P21

P21 is an investigational tumor-targeting peptide under preclinical development for oncology and neurotherapeutics. It acts by penetrating cancer cells via CXCR4 or similar receptors and may disrupt mitochondrial energy production. It is also being evaluated for cell-penetrant cargo delivery and cognitive enhancement.

• Tumor-specific internalization through CXCR4 receptor targeting
• Cell-penetrating peptide (CPP) architecture
• May inhibit mitochondrial ATP production in cancer cells
• Potential to deliver therapeutic cargos into malignant cells

• unit: mcg

  low dose: 100

  frequency: Dependent on clinical trial design and indication

  high dose: 500

  standard dose: 250

  administration route: Subcutaneous (SQ)

• Research-based peptide. Frequency and cycle duration determined by protocol in tumor or neurodegenerative studies.

common: ["Injection site discomfort"]

warnings: ["Potential immunogenicity in some patients","Effects on non-target cells in high systemic concentrations"]

long term: ["Unknown due to lack of human trials"]

sequence: Sequence varies; representative motif includes cell-penetrating and targeting domains

half life: Varies depending on structure and PEGylation/cyclization modifications

degradation: Primarily via hepatic enzymes; stability enhanced by structural modifications

molecular weight: 629.76

molecular formula: C31H47N9O7

tissue specificity: Designed for CXCR4-overexpressing tumor cells and inflamed tissues

• Neurotrophic factor small-molecule mimetics mediated neuroregeneration (P021).reviewPMID 27400746 ↗
• Early neurotrophic pharmacotherapy (P021) rescues deficits in the Ts65Dn mouse model.preclinicalPMID 28368015 ↗