A Dual MYC and GSPT1 Degrader Extended Survival by Over 300% in One Preclinical Model
A preclinical research article in Blood, announced by MD Anderson on 21 August 2026. Nishida, Andreeff and colleagues in the Leukemia department report a previously undescribed feedforward loop in which MYC activates the GSPT1 gene while GSPT1 supports production of MYC protein. They tested GT19630, a degrader that binds both proteins, across cell and animal models of leukemia, lymphoma and multiple myeloma, including TP53-mutated and venetoclax-resistant disease, with single-cell RNA analysis of AML stem cells.
- The loop is the discovery, not the degrader. MYC drives GSPT1 expression and GSPT1 in turn supports MYC translation. Breaking both arms produced what the authors describe as broader activity than degrading GSPT1 alone, which is the checkable claim a competitor can act on.
- Activity held in TP53-mutated models, the genotype most associated with treatment resistance across these malignancies, and across leukemia, lymphoma and myeloma models.
- Venetoclax-resistant AML cells carried elevated MYC and GSPT1. GT19630 restored venetoclax sensitivity and prolonged survival by more than 300% in one model. The release gives no absolute survival times, no group sizes and no identification of which model produced that result.
- Selectivity is asserted rather than measured. Single-cell analysis showed elevated MYC in TP53-mutant AML stem cells, and normal blood-forming stem cells were reported as less affected. No magnitude is attached to less affected.
GSPT1 degradation is not a new modality, and its constraint is well understood: GSPT1 is a translation termination factor that every cell requires, so a therapeutic window cannot come from where the target sits. It has to come from differential dependency, which is exactly what the stem cell comparison here is meant to establish and exactly what the release leaves unquantified. The genuinely new element is directional. If GSPT1 supports MYC translation, then degrading GSPT1 alone should permit MYC to recover, and any programme running a GSPT1-only degrader now has a reason to measure MYC protein over time rather than only target occupancy.