ATNM

These risks and uncertainties include, but are not limited to, the following: ● We are a clinical-stage company and have generated no revenue from commercial sales to date; ● We have incurred net losses every year since our inception and anticipate that we will continue to incur net losses in the future; ● If we fail to obtain additional financing, we will be unable to continue or complete our product development or product commercialization and you will likely lose your entire investment; ● We are highly dependent on the clinical, regulatory and commercial success of ATNM-400, Actimab-A, Iomab-ACT, ATNM-400 and other pipeline candidates which we may never achieve; ● We are highly dependent on our key personnel, and the demand for talent in the biotechnology industry is highly competitive; if we are not successful in attracting and retaining highly qualified personnel, we may not be able to successfully implement or execute our business strategy; ● We continuously evaluate our business strategy and may modify our strategy as necessary to respond to developments in our business and other factors, and any such modification such as a divestiture, spin-off, spin-out, merger or acquisition, if not successful, could have a material adverse effect on our business, financial condition, and results of operations; ● We may expand our business through the acquisition of rights to new product candidates that could disrupt our business, harm our financial condition and may also dilute current stockholders’ ownership interests in our company; ● Our business could be adversely affected by the effects of future health epidemics; ● Our business is subject to cybersecurity risk; ● We have not demonstrated that any of our products are safe or effective for any indication and will continue to expend substantial time and resources on clinical development before any of our current or future product candidates will be eligible for FDA approval, if ever; ● Our clinical trials may fail to demonstrate adequately the efficacy and safety of our product candidates, which would prevent or delay regulatory approval and commercialization; ● Preliminary, Interim, and “top-line” data from our clinical trials that we announce or publish from time to time may change as more data become available and are subject to audit and verification procedures that could result in material changes in the final data; ● Healthcare legislative reform measures intended to increase pressure to reduce prices of pharmaceutical products paid for by Medicare or, otherwise, affect the regulation of the U.S. healthcare system could have a material adverse effect on our business, future revenue, if any, and results of operations; ● Changes in the healthcare industry and in healthcare spending could adversely affect our grant funded clinical programs, business, financial condition and results of operations; ● We may rely on third parties to conduct certain aspects of our clinical trials.
Any disruption in the operations of our current third-party manufacturers, or other third-party manufacturers we may engage in the future, could adversely affect our business and results of operations; ● Our product candidates may cause undesirable side effects or have other properties that could halt their clinical development, prevent their regulatory approval, limit their commercial potential, or result in significant negative consequences; ● Disruptions at the FDA and other government agencies caused by leadership changes, changes to regulatory approach, layoffs, funding shortages or global health concerns could negatively impact our business; ● Our ability to advance clinical development of trials under our CRADA, obtain regulatory interactions/approvals, or secure government-funded grants may be delayed or disrupted by federal government shutdowns such as the shutdown that began October 1, 2025 and ended on November 12, 2025, as it curtailed operations of key agencies such as the FDA and the National Institutes of Health (“NIH”); ● Our patent position is highly uncertain and involves complex legal and factual questions; ● The use of hazardous materials, including radioactive and biological materials, in our research and development efforts imposes certain compliance costs on us and may subject us to liability for claims arising from the use or misuse of these materials; ● Certain provisions of our Certificate of Incorporation and Bylaws and Delaware law make it more difficult for a third party to acquire us and make a takeover more difficult to complete, even if such a transaction were in our stockholders’ interest; and ● Our ability to utilize our net operating loss carryforwards and certain other tax attributes may be limited.
We have incurred net losses every year since our inception and anticipate that we will continue to incur net losses in the future.
As of December 31, 2025 and December 31, 2024, we had an accumulated deficit of $409.7 million and $375.8 million, respectively.
We reported a net loss of $33.9 million and $38.2 million for the years ended December 31, 2025 and 2024, respectively.
We are highly dependent on the clinical, regulatory and commercial success of ATNM-400, Actimab-A, Iomab-ACT, ATNM-400 and other pipeline candidates which we may never achieve None of the drug candidates we are developing, or have developed, have received regulatory approval.
Based on the current status of our pipeline candidates, it will likely take several years and additional clinical studies before we can seek approval for any drug candidate.
ATNM-400 is currently being studied preclinically and has not yet been studied in human subjects.
