G17DT Immunogen

Summary

G17DT (also known as Gastrimmune or PAS) is an anti-gastrin therapeutic vaccine developed for the treatment of gastrin-dependent cancers, particularly pancreatic cancer, gastric cancer, and colorectal cancer. By inducing active immunity against gastrin-17, it blocks autocrine and paracrine trophic signaling that promotes tumor growth. It has been evaluated in multiple Phase II/III clinical trials.

Mechanism of Action

G17DT is a conjugate immunogen consisting of the N-terminal 9 amino acids of gastrin-17 (G17) linked to diphtheria toxoid (DT). It stimulates the host immune system to produce antibodies against gastrin-17, neutralizing its trophic (growth-promoting) effects on gastrin-dependent tumors, thereby inhibiting tumor cell proliferation and angiogenesis.

Routes of Administration

Goals & Uses

• Inhibition of tumor angiogenesisOncology / MechanisticLow
• Treatment of colorectal cancerOncologyLow
• Treatment of pancreatic cancerOncologyModerate
• Post-surgical adjuvant therapyOncologyLow
• Treatment of gastric cancerOncologyModerate

Contraindications

• Known hypersensitivity to diphtheria toxoidAllergy / ImmunologyHigh
• Active autoimmune disordersImmunologyModerate
• PregnancyPopulationModeratePotential fetal risk or insufficient safety data
• Severe immunosuppressionImmunologyModerate

Adverse Effects

• Flu-like symptomsSystemic/ImmunologicalCommon
• Hypersensitivity / allergic reactionsImmunologicRare
• Injection site reactionsLocalCommon
• Gastrointestinal disturbancesGastrointestinalUncommon
• Reduced gastric acid secretionGastrointestinal / PharmacodynamicUncommon

Drug Interactions

• Chemotherapy agentsModerate
• Proton pump inhibitors / H2 blockersLow
• Immunosuppressive agents (e.g., corticosteroids, methotrexate)Moderate

Population Constraints

• Patients with active severe infectionsInfectious DiseaseRelative
• Pediatric patientsAgeRelative
• Elderly patients with poor immune functionAge / ImmunologicRelative

Regulatory Status

• European UnionInvestigationalEvaluated in European clinical trials but not approved by the EMA.
• United StatesInvestigationalOrphan Drug Designation granted by FDA for pancreatic cancer. Not approved for any indication. Clinical development stalled after Aphton Corporation ceased operations.
• United KingdomInvestigationalClinical trials conducted in the UK; no regulatory approval obtained.

G17DT has not received regulatory approval from the FDA, EMA, or other major agencies. It has been granted Orphan Drug Designation by the FDA for pancreatic cancer. Clinical development was primarily conducted by Aphton Corporation; further development status is uncertain following company restructuring.

Evidence & Sources

No sources recorded yet.