Actinium Pharma highlights two presentations at the Health Physics Society annual meeting supporting the safety profile of Iomab-B for SIERRA trial caregivers

Actinium Pharmaceuticals, Inc. highlighted its presence at the Health Physics Society ("HPS") 64th Annual Meeting that is being held July 7th – 11th in Orlando, Florida. During HPS, Actinium presented the findings of two studies that support the safety of healthcare professionals who provide care to patients treated with Iomab-B , Actinium's lead product candidate, which is being studied in the pivotal Phase III SIERRA trial. The studies evaluated radiation exposure to healthcare professionals who cared for patients treated with Iomab-B and the exposure from handling blood samples from patients following Iomab-B infusion. Both studies reported minimal radiation exposure to the respective healthcare professionals. One study of 105 healthcare professionals from 5 SIERRA sites that provided care to patients receiving Iomab-B observed a mean cumulative radiation exposure of 0.09 mSv or millisieverts, which is significantly less than the 50 mSv annual occupational dose limit for staff. Iomab-B is an ARC or Antibody Radiation-Conjugate comprised of the CD45 targeting antibody, apamistamab, and the radioisotope iodine-131 that is intended to be a re-induction and conditioning agent prior to a BMT or Bone Marrow Transplant. The SIERRA trial is a multicenter, 150 patient study for patients with active, relapsed or refractory AML or Acute Myeloid Leukemia that is the only randomized Phase III trial to offer a potentially curative BMT to this patient population for which there is no standard of care.

Details of the HPS presentations on Iomab-B are as follows: Title: "Occupational Radiation Exposures to Clinical Staff Working With 131I – Iomab-B"- Summary: Data from 105 healthcare professionals from five SIERRA sites was analyzed. Staff monitored when only providing care to Iomab-B treated patients had a mean cumulative exposure of 0.07 mSv despite high levels of radiation being administered with targeted Iomab-B while staff who provided care for multiple patients, including those receiving other forms or radiation therapy, had a mean cumulative exposure of 0.11 mSv. Radiation exposure levels to all staff were found to be minimal, with mean cumulative exposure of 0.09 mSv, contributing minimal exposure to the 50 mSv annual occupational limit. The study sited training, education, customized physical shielding and more advanced safety procedures as leading to minimal additional radiation exposure.

Title: "Iomab-B Study Blood Sample Handling and Occupational Radiation Extremity Exposure"- Summary: Radiation exposure levels were minimal and not a safety concern to clinical staff involved in blood specimen collecting and handling.

Dr. Qing Liang, Actinium's Vice President, Head of Radiation Sciences, said, "Staff at clinical sites are often surprised to learn that they can be exposed to higher amounts of radiation when flying on an airplane than compared to providing care to patients treated with Iomab-B. These study data solidly support this fact with the 0.09 mSv mean exposure to staff significantly lower than the 50 mSv annual occupational limit and even lower than the annual radiation 3 mSv, we all receive from natural background. Since joining Actinium, I have focused on building relationships with the radiation safety and nuclear medicine caregivers at existing and prospective sites for our SIERRA trial, educating site staff and working with my clinical colleagues to further optimize the SIERRA trial for patients and site staff. I believe that such efforts bode well not only for the SIERRA trail but also for Iomab-B in a commercial setting, assuming its approval," concluded Dr. Liang."