nelmastobart (STT-003) / STCube Pharma - LARVOL DELTA

A phase II, open-label, multicenter study of nelmastobart in combination with docetaxel in patients with relapsed NSCLC expressing BTN1A1 (ESMO 2026) - No abstract available

Clinical • Combination therapy • P2 data • Lung Cancer • Non Small Cell Lung Cancer • Oncology • Solid Tumor • BTN1A1

BTN1A1 Blockade with Nelmastobart Enhances Osimertinib Antitumor Activity in EGFR-Mutant NSCLC, Including MET-Amplified Resistant Models (ESMO 2026) - No abstract available

Lung Cancer • Non Small Cell Lung Cancer • Oncology • Solid Tumor • BTN1A1 • EGFR • MET

BTN1A1 Expression and Spatial Immune Profiling as Predictive Biomarkers for Nelmastobart in NSCLC (IASLC-WCLC 2026) - P2 | "These findings support the potential role of BTN1A1 as a predictive biomarker and suggest that spatial immune profiling may further refine patient selection for Nelmastobart plus docetaxel in advanced NSCLC. This study is ongoing with active enrollment, and comprehensive efficacy and biomarker correlation analyses will be reported with larger sample sizes."

Biomarker • IO biomarker • Lung Cancer • Lung Non-Squamous Non-Small Cell Cancer • Non Small Cell Lung Cancer • Solid Tumor • Squamous Cell Carcinoma • BTN1A1 • CD4 • CD68 • CD8 • FOXP3 • PD-1 • PD-L1 • SLFN11 • YAP1

Nelmastobart Enhances Immune-Mediated Tumor Killing With First- and Second-Line Therapy in NSCLC Organoid Co-Culture Models (IASLC-WCLC 2026) - "In non-small cell lung cancer (NSCLC), platinum-based chemotherapy, including cisplatin with pemetrexed, remains the standard first-line treatment, while docetaxel is widely used in second-line settings. The absence of increased developmental toxicity in zebrafish supports a favorable therapeutic window. These findings provide a strong rationale for clinical development of BTN1A1-targeted immunotherapy in combination with standard-of-care chemotherapeutics across treatment lines in NSCLC."

Heart Failure • Lung Cancer • Non Small Cell Lung Cancer • Oncology • Solid Tumor • BTN1A1

Nelmastobart Plus Docetaxel in Advanced NSCLC: Initial Safety and Efficacy From a Single-Arm Phase 2 Study (STCUBE-004) (IASLC-WCLC 2026) - P2 | "Secondary endpoints include OS, ORR, DCR, and DoR per RECIST v1.1, PK parameters, and safety per NCI-CTCAE v5.0. BTN1A1 expression was evaluated by IHC using STC43H11-1, a diagnostic antibody developed by STCube."

Clinical • IO biomarker • Metastases • P2 data • Lung Cancer • Non Small Cell Lung Cancer • Solid Tumor • BTN1A1 • PD-1 • PD-L1

Development and Validation of an Immunohistochemistry Scoring Method for BTN1A1 Expression in NSCLC (IASLC-WCLC 2026) - P2 | "The ongoing phase 2 STCUBE-004 trial (NCT07306624) evaluating nelmastobart (hSTC810) plus docetaxel in advanced non-small cell lung cancer (NSCLC) enrolls patients with BTN1A1 tumor proportion score (TPS) ≥50 by immunohistochemistry (IHC); however, no standardized IHC scoring method exists for BTN1A1. Based on prior TMA findings of mutually exclusive BTN1A1 and PD-L1 expression, we anticipate that BTN1A1 will demonstrate independent expression from PD-L1 in resistant/relapsed NSCLC patients, supporting its role as a distinct biomarker. These validated methods are expected to strengthen patient selection for the ongoing STCUBE-004 trial and inform companion diagnostic development for BTN1A1-based stratification."

IO biomarker • IO Companion diagnostic • PD(L)-1 companion diagnostic • Lung Cancer • Non Small Cell Lung Cancer • Solid Tumor • Squamous Cell Carcinoma • BTN1A1

STCube's Nelmastobart Shows 26.1% Response Rate in Phase 2 Trial (Business Korea) - "An analysis of 23 patients who had undergone at least one tumor assessment as of the July 31 data cutoff showed an investigator-assessed objective response rate (ORR) of 26.1% and a disease control rate (DCR) of 87.0%. Median follow-up was 3.5 months, while median progression-free survival (mPFS) based on blinded independent central review (BICR) had not yet been reached...Of particular note were the responses observed in the EGFR mutation subgroup. An exploratory analysis showed that three of eight evaluable patients with EGFR mutations achieved an objective response, for an ORR of 37.5%, while all eight achieved disease control...STCube is continuing the trial at major medical institutions, including Samsung Seoul Hospital, with a target enrollment of 62 patients. The company plans to establish a fuller efficacy profile, including mPFS, through full enrollment and additional follow-up."

