ALT-801

ALT-801 is a recombinant fusion protein developed by Altor BioScience (now part of ImmunityBio) for the treatment of p53-positive malignancies, including relapsed or refractory multiple myeloma. The molecule consists of a single-chain T-cell receptor (scTCR) domain that specifically recognizes a peptide fragment of the p53 tumor suppressor protein (amino acids 264-272) presented by the HLA-A*0201 MHC class I molecule, fused to a human interleukin-2 (IL-2) moiety. This design is intended to direct the potent immunostimulatory activity of IL-2 specifically to tumor cells expressing p53, thereby activating and expanding tumor-infiltrating T cells and natural killer (NK) cells while potentially minimizing the systemic toxicities associated with high-dose IL-2 therapy. Clinical development in multiple myeloma reached Phase 1/2 but was terminated due to slow patient accrual.

Other names

p53-specific T-cell receptor-interleukin-2 fusion proteinp-53-specific T-cell receptor-interleukin-2 fusion proteinp 53-specific T-cell receptor-interleukin-2 fusion protein