Approval Probability
TA Base Rate
Adjusted LOA
ML Risk
131I-apamistamab · 1 trial · 11 indications
Defined as time from randomization to death from any cause. Subjects without documented death at the time of analysis will be censored at the date of last known contact.
Number of subjects achieving CR by Day 28 (±3 days) post-HSCT, based on bone marrow assessment.
Number and proportion of subjects developing grade ≥4 non-hematologic toxicities as graded by NCI CTCAE v5.0.
| Arm | Type | Description |
|---|---|---|
| Arm A: Experimental: I131-apamistamab + Fludarabine + TBI | EXPERIMENTAL | Participants receive a dosimetric dose and then a treatment dose of I131-apamistamab (at the marrow dose selected in Phase 2), followed by fludarabine 30 mg/m² IV daily on Days -6 through -2 and total body irradiation (TBI) 200 cGy on Day -1 prior to allogeneic hematopoietic stem cell transplant (HSCT) on Day 0. Graft-versus-host disease (GvHD) prophylaxis per investigator's choice: * Post-transplant cyclophosphamide (50 mg/kg on Days +3 and +4) + tacrolimus + mycophenolate mofetil, OR * Low-dose methotrexate + tacrolimus. |
| Arm B: Active Comparator - Standard of Care Conditioning Regimen | ACTIVE_COMPARATOR | Participants receive standard of care conditioning regimen prior to allogeneic hematopoietic stem cell transplant (HSCT) on Day 0 GvHD prophylaxis per investigator's choice: * Post-transplant cyclophosphamide (50 mg/kg on Days +3 and +4) + tacrolimus + mycophenolate mofetil, OR * Low-dose methotrexate + tacrolimus. |
| Name | Type | Description |
|---|---|---|
| 131I-apamistamab | DRUG | Iodine-131 radiolabeled anti-CD45 monoclonal antibody (apamistamab). Administered IV as a dosimetric dose followed by treatment dose. |
| Fludarabine | DRUG | Fludarabine phosphate, 30 mg/m² IV daily on Days -6 through -2. |
| Cyclophosphamide | DRUG | Cyclophosphamide |
| Total Body Irradiation (TBI) | RADIATION | TBI, 200 cGy on Day -1 prior to HSCT. |
| Allogeneic Hematopoietic Stem Cell Transplant (HSCT) | BIOLOGICAL | Unmodified, G-CSF-mobilized donor stem cells infused on Day 0. |
Inclusion Criteria: 1. Have active, relapsed, or refractory AML with ≥5% and ≤20% blasts in the marrow. 2. 2R/R AML is defined as one of the following: Primary induction failure after ≥2 cycles of therapy, first early relapse after remission \<6 months, relapse refractory to salvage combination the...
131I-apamistamab is an investigational radioimmunotherapy agent being studied as conditioning treatment before allogeneic transplant in patients with relapsed or refractory acute myeloid leukemia (AML). It is being developed in acute leukemia within the oncology therapeutic area.
131I-apamistamab is being developed by Actinium Pharmaceuticals, Inc. (Delaware), which trades under the ticker ATNM. The company is the sponsor of the clinical program evaluating the agent in acute leukemia.
131I-apamistamab is in Phase 2/3 clinical development. It is investigational and is being evaluated in a single registered trial that is currently active but not yet recruiting participants.
131I-apamistamab is being studied in trial NCT07157514, titled Radioimmunotherapy Conditioning With 131I-Apamistamab for Allogeneic Transplant in Relapse/Refractory AML. The Phase 2/3 trial is active controlled, randomized, and plans to enroll 306 participants aged 18 years and older.
131I-apamistamab is an antibody-based biologic, reflected in its -mab antibody designation, that delivers iodine-131 radioimmunotherapy as conditioning ahead of allogeneic transplant in relapsed or refractory AML. Its development focuses on acute leukemia.