Actinium Pharmaceuticals announced positive top-line results from its pivotal phase 3 SIERRA Trial. The trial evaluated the efficacy and safety of Iomab-B, a targeted radiotherapy, in patients with r/r AML. The study enrolled patients aged 55 and above who had active disease or had relapsed after previous treatment, or were refractory to current therapy.

The trial was designed to evaluate the efficacy of Iomab- B, compared to the current standard of care, in conditioning patients for an HSCT. The study's primary endpoint was to demonstrate a significant improvement in overall survival (OS) for patients receiving Iomab-B compared to those receiving the current standard of care. The trial also evaluated important secondary endpoints, including the rate of durable complete remission (dCR) and the rate of successful HSCT.

Preliminary findings demonstrated that treatment with the company's novel targeted radiotherapy (Iomab-B) resulted in the disappearance of all signs of cancer from treatment for six months in patients 55 years and older with r/r AML". Iomab-B is a first-in-class targeted radiotherapy intended to improve patient access to potentially curative bone marrow transplant (BMT) by simultaneously and rapidly depleting blood cancer, immune, and bone marrow stem cells that uniquely express CD45. It is designed to deliver targeted radiation to cancer cells while sparing healthy cells.

The SIERRA trial enrolled 153 patients who were ineligible for a BMT. These patients were randomly assigned to receive either Iomab-B followed by a BMT or the physician's choice of chemotherapy. The trial showed that Iomab-B met the primary endpoint of dCR of 6 months following initial complete remission after BMT with high statistical significance (p-value of (Source: Actinium's Investor Presentation).