GX-I7, a new immunotherapy candidate being developed jointly by Genexine and its U.S. affiliated firm NeoimmuneTech, showed a longer half-life than an existing drug and strong stability even in high dose in a phase-1b study.

The company released the interim results of the study for solid cancer patients at the annual meeting of the Society for Immunotherapy of Cancer (SITC 2019) in Maryland, the U.S, from Nov. 6-10. The results included key evaluation criteria, such as safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD).

The study was on 21 terminal patients with a solid tumor. Researchers administered the new drug to each group of three patients, sequentially from 60μg/kg to 1,200μg/kg. The results showed that the half-life of GX-I7 was 33-147 hours, longer than 8.7-34.6 hours of Cytheris’ CYT-107, the existing Interleukin-7 (IL-7). The findings showed that the new immunotherapy lasted more in the body, stably.

After the treatment, immune cells such as lymphocytes, T cells, CD4+ and CD8+T increased along with an increased dose. The experimental drug was effective in most patients with solid cancer who had lymphopenia before the treatment.

GX-I7 also showed meaningful results in terms of stability, Genexine said. Existing cytokines such as IL-7, IL-2, IL-10, IL-15 in trials require high dose administration to induce sufficient efficacy, but lose doses were only possible because of side effect concerns. However, it was possible to use a high dose of GX-I7 – over 1,000 μg/kg --, which raised anticipation for a phase-2 study, the company said.

Based on the latest results of the study, Genexine and NeoimmuneTech determined a stable and effective dose of GX-I7 for a phase-2 trial. The two companies are conducting trials of combination therapy for patients with triple-negative breast cancer and skin cancer, and a monotherapy and a combo for those with glioblastoma, a type of brain cancer.

“We confirmed that the investigational drug helped cancer patients recover to normal levels in immune strength from immunodeficiency, which is usually caused by chemotherapy-induced lymphopenia,” an official at Genexine said.

By confirming that the expression of the chemokine receptor CCR5 was increased in a dose-dependent relationship, the company expects that GX-I7 will be able to induce T cells with cell death functions into the tumor site, thereby increasing the possibility of anticancer effect, the official added.

Copyright © KBR Unauthorized reproduction, redistribution prohibited