Radium Ra-223 Dichloride

Combination Targets a $570M–$1.3B Addressable Global Market; ENV-105 Phase 2 Data Show 86% Clinical Benefit Rate in Resistant mCRPC LOS ANGELES--(BUSINESS WIRE)-- $KAPA #Bayer --Kairos Pharma, Ltd. (NYSE American: KAPA), a clinical-stage biopharmaceutical company focused on overcoming cancer drug resistance, today announced a strategic collaboration with Bayer to evaluate Kairos Pharma’s lead antibody ENV-105 (carotuximab), a first-in-class CD105/BMP signaling inhibitor, in combination with Bayer’s XOFIGO (radium-223 dichloride) in metastatic castration-resistant prostate cancer (mCRPC) involving bone. Kairos Pharma’s current programs with ENV-105 include a Phase 1 trial in EGFR-driven non-small cell lung cancer and a Phase 2 trial for castrate resistant prostate cancer. Last year, Kairos announced positive interim efficacy data from the Phase 2 trial showcasing median progression-free survival was more than 13 months, a significant improvement from standard of care. These data were presented at the 2025 ESMO Congress in Berlin. XOFIGO is the first and only FDA-approved alpha-emitting radiopharmaceutical for mCRPC with symptomatic bone metastases and is currently advancing through additional combination studies, including the Phase III PEACE-3 trial, which demonstrated a 24% reduction in mortality risk when combined with enzalutamide (HR 0.76; p=0.009). “Drug resistance remains one of the greatest challenges in advanced prostate cancer, and XOFIGO, like many standard-of-care therapies, can lose efficacy over time,” said John Yu, M.D., Kairos Pharma Chief Executive Officer. “ENV-105 has already demonstrated the ability to re-sensitize tumors to existing treatments with a strong safety profile, and this collaboration with Bayer represents a major milestone in our mission to deliver more durable and more effective treatment regimens for patients with metastatic prostate cancer.” ezstandalone.cmd.push(function () { ezstandalone.showAds(131); }); Previous published work has demonstrated the efficacy of ENV-105 in radiation sensitization in prostate cancer preclinical models. CD105 is upregulated in response to standard androgen receptor inhibition and in responses to ionizing radiation, driving pro-survival BMP-SMAD signaling pathways underlying therapy resistance. Targeting CD105 with ENV-105 re-sensitizes resistant tumors and may extend the duration and depth of response to XOFIGO's targeted alpha therapy. Neil Bhowmick, Ph.D., Chief Scientific Officer and Principal Investigator stated, "CD105's role as a central resistance mechanism validated now across multiple drug classes makes this collaboration scientifically compelling and clinically timely, given XOFIGO's recent Phase III momentum." About Kairos Pharma Ltd. Based in Los Angeles, California, Kairos Pharma Ltd. (NYSE American: KAPA) is at the forefront of oncology therapeutics, utilizing structural biology to overcome drug resistance and immune suppression in cancer. Kairos Pharma’s lead candidate, ENV-105, is an antibody that targets CD105—a protein identified as a key driver of resistance and disease relapse in response to standard therapy. ENV-105 aims to reverse drug resistance by targeting CD105 and restore the effectiveness of standard therapies across multiple cancer types. For more information, visit kairospharma.com . CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING STATEMENTS This press release contains “forward-looking statements” as defined in the Private Securities Litigation Reform Act of 1995. You can identify forward-looking statements as those that are not historical in nature, particularly those that use terminology such as “may,” “should,” “expects,” “anticipates,” “contemplates,” “estimates,” “believes,” “plans,” “projected,” “predicts,” “potential” or “hopes” or the negative of these or similar terms. The reader is cautioned not to rely on these forward-looking statements. If underlying assumptions prove inaccurate, or known or unknown risks or uncertainties materialize, actual results could vary materially from the expectations and projections of Kairos Pharma. We base these forward-looking statements on our expectations and projections about future events, which we derive from the information currently available to us. Such forward-looking statements relate to future events or our future performance. In evaluating these forward-looking statements, you should consider various factors, including: our expectations regarding the success and/or completion of our Phase 1 and Phase 2 clinical trials; our success in completing newly initiated clinical trials, commence new trials, and obtain regulatory approval following the conclusion of such trials; challenges and uncertainties inherent in product research and development; and the uncertainty regarding future commercial success. These and other factors may cause our actual results to differ materially from any forward-looking statement. Forward-looking statements are only predictions. The forward-looking statements discussed in this press release and other statements made from time to time by us or our representatives, may not occur, and actual events and results may differ materially and are subject to risks, uncertainties and assumptions about us, including those described in Kairos Pharma’s prospectus and our other filings made with the SEC. We are not obligated to publicly update or revise any forward-looking statement, and Kairos Pharma is not required to update any forward-looking statement as a result of new information or future events or developments, except as required by U.S. federal securities laws. Contacts investors@kairospharma.com

