Talabostat

Dipeptidyl Peptidase Inhibitor (small Molecule Dipeptide Mimic)Rx: ResearchCompound: Investigational

Also known as: L-valyl-L-boroproline, PT-100, Val-boroPro

Educational Only — Not medical advice. Consult a qualified clinician before using any peptide.

Summary

Talabostat (PT-100) is an orally bioavailable dipeptide boronic acid analog that inhibits post-prolyl cleaving enzymes including FAP and DPP4. It activates the NLRP1 inflammasome, triggering pyroptosis and pro-inflammatory cytokine release (IL-18, IL-1β), resulting in immune-mediated anti-tumor effects. It has been studied in clinical trials for metastatic melanoma, colorectal cancer, non-small cell lung cancer, and hematologic malignancies. Phase II/III trials showed modest single-agent activity and manageable toxicity, but it did not achieve primary endpoints in pivotal trials. Interest has been renewed due to its role as an NLRP1 inflammasome activator.

Mechanism of Action

Inhibits fibroblast activation protein (FAP) and dipeptidyl peptidase IV (DPP4/CD26), leading to activation of the NLRP1 inflammasome, induction of pyroptosis in tumor-associated stromal cells, and stimulation of innate and adaptive anti-tumor immunity via IL-18 and IL-1β release.

Routes of Administration

Oral

Goals & Uses

  • Colorectal cancer treatmentOncologyModerate
  • Combination immunotherapy enhancementOncologyLow
  • Metastatic melanoma treatmentOncologyModerate
  • NLRP1 inflammasome activation researchImmunology/researchHigh
  • Anti-tumor immunostimulationOncologyModerate
  • Hematologic malignancy treatmentOncologyLow

Contraindications

  • Uncontrolled infectionInfectious DiseaseModerate
  • Severe inflammatory syndromeImmunologicHigh
  • Active autoimmune diseaseAutoimmunityHigh

Adverse Effects

  • Cytokine release / flu-like symptomsImmunologicCommon
  • ThrombocytopeniaHematologicUncommonLow platelet count
  • Edema (peripheral/facial)Fluid/electrolyteCommon
  • AnemiaHematologicUncommonLow red blood cell count or hemoglobin
  • HypotensionCardiovascularCommonLow blood pressure
  • FatigueGeneralCommonLow energy or tiredness

Drug Interactions

  • Immunosuppressants (e.g., corticosteroids)Moderate
  • Antihypertensive agentsModerate
  • Other DPP4 inhibitors (gliptins)Moderate

Population Constraints

  • Pediatric patientsAgeRelative
  • Elderly patients (≥75 years)AgeRelative
  • Pregnant or lactating womenReproductiveAbsolute
  • Patients with severe hepatic impairmentHepaticRelative

Regulatory Status

  • European UnionInvestigationalNo EMA approval; studied in European academic trials.
  • United StatesInvestigationalInvestigated in multiple Phase II/III trials; no FDA approval. Not commercially available. Research use only.
  • United KingdomInvestigationalNo MHRA approval; research use in academic oncology settings.

Not approved by the FDA or EMA for any indication. Investigated in multiple Phase II and one Phase III clinical trials. Development by Point Therapeutics was discontinued; research continues in academic and combination immunotherapy settings.

Evidence & Sources

No sources recorded yet.

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