There can be no assurances that we will advance ATNM-400 into clinical trials and even if we are successful in doing so, our preclinical results to date may not translate in connection with human subjects.
We believe we have aligned with the FDA on a Phase 2/3 trial that is intended to support a BLA filing.
While we believe the initial results from this trial were encouraging, there can be no assurance that future results with Iomab-ACT from the commercial CAR-T trial at UTSW or sickle cell conditioning trial at Columbia will be positive.
As for Iomab-B in particular, as previously disclosed, we completed the Phase 3 SIERRA trial (Study of Iomab-B in Elderly Relapsed or Refractory AML) and presented the trial results in February 2023, which were expected to support a BLA filing.
The SIERRA trial met the primary endpoint of dCR with statistical significance (p-value<0.0001) but did not meet the secondary endpoint in achieving a statistically significant improvement in OS in the intent to treat population.
On August 5, 2024, we announced that the FDA determined that the SIERRA trial alone is not adequate to support a BLA filing and is requiring an additional randomized head-to-head clinical trial to demonstrate an OS benefit in an intent to treat population.
We are highly dependent on our key personnel, and if we are not successful in attracting and retaining highly qualified personnel, we may not be able to successfully implement our business strategy.
In February 2026, Steve O’Loughlin tendered his resignation as the Chief Financial Officer of our Company.
To fill this executive vacancy, our Board appointed Sandesh Seth, the current Chairman and Chief Executive Officer of the Company, to serve as our principal financial officer.
In the second quarter of 2025, we conducted a workforce optimization that reduced our headcount by approximately fourteen percent and announced a strategic pipeline prioritization which led to further departures from the workforce in 2025.
We do not expect these departures to have a material impact on our operations or ability to execute our operating plan and are actively seeking a strategic partner for Actimab-A and Iomab-B in the U.S. to advance the registrational Phase 2/3 trials required by the FDA.
Disruptions at the FDA and other government agencies caused by government shutdowns, leadership changes, changes to regulatory approach, layoffs, funding shortages or global health concerns could negatively impact our business The ability of the FDA to review proposed clinical trials or approve new products can be affected by a variety of factors, including government budget and funding levels, statutory, regulatory, and policy changes, the FDA’s ability to hire and retain key personnel and accept the payment of user fees, and other events that may otherwise affect the FDA’s ability to perform routine functions.
In addition, government funding of other government agencies that fund research and development activities is subject to the political process, including executive and congressional priorities, the impacts of which are inherently fluid and unpredictable.
Disruptions at the FDA and other agencies may slow the time necessary for new product candidates to be reviewed and/or approved, which would adversely affect our business.
In the recent past, the U.S. government shutdown on October 1, 2025 to November 12, 2025, which curtailed operations at key agencies such as the FDA and NIH.
Based on this shutdown, we expect trials under our CRADA with the NCI to be delayed.
There can be no assurances that additional shutdowns will occur in the future or how long such shutdowns may last.
For example, over the last several years, including for 35 days beginning on December 22, 2018, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical FDA employees and stop critical activities.
In addition, the current administration has enacted and continues to propose substantial reductions in force at various government agencies including the FDA, which could significantly reduce the FDA’s capacity to perform its functions in a manner consistent with its past practices and could delay reviews and negatively impact our business.
There has been significant turnover and changes in senior leadership at the FDA and other government agencies including the Center for Biologics Evaluation and Research (“CBER”), which is the division of the FDA that would oversee and review biologics based targeted radiotherapies like those we currently develop and plan to continue to develop.
We believe these changes could result in changes in the FDA’s perception of the approvability of therapies, the perceived value of certain therapies or therapeutic modalities, which could create material challenges for our development efforts.
As of the date of this Report, there is significant uncertainty and risks associated with future FDA regulatory policies and actions that could have a material negative impact on our business.
Any or all of these factors could cause us to amend, suspend or terminate the development of certain of our preclinical or clinical programs, which could have material adverse impacts on our business, our product candidates or our ability to continue operations.
Additionally, a future pandemic may result in delays in receiving approvals from local and foreign regulatory authorities, delays in necessary interactions with IRB, local and foreign regulators, ethics committees and other important agencies and contractors due to limitations in employee resources or forced furlough of government employees.
