FOXO4-DRI

What Is FOXO4-DRI?

FOXO4-DRI is a D-retro-inverso peptide built from a fragment of the FOXO4 transcription factor, synthesised with D-amino acids in reversed sequence so that it resists protease degradation and reaches its intracellular target intact. In senescent cells, which have stopped dividing but resist apoptosis and secrete inflammatory signals (the SASP), FOXO4 binds p53 in the nucleus and prevents it from triggering programmed cell death. FOXO4-DRI competitively disrupts the FOXO4-p53 interface, releasing p53 to the cytoplasm and mitochondria, where it initiates apoptosis in the senescent cell.

Non-senescent cells do not depend on the FOXO4-p53 interaction for survival and are left unaffected, which is the basis for its classification as a selective senolytic. In the 2017 Cell paper from the de Keizer laboratory (Baar et al.), FOXO4-DRI cleared p16-positive senescent cells from kidney, liver, muscle, and skin in naturally aged and chemotherapy-aged mice, restored renal function, reversed fur loss, and roughly doubled treadmill endurance relative to untreated age-matched controls.

No human randomised controlled trial data exist. Every efficacy and safety observation is from mouse models or in vitro work, which makes FOXO4-DRI one of the most preliminary compounds in the research literature.