P2 data • Trial status • Non Small Cell Lung Cancer

Nelmastobart in Combination With Tas-102 and Bevacizumab in Recurrent/Metastatic Colorectal Cancer (clinicaltrials.gov) - P1 | N=45 | Not yet recruiting | Sponsor: STCube, Inc.

New P1 trial • Colon Cancer • Colorectal Cancer • Oncology • Solid Tumor

Multiplexed immunohistochemistry (mIHC) analysis and clinical outcomes of nelmastobart in combination with trifluridine/tipiracil and bevacizumab in patients with refractory colorectal cancer (phase 1b/2). (ASCO 2026) - P1/2 | "Clinical Trial Registration Number: NCT06873763 Background: Colorectal cancer (CRC) patients who are refractory or intolerant to oxaliplatin- and irinotecan-based regimens face limited treatment options and poor prognoses. BTN1A1 is consistently and highly expressed in refractory CRC (median TPS 50). mIHC analysis confirms that BTN1A1 is closely integrated with key immune checkpoints and tumor markers within the TME. Initial clinical results, which show disease control in the majority of patients, particularly within the TPS ≥50 population, support the utility of BTN1A1 as a predictive biomarker for Nelmastobart combination therapy."

Clinical • Clinical data • Combination therapy • P1/2 data • Colorectal Cancer • Oncology • Solid Tumor • BTN1A1 • CD8 • SLFN11 • YAP1

STCube will present data on nelmastobart, its BTN1A1-targeting immuno-oncology candidate, in metastatic colorectal cancer. (Korea Biomedical Review) - "According to the abstract, about 65 percent of screened patients showed high BTN1A1 expression, exceeding the company’s earlier expectation of about 40 percent. STCube will also present spatial biology analysis exploring the relationship between BTN1A1 expression and the tumor microenvironment."

Clinical • P2 data • Colorectal Cancer

STCube’s Nelmastobart phase 2 data in colorectal cancer selected for ASCO poster (The Bio) - "The data to be presented at ASCO 2026 were derived from clinical studies evaluating the combination therapy of nelmastobart with trifluridine/tipiracil (TAS-102) and bevacizumab in patients with metastatic colorectal cancer who have received third-line treatment or beyond."

P2 data • Colorectal Cancer

Biomarkers of nelmastobart efficacy: BTN1A1 expression and tumor microenvironment dynamics in colorectal cancer (AACR 2026) - P1/2 | "BTN1A1 expression is linked to key immunological alterations in the colorectal cancer TME. A composite biomarker incorporating exhausted CD8⁺ T-cell features and tumor DNA damage-related repair activity provides superior predictive value for Nelmastobart response compared with BTN1A1 alone. These findings support a multidimensional biomarker strategy for optimizing BTN1A1-targeted therapies and warrant validation in larger clinical cohorts."

Biomarker • Clinical • Tumor microenvironment • Colorectal Cancer • Oncology • Solid Tumor • BTN1A1 • CD8 • FOXP3

BTN1A1 blockade with Nelmastobart potentiates cisplatin-induced tumor suppression in NSCLC (AACR 2026) - "BTN1A1 inhibition by Nelmastobart significantly enhances cisplatin-driven immune-mediated cytotoxicity in A549 3D spheroid models while maintaining a strong safety margin in vivo. These data support the continued clinical advancement of Nelmastobart, both as a monotherapy and in combination with standard chemotherapeutic agents."

Lung Cancer • Non Small Cell Lung Cancer • Oncology • Solid Tumor • BTN1A1

STCube highlights 1st-line potential of nelmastobart in NSCLC at AACR 2026 (Korea Biomedical Review) - "Results showed that nelmastobart alone induced immune-mediated antitumor activity, while the combination with cisplatin produced greater immune activation and tumor suppression than either agent alone. The data suggest potential for use in earlier lines of treatment, although clinical validation is needed...STCube also presented a separate investigator-initiated study on colorectal cancer biomarkers at AACR 2026....The company said it plans to report interim phase 2 data later this year, focusing on colorectal cancer and NSCLC patients with high BTN1A1 expression, with additional data to be presented at major conferences."

