CAR-T Therapy in Oncology. Where It Already Works and Where the Journey Is Just Beginning

Over the past few weeks, I have received several requests and had in-depth conversations with patients about CAR-T therapy in oncology. The technology is genuinely impressive. Yet I sense that patient expectations are sometimes running ahead of the evidence. CAR-T has undoubtedly become a routine part of modern medicine — but primarily in hematology. For solid tumors, this field is still very much in an active investigation phase rather than a stage of ready, widely available solutions.

What You Need to Know

• CAR-T stands for Chimeric Antigen Receptor T-cell therapy. A patient’s own T cells are collected, genetically engineered in a laboratory to recognize a specific protein on cancer cells, and then reinfused.
• Several CAR-T products have received regulatory approval in the United States (FDA) and Europe (EMA) for specific blood cancers.
• For solid tumors — carcinomas of the breast, lung, colorectum, stomach, and others — no approved CAR-T products exist yet. Research is active and promising, but results in the clinic are still preliminary.
• CAR-T is not chemotherapy. It is a one-time infusion, but it requires complex preparation, specialized infrastructure, and carries specific toxicity risks (cytokine release syndrome, neurotoxicity).
• Cost and availability remain significant barriers in many countries, including Russia.

Where CAR-T Already Works

The clearest, most well-established results are in blood cancers. Axicabtagene ciloleucel (axi-cel), tisagenlecleucel (tisa-cel), lisocabtagene maraleucel (liso-cel), and idecabtagene vicleucel (ide-cel), among others, have shown durable remissions in patients with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, mantle cell lymphoma, chronic lymphocytic leukemia (CLL), and multiple myeloma.

In some of these settings, CAR-T has moved into earlier lines of therapy — no longer only a last-resort option. For a carefully selected patient with relapsed/refractory disease, CAR-T can achieve complete remissions that last years. This is genuinely transformative for those who qualify.

Why Solid Tumors Are Harder

The biology of solid tumors creates obstacles that blood cancers largely do not. First, solid tumors lack truly tumor-specific surface targets. In leukemia, CD19 is expressed reliably on malignant B cells; eliminating all CD19-positive cells is manageable. In solid tumors, candidate targets like HER2 or EGFR are also expressed on healthy tissues, raising the risk of serious off-target toxicity.

Second, the tumor microenvironment in solid tumors is immunosuppressive. CAR-T cells must physically traffic into a dense, hypoxic, immunologically hostile mass, where they quickly become exhausted. The tumor “teaches” the immune system to stand down rather than attack. This is a fundamentally different challenge from what CAR-T faces in blood cancers, where tumor cells circulate freely and are more accessible.

Where the Most Interesting Signals Are Now

Three areas deserve particular attention for patients with solid tumors:

Brain tumors (glioblastoma and diffuse midline glioma). A 2024 publication in Nature described GD2-targeting CAR-T cells in children with H3K27M-mutant diffuse midline glioma — a disease with essentially no effective standard therapy. Some patients showed meaningful radiographic and clinical responses. IL13Rα2-targeting CAR-T is also being studied in glioblastoma. These are very early signals, but in a population with almost no options, they are noteworthy.

Gastrointestinal cancers with CLDN18.2 expression. Satricabtagene autoleucel (satri-cel), a CAR-T targeting Claudin 18.2, was evaluated in a Lancet Oncology study in patients with gastric and gastroesophageal junction cancer. In heavily pretreated patients with high CLDN18.2 expression, objective response rates were encouraging. CLDN18.2 is also expressed in pancreatic cancer, expanding potential interest. This remains investigational.

Hepatocellular carcinoma. GPC3 (glypican-3) is overexpressed in most hepatocellular carcinomas and is relatively tumor-specific. GPC3-targeting CAR-T cells are in early-phase trials with initial signals of activity. Given the limited options in advanced liver cancer, this direction is being watched closely.

When a Second Opinion Is Especially Helpful

• You have a hematologic malignancy and have relapsed after two or more prior lines of therapy — and no one has discussed CAR-T;
• You have a solid tumor with CLDN18.2, GD2, or GPC3 expression and want to understand clinical trial options;
• You have read about CAR-T and want an honest assessment of whether it applies to your specific diagnosis;
• You want to review all available treatment options after standard therapies have been exhausted.

What to Prepare for Your Consultation

To make the conversation as substantive as possible:

• Pathology report with histology and, if available, immunohistochemistry results;
• Molecular profiling results (NGS panel, CLDN18.2, HER2, PD-L1, MSI status, or other relevant markers);
• Summary of all prior treatment lines with response and reason for discontinuation;
• Most recent imaging (CT, PET-CT, MRI) with the radiologist’s report;
• Complete blood count and metabolic panel;
• Current medications and a description of significant comorbidities.

Frequently Asked Questions

More answers on the FAQ page.