Risks associated with these threats include, among other things: ● theft or misappropriation of funds; ● loss, corruption, or misappropriation of intellectual property, or other proprietary, confidential or personally identifiable information (including supplier, clinical data or employee data); ● disruption or impairment of our and our business operations and safety procedures; ● damage to our reputation with our potential partners, patients and the market; ● exposure to litigation; and ● increased costs to prevent, respond to or mitigate cybersecurity events.
For instance, as for Iomab-B, despite the Phase SIERRA 3 trial meeting the primary endpoint of durable Complete Remission (dCR) with statistical significance (p-value<0.0001), the FDA has determined that demonstrating an OS benefit in a randomized head-to-head trial is required for a BLA filing.
However, there are no assurances that the additional trials will be completed or successful or that we can satisfy all of the FDA’s requests.
As previously disclosed and noted above, Actinium has licensed to Immedica the exclusive product rights for commercialization of Iomab-B in the Europe, Middle East, and North Africa (EUMENA) region.
We are in the early stages of evaluating other product candidates consisting of conjugates of Ac-225 with human or humanized antibodies for pre-clinical and clinical development in other types of cancer such as ATNM-400.
The FDA may fail to approve any IND, BLA or NDA we submit for new product candidates or for new intended uses or indications for approved products or future product candidates.
Disruptions at the FDA and other agencies may slow the time necessary for new product candidates to be reviewed and/or approved, which would adversely affect our business and may cause us to amend our business strategy or.
From October 1, 2025 until November 12, 2025, the U.S federal government was shutdown, which curtailed operations of key agencies such as the FDA and the NIH.

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Gone since FY2024

These risks and uncertainties include, but are not limited to, the following: ● We are a clinical-stage company and have generated no revenue from commercial sales to date; ● We have incurred net losses in every year since our inception and anticipate that we will continue to incur net losses in the future; ● If we fail to obtain additional financing, we will be unable to continue or complete our product development or product commercialization and you will likely lose your entire investment; ● We are highly dependent on the clinical, regulatory and commercial success of Iomab-B, Actimab-A, Iomab-ACT and other pipeline candidates which we may never achieve; ● We continuously evaluate our business strategy and may modify our strategy as necessary to respond to developments in our business and other factors, and any such modification, if not successful, could have a material adverse effect on our business, financial condition, and results of operations; ● Our business could be adversely affected by the effects of future health epidemics; ● Our business is subject to cybersecurity risk; ● We have not demonstrated that any of our products are safe and effective for any indication and will continue to expend substantial time and resources on clinical development before any of our current or future product candidates will be eligible for FDA approval, if ever; ● Our clinical trials may fail to demonstrate adequately the efficacy and safety of our product candidates, which would prevent or delay regulatory approval and commercialization; ● Preliminary, Interim, and “top-line” data from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.; ● Healthcare legislative reform measures intended to increase pressure to reduce prices of pharmaceutical products paid for by Medicare or, otherwise, affect the federal regulation of the U.S. healthcare system could have a material adverse effect our business, future revenue, if any, and results of operations; ● Changes in the healthcare industry and in healthcare spending could adversely affect our grant funded clinical programs, business, financial condition and results of operations ● We may rely on third parties to conduct certain aspects of our clinical trials.
Any disruption in the operations of our current third-party manufacturers, or other third-party manufacturers we may engage in the future, could adversely affect our business and results of operations; ● Our product candidates may cause undesirable side effects or have other properties that could halt their clinical development, prevent their regulatory approval, limit their commercial potential, or result in significant negative consequences; ● Our patent position is highly uncertain and involves complex legal and factual questions. ● The use of hazardous materials, including radioactive and biological materials, in our research and development efforts imposes certain compliance costs on us and may subject us to liability for claims arising from the use or misuse of these materials; ● We are highly dependent on our key personnel, and the demand for talent in the biotechnology industry is highly competitive; if we are not successful in attracting and retaining highly qualified personnel, we may not be able to successfully implement or execute our business strategy; ● Certain provisions of our Certificate of Incorporation and Bylaws and Delaware law make it more difficult for a third party to acquire us and make a takeover more difficult to complete, even if such a transaction were in our stockholders’ interest; and ● Our ability to utilize our net operating loss carryforwards and certain other tax attributes may be limited.
We have incurred net losses in every year since our inception and anticipate that we will continue to incur net losses in the future.
