Preliminary EVICTION Phase I/IIa trial data shows butyrophilin-targeted mAb ICT01’s dose-dependent and specific activation of γ9δ2 T cells

Marseille, France, November 11, 2020 – ImCheck Therapeutics presented preliminary results from its ongoing EVICTION Phase I/IIa clinical trial evaluating ICT01, a first-in-class gamma delta (γδ) T cell-activatingmonoclonal antibody, in patients with advanced, relapsed/refractory cancers. The data from the first cohort of six solid tumor cancer patients treated with ICT01 monotherapy demonstrated dose-dependent and specific γ9δ2 T cell activation and trafficking out of the circulation without dose-limiting toxicities or related serious adverse events.

In addition, a limited immunohistochemistry (IHC) analysis in one melanoma patient provided a first demonstration in humans of infiltration of γδ T cells into the tumor including increases over baseline in γ9δ2 T cell density and CD3+/pan-γδTCR+ cell density in the tumor after the 2^nd dose of ICT01. The IHC analysis also showed increases in the number of activated CD3, CD4 and CD8 T cells in this patient’s tumor, indicating that ICT01 may activate a range of immune cells with the potential of generating a more complete anti-tumor immune response.

These results are being presented at the 2020 Society for Immunotherapy of Cancer (SITC) Annual Meeting in a virtual poster session.

Based on recommendation from an independent Safety Review Committee, the EVICTION trial has continued enrollment. The second cohort of patients with solid tumors receiving ICT01 as monotherapy has been enrolled and the Safety Review Committee unanimously approved further dose escalation. The trial is also currently recruiting patients with hematologic malignancies for ICT01 monotherapy, and a group of patients with solid tumors who will receive ICT01 in combination with pembrolizumab.

“The data presented at SITC are in line with ImCheck’s preclinical results showing that targeting BTN3A with ICT01 specifically and dose-dependently activates γ9δ2 T cells against tumor cells. The preliminary immunohistochemistry analysis also shows that ICT01 activates a range of immune cells, which is very exciting,” commented Aurélien Marabelle, MD, PhD, Immuno-Oncologist at the Gustave Roussy Cancer Centre, Villejuif, France and Principal Investigator for EVICTION. “We look forward to the trial continuation and further insight on ICT01’s mechanism of action through biomarker and sequential tumor biopsies.”

“As a first-in-class, immune-activating antibody, we are encouraged to see rapid and potent dose-dependent activity of ICT01 without safety concerns in the patients treated to date. We are thankful for the efforts of the EVICTION investigators and their study teams, and their patients’ willingness to participate in our trial despite the ongoing pandemic,” said Paul Frohna, MD, PhD, Chief Medical Officer at ImCheck Therapeutics. “We remain on target to report on the topline results from the dose escalation part of the trial in 2021.”

ImCheck is presenting three additional ICT01 posters at the SITC 2020 Annual Meeting:

• “Enhancement of anti-tumor immunity by ICT01: a novel γ9δ2 T cell-activating antibody targeting Butyrophilin-3A (BTN3A)”;
• “Characterization of Butyrophilin 3A Expression Across Multiple Tumor Types to Support Target Patient Population Selection in the EVICTION Study with ICT01, an Anti-BTN3A Monoclonal Antibody that Selectively Activates Vγ9Vδ2 T Cells”;
• “ICT01, an anti-BTN3A mAb that activates Vγ9Vδ2 T cells, plus interleukin-2: a potent and promising combination for cancer immunotherapy”.

The company is also presenting preclinical data on ICT03, its earlier-stage pipeline program targeting BTN2A1, another butyrophilin implicated in the activation of γ9δ2 T cells.