P1/2 data • P2 data • Preclinical • Colorectal Cancer • Non Small Cell Lung Cancer

BTN1A1 and YAP1 expression as biomarkers in colon cancer: Phase 1b trial results of hSTC810 (AACR 2025) - "The subsequent Phase 1b/2 trial investigating BTN1A1 inhibition in combination with chemotherapy is currently ongoing. Colon cancer patients were enrolled in the study and treated with hSTC810 in combination with capecitabine to evaluate the efficacy and safety of the combination therapy. Findings from this Phase 1b trial suggest that targeting BTN1A1 with hSTC810 is a safe and promising therapeutic strategy for colon cancer, particularly in patients with highYAP1 expression. These results support further investigation in larger, randomized trials to confirm the efficacy and biomarker-driven utility of hSTC810 in colon cancer therapy."

Biomarker • Late-breaking abstract • P1 data • Colon Cancer • Colorectal Cancer • Oncology • Solid Tumor • BTN1A1 • YAP1

BTN1A1 and YAP1 crosstalk: A key mechanism in tumor immune evasion and therapeutic targeting (AACR 2025) - "A549lung cancer cell lines were labeled and cultured as 3D spheroids with human peripheral bloodmononuclear cells (hPBMC), hSTC810, and docetaxel...Similarly, LS1034 colon cancer celllines were labeled and cultured as 3D spheroids with hPBMC, hSTC810, and TAS-102...By simultaneously downregulating YAP1-driven oncogenic pathways andenhancing immune activation, BTN1A1 inhibition offers a novel dual mechanism for combatinglung and colon cancers. These findings pave the way for future clinical exploration of BTN1A1as a key target in cancer immunotherapy."

IO biomarker • Late-breaking abstract • Colon Cancer • Colorectal Cancer • Lung Cancer • Oncology • Solid Tumor • BTN1A1 • YAP1

The company reported that...enrollment in the non-small cell lung cancer Phase 2 trial is also progressing smoothly, indicating that overall clinical development is advancing ahead of schedule. (BioNews)

Enrollment status • Non Small Cell Lung Cancer

[AACR] STCube to present two posters on its immuno-oncology candidate Nelmastobart (BioNews) - "The poster presentations will cover the results of a multi-biomarker analysis performed on patient tissue samples obtained from investigator-initiated Phase 1b/2 clinical trials in colorectal cancer, and preclinical data demonstrating enhanced immune-mediated anti-tumor activity when Nelmastobart is administered in combination with other drugs in a non-small cell lung cancer model...The findings confirmed that not only BTN1A1 expression alone but also complex biological indicators, such as the spatial infiltration patterns of exhausted CD8⁺ T cells and DNA damage repair-related activity, enables a more accurate prediction of therapeutic response to Nelmastobart."

P1/2 data • Preclinical • Colorectal Cancer

STCube reports 2 PRs and 4 SDs with nelmastobart in Phase 1b colorectal cancer trial [Google translation] (BioNews) - "These patient groups demonstrated a positive correlation between BTN1A1 expression and treatment responsiveness. In addition, immunofluorescence analysis showed that the median proportion of nuclear YAP1-expressing tumor cells among BTN1A1-positive cells was 49.89%. Clinical benefit was found to be particularly high in patients who were positive for both biomarkers....'Based on this, we are developing a refined predictive model and are optimizing our 2 clinical trial development strategy, thereby further strengthening the development potential of nelmastobart.'"

P1 data • Trial status • Colorectal Cancer

BTN1A1 expression as a biomarker for patient selection: Phase 1b IHC analysis and clinical outcomes supporting a biomarker-guided phase 2 trial in colorectal cancer. (ASCO-GI 2026) - P1/2 | "Background: Metastatic colorectal cancer (CRC) has poor prognosis in patients resistant or intolerant to oxaliplatin- and irinotecan-based chemotherapy, and durable responses to salvage regimens such as trifluridine/tipiracil plus bevacizumab remain limited...Nelmastobart, a first-in-class anti-BTN1A1 monoclonal antibody, is being tested in the STCUBE-003 Phase Ib/II trial (NCT06873763) in combination with trifluridine/tipiracil and bevacizumab... BTN1A1 was consistently expressed across all tumors, with high TPS associated with favorable outcomes. These findings support BTN1A1 as a robust biomarker for patient selection and provide rationale for the ongoing BTN1A1-guided Phase 2 trial."

