The early results were revealed recently at the Cambridge Healthtech Institute’s 7th Annual Immuno-Oncology Summit, in the presentation, “Targeting Soluble TNF to Improve Efficacy of Combination Immunotherapy.” Raymond J. Tesi, MD, CEO and chief medical officer of INmune Bio, was there to share the findings.
Myeloid-derived suppressor cells (MDSCs), commonly found in advanced tumors, work as an immunosuppressive shield to protect tumors from immune system attacks. These cells are key players in cancer resistance, particularly to treatments that harness the immune system, like immune checkpoint inhibitors.
INB03 was designed to inactivate MDSCs and destroy the protective shield that prevents immune cells from entering to fight cancer. Specifically, INB03 is a second-generation inhibitor of cell-free tumor necrosis factor (TNF) while not affecting TNF molecules attached to cell membrane.
This means that INB03 does not suppress the immune system, a side-effect seen with currently approved first-generation TNF inhibitors.
The Phase 1 trial (ACTRN12618000675224) is an open-label study in Australia testing escalating doses of INB03 in patients with advanced tumors whose disease progressed after trying other lines of therapy. Participants have tested positive for increased biomarkers of inflammation and a high number of MDSCs in their blood.
“The goal of the Phase I study is to determine, in order of priority, the safety of INB03 in cancer patients, the dose of INB03 to take into the Phase II trials in cancer, and evidence of a biologic effect of INB03,” INmune Bio’s Tesi said in a press release. “All of these goals have been met,” Tesi said.
To date, the trial enrolled 11 patients who received one of three INB03 doses — 0.3, 1.0 and 3.0 mg/kg — injected under the skin, once a week.
Tesi presented preliminary data for the six patients receiving the two lowest doses. They had advanced prostate cancer, ovarian cancer, colon cancer, bile duct cancer, and lung cancer, and had failed to respond to three prior lines of therapy, on average.
INB03 was given for a median of 74 days. The treatment was well-tolerated, without serious treatment-related adverse effects. Disease progression was the reason why patients stopped treatment with INB03.
Signs of treatment activity were seen in half the patients; INB03 lowered by more than 50% the levels of the inflammatory cytokine interleukin (IL)-6, a biomarker of soluble TNF.
Also, all three patients in the 1.0 mg/kg dosing group reached the target dose concentration of INB03 before the next dosing.
“Using data from this trial, we have begun planning a Phase II trial using INB03 as part of combination immunotherapy in patients with cancer,” said Tesi.