Kineta provides update on ongoing Phase 1/2 VISTA-101 trial of KVA12123

Kineta announced an update on its ongoing VISTA-101 Phase 1/2 clinical trial evaluating KVA12123 in patients with advanced solid tumors. KVA12123, Kineta’s novel VISTA blocking immunotherapy, cleared the first four monotherapy dose levels and the first cohort in combination with Merck’s anti-PD-1 therapy, KEYTRUDA. KVA12123 was well tolerated with no dose limiting toxicitie or cytokine related adverse events at any dose level. Additionally, KVA12123 demonstrates robust and dose proportional induction of pro-inflammatory biomarkers required for strong anti-tumor activity, demonstrating on target effects of blocking VISTA. In the VISTA-101 trial, a total of 18 patients have been dosed with KVA12123. 15 patients with advanced solid tumors were enrolled in the first four monotherapy dose-escalation cohorts, where subjects received either 3, 10, 30 or 100 mg of KVA12123 by intravenous infusion every two weeks. Additionally, 3 patients were enrolled in the initial combination cohort with 30 mg KVA12123 and 400mg of pembrolizumab. 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. Patients enrolled in the study were heavily pretreated with multiple prior lines of therapy including chemotherapy, radiation, and immunotherapy. Approximately half of the enrolled patients failed prior checkpoint inhibitor therapy. Dosing of the 300 mg monotherapy and 100 mg in combination with pembrolizumab cohorts have been initiated. In the first four monotherapy cohorts and initial cohort in combination with pembrolizumab, KVA12123 was well tolerated at all doses and no DLTs were observed. During Phase 1, the study is closely monitoring the proinflammatory IL-6 and TNFalpha cytokines that are associated with cytokine release syndrome. No evidence of CRS-associated cytokine induction has been observed at any dose level with KVA12123 in the initial cohorts. KVA12123 demonstrated dose proportional induction of pro-inflammatory biomarkers including CXCL10, CCL2, CCL3 and CCL4 that are required for strong anti-tumor activity. Consistent increases in anti-tumor non-classical monocytes, NK cells, helper and cytotoxic T cells in the blood were also observed. These key pro-inflammatory myeloid derived cytokines and chemokines are involved in immune cell activation and recruitment in the tumor microenvironment. To guide the recommended Phase 2 dose decision, Kineta developed a proprietary assay to evaluate VISTA RO on immune cells from patients in the clinical trial. KVA12123 achieved a greater than 90% VISTA RO at the 30 and 100 mg doses. Furthermore, pharmacokinetic analyses demonstrated a greater than dose-proportional increase in drug exposure across all evaluated doses, consistent with target-mediated drug disposition at lower doses.