Actinium Pharmaceuticals, Inc. (NYSE American:ATNM) announced on November 4, 2026 that an abstract evaluating long-term safety and tolerability of Actimab-A (lintuzumab-Ac225) in combination with CLAG-M intensive salvage chemotherapy in relapsed or refractory acute myeloid leukemia patients will be presented at the 2026 American Society of Hematology Annual Meeting.

Key Highlights

  • Abstract accepted: Long-term safety and tolerability data from a Phase 1 study of Actimab-A plus CLAG-M will be presented as a poster at ASH 2026 on Sunday, December 13, 2026, from 6:00 PM to 8:00 PM at the Ernest N. Morial Convention Center, Hall F.
  • Presenting author: Sameem Abedin, MD, of the Medical College of Wisconsin is the named presenting author of the abstract.
  • Safety focus: The abstract analyzes blood count recovery and potential delayed kidney and liver toxicities in patients who survived at least three months after treatment.
  • Prior efficacy data: According to the filing, efficacy data previously presented at ASH 2022 reported estimated one-year and two-year overall survival of 59% and 32%, respectively, in patients previously treated with venetoclax, and 51% and 19%, respectively, in patients with TP53-mutated AML.
  • Therapeutic rationale: The company disclosed that the findings are intended to support further evaluation of Actimab-A as "a potential mutation agnostic therapeutic backbone for CD33-positive AML."
  • Transplant pathway: The abstract addresses recovery and "the ability to proceed to allogeneic hematopoietic cell transplantation," according to the filing.

Actimab-A Phase 1 Follow-Up Data to Be Presented at ASH Annual Meeting

Actinium Pharmaceuticals disclosed in a press release dated November 4, 2026 that an abstract covering follow-up from a Phase 1 study of Actimab-A plus CLAG-M will appear at the 2026 ASH Annual Meeting. The abstract is titled "Long-Term Safety and Tolerability after Intensive Salvage therapy with CLAG-M for Relapsed/Refractory AML" and is assigned to Session 616, "Acute Myeloid Leukemias: Investigational Drug and Cellular Therapies: Poster I," according to the filing.

The company disclosed that the follow-up analysis focuses on bone marrow recovery and potential delayed kidney and liver toxicities among patients who survived at least three months after treatment. The filing noted that these safety findings complement efficacy data previously presented at ASH 2022, which reported estimated one-year and two-year overall survival rates of 59% and 32%, respectively, in venetoclax-pretreated patients, and 51% and 19%, respectively, in patients with TP53-mutated AML.

According to the filing, Actinium Chairman and CEO Sandesh Seth stated that the long-term safety findings support the company's strategy to advance Actimab-A as "a potential mutation-agnostic therapeutic backbone for AML," including in patients whose disease has failed venetoclax-based therapy and those with TP53 mutations. The company also disclosed it holds approximately 250 patents and patent applications and is advancing Actimab-A toward a Phase 2/3 trial, with additional development ongoing through a CRADA with the National Cancer Institute. The filing notes that forward-looking statements are subject to risks and uncertainties and that actual results may differ materially.

What Was Disclosed

Actinium Pharmaceuticals announced the acceptance of an ASH 2026 abstract covering long-term safety follow-up for Actimab-A plus CLAG-M in relapsed or refractory AML, including analysis of blood count recovery and delayed organ toxicities in patients surviving at least three months post-treatment.