Express The Phase 3 clinical results of refractory blood cancer therapy are eye-catching, and a regulatory application will be submitted soon

Actinium Pharmaceuticals today announced positive top-line results in its pivotal Phase 3 clinical trial of targeted radiotherapy Iomab-B.

Compared with the control group, more patients treated with Iomab-B had a complete response lasting more than
6 months after bone marrow transplantation.
Actinium expects to submit a Biologics License Application (BLA) to the U.
S.
FDA to provide treatment options
for AML patients over the age of 55 who cannot undergo bone marrow transplantation using existing therapies.

IOMAB-B is a targeted radiation therapy designed to improve access to bone marrow transplant treatment by rapidly depleting cancer cells, immune cells, and bone marrow stem cells in blood cancer patients
.
The drug molecule design of Iomab-B links the monoclonal antibody apamistama to the radioactive isotope iodine-131 and targets CD45 on the cell surface, an antigen widely expressed on the surface of all types of blood cancer cells and immune cells, including bone marrow hematopoietic stem cells/progenitor cells
.
When Iomab-B attaches to target cells, it releases energy that can destroy cancer cells in AML patients and eliminate their own bone marrow
.
By injecting iodine-131 directly into the bone marrow, Iomab-B is expected to avoid damage to healthy tissue caused by non-targeted radiotherapy or external beam radiotherapy, while effectively killing cancer cells and bone marrow cells in patients, laying the foundation
for bone marrow transplantation.
Iomab-B has been granted orphan drug designation
by the U.
S.
FDA.

Several studies have shown that bone marrow transplantation can significantly improve the survival rate of blood cancer patients, but the vast majority of blood cancer patients do not receive bone marrow transplantation because current treatments cannot alleviate the patient's condition, which is necessary
to advance bone marrow transplant treatment 。 Actinium's data for this study are derived from its pivotal Phase 3 clinical trial, SIERRA, a multicenter randomized controlled trial of 153 elderly patients with relapsed or refractory AML (age ≥ 55 years) to analyze the effect
of Iomab-B as a pre-bone marrow transplant treatment regimen compared with salvage therapy (control).

Image source: 123RF

In the SIERRA trial, treatment options for control patients included chemotherapy (e.
g.
, cytarabine and daunorubicin) and targeted therapies (e.
g.
, Bcl-2 inhibitor venetoclax, FLT3 inhibitor, and IDH1/2 inhibitor).

The control group members' treatment regimens reflect the real-world treatment of patients with relapsed/refractory AML (e.
g.
, monotherapy or a combination of more than 20 drugs), for which there is currently no standard treatment
.
Based on the Phase 3 study released this time, the SIERRA trial met the primary endpoint of achieving a durable complete response of up to 6 months in more patients in the Iomab-B group than in the control group, with a statistically significant difference between the two groups (P<0.
0001).

Dr.
Avinash Desai, Chief Medical Officer of Actinium, said in a press release: "We are pleased that this randomized controlled, multicenter, pivotal trial brings these findings
to patients in urgent need of new treatments.
Our goal is to use Iomab-B to increase the chances of bone marrow transplantation and improve patient outcomes, and given its statistical significance, these top-line results will propel us in that direction
.
" We remain committed to submitting a biologics license application to the U.
S.
FDA for Iomab-B approval
.
On behalf of Actinium, I would like to thank those patients who participated in the SIERRA trial with confidence, the families and caregivers who supported them, and the researchers who contributed their efforts and suggestions to make this trial possible
.
Without them, these results would not have been possible, allowing us to continue the development of Iomab-B
.
”