Kineta, Inc. announced the presentation of new positive data from its ongoing VISTA-101 Phase 1/2 clinical trial evaluating KVA12123, the company?s VISTA blocking immunotherapy, in patients with advanced solid tumors at the Society for Immunotherapy of Cancer?s (SITC) 38th Annual Meeting. Thierry Guillaudeux, Ph.D., Chief Scientific Officer of Kineta, presented the company?s poster unveiling the new clinical data. The Phase 1/2 VISTA-101 trial (NCT05708950) enrolled 11 patients with advanced solid tumors in the first three monotherapy dose-escalation cohorts, where subjects received either 3, 10 or 30 mg of KVA12123 by intravenous (IV) infusion every two weeks.

Primary objectives of the Phase 1/2 study are to evaluate the safety and tolerability of KVA12123 and to determine the recommended Phase 2 dose (RP2D). Patients enrolled in the study were heavily pretreated with multiple prior lines of therapy including chemotherapy, radiation and immunotherapy. Additional monotherapy and initial combination therapy data are anticipated in the second quarter of 2024.

Safety Eleven patients were dosed and cleared the first three monotherapy cohorts. KVA12123 was well tolerated at all doses and no dose limiting toxicities (DLT) were observed. All KVA12123 treatment emergent adverse events were grades 1-2. Furthermore, no evidence of cytokine release syndrome (CRS) or associated cytokines including IL-6, TNFa & IL-10 were detected at any of the dose levels.

Pharmacokinetics and VISTA Receptor Occupancy (RO) KVA12123 exhibited a greater than dose-proportional pharmacokinetic profile in drug exposure across all evaluated doses, consistent with target-mediated drug disposition at lower doses. To guide the RP2D decision, Kineta developed a proprietary assay to evaluate VISTA RO on immune cells from patients treated with KVA12123. KVA12123 achieved a greater than 90% VISTA RO at the 30 mg dose indicating that KVA12123 may be approaching an optimal clinical dose.

Biomarkers: KVA12123 demonstrated dose-proportional on-target biomarker immune responses involved in anti-tumor activity. KVA12123 demonstrated significant efficacy-related cytokine induction of CXCL10, MCP1, MIP1a and MIP1ß, which are involved in immune cell activation and recruitment to the tumor microenvironment. Additionally, increases in anti-tumor immune cell subpopulations including nonclassical monocytes, NK cells, CD4+ T cells and CD8+ T cells were observed during treatment.

Changes in these key biomarkers and immune cell populations are indicative of the anti-tumor effects of blocking VISTA.