KLS-3021 / Kolon Life Sci - LARVOL DELTA

KLS-3021: A next-generation oncolytic vaccinia virus induces durable cancer-specific immune memory via remodeling of the tumor microenvironment in triple-negative breast cancer (ASGCT 2026) - "These findings suggest that KLS-3021 may overcome key limitations of current TNBC therapies, such as incomplete tumor eradication and high recurrence rates, by enabling both effective primary tumor control and sustained immunological surveillance. Collectively, these results support the further clinical development of KLS-3021 as a promising immuno-virotherapeutic strategy for patients with TNBC."

Biomarker • IO biomarker • Oncolytic virus • Tumor microenvironment • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Hormone Receptor Breast Cancer • Oncology • Solid Tumor • Triple Negative Breast Cancer • CD8 • ER • HER-2 • IFNG • IL12A • PGR

Strong therapeutic efficacy of oncolytic virus KLS-3021 in orthotopic head and neck cancer models regardless of PD-L1 expression via tumor microenvironment remodeling (AACR 2026) - "Syngeneic NOOC1 (PD‑L1-high) and MOC2 (PD‑L1-low) models were used to study PD-L1-independent tumor control by KLS-3021 and to compare efficacy against standard therapies—anti-PD-1 antibody and cisplatin, respectively—while characterizing TME remodeling and immune activation. Collectively, these findings indicate that KLS-3021 elicits potent antitumor immunity and remodels the TME regardless of PD-L1 levels, exceeding current conventional standards. Given its capacity for local tumor debulking and immune activation, KLS-3021 implicates strong translational potential as a next-generation therapeutic, including neoadjuvant applications for HNSCC."

Biomarker • Clinical • IO biomarker • Oncolytic virus • Preclinical • Tumor microenvironment • Head and Neck Cancer • Oncology • Solid Tumor • Squamous Cell Carcinoma • Squamous Cell Carcinoma of Head and Neck • CD86 • CXCL10 • IL12A • MRC1 • PD-L1 • SPAM1 • TNFA

KLS-3021: Innovative oncolytic virotherapy for the treatment of advanced primary and metastatic cutaneous squamous cell carcinoma. (PubMed, Mol Ther Oncol) - "Similar findings were observed in metastatic lymph nodes, demonstrating viral activity and tumor suppression. Collectively, these results indicate that KLS-3021 exerts potent anti-tumor efficacy in both primary and metastatic cSCC models, supporting its clinical translation as a multifunctional oncolytic virotherapy targeting the physical and immunological barriers of the tumor microenvironment."

Journal • Infectious Disease • Non-melanoma Skin Cancer • Oncology • Squamous Cell Carcinoma • Squamous Cell Skin Cancer • IL12A • PD-1

KLS-3021, a multifunctional oncolytic virus, demonstrates potent early-intervention efficacy in preclinical models of prostate-confined and locally advanced prostate cancer. (PubMed, Front Oncol) - "Mice were randomized to receive vehicle, docetaxel, or KLS-3021, administered on day 9 (prostate-confined) or day 29 (visible/locally invasive) after implantation of luciferase-labeled PC-3 cells. Mechanistic analyses revealed extracellular matrix degradation, enhanced viral spread, increased immune cell infiltration, M1 macrophage polarization, and features of immunogenic cell death in KLS-3021-treated tumors. These results collectively demonstrate the translational potential of KLS-3021 as a minimally invasive or neoadjuvant therapeutic strategy for prostate cancer, especially in patients for whom early, localized intervention is medically feasible."

Journal • Preclinical • Genito-urinary Cancer • Oncology • Prostate Cancer • Solid Tumor • IL12A • PD-1 • SPAM1

Demonstrating efficacy of KLS-3021, oncolytic vaccinia virus, on PC-3 human prostate cancer cells growing in prostate and regional lymph nodes using orthotopic mouse models (ESMO 2025) - "Mice were treated with vehicle, docetaxel (10 mg/kg, i.v., weekly), or KLS-3021 (1×10 7 TCID 50 , lobular or intratumoral, single dose). Legal entity responsible for the study Kolon Life Science, Inc. Funding Kolon Life Science, Inc."

Oncolytic virus • Preclinical • Genito-urinary Cancer • Oncology • Prostate Cancer • Solid Tumor • IL12A • SPAM1

Kolon Life Science unveiled preclinical data for KLS-3021 via an e-poster at the European Society for Medical Oncology Annual Congress (ESMO 2025)… (Korea Biomedical Review) - "In preclinical studies using a syngeneic mouse model with prostate cancer cells (PC3), the KLS-3021 monotherapy group showed a significant reduction in tumor volume compared to the chemotherapy drug docetaxel (10 mg/kg, intravenously once weekly). Notably, tumor clearance was confirmed in both the primary lesion and lymph nodes even in a locally invasive model where lymph node metastasis was observed."

Preclinical • Prostate Cancer

Kolon Life Science presents 'KLS-3021' as a treatment for squamous cell carcinoma of the skin at ASGCT [Google translation] (BioTimes) - "Kolon Life Science announced on the 19th that it had presented a poster presentation on the preclinical results of its anticancer treatment candidate 'KLS-3021' for cutaneous squamous cell carcinoma (cSCC) at the '2025 American Society for Gene and Cell Therapy (ASGCT)' held in New Orleans, USA from the 13th to the 17th (local time)....The research team observed that the tumor completely disappeared with just a single injection of KLS-3021 into the tumor in an orthotopic tumor model1 anticancer efficacy evaluation. In particular, in the metastatic tumor model, the therapeutic effect was shown to extend to adjacent lymph nodes as well as the primary tumor, suggesting the possibility of future metastatic cancer treatment."

Preclinical • Squamous Cell Skin Cancer

KLS-3021: Innovative Oncolytic Virotherapy for the Treatment of Advanced and Metastatic Cutaneous Squamous Cell Carcinoma (ASGCT 2025) - "Preclinical evaluation of KLS-3021 demonstrates its potential as a potent oncolytic virotherapy for advanced and metastatic cSCC. KLS-3021 showed selective cytotoxicity and robust replication in cSCC cell lines, leading to significant tumor regression and effective eradication of metastatic lesions. The observed hyaluronan degradation, enhanced viral dissemination, and favorable immune cell infiltration highlight its multifaceted mechanism."

IO biomarker • Late-breaking abstract • Metastases • Oncolytic virus • Genetic Disorders • Infectious Disease • Non-melanoma Skin Cancer • Skin Cancer • Solid Tumor • Squamous Cell Carcinoma • Squamous Cell Skin Cancer • IL12A • SPAM1

Kolon Life Science secures European patent for oncolytic virus therapy KLS-3021 (Korea Biomedical Review) - "Kolon Life Science announced Thursday that Europe has granted a patent titled 'recombinant vaccinia virus and pharmaceutical composition comprising same,' related to KLS-3021, a gene therapy candidate for the treatment of solid tumors. This European patent marks the ninth registration, following approvals in Korea, Japan, Canada, Singapore, and China. The patent is currently under review in the U.S. and Brazil."

Patent • Oncology • Solid Tumor