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Actinium Pharmaceuticals, Inc.

For the period ended Sep 30, 2025. Filed Nov 14, 2025.

View on SEC.gov

About this filing

A company's report for each of its first three quarters. The financial statements are not audited. It shows how the business has moved since the last annual report, and what management says changed.

Sep 30, 2025 · Filed Nov 14, 2025

ATNM$1.43+10.0%Stored close · as of Nov 6, 2026

What changed in Risk Factors?

Read the current filing

The baseline is this issuer’s latest earlier reporting period of the same form that was filed before the current report. A previous 10-Q is a different quarter, not a year-over-year comparison. Amendments are excluded.

Compared 221 previous paragraphs and 223 current paragraphs.

198 unchanged; 23 reworded; 2 added; 0 removed; 0 previous and 0 current paragraphs rearranged.

Tables are not compared: 50 previous and 53 current tables excluded. Dates, whitespace, punctuation and numbering changes are ignored; changes to financial figures remain significant.

A changed paragraph is not evidence that risk increased or decreased. An unchanged paragraph does not establish that risk stayed the same.

Added paragraphs (2)

Current report

More recently, the current Trump Administration is pursuing policies intended to, among other things, reduce regulations and expenditures across government (including at the HHS, FDA, NIH, CMS, and other related agencies), lower prescription drug prices, and enhance drug price transparency. These actions, such as those directed by executive orders, may propose policy changes that create additional uncertainty for our business. For example, on April 15, 2025, the Trump Administration released an executive order entitled, “Lower Drug Prices by Once Again Putting Americans First,” which among other things, included multiple directives to various agencies aimed at lowering prescription drug prices. Additionally, on September 30, 2025, the Trump Administration announced the first agreement with a major pharmaceutical company that requires the drug manufacturer to offer, through a direct-to-consumer platform, U.S. patients and Medicaid programs prescription drug Most-Favored Nation (“MFN”) pricing equal to or lower than those paid in other developed nations, with additional mandates for direct-to-patient discounts and repatriation of foreign revenues. Other recent actions and proposals include, for example, (1) reducing federal agencies workforces; (2) directing program cuts; (3) rescinding a Biden administration executive order tasking the Center for Medicare and Medicaid Innovation to consider new payment and healthcare models to limit drug spending and eliminating the Biden administration’s executive order that directed HHS to establishing an AI task force and developing a strategic plan; (4) directing HHS and other agencies to lower prescription drug costs for Medicare through a variety of initiatives, including by improving upon the Medicare Drug Price Negotiation Program and establishing MFN pricing for pharmaceutical products; (5) directing certain federal agencies to enforce existing law regarding hospital and price plan price transparency and by standardizing prices across hospitals and health plans; and (6) as part of the Make America Healthy Again (MAHA) Commission’s recent Strategy Report, working across government agencies to increase enforcement on direct-to-consumer pharmaceutical advertising. These actions and policies may significantly reduce drug prices, potentially impacting manufacturers’ drug pricing strategies and profitability, while increasing operational costs and compliance risks.

Current report

The ability of the FDA or comparable foreign regulatory authorities to review and approve new products can be affected by a variety of factors, including government shutdowns, which recently occurred from October 1, 2025 until November 12, 2025, budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes that may otherwise affect the FDA’s or comparable foreign regulatory authorities’ ability to perform routine functions. In addition, government funding of the SEC and other government agencies or comparable foreign regulatory authorities on which our operations may rely, including those that fund research and development activities, is subject to the political process, which is inherently fluid and unpredictable. Further, continuation of the current government shutdown or future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue to fund our operations.
Reworded paragraphs (23)

Previous wording

We are not profitable and have incurred losses in each period since our inception. As of June 30, 2025 and December 31, 2024, we had an accumulated deficit of $398.6 million and $375.8 million, respectively. We reported a net loss of $22.8 million and $20.0 million for the six months ended June 30, 2025 and 2024, respectively. We expect to continue to operate at a net loss as we continue our research and development efforts, continue to conduct clinical trials and develop manufacturing, sales, marketing and distribution capabilities. There can be no assurance that the products under development by us will be approved for sale in the United States or elsewhere. Furthermore, there can be no assurance that if such products are approved, they will be successfully commercialized, which would have an adverse effect on our business prospects, financial condition and results of operation.

Current wording

We are not profitable and have incurred losses in each period since our inception. As of September 30, 2025 and December 31, 2024, we had an accumulated deficit of $403.8 million and $375.8 million, respectively. We reported a net loss of $27.9 million and $31.6 million for the nine months ended September 30, 2025 and 2024, respectively. We expect to continue to operate at a net loss as we continue our research and development efforts, continue to conduct clinical trials and develop manufacturing, sales, marketing and distribution capabilities. There can be no assurance that the products under development by us will be approved for sale in the United States or elsewhere. Furthermore, there can be no assurance that if such products are approved, they will be successfully commercialized, which would have an adverse effect on our business prospects, financial condition and results of operation.

Previous wording

We are highly dependent on the clinical, regulatory and commercial success of Actimab-A, Iomab-ACT, ATNM-400 and other pipeline candidates which we may never achieve

Current wording

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

Previous wording

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.

Current wording

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.

Previous wording

Our Actimab-A drug candidate was studied in a Phase 2 clinical trial as a monotherapy and we are now studying it in combination with other therapies. We believe we have aligned with the FDA on a Phase 2/3 trial that is intended to support a BLA filing. There can be no assurance that the Phase 2 portion of the trial will be successful and support advancing to the Phase 3 portion of the trial. In addition, our Iomab-ACT drug candidate has only been studied in a limited number of human subjects in a Phase 1 trial with a novel CAR-T therapy. 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.

Current wording

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 successful in doing so, our preclinical results to date may not translate in human subjects. Our Actimab-A drug candidate was studied in a Phase 2 clinical trial as a monotherapy, and we are now studying it in combination with other therapies. We believe we have aligned with the FDA on a Phase 2/3 trial that is intended to support a BLA filing. There can be no assurance that the Phase 2 portion of the trial will be successful and support advancing to the Phase 3 portion of the trial. In addition, our Iomab-ACT drug candidate has only been studied in a limited number of human subjects in a Phase 1 trial with a novel CAR-T therapy. 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.

Previous wording

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. Further, the FDA is also requiring an additional dose optimization trial to calculate the dose of Iomab-B based on absorbed dose by the bone marrow, rather than the maximum tolerable dose of 24 Gy of radiation to the liver as was done in the SIERRA trial based on several interactions with the FDA prior to the start of the SIERRA trial. Based on this revised approach now required by the FDA, the safety and efficacy data generated from all Iomab-B studies, including the SIERRA trial, are inadequate to seek regulatory approval for Iomab-B, as dosing based on maximum tolerable dose of 24 Gy to the liver will lead to variable doses to the bone marrow (the target organ), result in underdosing or overdosing of patients and translate to a global patient safety risk. We are seeking a strategic partner for the U.S. in order to conduct the additional studies required by the FDA; however, we may not be successful in our efforts to find such a partner, or the trials and studies may not be successful. Further, there are no assurances that we can satisfy all of the FDA’s requests, and there could be additional regulatory hurdles that may result in either non-acceptance or non-approval of a future BLA filing. The U.S. commercial opportunity for Iomab-B may thus never be realized.

Current wording

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 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. Further, the FDA is also requiring an additional dose optimization trial to calculate the dose of Iomab-B based on absorbed dose by the bone marrow, rather than the maximum tolerable dose of 24 Gy of radiation to the liver as was done in the SIERRA trial based on several interactions with the FDA prior to the start of the SIERRA trial. Based on this revised approach now required by the FDA, the safety and efficacy data generated from all Iomab-B studies, including the SIERRA trial, are inadequate to seek regulatory approval for Iomab-B, as dosing based on maximum tolerable dose of 24 Gy to the liver will lead to variable doses to the bone marrow (the target organ), result in underdosing or overdosing of patients and translate to a global patient safety risk. We are seeking a strategic partner for the U.S. in order to conduct the additional studies required by the FDA; however, we may not be successful in our efforts to find such a partner, or the trials and studies may not be successful. Further, there are no assurances that we can satisfy all of the FDA’s requests, and there could be additional regulatory hurdles that may result in either non-acceptance or non-approval of a future BLA filing. The U.S. commercial opportunity for Iomab-B may thus never be realized.

Previous wording

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

Current wording

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

Previous wording

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. 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 proposed 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 recent 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. At this time, 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.

Current wording

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. Recently, the U.S. government shutdown from 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 if additional shutdowns will occur in the future. 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 recent 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. At this time, 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.

Previous wording

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. In addition, the FDA is also requiring that an additional dose optimization trial demonstrating safety and efficacy be completed to calculate the dose of Iomab-B based on absorbed dose by the bone marrow, rather than the maximum tolerable dose of 24 Gy of radiation to the liver as was done in the SIERRA trial based on several interactions we had with the FDA before starting the SIERRA trial. The head-to-head Phase 3 trial will evaluate allogeneic bone marrow transplant (BMT) using Iomab-B plus a reduced intensity conditioning regimen of fludarabine and total body irradiation (Flu/TBI) versus allogeneic BMT using reduced intensity conditioning comprised of cyclophosphamide plus Flu/TBI. This is different from the SIERRA trial, which allowed physician’s choice of salvage therapies and heterogenous conditioning regimens in the control arm. 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. There could also be additional regulatory hurdles that may result in either non-acceptance or non-approval of a future BLA filing.

Current wording

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. In addition, the FDA is also requiring that an additional dose optimization trial demonstrating safety and efficacy be completed to calculate the dose of Iomab-B based on absorbed dose by the bone marrow, rather than the maximum tolerable dose of 24 Gy of radiation to the liver as was done in the SIERRA trial based on several interactions we had with the FDA before starting the SIERRA trial. The head-to-head Phase 3 trial will evaluate allogeneic bone marrow transplant (BMT) using Iomab-B plus a reduced intensity conditioning regimen of fludarabine and total body irradiation (Flu/TBI) versus allogeneic BMT using reduced intensity conditioning comprised of cyclophosphamide plus Flu/TBI. This is different from the SIERRA trial, which allowed physician’s choice of salvage therapies and heterogenous conditioning regimens in the control arm. 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. There could also be additional regulatory hurdles that may result in either non-acceptance or non-approval of a future BLA filing.

Previous wording

Our Actimab-A (lintuzumab-Ac-225) product candidate has also been studied in several Phase 1 and 2 trials under our sponsorship and investigator-initiated trials in patients with r/r AML and we plan to continue to study Actimab-A in clinical trials. Actimab-A is also being developed under a cooperative research and development agreement (CRADA) with the National Cancer Institute (NCI) and we expect clinical trials to be initiated that will study Actimab-A as a single agent or in combination with other therapies. Product candidates utilizing the lintuzumab antibody would require BLA approval before they can be marketed in the United States. 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 not approve these products for the indications that are necessary or desirable for successful commercialization. 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. Failure to obtain FDA approval for our products in the proposed indications would have a material adverse effect on our business prospects, financial condition and results of operations.

Current wording

Our Actimab-A (lintuzumab-Ac-225) product candidate has also been studied in several Phase 1 and 2 trials under our sponsorship and investigator-initiated trials in patients with r/r AML and we plan to continue to study Actimab-A in clinical trials. Actimab-A is also being developed under a cooperative research and development agreement (CRADA) with the National Cancer Institute (NCI) and we expect clinical trials to be initiated that will study Actimab-A as a single agent or in combination with other therapies. Product candidates utilizing the lintuzumab antibody would require BLA approval before they can be marketed in the United States. 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 not approve these products for the indications that are necessary or desirable for successful commercialization. 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. Failure to obtain FDA approval for our products in the proposed indications would have a material adverse effect on our business prospects, financial condition and results of operations.

Previous wording

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. 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 proposed 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. At this time, 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.

Current wording

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. Our ability to advance clinical development, obtain regulatory interactions/approvals, or secure government-funded grants may be delayed or disrupted by this recent federal government shutdown. For example, the NCI with whom we have a CRADA with for the development of Actimab-A was not operating during the shutdown. As a result, trials active and planned under our CRADA are expected to be delayed. 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. At this time, 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.

Previous wording

Initiating and completing clinical trials necessary to support FDA approval of a BLA for Iomab-B, Actimab-A, Iomab-ACT, ATNM-400 and other product candidates, is a time-consuming and expensive process, and the outcome is inherently uncertain. Moreover, the results of early clinical trials are not necessarily predictive of future results, and any product candidate we advance into clinical trials may not have favorable results in later clinical trials.

Current wording

Initiating and completing clinical trials necessary to support FDA approval of a BLA for ATNM-400, Actimab-A, Iomab-ACT, Iomab-B, and other product candidates, is a time-consuming and expensive process, and the outcome is inherently uncertain. Moreover, the results of early clinical trials are not necessarily predictive of future results, and any product candidate we advance into clinical trials may not have favorable results in later clinical trials.

Previous wording

Even if our preclinical studies are favorable and 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. Success in pre-clinical studies and early clinical trials does not ensure that later clinical trials will be successful, and we cannot be sure that the later trials will replicate the results of prior trials and pre-clinical studies. The clinical trial process may fail to demonstrate that our product candidates are safe and effective for the proposed indicated uses. If the FDA concludes that any current or future clinical trials for Actimab-A, Iomab-ACT, Iomab-B, ATNM-400 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. In addition, such an outcome could cause us to abandon the product candidate and might delay the development of others. Any delay or termination of our clinical trials will delay or preclude the filing of any submissions with the FDA and, ultimately, our ability to commercialize our product candidates and generate revenues. It is also possible that patients enrolled in clinical trials will experience adverse side effects that are not currently part of a product candidate’s profile.

Current wording

Even if our preclinical studies are favorable and 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. Success in pre-clinical studies and early clinical trials does not ensure that later clinical trials will be successful, and we cannot be sure that the later trials will replicate the results of prior trials and pre-clinical studies. The clinical trial process may fail to demonstrate that our product candidates are safe and effective for the proposed indicated uses. If the FDA concludes that any current or future clinical trials for ATNM-400, Actimab-A, Iomab-ACT, Iomab-B 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. In addition, such an outcome could cause us to abandon the product candidate and might delay the development of others. Any delay or termination of our clinical trials will delay or preclude the filing of any submissions with the FDA and, ultimately, our ability to commercialize our product candidates and generate revenues. It is also possible that patients enrolled in clinical trials will experience adverse side effects that are not currently part of a product candidate’s profile.

Previous wording

The intellectual property related to antibodies we have licensed has expired or likely expired.

Current wording

The intellectual property related to certain antibodies we have licensed has expired or likely expired.

Previous wording

The key patents related to the humanized antibody lintuzumab, which we use in our Actimab-A product candidate, have expired. It is generally possible that others may be eventually able to use an antibody with the same sequence, and we will then need to rely on additional patent protection covering alpha particle drug products comprising Ac-225. Our final drug construct, Actimab-A, consists of the lintuzumab antibody labeled with the isotope Ac-225. We currently own issued and pending patents relating to methods of manufacturing Actimab-A, methods of treatment using Actimab-A and production of the Ac-225 isotope. In addition, we possess trade secrets and know how related to the manufacturing and use of isotopes. Any competing product based on the lintuzumab antibody is likely to require several years of development before achieving our product candidate’s current status and may be subject to significant regulatory hurdles, but such development by others is nevertheless a possibility that could negatively impact our business in the future. We own 4 issued U.S. patents, 2 issued Canadian patents, 2 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. Patent applications relating to Iomab-B are also pending in the U.S. and internationally. We have and may continue to file patents related to Iomab-B that can provide barriers to entry but there is no certainty that these patents will be granted or such granting thereof will adequately prevent others from seeking to replicate and use the apamistamab antibody or the construct. Our patent portfolio includes pending applications related to radioimmunoconjugate composition, formulation administration, and methods of use in treating solid or liquid cancers. This subject matter includes composition, administration, and methods of treatment for our product candidates Actimab-A and Iomab-B. Any competing product based on the antibody used in Iomab-B is likely to require several years of development before achieving our product candidate’s current status and may be subject to significant regulatory hurdles. 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 product referencing Iomab-B can be granted marketing approval.

Current wording

The key patents related to the humanized antibody lintuzumab, which we use in our Actimab-A product candidate, have expired. It is generally possible that others may be eventually able to use an antibody with the same sequence, and we will then need to rely on additional patent protection covering alpha particle drug products comprising Ac-225. Our final drug construct, Actimab-A, consists of the lintuzumab antibody labeled with the isotope Ac-225. We currently own issued and pending patents relating to methods of manufacturing Actimab-A, methods of treatment using Actimab-A and production of the Ac-225 isotope. In addition, we possess trade secrets and know how related to the manufacturing and use of isotopes. Any competing product based on the lintuzumab antibody is likely to require several years of development before achieving our product candidate’s current status and may be subject to significant regulatory hurdles, but such development by others is nevertheless a possibility that could negatively impact our business in the future. We own 4 issued U.S. patents, 2 issued Canadian patents, 2 issued European patent (each validated as a national patent in several countries) and 1 issued Japanese patent that relate to the composition of our Iomab-B product candidate. Patent applications relating to Iomab-B are also pending in the U.S. and internationally. We have and may continue to file patents related to Iomab-B that can provide barriers to entry but there is no certainty that these patents will be granted or such granting thereof will adequately prevent others from seeking to replicate and use the apamistamab antibody or the construct. Our patent portfolio includes pending applications related to radioimmunoconjugate composition, formulation administration, and methods of use in treating solid or liquid cancers. This subject matter includes composition, administration, and methods of treatment for our product candidates Actimab-A and Iomab-B. Any competing product based on the antibody used in Iomab-B is likely to require several years of development before achieving our product candidate’s current status and may be subject to significant regulatory hurdles. 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 product referencing Iomab-B can be granted marketing approval.

Previous wording

**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 on our business, future revenue, if any, and results of operations. **

Current wording

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.

Previous wording

There have been significant judicial, administrative, executive, and legislative initiatives to modify, limit, replace, or repeal the Affordable Care Act since its enactment. For example, during his first term, former President Trump issued several Executive Orders and other directives designed to delay the implementation of certain provisions of the Affordable Care Act or otherwise circumvent some of the requirements for health insurance mandated by the Affordable Care Act. Concurrently, Congress considered legislation that would repeal or replace all or part of the Affordable Care Act. While Congress has not passed comprehensive repeal legislation, several bills affecting the implementation the Affordable Care Act have been passed. For example, the Tax Cuts and Jobs Act of 2017 eliminated the Affordable Care Act provision requiring individuals to purchase and maintain health coverage, or the “individual mandate,” by reducing the associated penalty to zero, beginning in 2019. In December 2018, a district court in Texas held that the individual mandate is unconstitutional and that the rest of the Affordable Care Act is, therefore, invalid. On appeal, the Fifth Circuit Court of Appeals affirmed the holding on the individual mandate but remanded the case back to the lower court to reassess whether and how such holding affects the validity of the rest of the Affordable Care Act. The Fifth Circuit’s decision on the individual mandate was appealed to the U.S. Supreme Court. On June 17, 2021, the Supreme Court held that the plaintiffs (comprised of the state of Texas, as well as numerous other states and certain individuals) did not have standing to challenge the constitutionality of the Affordable Care Act’s individual mandate and, accordingly, vacated the Fifth Circuit’s decision and instructed the district court to dismiss the case. As a result, the Affordable Care Act remained in effect in its then-current form; however, we cannot predict what additional challenges may arise in the future, the outcome thereof, or the impact any such actions may have on our business. This uncertainty has become even greater given the new Trump administration and its proposed agenda.

Current wording

There have been significant judicial, administrative, executive, and legislative initiatives to modify, limit, replace, or repeal the Affordable Care Act since its enactment. For example, during his first term, former President Trump issued several Executive Orders and other directives designed to delay the implementation of certain provisions of the Affordable Care Act or otherwise circumvent some of the requirements for health insurance mandated by the Affordable Care Act. Concurrently, Congress considered legislation that would repeal or replace all or part of the Affordable Care Act. While Congress has not passed comprehensive repeal legislation, several bills affecting the implementation of the Affordable Care Act have been passed. For example, the Tax Cuts and Jobs Act of 2017 eliminated the Affordable Care Act provision requiring individuals to purchase and maintain health coverage, or the “individual mandate,” by reducing the associated penalty to zero, beginning in 2019. In December 2018, a district court in Texas held that the individual mandate is unconstitutional and that the rest of the Affordable Care Act is, therefore, invalid. On appeal, the Fifth Circuit Court of Appeals affirmed the holding on the individual mandate but remanded the case back to the lower court to reassess whether and how such holding affects the validity of the rest of the Affordable Care Act. The Fifth Circuit’s decision on the individual mandate was appealed to the U.S. Supreme Court. On June 17, 2021, the Supreme Court held that the plaintiffs (comprised of the state of Texas, as well as numerous other states and certain individuals) did not have standing to challenge the constitutionality of the Affordable Care Act’s individual mandate and, accordingly, vacated the Fifth Circuit’s decision and instructed the district court to dismiss the case. As a result, the Affordable Care Act remained in effect in its then-current form; however, we cannot predict what additional challenges may arise in the future, the outcome thereof, or the impact any such actions may have on our business. This uncertainty has become even greater given the new Trump administration and its proposed agenda.

Previous wording

The Biden administration also introduced various measures in 2021 focusing on healthcare and drug pricing, in particular. For example, on January 28, 2021, former President Biden issued an executive order that initiated a special enrollment period for purposes of obtaining health insurance coverage through the Affordable Care Act marketplace, which began on February 15, 2021, and remained open through August 15, 2021. 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. On the legislative front, the American Rescue Plan Act of 2021 was signed into law on March 11, 2021, which, in relevant part, eliminates the statutory Medicaid drug rebate cap, currently set at 100% of a drug’s average manufacturer price, for single source drugs and innovator multiple source drugs, which began on January 1, 2024. And, in July 2021, the Biden administration released an executive order entitled, “Promoting Competition in the American Economy,” with multiple provisions aimed at prescription drugs. In response, on September 9, 2021, HHS released a “Comprehensive Plan for Addressing High Drug Prices” that outlines principles for drug pricing reform and sets out a variety of potential legislative policies that Congress could pursue as well as potential administrative actions HHS can take to advance these principles.

Current wording

The Biden administration also introduced various measures in 2021 focusing on healthcare and drug pricing, in particular. For example, on January 28, 2021, former President Biden issued an executive order that initiated a special enrollment period for purposes of obtaining health insurance coverage through the Affordable Care Act marketplace, which began on February 15, 2021, and remained open through August 15, 2021. 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. On the legislative front, the American Rescue Plan Act of 2021 was signed into law on March 11, 2021, which, in relevant part, eliminates the statutory Medicaid drug rebate cap, currently set at 100% of a drug’s average manufacturer price, for single source drugs and innovator multiple source drugs, which began on January 1, 2024. And, in July 2021, the Biden administration released an executive order entitled, “Promoting Competition in the American Economy,” with multiple provisions aimed at prescription drugs. In response, on September 9, 2021, the Department of Health and Human Services (“HHS”) released a “Comprehensive Plan for Addressing High Drug Prices” that outlines principles for drug pricing reform and sets out a variety of potential legislative policies that Congress could pursue as well as potential administrative actions HHS can take to advance these principles.

Previous wording

More recently, on August 16, 2022, former President Biden signed into law the Inflation Reduction Act of 2022 (the “IRA”), which, among other provisions, included several measures intended to lower the cost of prescription drugs and related healthcare reforms. Specifically, the IRA authorizes and directs the Department of Health and Human Services (the “DHHS”) to set drug price caps for certain high-cost Medicare Part B and Part D qualified drugs, with the initial list of drugs announced on August 29, 2023, and the first year of maximum price applicability to begin in 2026. The IRA further authorizes the DHHS to penalize pharmaceutical manufacturers that increase the price of certain Medicare Part B and Part D drugs faster than the rate of inflation. Finally, the IRA creates significant changes to the Medicare Part D benefit design by capping Part D beneficiaries’ annual out-of-pocket spending at $2,000 beginning in 2025.

Current wording

On August 16, 2022, former President Biden signed into law the Inflation Reduction Act of 2022 (the “IRA”), which, among other provisions, included several measures intended to lower the cost of prescription drugs and related healthcare reforms. Specifically, the IRA authorizes and directs the HHS to set drug price caps for certain high-cost Medicare Part B and Part D qualified drugs, with the initial list of drugs announced on August 29, 2023, and the first year of maximum price applicability to begin in 2026. The IRA further authorizes the HHS to penalize pharmaceutical manufacturers that increase the price of certain Medicare Part B and Part D drugs faster than the rate of inflation. The IRA creates significant changes to the Medicare Part D benefit design by capping Part D beneficiaries’ annual out-of-pocket spending at $2,000 beginning in 2025. Further, on July 4, 2025, President Trump signed the One Big Beautiful Bill Act into law which, among other things, is expected to reduce funding to federal healthcare programs, imposes additional requirements to be eligible for healthcare, and clarifies exclusions for orphan drugs under IRA’s Drug Price Negotiation Program

Previous wording

On April 15, 2025, the Trump Administration released an executive order entitled, “Lower Drug Prices by Once Again Putting Americans First,” which among other things, included multiple directives to various agencies aimed at lowering prescription drug prices. These directives included reports and proposals for new regulations related to reforming the IRA’s Medicare Drug Price Negotiation Program, reducing the prices of high-cost drugs, and enhancing price transparency. On May 12, 2025, President Trump issued an executive order implementing the concept of most-favored nation pricing. Under this order, DHHS, in coordination with other federal agencies, is directed to take actions to ensure that the price of prescription drugs paid by federal health insurers, including Medicare and Medicaid, is in line with the prices paid in comparable nations. Any reduction in reimbursement from Medicare, Medicaid, or other government programs may result in a similar reduction in payments from private payors. Further, on July 4, 2025, President Trump signed the One Big Beautiful Bill Act into law which, among other things, is expected to reduce funding to federal healthcare programs, imposes additional requirements to be eligible for healthcare, and clarifies exclusions for orphan drugs under IRA’s Drug Price Negotiation Program. Current and future legislative and regulatory changes to further reform healthcare or reduce healthcare costs may limit coverage of or lower reimbursement for healthcare products and treatments that could significantly impact pharmaceutical companies and the success of our product candidates. At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.

Current wording

Current and future legislative and regulatory changes aimed to further reform healthcare or reduce healthcare costs may limit coverage of or lower reimbursement for healthcare products and treatments. Any reduction in coverage or reimbursement from Medicare, Medicaid, or other government programs may result in similar actions taken by private payors such as reductions in payments. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability, or commercialize our product candidates.

Previous wording

Our business and research efforts rely, in part, on funding and support from U.S. government agencies such as the National Institutes of Health (“NIH”), National Cancer Institute (“NCI”) and the Department of Health and Human Services (“HHS”). Government funding for these programs is subject to annual budgetary decisions, which can be unpredictable and influenced by shifting political and economic priorities. Reductions in government support for cancer research or other healthcare initiatives could limit grants, contracts, or other financial resources that we or our research collaborators depend on, potentially delaying our clinical programs and increasing our reliance on alternative funding sources. For instance, we have a CRADA with the NCI for the development of Actimab-A. While we have been informed that the funding for our CRADA is not expected to be impacted, there can be no assurances that this will remain the case and any reduction or elimination of funding can have a material adverse impact on our business.

Current wording

Our business and research efforts rely, in part, on funding and support from U.S. government agencies such as the NIH, NCI and HHS. Government funding for these programs is subject to annual budgetary decisions, which can be unpredictable and influenced by shifting political and economic priorities. Reductions in government support for cancer research or other healthcare initiatives could limit grants, contracts, or other financial resources that we or our research collaborators depend on, potentially delaying our clinical programs and increasing our reliance on alternative funding sources. 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. The NCI, with whom we have a CRADA with for the development of Actimab-A, was not operating during the shutdown. As a result, our ability to advance clinical development, obtain regulatory interactions/approvals, or secure government-funded grants may be delayed or disrupted by the federal government shutdown. For example, active and planned trials under our CRADA are expected to be delayed.

Previous wording

Disruptions at the FDA, the SEC and other government agencies or comparable regulatory authorities caused by funding shortages or global health concerns, in addition to substantial uncertainty regarding the new Administration’s initiatives and how these might impact the FDA, its implementation of laws, regulations, policies and guidance, and its personnel, could hinder government agencies’ ability to hire and retain key leadership and other personnel, or otherwise prevent new products and services from being developed or commercialized in a timely manner, or otherwise prevent those agencies from performing normal business functions on which our business operations rely, including timely reviews, which could negatively impact our business.

Current wording

Disruptions at the FDA, the SEC and other government agencies or comparable regulatory authorities caused by government shutdowns, funding shortages or global health concerns, in addition to substantial uncertainty regarding the new Administration’s initiatives and how these might impact the FDA, its implementation of laws, regulations, policies and guidance, and its personnel, could hinder government agencies’ ability to hire and retain key leadership and other personnel, or otherwise prevent new products and services from being developed or commercialized in a timely manner, or otherwise prevent those agencies from performing normal business functions on which our business operations rely, including timely reviews, which could negatively impact our business.

Previous wording

We may have conflicts with our partners, such as conflicts concerning the interpretation of preclinical or clinical data, pertaining to the global patient safety profile or efficacy results of our products, the achievement of milestones, the interpretation of contractual obligations, payments for services, development obligations or the ownership of intellectual property developed during our collaboration. We may seek to amend, modify or terminate agreements with partners, suppliers or service providers related to Iomab-B, Actimab-A or Iomab-ACT but there can be no assurance that we can do so successfully or negotiate terms that are favorable to us. Failure of which can increase the risk of or result in litigation or alternative dispute resolution options taken against us. Further, we may exercise our decision-making authority under certain circumstances pertaining to global patient safety related to our products, which our partners may disagree with and may result in potential conflicts and public disclosure of our rationale and position. If any conflicts arise with any of our partners, such partner may act in a manner that is adverse to our best interests. Any such disagreement could result in one or more of the following, each of which could delay or prevent the development or commercialization of our product candidates, and in turn prevent us from generating revenues: unwillingness on the part of a partner to pay us milestone payments or royalties we believe are due under a collaboration; uncertainty regarding ownership of intellectual property rights arising from our collaborative activities, which could prevent us from entering into additional collaborations; unwillingness by the partner to cooperate in the development or manufacture of the product, including providing us with product data or materials; unwillingness on the part of a partner to keep us informed regarding the progress of its development and commercialization activities or to permit public disclosure of the results of those activities; initiating litigation or alternative dispute resolution options by either party to resolve the dispute; or attempts by either party to terminate the agreement. Litigation or alternative dispute resolution options can be lengthy and expensive, require significant time and attention from our management and are highly uncertain. There can be no assurance that if we pursue, or a partner pursues litigation or alternative dispute resolution options, that we will prevail. Monetary and equitable damages awarded against us could have a material adverse effect on our business.

Current wording

We may have conflicts with our partners, such as conflicts concerning the interpretation of preclinical or clinical data, pertaining to the global patient safety profile or efficacy results of our products, the achievement of milestones, the interpretation of contractual obligations, payments for services, development obligations or the ownership of intellectual property developed during our collaboration. We may seek to amend, modify or terminate agreements with partners, suppliers or service providers related to ATNM-400, Actimab-A, Iomab-ACT or Iomab-B, but there can be no assurance that we can do so successfully or negotiate terms that are favorable to us. Failure of which can increase the risk of or result in litigation or alternative dispute resolution options taken against us. Further, we may exercise our decision-making authority under certain circumstances pertaining to global patient safety related to our products, which our partners may disagree with and may result in potential conflicts and public disclosure of our rationale and position. If any conflicts arise with any of our partners, such partner may act in a manner that is adverse to our best interests. Any such disagreement could result in one or more of the following, each of which could delay or prevent the development or commercialization of our product candidates, and in turn prevent us from generating revenues: unwillingness on the part of a partner to pay us milestone payments or royalties we believe are due under a collaboration; uncertainty regarding ownership of intellectual property rights arising from our collaborative activities, which could prevent us from entering into additional collaborations; unwillingness by the partner to cooperate in the development or manufacture of the product, including providing us with product data or materials; unwillingness on the part of a partner to keep us informed regarding the progress of its development and commercialization activities or to permit public disclosure of the results of those activities; initiating litigation or alternative dispute resolution options by either party to resolve the dispute; or attempts by either party to terminate the agreement. Litigation or alternative dispute resolution options can be lengthy and expensive, require significant time and attention from our management and are highly uncertain. There can be no assurance that if we pursue, or a partner pursues litigation or alternative dispute resolution options, that we will prevail. Monetary and equitable damages awarded against us could have a material adverse effect on our business.

Previous wording

As a result, our owned and licensed patents may not be valid, and we may not be able to obtain and enforce patents and to maintain trade secret protection for the full commercial extent of our technology. The extent to which we are unable to do so could materially harm our business.

Current wording

As a result, our owned and licensed patents may be held invalid, and we may not be able to obtain and enforce patents and to maintain trade secret protection for the full commercial extent of our technology. The extent to which we are unable to do so could materially harm our business.