Biomarker • Clinical • Clinical data • IO biomarker • P1 data • P2 data • Colorectal Cancer • Gastrointestinal Cancer • Oncology • Solid Tumor • BTN1A1 • CD8 • PD-L1 • SLFN11 • YAP1

Nelmastobart in Combination With Docetaxel in Non Small Cell Lung Cancer (clinicaltrials.gov) - P2 | N=62 | Recruiting | Sponsor: STCube, Inc.

New P2 trial • Lung Cancer • Non Small Cell Lung Cancer • Oncology • Solid Tumor

Professor Lee Soo-hyun and her research team from the Department of Oncology at Korea University Anam Hospital presented findings from the Phase 1b and Phase 2 trials evaluating the combination therapy of Nelmastobart + capecitabine. [Google translation] (BioNews) - "Among them, 30 patients (57.7%) had liver metastases, 42 (80.8%) had microsatellite-stable (MSS) colorectal cancer, and 23 (44.2%) carried genetic mutations (RAS or BRAF). In the Phase 2b trial, no DLTs associated with nelmastobart were reported, and the RP2D was confirmed as nelmastobart 800 mg and capecitabine 1000 mg/m2....The efficacy analysis (data cutoff date: June 13, 2025) revealed that 7 out of the 52 enrolled patients achieved a partial response (PR), while 33 exhibited stable disease (SD), resulting in an objective response rate (ORR) of 13.5% (7/52) and a disease control rate (DCR) of 77.0% (40/52). The median progression-free survival (mPFS) was 4.2 months, indicating superior therapeutic efficacy compared with the standard of care (ORR 0-6%, mPFS 2-3 months)....As several patients remain on treatment, the final analysis, including overall survival (OS), has been rescheduled for release in H1 2026."

P1/2 data • Colorectal Cancer

STCube's Phase 1b clinical trial in colorectal cancer demonstrates tumor reduction in all patients, highlighting strong efficacy and tolerability [Google translation] (BioNews) - "The Phase 1b safety evaluation revealed no dose-limiting toxicities (DLTs). The most frequently observed adverse events were leukopenia and neutropenia, both associated with chemotherapy rather than with Nelmastobart itself. Based on these findings, the recommended RP2D was established as Nelmastobart 800 mg, TAS-102 35 mg/m2, and bevacizumab 5 mg/kg....According to the company, based on the predefined efficacy criteria (BTN1A1 TPS ≥ 50), the objective response rate (ORR) was 40% (2/5), and the disease control rate (DCR) reached 100% (5/5), indicating that the initial data exceeded the current standard of care."

P1 data • Colorectal Cancer

A phase 1b/2 study of Nelmastobart with Capecitabine in Patients with Refractory mCRC (SITC 2025) - "Background Patients with metastatic colorectal cancer (mCRC) who are refractory to or intolerant of oxaliplatin and irinotecan have few effective treatment options.1 2 Nelmastobart, a humanized monoclonal antibody targeting Butyrophilin 1A1 (BTN1A1), has shown preclinical and clinical antitumor activity with immunomodulatory effects.3 This study evaluated the safety and efficacy of Nelmastobart combined with capecitabine in patients with refractory mCRC.Methods This multicenter, open-label, phase 1b/2 study included a dose-escalation safety lead-in followed by dose expansion. These findings support further evaluation in larger, randomized trials, with an emphasis on biomarker-driven patient selection strategies.Acknowledgements This study was supported by grants and research funds from STCube Pharmaceutical.Trial Registration NCT05990543Ethics Approval This study was approved by the IRB of Korea University Anam Hospital under the designation 2023AN0515.Consent Written..."

Clinical • Late-breaking abstract • P1/2 data • Colorectal Cancer • Oncology • BTN1A1

Nelmastobart Combination Shows Excellent Tolerability and Early Antitumor Activity in Refractory mCRC (SITC 2025) - P1, P1/2 | "This abstract reports Phase 1b safety run-in results focusing on safety, pharmacokinetics (PK), and preliminary efficacy.Methods This Phase 1b safety run-in of the open-label Phase 1b/2 trial evaluates Nelmastobart with trifluridine/tipiracil and bevacizumab in patients with metastatic or recurrent CRC refractory or intolerant to oxaliplatin- and irinotecan-based therapy. The study was conducted in accordance with the Declaration of Helsinki and with all applicable laws and regulations of the locale and country where the study was conducted, and in compliance with Good Clinical Practice Guidelines. The number of the IRB approval is 2025AN0204.Consent In this study, we don't contain sensitive and identifiable information about patients."

Late-breaking abstract • Colorectal Cancer • Oncology • BTN1A1