Actinium Pharmaceuticals, Inc. announced that two posters detailing positive clinical experiences of sites in the pivotal Phase 3 SIERRA trial of Iomab-B, including the ease of Iomab-B administration, the rapid proficiency of sites and minimal radiation exposure to personnel are being presented at the 48(th) Annual Oncology Nursing Society (ONS) Congress, which is being held on April 26--30, 2023, in San Antonio, Texas. The SIERRA trial is the first randomized Phase 3 trial intended to take patients with active, relapsed or refractory (r/r) acute myeloid leukemia (AML) to a BMT, which is only feasible due to Iomab-B's targeted radiotherapy approach that enables these patients who are considered unfit and transplant ineligible in current routine clinical practice to access BMT without first achieving a remission. Actinium's ONS posters demonstrate that Iomab-B can be adopted across a wide variety of BMT centers, evidenced by the 24 sites, which perform over 30% of all allogeneic BMT procedures in the United States, that participated in the SIERRA trial.

Through education and utilizing Actinium-developed shielding solutions, site personnel became rapidly adept at Iomab-B administration. Importantly, treating nursing site personnel had minimal average radiation exposure of 0.009 millisievert (mSv), which is similar to the exposure from a roundtrip cross country flight, less than 1/10(th) the general public exposure limit of 1 mSv and significantly below the occupational radiation exposure limit for nursing staff of 50 mSv, clearly demonstrating no increased risk to nursing staff caring for Iomab-B patients. ONS Poster Details: Successful Interdisciplinary Approach to Treat Patients With R/R AML with Iomab-B Prior to HCT: The SIERRA Trial Experience: SRRA sisite staff became rapidly adept to administering Iomab-B and caring r patients via Actinium led ededucational efforts focused on nursing, radiation safety and nuclear medicine; All SIERRA sites operated fully independently after treating their initial Iomab-B patient; SIERRA sites were able to establish tailormade individual approaches for their site and quickly established a cadence for subsequent Iomab-B patients.

Eosure R Rates of Staff Caring for SIERRA Trial Patients Receiving Iomab-B: Experiences at Five Sites: Data was collected from 105 personnel from 5 SIERRA trial sites who were monitored while providing care for Iomab-B treated patients; The average radiation exposure was 0.009 mSv, which is approximately 1/10th of the annual exposure limit for the general public of 1 mSv; The average SIERRA treating nursing staff exposure of 0.009 mSv is approximately equal to the exposure on a roundtrip flight across the U.S.; For hospital personnel such as nurses, the occupational dose limit is increased to 50 mSv; These results indicate that Iomab-B radiation exposure to caregivers from Iomab-B is minimal.