On November 4, 2023 TriSalus Life Sciences Inc., (Nasdaq: TLSI), an oncology company integrating its novel delivery technology with immunotherapy to transform treatment for patients with liver and pancreatic tumors, reported additional Phase 1 clinical data during the late-breaker oral presentation session at the Society of Immunotherapy for Cancer (SITC) (Free SITC Whitepaper) 2023 Annual Meeting (Press release, TriSalus Life Sciences, NOV 4, 2023, View Source [SID1234636980]).

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The PERIO-01 Phase 1 study for uveal melanoma with liver metastases (UMLM), studied SD-101 delivered via PEDD with the TriNav Infusion System in combination with intravenous checkpoint inhibitors. The data presented today at SITC (Free SITC Whitepaper) demonstrate that SD-101 is well tolerated when given by the PEDD method and is associated with immunologic effects both within the liver and systemically, which may enable better outcomes with systemic checkpoint inhibition. The Progression-Free Survival (PFS), Disease Control Rate (DCR), and ctDNA molecular response data in PERIO-01 patients in combination with nivolumab are encouraging for UMLM and for other indications under development. At the optimal biologic dose of SD-101 (2 mg) in combination with nivolumab (n=7), the median PFS was 11.7 months with an 81% DCR.

"We are encouraged to see that SD-101 is well tolerated when given by PEDD, in association with immunologic effects within the liver and systemically, which may enable better outcomes with systemic checkpoint inhibition," said Steven C. Katz, M.D., FACS, Chief Medical Officer at TriSalus. "The PFS and ctDNA molecular response data in PERIO-01 patients in combination with nivolumab are promising for UMLM and as well as for other indications that we are pursuing."

"The results of PERIO-01 highlight the importance of getting the biology right and not just pushing a drug to its maximum tolerated dose. The biological effects of SD-101 are best at the lowest dose tested, revealing tumor microenvironment reprogramming and inflammatory cell trafficking from normal to metastatic liver tumors," said Sapna Patel, M.D., director of the uveal melanoma program at The University of Texas MD Anderson Cancer Center. "This is not seen at higher doses of SD-101, and these findings ensure we are entering the next phase with the optimal dose in combination with checkpoint inhibition, for patients with metastatic uveal melanoma."

PERIO-01 is an open-label, first-in-human Phase 1 trial of SD-101, administered by hepatic arterial infusion with TriNav using PEDD in UMLM. The study consists of dose-escalation cohorts of SD-101 (2, 4, or 8 mg) alone or with immune checkpoint inhibition. At the data cutoff as of September 29, 2023, 56 patients were enrolled, with each having received at least one dose of SD-101. Of the patients with available data, 16 patients (29%) were treatment-naïve and 40 (71%) had failed at least one prior line of therapy, including 8 patients (14%) on 3rd or greater line of treatment. SD-101 infused via PEDD in combination with systemic checkpoint inhibition was well tolerated, with an overall serious grade 3/4 adverse event rate related to treatment of 11% (n=56), and no such events at the optimal SD-101 dose level of 2 mg in combination with nivolumab (n=7). The most common adverse events overall were gastrointestinal (41%), fatigue (30%), and skin toxicity (27%), with the majority being minor.

Encouraging early efficacy signals were noted in the UMLM patients treated in PERIO-01. Overall, the ctDNA molecular response rate was 65% using specified time points (n=20), and 82% when analyzing the best on-treatment response (n=26). Clearance of ctDNA was noted in 59% of subjects when assessing the best on-treatment response. There was an 81% disease control rate at 2 mg SD-101 via PEDD with nivolumab (n=7). Across all subjects, two partial responses (≥30% decrease) and five minor responses (10-29% decrease) were documented as the best on-treatment response. The median progression free survival at the optimal dose of SD-101 via PEDD (2 mg) in combination with nivolumab was 11.7 months with a 1-year overall survival rate of 86% (n=7).

Among PERIO-01 patients who received SD-101 via PEDD in combination with intravenous nivolumab, there was evidence of increases in CD8+ T cells, CD4+ T cells, and natural killer cells within their liver metastases. Gene expression analysis by Nanostring revealed increased TLR signaling, interferon signaling, cytokine signaling, Th1 T cell activation, and lymphocyte activation. At the optimal SD-101 dose of 2 mg in combination with nivolumab, decreases in monocytic myeloid derived suppressor cells (MDSC), M2 macrophages, and regulatory T cells were found in liver metastases. Along with predicted immune changes within liver metastases, encouraging peripheral immune signals were detected. Increases in IFNγ, soluble IL2-receptor, IL-15, IL-18, T cell activation, and NK cell proliferation were found in the blood.

Dr. Katz added, "These data reflect additional validation of our innovative immunotherapy approach for liver and pancreas tumors. SD-101 was selected based on its mechanism of action, which has the potential to reverse immunosuppression in the liver and pancreas through depletion of MDSC in concert with broad stimulation of immune cells in the tumor microenvironment. TriSalus delivery systems, which use the PEDD method, are designed to overcome mechanical barriers to immunotherapy success, which may be underappreciated factors in limiting performance of TLR agonists in liver and pancreas tumors."

Overall, the data emerging from the PERIO-01 and PERIO-03 also presented at SITC (Free SITC Whitepaper) indicate immunologic changes are occurring within the liver and pancreas, with favorable safety profiles. Patients with liver metastases in the PERIO-01 study have had favorable outcomes despite pre-treatment.

All TriSalus presentations from SITC (Free SITC Whitepaper) is available here following their respective sessions.

About Pressure-Enabled Regional Immuno-Oncology (PERIO) clinical trials

The Pressure-Enabled Regional Immuno-Oncology (PERIO) clinical trials are studying an investigational class C toll-like receptor-9 agonist, SD-101, delivered intravascularly by TriSalus’ TriNav Infusion System (TriNav) using the Company’s proprietary Pressure-Enabled Drug Delivery (PEDD) method of administration in three Phase 1 trials.

The PERIO-01 Phase 1 clinical study for uveal melanoma with liver metastases (UMLM), is studying SD-101 delivered via PEDD with the TriNav in combination with intravenous checkpoint inhibitors.

The PERIO-02 trial is evaluating whether this same platform approach (PERIO-01) with SD-101 and PEDD can improve the performance of systemic checkpoint inhibitors in treating patients with hepatocellular carcinoma or intrahepatic cholangiocarcinoma.

The PERIO-03 study is an open-label, Phase 1/1b study of the pressure-enabled intrapancreatic infusion of SD-101, a TLR 9 agonist, alone or in combination with intravenous checkpoint blockade in adults with locally advanced pancreatic cancer.