IN8bio, Inc. announced updated data from the ongoing Phase 1 clinical trial of INB-200 in patients with newly diagnosed glioblastoma multiforme (GBM). The data were featured as one-of-four oral presentations and the only Phase 1 study during the immunotherapy section of the Central Nervous System Tumors session at the American Society of Clinical Oncology (ASCO) 2023 Annual Meeting in Chicago, Illinois. The oral presentation at ASCO includes efficacy and safety data as of a data cutoff of April 30, 2023.

Eight patients have been treated with INB-200: three in Cohort 1 (single dose), four in Cohort 2 (three doses) and one in Cohort 3 (six doses). As of May 19, 2023 key findings from the ongoing study include: Cohort 1 patients remained progression-free at 8.3, 11.9, and 7.4 months, with respective overall survival (OS) of 15.6, 17.7, and 9.6 months. Two patients in Cohort 2 remain alive and progression-free at 23.5 and 19.4 months, respectively, exceeding median OS of GBM patients without progression.

In Cohort 3, the first patient dosed received five of six planned doses of gamma-delta T cells and had a progression-free survival (PFS) of 7.1 months and OS of 11.8 months with no evidence of additional toxicities. This patient who had an LZRT1 mutation experienced a rare leptomeningeal relapse, along with widespread relapse in their liver, lungs and pelvis. However, there was no progression in their brain, where INB-200 was administered.

No treatment-related deaths have been reported in any cohort. Six deaths were observed, three due to progression of disease and three unrelated to either treatment or progression (the deaths were due to sepsis, a cardiac event and pulmonary embolism). No treatment-related serious adverse events (SAEs), dose-limiting toxicities (DLTs) cytokine release syndrome (CRS), infusion reactions, or immune effector cell-associated neurotoxicity syndrome (ICANS) have been reported in any cohort.

The most common treatment emergent adverse events (TEAEs) were white blood cell and platelet count decreases related to standard-of-care temozolomide, asthenia, headache and hydrocephalus, mostly Grade 1-2. Three additional patients have been consented in Cohort 3 to date and are advancing through treatment. INB-200 is a genetically modified autologous drug resistant immunotherapy (DRI) product candidate for the treatment of solid tumors. This novel platform utilizes genetic engineering to generate chemotherapy resistant gamma delta T cells which can be administered concurrently with standard-of-care treatment in solid tumors.

This is a powerful, synergistic treatment approach is intended to enable gamma-delta T cells to persist in the presence of chemotherapy, and maintain their natural ability to recognize, engage and kill cancer cells. INB-200 is the first genetically engineered gamma-delta T cell therapy to be administered to patients with solid tumors and initial indication is in GBM.