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CLINICAL GUIDE ยท SOLID TUMOUR CELL THERAPY

SOLID-TUMOUR CAR-T IN CHINA:
CLDN18.2, GPC3, GD2 & MESOTHELIN

Blood cancers respond to CAR-T reliably โ€” solid tumours are the next frontier. China is running more solid tumour CAR-T trials than any other country, with early signals of activity in gastric, liver, and paediatric cancers.

analyticsAt a Glance

  • check_circleSolid tumours resist CAR-T due to immunosuppressive microenvironment, antigen heterogeneity, and T-cell exhaustion
  • check_circleCLDN18.2 is China's largest solid tumour CAR-T target โ€” multiple Phase I/II trials in gastric and pancreatic cancer
  • check_circleGPC3 CAR-T shows early response signals in hepatocellular carcinoma at PUTH and Ruijin Hospital
  • check_circleCancerFax facilitates eligibility review and access to solid tumour CAR-T trials for international patients
Reviewed by: CancerFax Medical Team, Oncology & Haematology SpecialistsLast reviewed: June 9, 2026

Why Solid Tumours Are Harder for CAR-T Therapy

CAR-T therapy transformed outcomes in blood cancers because target antigens (CD19, BCMA) are expressed uniformly and CAR-T cells can circulate freely. Solid tumours present four distinct barriers that collectively explain why response rates have been far lower.

โ€œSolid tumour CAR-T is not a matter of whether โ€” it is a matter of engineering around four well-defined biological barriers. China's programmes are attacking all four simultaneously.โ€
  • Immunosuppressive Tumour Microenvironment (TME)

    Solid tumours recruit regulatory T-cells, MDSCs, and M2 macrophages that actively suppress CAR-T activity. High TGF-ฮฒ and IL-10 levels within the tumour exhaust infiltrating T-cells before they can eliminate cancer cells.

  • Antigen Heterogeneity and Loss

    Solid tumours are genetically unstable โ€” tumour cells can downregulate or lose the target antigen under CAR-T selection pressure. Cells that never expressed the antigen survive and re-populate the tumour.

  • Poor T-Cell Trafficking to Tumour

    CAR-T cells must physically reach the tumour mass, but abnormal tumour vasculature and lack of appropriate chemokine gradients prevent efficient homing of CAR-T cells to the tumour site.

  • T-Cell Exhaustion

    Persistent antigen exposure in the immunosuppressive TME drives CAR-T cells into an exhausted phenotype โ€” expressing PD-1, TIM-3, and LAG-3 โ€” progressively losing cytotoxic function over days to weeks.

China's Leading Solid Tumour CAR-T Targets

Chinese programmes target solid tumour antigens that are highly expressed in common cancer types with high unmet need โ€” particularly gastric, liver, and paediatric cancers where China has the world's largest patient populations.

Target AntigenCancer TypesLead InstitutionsCurrent Phase
CLDN18.2 (Claudin 18.2)Gastric cancer, pancreatic cancer, oesophageal adenocarcinomaPUTH, Ruijin Hospital, RenJi Hospital ShanghaiPhase I/II โ€” multiple trials active
GPC3 (Glypican-3)Hepatocellular carcinoma (HCC), hepatoblastomaPUTH, Ruijin Hospital Shanghai, West China HospitalPhase I/II
GD2 (Disialoganglioside)Neuroblastoma, osteosarcoma, small cell lung cancerCAMS Institute, Beijing Children's HospitalPhase I โ€” paediatric focus
MesothelinMalignant mesothelioma, ovarian cancer, non-small cell lung cancerSYSUCC Guangzhou, Zhongshan HospitalPhase I/II
EGFRvIII / EGFRGlioblastoma (GBM), head and neck squamous cellXuanwu Hospital Beijing, Huashan Hospital ShanghaiPhase I

CLDN18.2 CAR-T: China's Largest Solid Tumour Programme

CLDN18.2 (Claudin 18.2) is a tight junction protein expressed in gastric mucosa normally, but re-expressed at high levels in 40โ€“50% of gastric cancers and 30โ€“35% of pancreatic cancers โ€” making it one of the most attractive solid tumour targets globally.

  1. 1

    Why CLDN18.2 Is Targetable

    CLDN18.2 is expressed in normal gastric mucosa but is not accessible to the immune system (located on the luminal surface). In gastric and pancreatic cancer, tight junction disruption exposes CLDN18.2 to circulating immune cells and CAR-T cells.

  2. 2

    Patient Selection: IHC Testing Required

    CLDN18.2 CAR-T trials require IHC (immunohistochemistry) confirmation of CLDN18.2 expression at โ‰ฅ2+ intensity in โ‰ฅ40โ€“50% of tumour cells on archival or fresh biopsy. CancerFax helps patients obtain CLDN18.2 testing before applying.

  3. 3

    Early Clinical Results

    Phase I data from PUTH and RenJi Hospital have shown disease control rates of 50โ€“70% in heavily pretreated gastric cancer patients, with partial responses in some cases. Combination with anti-PD-1 is being explored to overcome TME suppression.

  4. 4

    Combination Strategy: CAR-T + Anti-PD-1

    Several Chinese CLDN18.2 CAR-T trials include PD-1 checkpoint inhibitor combination arms to prevent exhaustion in the immunosuppressive gastric cancer microenvironment โ€” a strategy showing improved CAR-T persistence in early data.

Solid Tumour CAR-T โ€” Key Early Results

Phase I solid tumour CAR-T data from Chinese centres demonstrate early proof-of-concept activity across multiple targets, with CLDN18.2 and GPC3 showing the most consistent signals.

