrants to purchase Common Shares at an exchange price of $1.71 per Warrant Share.

At-The-Market Facilities

On December 9, 2022, the Company entered into an equity distribution agreement pursuant to which the Company may, from time to time, sell Common Shares having an aggregate offering value of up to $50 million through Jones Trading Institutional Services LLC ("Jones Trading") on Nasdaq (the "2022 ATM Facility"). During the year ended December 31, 2022, the Company issued 4,836 Common Shares under this 2022 ATM Facility at an average price of $10.81 per Common Share for gross proceeds of $52 thousand ($51 thousand net of share issuance costs). During the year ended December 31, 2023, the Company issued 336,690 Common Shares under this 2022 ATM Facility at an average price of $5.62 for gross proceeds of $1.9 million ($1.8 million net of share issueissuance costs). As of December 31, 2023, the Company had raised a total of $1.9 million gross proceeds ($1.9 million net of share issuance costs) under the 2022 ATM Facility. Costs associated with the proceeds consisted of 3% cash commission.

On May 5, 2020, the Company entered an “at-the-market” equity distribution agreement with Piper Sandler & Co. (“Piper Sandler”) and Canaccord Genuity LLC (“Canaccord Genuity”) acting as co-agents (the “2020 ATM Facility”). Under the terms of the 2020 ATM Facility, the Company may,could, from time to time, sell Common Shares having an aggregate offering value of up to $75 million through Piper Sandler and Canaccord Genuity on Nasdaq. During the Nasdaq Capital Market.period from January 1, 2022 to October 31, 2022, the date the Agreement was terminated, the company issued During the year ended December 31, 2020,2022, the Company did not issue any sharesissued 3,646 Common Shares under the 2020 ATM Facility.

During the year ended December 31, 2019, the Company completed two CMPOs, with RBC Capital Markets, LLC (“RBC Capital Markets”) and Canaccord Genuity, as representativesFacility at an average price of the underwriters, and Piper Jaffray & Co (now Piper Sandler) as the representative of the underwriters, respectively, through the issuance of, in the aggregate, 30,043,750$14.25 per Common SharesShare for aggregate gross proceeds of $95.45 million (approximately $88.18 million$52 thousand ($50 thousand net of share issueissuance costs). TheAs of October 31, 2022, the date the 2020 ATM Facility was terminated, the Company alsohad raised capital pursuant to two separate share purchase agreements with Aspire Capital Fund, LLC (“Aspire Capital”) through the issuancea total of an aggregate of 7,302,433 Common Shares for aggregate$89 thousand gross proceeds ($86 thousand net of $14.4 million. We do not expect that COVID-19 will haveshare issuance costs) under the 2020 ATM Facility. Costs associated with the proceeds consisted of a significant impact on our liquidity and capital resources and we are not incurring significant additional costs to support our ongoing operations during this time. We have not entered into long term manufacturing contracts and should there be a delay in our trials we have flexibility to reduce future planned manufacturing campaigns without incurring additional costs.3% cash commission.

2022 Base Shelf

We expect that we will need to raise additional capital or incur indebtedness to continue to fund our operations in the future. In December 2019,October 2022, we filed a short form base shelf prospectus (the 2022 “Base Shelf”) that allows us to distribute, upon the filing of prospectus supplements, up to $200,000,000 of Common Shares, warrants, or units comprising any combination of Common Shares and warrants. The Base Shelf was declared effective by the SEC on January 9, 2020October 21, 2022 and expires on January 9, 2023.October 7, 2025.

Our ability to raise additional funds could be affected by adverse market conditions, the status of our product pipeline, possible delays in enrollment in our trial related to COVID-19, and various other factors and we may be unable to raise capital when needed, or on terms favorable to us. If the necessary funds are not available, we may need to delay, reduce the scope of, or eliminate some of our development programs, potentially delaying the time to market for any of our product candidates. As of the filing date, we have sufficient liquidity to support the Company's operations until August 2024.

Cash flows:

The following table presents a summary of our cash flows for the years ended December 31, 20202023 and 2019:2022:

Cash used in operating activities:

Our cash used fromin operating activities for the years ended December 31, 20202023 and 20192022 was approximately $33.9$44.6 million and $21.6$32.3 million, respectively. Net cash used in operating activities was higher in the year ended December 31, 2020 as compared with the year ended December 31, 2019 resulting mostly from a higher net loss in the current year. See “Results of Operations”. Our uses of cash for operating activities for both years consisted primarily of salaries and wages for our employees, facility and facility-related costs for our offices and laboratories, fees paid in connection with preclinical and clinical studies, drug manufacturing costs, laboratory supplies and materials, and professional fees. Net cash used in operating activities was higher in the year ended December 31, 2023 as compared with the year ended December 31, 2022 resulting mostly from higher operating expenses, as discussed further below. See “Results of Operations.”

