Immune Design, a US-based clinical-stage immunotherapy firm, has initiated an investigator-sponsored Phase I clinical trial of its investigational immuno-oncology agent, G100, in combination with radiation therapy in patients with metastatic sarcoma.

G100 is designed to generate a robust anti-tumour immune response when administered directly to the tumour micro-environment.

The trial, being conducted at the Fred Hutchinson Cancer Research Center, is designed to evaluate the safety, clinical efficacy and immunogenicity of intra-tumoral G100 in combination with palliative radiation therapy in these patients.

"G100 is designed to activate antigen presenting cells (APCs) and boost pre-existing anti-tumor cytotoxic T cells or CTLS."

Fred Hutchinson Cancer Research Center assistant member and principal investigator Seth Pollack said: "We look forward to investigating the potential of G100 in combination with radiation therapy to induce an immune response in patients with metastatic soft tissue sarcoma, an aggressive disease with limited treatment options.

"G100 is designed to activate antigen presenting cells (APCs) and boost pre-existing anti-tumor cytotoxic T cells or CTLS.

"In addition, radiation therapy can lead to lysis of tumor cells that release tumor antigens that can be recognized by APCs.

"The combination of intra-tumoral G100 with local radiation is expected to boost the immune system’s response to tumor antigens in the tumor microenvironment and lead to a broad, systemic anti-tumor response."

The company said that as per protocol, patients will receive weekly treatment with G100 starting prior to the radiation therapy and continuing for eight weeks, and efficacy will be evaluated based on radiographic response in metastatic lesions.

Immune Design chief medical officer Richard Kenney said: "We are pleased that intra-tumoral administration of G100 is now being actively studied in two indications – metastatic soft tissue sarcoma and Merkel cell carcinoma – both alone and in combination with local radiation.

"The key component of G100, GLA, has been evaluated in more than 1,000 subjects and has demonstrated the ability to stimulate both the innate and adaptive immune system while being well tolerated."

G100 is a product of the company’s GLAAS discovery platform and includes a specific formulation of Glucopyranosyl Lipid A (GLA), a synthetic, Toll-like Receptor-4 (TLR-4) agonist.

The company said that preclinical and clinical data have showed the ability of G100 to activate dendritic cells in tumours and to increase antigen-dependent systemic humoral and cellular Th1 immune responses.