As of December 31, 2024 and December 31, 2023, we had an accumulated deficit of $375.8 million and $337.6 million, respectively.
We reported a net loss of $38.2 million and $48.8 million for the years ended December 31, 2024 and 2023, respectively.
We are highly dependent on the clinical, regulatory and commercial success of Actimab-A, Iomab-ACT and other pipeline candidates which we may never achieve None of the drug candidates we are developing, or have developed, have received regulatory approval.
Based on the current status of our pipeline candidates, it will likely take several years or additional clinical studies before we can seek approval for any drug candidate.
We have aligned with the FDA on an operationally seamless Phase 2/3 trial that is intended to support a BLA filing.
While the initial results from this trial were encouraging, there can be no assurance that future results with Iomab-ACT from the commercial CAR-T trial at UTSW or sickle cell conditioning trial at Columbia will be positive.
As for Iomab-B in particular, as previously disclosed, we completed the pivotal Phase 3 SIERRA trial (Study of Iomab-B in Elderly Relapsed or Refractory AML) and presented the trial results in February 2023, which were expected to support a BLA filing.
The SIERRA trial met the primary endpoint of dCR with statistical significance (p-value<0.0001) but did not meet the secondary endpoint in achieving a statistically significant improvement in overall survival in the intent to treat population.
On August 5, 2024, we announced that the FDA determined that the SIERRA trial alone is not adequate to support a BLA filing and is requiring an additional randomized head-to-head clinical trial to demonstrate an overall survival benefit in an intent to treat population.
Additionally, a future pandemic may result in delays in receiving approvals from local and foreign regulatory authorities, delays in necessary interactions with IRB’s or Institutional Review Boards, local and foreign regulators, ethics committees and other important agencies and contractors due to limitations in employee resources or forced furlough of government employees.
Risks associated with these threats include, among other things: ● theft or misappropriation of funds; ● loss, corruption, or misappropriation of intellectual property, or other proprietary, confidential or personally identifiable information (including supplier, clinical data or employee data); ● disruption or impairment of our and our business operations and safety procedures; ● damage to our reputation with our potential partners, patients and the market; ● exposure to litigation; ● increased costs to prevent, respond to or mitigate cybersecurity events.
For instance, as for Iomab-B, despite the Phase SIERRA 3 trial meeting the primary endpoint of durable Complete Remission (dCR) with statistical significance (p-value<0.0001), the FDA has determined that demonstrating an overall survival benefit in a randomized head-to-head trial is required for a BLA filing.
However, there are no assurances that the additional trials will be successful or that we can satisfy all of the FDA’s requests.
We are in the early stages of evaluating other product candidates consisting of conjugates of Ac-225 with human or humanized antibodies for pre-clinical and clinical development in other types of cancer.
The FDA may fail to approve any BLA we submit for new product candidates or for new intended uses or indications for approved products or future product candidates.
We have not demonstrated that any of our products are safe and effective for any indication and will continue to expend substantial time and resources on clinical development before any of our current or future product candidates will be eligible for FDA approval, if ever.
In the United States, the FDA regulates pharmaceutical and biological product candidates under the FDCA and the Public Health Service Act (“PHSA”), as well as their respective implementing regulations.
The process required by the FDA before a drug or biological product may be marketed in the United States generally involves the following: ● completion of preclinical laboratory tests and animal studies in accordance with FDA’s good laboratory practices (“GLPs”) and applicable requirements for the humane use of laboratory animals or other applicable regulations; ● submission to the FDA of an Investigational New Drug (“IND”), which must become effective before human clinical trials in the United States may begin; ● performance of adequate and well-controlled human clinical trials in accordance with FDA’s IND regulations, good clinical practices (“GCPs”), and any additional requirements for the protection of human research subjects and their health information, to establish the safety and efficacy of the proposed biological product for its intended use; ● submission to the FDA of a BLA for marketing approval that meets applicable requirements to ensure the continued safety, purity, and potency of the product that is the subject of the BLA based on results of preclinical testing and clinical trials; ● satisfactory completion of an FDA inspection of the manufacturing facility or facilities where the biological product is produced, to assess compliance with current good manufacturing practices (“cGMPs”) and assure that the facilities, methods and controls are adequate to preserve the biological product’s identity, strength, quality and purity; ● potential FDA audit of the nonclinical study and clinical trial sites that generated the data in support of the BLA; and ● FDA review and approval, or denial, of the BLA.