U.S. government agencies have recovered large quantities of a rare and valuable feedstock material used for medical radioisotope production, radium-226 (Ra-226), from obsolete materials stored as radiological waste at National Institute of Standards and Technology (NIST) facilities. In essence, they’ve developed a scalable, cost-effective model that helps secure a domestic supply of scarce medical radioisotope feedstocks, while reducing legacy radiological waste, according to a recent press release by the U.S. Department of Energy (DOE). For decades, obsolete radioactive sources, such as the Ra-226 seeds once used in pioneering brachytherapy, were viewed strictly as hazardous waste. They represented a costly, long-term liability that hospitals and federal facilities had to safely secure, store, and eventually dispose of, said Manny Mejias, chief of NIST’s Radiation Safety Division and NIST’s coordinator on this project. “This initiative flips that paradigm, offering a powerful proof-of-concept for reuse of materials in medical technology. By collaborating across agencies (DOE and NIST), we've proven that we can essentially ‘mine’ these historical liabilities for high-value, strategic materials. Materials that currently cost institutions money to dispose of can be transformed into feedstock for life-saving medical therapies,” Mejias told MD+DI . Recovering and repurposing these waste materials is key to strengthening a secure, resilient domestic medical isotope supply chain, according to Christopher Landers, director of DOE’s Office of Isotope R&D and Production (IRP). Tapping the untapped resource Modern brachytherapy has replaced Ra-226 brachytherapy treatments, which involved delivering targeted radiation directly into cancerous tumors. Today’s treatment uses safer isotopes such as iridium-192 and iodine-125, and precise external radiation technologies that can target tumors from outside the body. This created a vacuum of unwanted radioactive seeds stored in NIST facilities, without good access to routine waste streams. However, recovered Ra-226 is a feedstock for producing alpha-emitting isotopes. “Right now, there is a great need to secure a resilient, domestic supply chain for alpha-emitting medical radioisotopes,” said Mejias, who pointed to industry’s “explosion of clinical interest in targeted alpha therapy (TAT) — a revolutionary approach that pairs an alpha-emitting isotope with a biological targeting molecule to seek out and destroy advanced, metastatic cancer cells with incredible precision, sparing surrounding healthy tissue.” In a review published in the European Journal of Nuclear Medicine and Molecular Imaging, authors wrote that targeted alpha therapy has emerged as a promising radiopharmaceutical modality in precision oncology. Pharmaceutical companies, including Bayer Global are developing TAT therapies. The global alpha emitters market size is on course to nearly double from close to $756 million in 2024 to about $1.56 billion by 2032, with an 11.44% compound annual growth rate, according to the Alpha Emitters Market Size, Trends, Share, Analysis [2032] report by Sac Insight. Global supply of the necessary isotopes for TAT (such as actinium-225 and lead-212) is severely constrained, Mejias said. “Our contacts at research organizations and commercial suppliers tell us that this scarcity creates a massive bottleneck for clinical trials and commercialization. Radium-226 is a critical, highly sought-after precursor material needed to produce these therapies,” Mejias said. According to DOE, through irradiation in reactors or cyclotrons, Ra-226 can be converted into: actinium-225, a high-priority radioisotope for targeted alpha therapy; actinium-227, which decays to radium-223 used in an FDA-approved prostate cancer treatment; and thorium-228, capable of decaying into a radium-224/lead-212 generator with the lead-212, which has an increasing impact in targeted cancer therapies. “By leveraging existing Ra-226, we can increase the domestic production capacity of actinium-225,” said Matt Fountain, Pacific Northwest National Laboratory’s (PNNL’s) project manager for the initiative. PNNL was charged with developing and executing the technical capabilities needed to safely recover Ra-226 at different sites and in diverse material forms. This includes safe Ra-226 material handling, packaging, and transport to support IRP’s ongoing efforts to aggregate domestic Ra-226 inventories, process and purify the material, and distribute it, according to DOE. PNNL developed and executed technical capabilities to enable scalable recovery operations across diverse sites, including multiple type A shipping package configurations with various shielding levels; radioactivity activity allowances; physical mass and volume capacities; and remote handling tools, according to Fountain. Model specifics PNNL developed a specially designed type A shipping cask and special form capsule to enable the safe recovery and transport of Ra-226 from sites across the U.S. and globally. The shipping cask allows PNNL researchers to safely recover the medical waste and convert it into a usable precursor for nuclear medicine, according to a PNNL news release . In the initial test, the PNNL designed and fabricated a cask and material handling tools that were flexible enough to be applied in widely varying configurations at remote recovery sites. They created site survey and planning documents to mitigate risk and maximize efficiency in coordinating between PNNL and the remote site, according to the release. PNNL performed mockups to become more proficient with the special extension tools, temporary shielding, choreographed handling, and special form closure steps needed to safely manage the process. PNNL and NIST later safely performed the same steps with real Ra-226 at NIST. “The mockup efforts were crucial to developing a smooth and efficient process,” said Jamin Trevino, a PNNL leader in the on-site efforts. “We were able to test procedures without the risk of radiation exposure to be confident in our approach. When we finally were working with the Ra-226 samples, we knew exactly how to operate.” The demonstration validated the model, and the devices have since been shipped back to PNNL for recovery, purification, dispensing, and subsequent internal use or shipping of purified Ra-226 to customers based on requests to IRP’s National Isotope Development Center, according to PNNL’s release. Big picture possibilities beyond Ra-226 “For engineers and manufacturers, this is a call to think about end-of-life recovery during the design phase of medical technologies. How can we build devices, or utilize rare materials, in ways that allow for easier extraction and upcycling decades later?” Mejias said.