We do not expect to generate positive cash flow from operations for the foreseeable future due to additional research and development costs, including costs related to drug discovery, preclinical testing, clinical trials, and manufacturing, as well as operating expenses associated with supporting these activities, and potential milestone payment to our collaborators. It is expected that negative cash flow will continue until such time, if ever, that we receive regulatory approval to commercialize any of our products under development and/or royalty or milestone revenue from any such products exceeds expenses.

Cash flow from investing activities:

Our cash provided by investing activities for the yearyears ended December 31, 20202023 and December 31, 2022 was $12.6$10.0 million and consisted$30.1 million, consisting mainly of maturitiesproceeds from the maturity of investments of $12.7 million and purchases of property and equipment of $79 thousand. Our cash used by investing activities for the year ended December 31, 2019 was $17.4 million, and consisted of net purchases of investments of $17.3 million and purchases of property and equipment of $102 thousand.

investments.

The composition and mix of cash, cash equivalents and investments is based on our evaluation of conditions in financial markets and our near-term liquidity needs. We have exposure to credit risk, liquidity risk and market risk related to our investments. The Company manages credit risk associated with its cash and cash equivalents and investments by maintaining minimum standards of R1-lowR1‑low or A-lowA‑low investments. The Company invests only in highly rated corporations and treasury bills which are capable of prompt liquidation. The Company manages its liquidity risk by continuously monitoring forecasts and actual cash flows. The Company is subject to interest rate risk on its cash and cash equivalents and investments. The Company does not believe that the results of operations or cash flows would be affected to any significant degree by a sudden change in market interest rates relative to interest rates on the investments, owing to the relative short-termshort‑term nature of the investments.

Cash flow from financing activities:

Our cash flow from financing activities for the year ended December 31, 20202023 was approximately $58.8$6.9 million, and consisted mostly of $3.0 million in proceeds from shares issued to Hanmi, $2.1 million in proceeds from the CMPO we completed in JulyCommitted Equity Facility, $1.8 million from shares issued from the 2022 ATM facility, and August$29 thousand from the issuance of shares under the ESPP plan.

Our cash flow from financing activities for the year ended December 31, 2022 was approximately $116 thousand, and consisted of proceeds from the from shares issued from the 2022 ATM Facility of approximately $51 thousand, proceeds from shares issued from the 2020 as described aboveATM Facility of $50 thousand, and of proceeds from the exercise of stock options of $573$15 thousand. Net cash provided by financing activities in the year ended December 31, 2019 reflects mostly:

At-The-Market Facilities

On May 5, 2020, the Company entered into an equity distribution agreement with Piper Sandler and Canaccord Genuity acting as co-agents in connection with the 2020 ATM Facility. Under the terms of the 2020 ATM Facility, the Company may, from time to time, sell Common Shares having an aggregate offering value of up to $75 million through Piper Sandler and Canaccord Genuity on the Nasdaq Capital Market. During the year ended December 31, 2020, the Company did not issue any shares under the 2020 ATM Facility.

On May 24, 2019, we entered an at-the-market equity facility (the “2019 ATM Facility”) with Piper Jaffray & Co. (now Piper Sandler) and Canaccord Genuity, acting as co-agents. The 2019 ATM Facility replaced the previous facility that we had entered into with Cantor Fitzgerald (the “2018 ATM Facility”). The 2019 ATM Facility allowed us to instruct our co-agents to offer up to approximately 20.2 million Common Shares, having an aggregate offering value of up to $40.0 million, at the prevailing market price from time to time. The Company did not issue any shares under the 2019 ATM Facility, and on December 16, 2019, the Company terminated the 2019 ATM Facility.

On March 27, 2018, the Company entered into an equity distribution agreement with Cantor Fitzgerald acting as sole agent in connection with the 2018 ATM Facility. Under the terms of the 2018 ATM Facility, the Company was allowed, from time to time, to sell Common Shares having an aggregate offering value of up to $30 million through Cantor Fitzgerald on the Nasdaq Capital Market. During the year ended December 31, 2019, the Company issued 77,349 shares under the 2018 ATM Facility at an average price of $2.37 for gross proceeds of $183 thousand ($178 thousand net of share issue costs). On a cumulative basis to December 31, 2019, the Company had raised a total of $11.2 million gross proceeds ($10.9 million net of share issue costs) under the 2018 ATM Facility. The Company terminated this agreement on May 24, 2019.

Common Share Purchase Agreements

On May 30, 2018, the Company entered into a common share purchase agreement to sell up to $20.0 million of Common Shares to Aspire Capital over approximately 30 months (the “2018 Aspire Purchase Agreement”). Pursuant to the terms of this agreement, on June 8, 2018, the Company issued 170,261 Common Shares to Aspire Capital in consideration for entering into the 2018 Aspire Purchase Agreement for a total cost of $600 thousand. During the year ended December 31, 2019, the Company issued 5,502,433 Common Shares to Aspire Capital pursuant to the 2018 Aspire Purchase Agreement at an average price of $1.82 per Common Share for gross and net proceeds of $10 million. On a cumulative basis, the Company raised a total of approximately $11.9 million gross and net proceeds under the 2018 Aspire Purchase Agreement. As of May 24, 2019 the Company had issued 6,409,980 Common Shares, the maximum number of Common Shares issuable under this facility without shareholder approval, and the 2018 Aspire Purchase Agreement was accordingly terminated.

