NCT03953235

A Study of a Personalized Cancer Vaccine Targeting Shared Neoantigens

A Phase 1/2 Study of GRT-C903/GRT-R904, a Vaccine Targeting Shared Neoantigens, in Combination With Immune Checkpoint Blockade for Patients With Advanced Solid Tumors

• Status: Completed
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 39 (actual)
• Sponsor: Gritstone bio, Inc. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this study is to evaluate the dose, safety, immunogenicity and early clinical activity of GRT-C903 and GRT-R904, a neoantigen-based therapeutic cancer vaccine, in combination with immune checkpoint blockade, in patients with advanced or metastatic non-small cell lung cancer, microsatellite stable colorectal cancer, pancreatic cancer, and shared neoantigen-positive tumors. Based on the Phase 1 data, an updated vaccine candidate (SLATE-KRAS or version 2) was developed that removed 16 of the 20 mutations included in the original vaccine (version 1) and solely targets KRAS mutations.

Detailed description

Tumors harboring non-synonymous deoxyribonucleic acid (DNA) mutations can present peptides containing these mutations as non-self antigens in the context of HLA on the tumor cell surface. A fraction of mutated peptides result in neoantigens capable of generating T-cell responses that exclusively target tumor cells. Some of these tumor-specific neoantigens are known or expected to be common across a subset of patients and are called shared neoantigens. This study aims to target shared neoantigens using a heterologous prime/boost therapeutic vaccine approach (GRT-C903 first followed by GRT-R904) in combination with checkpoint blockade to stimulate an immune response. This study will explore the safety and early clinical activity of this neoantigen-based immunotherapy intended to induce T-cell responses specific for the shared neoantigens contained within the therapeutic vaccine. Phase 1 will test multiple doses and combinations with checkpoint blockade and Phase 2 will test for early signs of clinical activity using a vaccine regimen based on Phase 1 data.

Conditions

• Non-Small Cell Lung Cancer
• Colorectal Cancer
• Pancreatic Cancer
• Solid Tumor
• Shared Neoantigen-Positive Solid Tumors

Interventions

Type	Name	Description
BIOLOGICAL	GRT-C903	a shared neoantigen cancer vaccine prime
BIOLOGICAL	GRT-R904	a shared neoantigen cancer vaccine boost
BIOLOGICAL	nivolumab	anti-PD-1 monoclonal antibody
BIOLOGICAL	ipilimumab	anti-CTLA-4 monoclonal antibody

Timeline

• Start date: 2019-07-18
• Primary completion: 2023-03-10
• Completion: 2023-03-10
• First posted: 2019-05-16
• Last updated: 2023-09-13

Locations

12 sites across 1 country: United States

Regulatory

• FDA-regulated drug study