  • 50โ€“70%Disease control rate โ€” CLDN18.2 CAR-T in gastric cancer (Phase I)Includes partial responses and stable disease; from PUTH and RenJi Hospital Phase I data.
  • ~30%Objective response rate โ€” GPC3 CAR-T in HCC (Phase I)Partial responses in heavily pretreated hepatocellular carcinoma; being combined with sorafenib in Phase II.
  • 40โ€“50%CLDN18.2 expression rate in gastric cancerProportion of gastric cancers that are CLDN18.2 IHC positive โ€” the key patient selection biomarker.

Target Antigen Expression โ€” Patient Population Estimates

Proportion of patients with each cancer type who express the target antigen at levels sufficient for CAR-T trial eligibility, based on published IHC data.

CLDN18.2 Expression by Cancer Type

Based on published IHC cohort studies; โ‰ฅ2+ in โ‰ฅ40% cells threshold used

  • Gastric adenocarcinoma~48%
  • Pancreatic ductal adenocarcinoma~35%
  • Oesophageal adenocarcinoma~20%

Other Solid Tumour Target Positivity Rates

GPC3 by Wangchun et al; GD2 by paediatric oncology cohort studies; mesothelin by IHC

  • GPC3 in HCC~75%
  • GD2 in neuroblastoma~90%
  • Mesothelin in mesothelioma~80%
  • Mesothelin in ovarian cancer~70%

Solid Tumour vs Blood Cancer CAR-T: Realistic Expectations

Patients considering solid tumour CAR-T trials should enter with a clear understanding of where the evidence currently stands โ€” solid tumour CAR-T is promising but not yet at the efficacy level of blood cancer CAR-T.

What Solid Tumour CAR-T Can Offer Now

  • Access to investigational therapy when standard options are exhaustedFor patients with CLDN18.2+ gastric cancer or GPC3+ HCC post-standard therapy, Chinese Phase I/II trials offer a legitimate investigational option.
  • Disease control rather than cure as realistic goalPhase I data show disease stabilisation and partial responses โ€” meaningful clinical benefit in heavily pretreated patients even without complete remission.
  • Combinations improving outcomesAnti-PD-1 + CAR-T combinations are producing better persistence data in early combination cohorts.

Current Limitations vs Blood Cancer CAR-T

  • Response rates are lower than in blood cancersComplete remission rates of 70โ€“90% seen in CD19 CAR-T are not yet replicated in solid tumours โ€” current ORR is 20โ€“40% in most Phase I datasets.
  • Response duration is often shorterAntigen escape and T-cell exhaustion in the TME limit the duration of response compared to sustained remissions seen in B-cell malignancies.
  • All access is via clinical trial โ€” no approved solid tumour productsNo solid tumour CAR-T product has NMPA or FDA approval; access is exclusively through trial enrolment.

Frequently Asked Questions โ€” Solid Tumour CAR-T

Common questions from patients with solid tumours exploring CAR-T trials in China.

Eligibility and Testing

  • How do I know if my cancer expresses CLDN18.2 or GPC3?

    Both markers can be tested by immunohistochemistry (IHC) on archived tumour tissue from a prior biopsy or surgical specimen. Most major pathology laboratories in India, the Middle East, and Europe can perform CLDN18.2 and GPC3 IHC. CancerFax can advise on where to get this testing done and how to submit results for eligibility pre-screening at Chinese trial sites.

  • My gastric cancer is CLDN18.2 negative โ€” are there other options?

    Yes. CLDN18.2-negative gastric cancer patients may still have other solid tumour CAR-T options depending on molecular profiling. Some patients express mesothelin, HER2, or EGFR at levels sufficient for other trials. CancerFax reviews the full molecular profile and matches it against the current trial landscape at partner centres.

  • Do I have to travel to China for the entire treatment?

    For most solid tumour CAR-T trials, yes โ€” the infusion and at least 4โ€“6 weeks of monitoring must occur at the trial site in China. Some programmes allow return home after the mandatory monitoring period with remote follow-up. CancerFax coordinates all logistics including medical visa, travel, accommodation, and interpretation for the entire stay.

  • Are Chinese solid tumour CAR-T trials free?

    Some trials are sponsor-funded and provide the CAR-T product at no cost to the patient, while others are patient-paid. In both cases, hospitalisation, monitoring, and supportive care costs are typically borne by the patient. CancerFax clarifies the financial model for each specific trial before patients commit to the process.

How CancerFax Helps

CancerFax is a specialist cancer access and patient-navigation platform. We help patients and families understand their options, organise medical records, coordinate hospital communication, and support cross-border treatment planning where appropriate.

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Medical Record Review

We help collect and organise reports, scans, pathology, biomarker results, and treatment history for structured case review.

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Eligibility Coordination

We communicate with hospitals or trial teams to assess whether a case may be suitable for further screening.

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Hospital Communication

We support appointment coordination, document submission, translation, and direct communication with international departments.

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Travel & Admission Support

For international patients, we help with practical coordination โ€” travel planning, hospital admission guidance, and local support.

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Treatment & Trial Navigation

If this option is not suitable, we help explore other relevant treatments, clinical trials, or advanced care pathways.

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End-to-end Coordination

From inquiry through to follow-up, our coordinators provide a single point of contact for the family.

CancerFax does not guarantee treatment access, eligibility, or clinical outcome. Our role is to help patients access accurate information, structured review, and appropriate specialist pathways.

Does Your Cancer Type Have a Solid-Tumour CAR-T Trial in China?

CancerFax reviews your pathology, molecular markers (CLDN18.2, GPC3, GD2, mesothelin expression), and medical history to identify which Chinese trials you may be eligible for.

This content is for informational purposes only and does not constitute medical advice. Always consult a qualified oncologist before making treatment decisions.