Oncology · Medical Literature
VEBrant: a multicenter, phase II study of MET inhibitor vebreltinib combined with PD-1-based immunotherapy in advanced clear cell sarcoma.
Abstract
Clear cell sarcoma (CCS) is an ultra-rare sarcoma with no established standard systemic therapy of proven efficacy. Mesenchymal-epithelial transition factor (MET) overexpression drives CCS progression and serves as a promising therapeutic target. Vebreltinib is a highly selective MET inhibitor with potential therapeutic benefits for CCS. Additionally, given that MET and programmed cell death protein 1 (PD-1) are both downstream molecules of melanocyte transcription factor (MITF), combined MET and PD-1 inhibition may block the MITF pathway more effectively. Moreover, aberrant MET activation indirectly upregulates programmed death ligand 1 (PD-L1), causing immune escape and resistance to PD-1 inhibitors; MET inhibition may potentially reverse this resistance. Here, we describe the rationale and design of VEBrant, a multicenter, phase II study aimed to evaluate the efficacy and safety of vebreltinib combined with PD-1-based immunotherapy in advanced CCS. Thirty patients will be enrolled, with the treatment cohort receiving combination therapy of vebreltinib and PD-1 inhibitor, and a reference cohort receiving physician's choice therapy or best supportive care. Primary endpoint is Objective Response Rate (ORR) by Simon two-stage design. This study will provide evidence for vebreltinib combined with PD-1-based immunotherapy and improve understanding of advanced CCS management.Clinical trial registration: www.clinicaltrials.gov identifier is NCT07153887.
Clinical relevance
In patients with advanced clear cell sarcoma (CCS), does the combination of the selective MET inhibitor vebreltinib with PD-1-based immunotherapy produce meaningful objective responses compared with physician's choice therapy or best supportive care? __SNAPSHOT__ {"studyDesign":"Multicenter, prospective, phase II study with two non-randomized cohorts: a treatment cohort (vebreltinib + PD-1 inhibitor) and a reference cohort (physician's choice or best supportive care); NCT07153887","setting":"Multicenter; China (institutional affiliation not fully specified in abstract); trial registration NCT07153887","sampleSize":"Planned n=30 total (treatment cohort and reference cohort sizes not individually specified in the abstract)","population":"Adults with advanced (unresectable or metastatic) clear cell sarcoma; detailed eligibility criteria (performance status, prior therapy lines, MET expression requirements) not reported in the available abstract excerpt","intervention":"Vebreltinib (highly selective MET inhibitor, 200 mg twice daily orally per NCT registration) combined with a PD-1 inhibitor (specific agent not specified in the abstract excerpt)","comparator":"Physician's choice systemic therapy or best supportive care (reference cohort); non-randomized, non-blinded","primaryOutcome":"Objective response rate (ORR) — exact response criteria (e.g., RECIST v1.1) and threshold for success not fully reported due to abstract truncation","followUp":"Not reported in the available abstract excerpt","fundingSource":"Industry (Beijing Pearl Biotechnology Co., Ltd., confirmed via conference disclosure)"}
Key findings
This publication describes the rationale and study protocol only; no efficacy or safety results are reported within the available abstract, which is truncated prior to the complete primary endpoint definition. The biological rationale articulated in the abstract centers on three mechanistic premises: (1) MET overexpression drives CCS progression and is a potential therapeutic target; (2) both MET and PD-1 are downstream effectors of the melanocyte transcription factor (MITF), so dual inhibition may more completely block the MITF pathway; and (3) aberrant MET activation upregulates PD-L1, promoting immune escape and potential resistance to PD-1 blockade, which MET inhibition may reverse. No primary outcome data, response rates, progression-free survival, overall survival, confidence intervals, p-values, or adverse event rates are available from this protocol paper. Separately, an ASCO 2026 abstract (Abstract 11503, Li et al.) reporting preliminary VEBrant results cited an ORR of 41.2% and a median PFS of 4.14 months at a median follow-up of 134 days, with median OS not reached — but these figures derive from a distinct conference presentation, are not part of this protocol publication, have not undergone full peer review, and should be interpreted with caution pending full manuscript.
Practice implications
This paper establishes the scientific rationale and trial architecture for VEBrant but does not provide efficacy or safety evidence. The study addresses a critical unmet need: CCS is an ultra-rare sarcoma with no established systemic therapy of proven efficacy, and the MET–MITF–PD-L1 mechanistic axis provides a biologically coherent basis for the combination strategy. The planned enrollment of 30 patients across both cohorts is extremely small, which reflects the rarity of the disease rather than a powered comparative design; the trial is not randomized, precluding causal inference regarding the combination versus the reference cohort. Whether the reference cohort is prospectively concurrent, historical, or otherwise defined is not specified in the available abstract. Patients not represented include those with non-MET-driven CCS variants, pediatric patients, and those with significant comorbidities or prior MET-directed therapy. Practice should not change on the basis of this protocol paper alone. The separately reported preliminary ASCO 2026 data (ORR ~41%) are hypothesis-generating but require full peer-reviewed publication with mature follow-up before meaningful clinical translation. Additionally, only the abstract was available for this review; the full-text protocol paper may contain methodological detail, statistical assumptions, and eligibility criteria that would materially affect interpretation. __LIMITATIONS__ Protocol/design paper only — no efficacy or safety results are presented or evaluable from the available abstract,Abstract is truncated; the primary endpoint definition, success threshold, and statistical design are incompletely reported,Extremely small planned sample size (n=30 total across both cohorts) severely limits statistical power and generalizability,Non-randomized, open-label design with a non-concurrent reference cohort introduces substantial selection bias and confounding,Ultra-rare disease population makes enrollment challenging and may lead to significant baseline heterogeneity between cohorts,Specific PD-1 inhibitor agent, dosing schedule, and combination sequencing are not defined in the available abstract,MET overexpression as a patient selection criterion and its exact measurement threshold are not described in the available abstract,Industry funding (Beijing Pearl Biotechnology Co., Ltd.) introduces potential for sponsorship bias in design and reporting,Generalizability may be limited if enrollment is primarily within a single country or healthcare system,Surrogate endpoint (ORR) may not capture long-term clinical benefit in a disease where disease stabilization may be meaningful __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ VEBrant is a small, non-randomized, phase II protocol studying vebreltinib plus PD-1 inhibition in the ultra-rare, treatment-refractory disease clear cell sarcoma, grounded in a mechanistically coherent MET–MITF–PD-L1 rationale. This publication reports only the study design and should not influence clinical practice; preliminary conference data suggest potential activity but require full peer-reviewed results with mature follow-up before any practice implications can be drawn. Clinicians managing CCS should consider enrollment in this or similar trials given the absence of any established systemic therapy of proven efficacy.