The clinical trial sponsor must submit the results of the preclinical tests, together with manufacturing information, analytical data, any available clinical data or literature and a proposed clinical protocol, to the FDA as part of the IND.
Some preclinical testing may continue even after the IND is submitted.
The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA raises concerns or questions regarding the proposed clinical trials and places the trial on a clinical hold within that 30-day time period.
Accordingly, we cannot be sure that submission of an IND will result in the FDA allowing clinical trials to begin or that, for those that have already commenced under an active IND, that issues will not arise that suspend or terminate such trials.
Each protocol and any amendments to the protocol must be submitted to the FDA as part of the IND.
Further, each clinical trial must be reviewed and approved by an independent institutional review board, or IRB, at or servicing each institution at which the clinical trial will be conducted.
The clinical trial process is also lengthy and requires substantial time and effort.
Any of the following could delay or disrupt the clinical development of our product candidates and potentially cause our product candidates to fail to receive regulatory approval: ● conditions imposed on us by the FDA or comparable foreign authorities regarding the scope or design of our clinical trials; ● delays in receiving, or the inability to obtain, required approvals from IRBs or other reviewing entities at clinical sites selected for participation in our clinical trials; ● delays in enrolling patients into clinical trials; ● a lower than anticipated retention rate of patients in clinical trials; ● the need to repeat or discontinue clinical trials as a result of inconclusive or negative results or unforeseen complications in testing or because the results of later trials may not confirm positive results from earlier preclinical studies or clinical trials; ● inadequate supply, delays in distribution, deficient quality of, or inability to purchase or manufacture drug product, comparator drugs or other materials necessary to conduct our clinical trials; ● unfavorable FDA or other foreign regulatory inspection and review of a clinical trial site or records of any clinical or preclinical investigation; ● serious and unexpected drug-related side effects experienced by participants in our clinical trials, which may occur even if they were not observed in earlier trials or only observed in a limited number of participants; ● a finding that the trial participants are being exposed to unacceptable health risks; ● the placement by the FDA or a foreign regulatory authority of a clinical hold on a trial; or ● delays in obtaining regulatory agency authorization for the conduct of our clinical trials.
Initiating and completing clinical trials necessary to support FDA approval of a BLA for Iomab-B, Actimab-A, and other product candidates, is a time-consuming and expensive process, and the outcome is inherently uncertain.
Preliminary, Interim, and “top-line” data from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.
Our clinical trials may fail to demonstrate adequately the efficacy and safety of our product candidates, which would prevent or delay regulatory approval and commercialization.
Even if our clinical trials are completed as planned, we cannot be certain that their results will support our product candidate claims or that the FDA or foreign authorities will agree with our conclusions regarding them.
If FDA concludes that the clinical trials for Actimab-A, Iomab-ACT, or any other product candidate for which we might seek approval, have failed to demonstrate safety and effectiveness, we would not receive FDA approval to market that product candidate in the United States for the indications sought.
The intellectual property related to antibodies we have licensed has expired or likely expired.
We own 4 issued U.S. patents, 2 issued Canadian patents, 1 issued European patent (validated as a national patent in several countries) and 1 issued Japanese patent that relate to the composition of our Iomab-B product candidate.
Further, if approved, Iomab-B would be entitled to 12 years of market exclusivity in the U.S. and 10 years in Europe, during which time no generic biologic or biosimilar referencing Iomab-B can be granted marketing approval.
Negative results from any of these trials could negatively impact our ability to enroll or complete our other trials studying lintzumab-Ac-225, including future studies conducted under our CRADA with the NCI.
Actinium-225 is a key component of our Actimab-A product candidate, technology platform, preclinical R&D programs and other drug candidates that we might consider for development with the Ac-225 payload.
The Ac-225 currently supplied for our clinical trials from the DOE is derived from the natural decay of thorium-229 from so-called ‘thorium-cows’ and is able to produce sufficient quantities that are several multiples of the amount of Ac-225 we require to supply our clinical programs through to early commercialization phase.

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Sentence-level comparison of Item 1A in the two most recent 10-Ks (FY2024 ↗, FY2025 ↗). A reworded sentence counts as one dropped and one added, so heavy edits read as low “kept”. Headings and page furniture are stripped; nothing is summarised by a model.

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