On May 7, 2019, the Company entered into the a common share purchase agreement with Aspire Capital (the “2019 Aspire Purchase Agreement”), which provided that, upon the terms and subject to the conditions and limitations set forth therein, Aspire Capital was committed to purchase up to an aggregate of $20 million of Common Shares over approximately 30 months. Pursuant to the terms of this agreement, on May 13, 2019, the Company issued 171,428 Common Shares to Aspire Capital in consideration for entering into the 2019 Aspire Purchase Agreement for a total cost of $360 thousand. During the period from May 7, 2019 up to December 16, 2019, the date the 2019 Aspire Purchase Agreement was terminated, the Company issued 1,800,000 Common Shares under the agreement at an average price of $2.43 per Common Share for gross and net proceeds of $4.4 million.

Contractual Obligations and Off-Balance Sheet Financing

As atof December 31, 2020,2023, we have not entered into any off-balance sheet arrangements.

The Company enters into research, development and license agreements in the ordinary course of business where the Company receives research services and rights to proprietary technologies. Milestone and royalty payments that may become due under various agreements are dependent on, among other factors, clinical trials, regulatory approvals and ultimately the successful development of a new drug, the outcome and timing of which is uncertain.

On November 4, 2021, the Company entered into the Tuspetinib Licensing Agreement with Hanmi for exclusive global rights to its compound named tuspetinib. Under the Tuspetinib Licensing Agreement, the Company has maximum obligations for clinical development and global regulatory milestones totaling $64.5 million for the first potential clinical indication of tuspetinib, $34 million for the second indication, and $29 million for the third indication. The Company has maximum obligations for tiered global sales-based milestones totaling $280 million. The Company also has an obligation for tiered royalty payments on global sales of commercialized product. The timing of any milestone or royalty payments that may become due is not yet determinable.

Under the license agreement with CG with regards to the Rights (other than the China Rights), the Company has obligations for development milestones of $16 million related to the initiation of Phase 2 and pivotal clinical trials, and regulatory milestones totaling $44 million. The Company also has an obligation to pay royalty payments on sales of commercialized product. The timing of any milestone or royalty payments that may become due is not yet determinable.

Under the license agreement with CG with regards to the China Rights, we entered into a license agreement with CG to gain an exclusive license to CG-806luxeptinib in China (including the People’s Republic of China, Hong Kong and Macau). The Company has future obligations of development milestones of $6 million related to approval of an IND and to the initiation of Phase 2 and pivotal clinical trials, and regulatory milestones totaling $20 million. The Company also has an obligation to pay sales milestones and royalty payments on sales of commercialized product. The timing of any milestone or royalty payments that may become due is not yet determinable.

RESULTS OF OPERATIONS

A summary of the results of operations for the years ended December 31, 20202023 and 20192022 is presented below:

Net loss of $55.2$51.2 million for the year ended December 31, 20202023 increased by approximately $28.9$9.4 million as compared with $26.3$41.8 million for the year ended December 31, 2019,2022, primarily as of a result of an increase of $19.1 million in stock-based compensation in the current period, a combined increase inresearch and development program costs and related labor costspersonnel expenses of approximately $9.8$8.7 million, on our luxeptinib development program and higher cash-baseda $1.1 million increase in general and administrative expenses of approximately $549 thousand. These expenses were partially offset by lower costs of $545 thousand on our APTO-253 development programs.

costs.

Research and Development Expenses

Research and development expenses consist primarily of costs incurred related to the research and development of our product candidates. Costs include the following:

We have ongoing Phase 1 clinical trials for our product candidates tuspetinib and luxeptinib. Tuspetinib was licensed into Aptose in November 2021 and we assumed sponsorship, and the related costs, of the tuspetinib study effective January 1, 2022. In December 2021, we discontinued the APTO-253 program.

We expect our research and development expenses to be higher for the foreseeable future as we continue to advance tuspetinib into larger clinical trials.

The research and development (“R&D”) expenses for the years ended December 31, 20202023 and 20192022 were as follows:

R&D expenses increased by $12.5$8.7 million to $29.3$36.8 million for the year ended December 31, 20202023 as compared with $16.8$28.1 million for the comparative period in 2019.2022. Changes to the components of our R&D expenses presented in the table above are primarily as a result of the following activities:

General and Administrative Expenses

General and administrative expenses consist primarily of salaries, benefits and travel, including stock-based compensation for our executive, finance, business development, human resource, and support functions. Other general and administrative expenses and professional fees for auditing, and legal services, investor relations and other consultants, insurance and facility related expenses.

We expect that our general and administrative expenses will increase for the foreseeable future as we incur additional costs associated with being a publicly traded company and to support our expanding pipeline of activities. We also expect our intellectual property related legal expenses to increase as our intellectual property portfolio expands.

The general and administrative expenses for the years ended December 31, 20202023 and 20192022 are as follows: