Actinium Pharmaceuticals (ATNM) Risk Analysis

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 with 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. 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. 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. As previously disclosed and noted above, Actinium has licensed to Immedica the exclusive product rights for commercialization of Iomab-B in the EUMENA region. We are evaluating the impact of the FDA's 2024 determination of the SIERRA trial results in the context of global regulatory submissions for Iomab-B. At this time, filings for regulatory approval, obtaining regulatory approvals, and successful commercialization of Iomab-B in the EUMENA region and on a global basis are highly uncertain and may never be realized.

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. For instance, we worked with the FDA to develop the SIERRA clinical trial to test the safety and efficacy of Iomab-B in patients with r/r AML who are aged 55 and above prior to a BMT. Even though the SIERRA trial met the primary endpoint of dCR with statistical significance (p-value<0.0001), the FDA has determined that the analyses from the SIERRA trial do not support a BLA filing for Iomab-B. The FDA now requires an additional head-to-head Phase 3 clinical study. We have further discussed the specifics of this additional clinical trial with the FDA. Based on these discussions, Actinium believes it has aligned with the FDA on the patient population for this additional clinical trial, which can include all adult patients aged 18 and above with active AML with blasts counts greater than 5% and less than 20%. This is a broader patient population than the patients enrolled on the SIERRA trial, which only enrolled patients aged 55 and above. Further, 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. We are seeking a strategic partner for Iomab-B in the U.S. to advance these additional trials. Even if we are able to secure a partner, there are no assurances that the additional trials will be 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.

From time to time, we may publicly disclose preliminary, interim, and top-line data from our clinical trials, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change as more patient data become available or following a more comprehensive review of the data related to the particular study or trial. We may also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. Our clinical trials may be open label studies and certain of our clinical development and/or operations staff may review interim or preliminary safety or efficacy data during routine data collection, cleaning and analysis from time to time. Interim or preliminary results that we report may differ from future results of the same studies, or different conclusions or considerations may qualify such results once additional data have been received and fully evaluated. Preliminary, interim or top-line data also remain subject to audit and verification procedures that may result in the final data being materially different from the top-line, interim or preliminary data we previously published. As a result, top-line, interim and preliminary data should be viewed with caution until the final data are available. From time to time, we may also disclose interim data from our preclinical studies and clinical trials. Interim data from preclinical studies are not necessarily predictive of future success in clinical trials. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. Adverse differences between interim data and final data could significantly harm our business prospects. Further, disclosure of interim data by us or by our competitors could result in volatility in the price of our common stock. Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions, or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our company in general. In addition, the information we choose to publicly disclose regarding a particular study or clinical trial is based on what is typically extensive information, and you or others may not agree with what we determine is material or otherwise appropriate information to include in our disclosure. If the interim, top-line or preliminary data that we report differ from final results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize, our product candidates may be harmed, which could harm our business, operating results, prospects or financial condition.

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 preclinical 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 preclinical 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.

Our Actimab-A program is comprised of several clinical trials conducted under the CRADA with NCI, Actinium sponsored trials, investigator-initiated trials in AML and other myeloid indications and solid tumors that will study the same drug construct consisting of lintuzumab-Ac-225. Negative results from any of these trials could adversely impact our ability to enroll or complete our other trials studying lintuzumab-Ac-225, including future studies conducted under our CRADA with the NCI. Additionally, negative outcomes including safety concerns, may result in the FDA requiring amendment to certain clinical trials, placing a clinical hold on certain or all clinical trials or discontinuing other trials utilizing lintuzumab-Ac-225.

We are currently developing, and may develop future product candidates, for use in combination with one or more currently approved therapies. For example, Actimab-A is expected to be tested in combination with KEYTRUDA and OPDIVO for treating HNSCC and NSCLC. If any of the approved therapies we currently or may, in the future, use in combination with a current or future product candidate is found defective, removed from the market, or otherwise becomes unavailable, our clinical trials may face significant delays, be suspended, or terminated. Any such events would likely have a material impact on our operations and the development of the affected product candidate(s) and may ultimately prevent the approval of such product candidate or render continued development efforts too costly to proceed. Even if a current or future product candidate were to receive FDA approval to be commercialized in the U.S. for use in combination with one or more existing therapies, we would continue to be subject to the risk that the FDA or similar foreign regulatory authorities could revoke approval of the therapy used in combination with our product candidate or that safety, efficacy, manufacturing or supply issues could arise with any such existing therapies. This could result in our own products being removed from the market or cause material delays in, or the suspension or discontinuation, of our production and/or distribution of the applicable product, as our ability to market any such product will be limited to the extent specified in the FDA's approval, if granted.

The timely completion of clinical trials in accordance with their protocols depends on our ability to enroll a sufficient number of patients who remain in the trial until its conclusion. We may experience difficulties in patient enrollment in our clinical trials for a variety of reasons, including: - the size and nature of the patient population;- the patient eligibility criteria defined in the protocol;- the size of the study population required for analysis of the trial's primary endpoints;- the proximity of patients to trial sites;- the design of the trial;- our ability to recruit clinical trial investigators with the appropriate competencies and expertise;- competing clinical trials for similar or alternate therapeutic treatments;- clinician's and patients' perceptions as to the potential advantages and side effects of the product candidate being studied in relation to other available therapies;- our ability to obtain and maintain patient consents; and - the risk that patients enrolled in clinical trials will not complete a clinical trial. In addition, refractory patients, which several of our trials have or are expected to enroll, participating in clinical trials are seriously and often terminally ill and therefore may not complete the clinical trial due to reasons including comorbid conditions or occurrence of adverse medical events related or unrelated to the investigational products, or death. Even if we are able to enroll a sufficient number of patients in our clinical trials, delays in patient enrollment will result in increased costs or affect the timing of our planned trials, which could adversely affect our ability to advance the development of our product candidates.

We expect that a substantial portion of our efforts and expenditures over the next few years will be devoted to development of our existing and contemplated biological product candidates. Accordingly, our business currently depends heavily on the successful development, FDA approval, and commercialization of such candidates, which may never receive FDA approval or be successfully commercialized even if FDA approval is received. The research, testing, manufacturing, labeling, approval, sale, marketing, and distribution of our biological product candidates are, and will remain, subject to extensive regulation by the FDA and other regulatory authorities in the United States and other countries, as applicable. We are currently not permitted to market any of our current or future product candidates in the United States until we receive FDA approval (of each) via the BLA process. To date, we have three product candidates in clinical development and have not-yet submitted a BLA for any of our candidates and, for many such candidates, do not expect to be in a position to do so for the foreseeable future, as there are numerous developmental steps that must be completed before we can prepare and submit a BLA. In the United States, the FDA regulates pharmaceutical and biological product candidates under the Federal Food, Drug, and Cosmetic Act ("FDCA") and the Public Health Service Act ("PHSA"), as well as their respective implementing regulations. Such products and product candidates are also subject to other federal, state, and local statutes and regulations. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local, and foreign statutes and regulations requires the expenditure of substantial time and financial resources. 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") application, 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. Before testing any biological product candidate in humans, the product candidate enters the preclinical testing stage. Preclinical tests include laboratory evaluations of product chemistry, toxicity and formulation, as well as animal studies to assess the potential safety and activity of the product candidate. The conduct of the preclinical tests must comply with federal regulations and requirements including GLPs. 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 application. Some preclinical testing may continue even after the IND application is submitted. The IND application 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. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin. The FDA may also impose clinical holds on a biological product candidate at any time before or during clinical trials due to safety concerns or non-compliance. If the FDA imposes a clinical hold, trials may not recommence without FDA authorization and then only under terms authorized by the FDA. Accordingly, we cannot be sure that submission of an IND application will result in the FDA allowing clinical trials to begin or that, for those that have already commenced under an active IND application, that issues will not arise that suspend or terminate such trials. Clinical trials involve the administration of the biological product candidate to healthy volunteers or patients under the supervision of qualified investigators, generally physicians not employed by or under the trial sponsor's control. Clinical trials are conducted under protocols detailing, among other things, the objectives of the clinical trial, dosing procedures, subject selection and exclusion criteria, and the parameters to be used to monitor subject safety, including stopping rules that assure a clinical trial will be stopped if certain adverse events should occur. Each protocol and any amendments to the protocol must be submitted to the FDA as part of the IND application. Clinical trials must be conducted and monitored in accordance with the FDA's regulations composing the GCP requirements, including the requirement that all research subjects provide informed consent. Further, each clinical trial must be reviewed and approved by an IRB, at or servicing each institution at which the clinical trial will be conducted. An IRB is charged with protecting the welfare and rights of trial participants and considers such items as whether the risks to individuals participating in the clinical trials are minimized and are reasonable in relation to anticipated benefits. The IRB also approves the form and content of the informed consent that must be signed by each clinical trial subject or his or her legal representative and must monitor the clinical trial until completed. Human clinical trials are typically conducted in three sequential phases that may overlap or be combined: - Phase 1. The biological product is initially introduced into healthy human subjects and tested for safety. In the case of some products for severe or life-threatening diseases, especially when the product may be too inherently toxic to ethically administer to healthy volunteers, the initial human testing is often conducted in subjects. - Phase 2. The biological product is evaluated in a limited patient population to identify possible adverse effects and safety risks, to preliminarily evaluate the efficacy of the product for specific targeted diseases and to determine dosage tolerance, optimal dosage and dosing schedule.         - Phase 3. Clinical trials are undertaken to further evaluate dosage, clinical efficacy, potency, and safety in an expanded patient population at geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall risk to benefit ratio of the product and provide an adequate basis for product labeling. Post-approval clinical trials, sometimes referred to as Phase 4 clinical trials, may be conducted after initial marketing approval. These clinical trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication, particularly for long-term safety follow-up. After the completion of clinical trials of a biological product, FDA approval of a BLA must be obtained before commercial marketing of the biological product. The BLA must include results of product development, laboratory and animal studies, human trials, information on the manufacture and composition of the product, proposed labeling and other relevant information. The FDA may grant deferrals for submission of data, or full or partial waivers. The testing and approval processes require substantial time and effort and there can be no assurance that the FDA will accept the BLA for filing and, even if filed, that any approval will be granted on a timely basis, if at all. Before approving a BLA, the FDA will inspect the facilities at which the product is manufactured. The FDA will not approve the product unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving a BLA, the FDA will typically inspect one or more clinical sites to assure that the clinical trials were conducted in compliance with IND trial requirements and GCP requirements. To assure cGMP and GCP compliance, an applicant must incur significant expenditure of time, money and effort in the areas of training, record keeping, production, and quality control. Notwithstanding the submission of relevant data and information, the FDA may ultimately decide that the BLA does not satisfy its regulatory criteria for approval and deny approval. Data obtained from clinical trials are not always conclusive and the FDA may interpret data differently than we interpret the same data. We cannot predict with any certainty if or when we might submit a BLA for regulatory approval for our product candidates or whether any such BLA will be approved by the FDA. Human clinical trials are very expensive and difficult to design and implement, in part because they are subject to rigorous regulatory requirements. For example, the FDA may not agree with our proposed endpoints for any clinical trial we propose, which may delay the commencement of our clinical trials. The clinical trial process is also lengthy and requires substantial time, effort and expense. We expect that the clinical trials we need to conduct to be in a position to submit BLAs for our product candidates currently in-development will take at least several years to complete. Moreover, failure can occur at any stage of the trials, and we could encounter problems that cause us to abandon or repeat clinical trials. Also, the results of early preclinical and clinical testing may not be predictive of the results of subsequent clinical trials. A number of companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to lack of efficacy or adverse safety profiles, notwithstanding promising results in earlier studies, and preclinical and clinical data are often susceptible to multiple interpretations and analyses. Many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have, nonetheless, failed to obtain marketing approval of their products. Success in preclinical testing and early clinical trials does not ensure that later clinical trials, which involve many more subjects, and the results of later clinical trials may not replicate the results of prior clinical trials and preclinical testing. Any failure or substantial delay in our product development plans may have a material adverse effect on our business.