Stomach Cancer Immunotherapy and Targeted Therapy
Introduction
Gastric cancer, or stomach cancer, is still one of the most virulent cancers globally, particularly in nations such as China, Japan, and South Korea. Although surgery and chemotherapy have been the cornerstone of treatment for a long time, stomach cancer immunotherapy and targeted therapy are now transforming the management of this disease. These cutting-edge treatments bring new hope, especially to patients with advanced or refractory disease, by targeting more specifically cancer cells and enhancing the body’s immune system.
This article gives a general picture of the contribution of targeted therapies and immunotherapy to the treatment of stomach cancer, such as drug choices, efficacy, prices, and current clinical trials in China.
About the Disease
Stomach cancer originates from the lining of the stomach and is usually classified as adenocarcinoma. It tends to spread quickly if not detected early. Risk factors include:
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Chronic H. pylori infection
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Smoking and alcohol consumption
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Diet high in salty and smoked foods
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Genetic predisposition
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Family history of stomach cancer
Staging includes localized, locally advanced, and metastatic disease. Advanced stages are often treated with systemic therapies like chemotherapy, immunotherapy, and targeted drugs.
Indications
Immunotherapy and targeted therapy are generally recommended in the following settings:
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Advanced or metastatic stomach cancer
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HER2-positive gastric cancer
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MSI-H (microsatellite instability-high) or dMMR (deficient mismatch repair) tumors
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PD-L1 positive tumors
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Patients who have failed standard chemotherapy regimens
These therapies are not typically used for early-stage cancers unless part of a clinical trial.
Treatment Details
Immunotherapy
Immunotherapy uses drugs that help the immune system recognize and destroy cancer cells. The most widely used types in stomach cancer are immune checkpoint inhibitors:
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PD-1 inhibitors: Block the PD-1 receptor on immune cells, helping T-cells attack tumors.
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Examples: Nivolumab (Opdivo), Pembrolizumab (Keytruda)
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These drugs are used alone or in combination with chemotherapy or other targeted therapies.
Targeted Therapy
Targeted therapy focuses on specific genes, proteins, or tissue environments that contribute to cancer growth.
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HER2 inhibitors: For tumors overexpressing the HER2 protein.
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Example: Trastuzumab (Herceptin)
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VEGF inhibitors: Target tumor blood supply.
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Example: Ramucirumab (Cyramza)
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Claudin 18.2 targeting drugs: An emerging field in Asia with promising clinical data.
Medicines Used
Here’s a breakdown of common immunotherapy and targeted therapy drugs used in stomach cancer:
| Drug Name | Type | Indication |
|---|---|---|
| Nivolumab | PD-1 inhibitor | Advanced gastric cancer, often with chemo |
| Pembrolizumab | PD-1 inhibitor | MSI-H, PD-L1 positive tumors |
| Trastuzumab | HER2-targeted | HER2-positive gastric and gastroesophageal cancer |
| Ramucirumab | VEGFR-2 inhibitor | Second-line treatment with paclitaxel |
| Zolbetuximab | Claudin 18.2 | Trials in Claudin 18.2-positive tumors |
These are often combined with chemotherapy agents like 5-FU, oxaliplatin, or capecitabine for enhanced efficacy.
Effectiveness
The effectiveness of immunotherapy and targeted therapies depends on tumor type and genetic markers:
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HER2-positive gastric cancer: Trastuzumab combined with chemo improves survival (ToGA trial).
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MSI-H/dMMR tumors: Respond very well to immune checkpoint inhibitors.
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PD-L1-positive tumors: Nivolumab + chemotherapy improves overall survival.
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Ramucirumab: Effective in second-line treatment, prolonging progression-free survival.
Response rates vary:
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Checkpoint inhibitors: 15–25% (higher in biomarker-positive tumors)
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HER2-targeted therapy: 40–60% response rate
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VEGF inhibitors: Moderate improvement in survival, especially in second-line use
Risks and Side Effects
Immunotherapy and targeted therapy are usually better tolerated than chemotherapy but may still cause side effects.
Immunotherapy Side Effects:
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Fatigue
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Diarrhea
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Skin rashes
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Loss of appetite
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Immune-related adverse events (e.g., thyroiditis, pneumonitis, hepatitis)
Targeted Therapy Side Effects:
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Trastuzumab: Heart toxicity (rare), infusion reactions
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Ramucirumab: High blood pressure, bleeding risk
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Claudin-targeted agents: Gastrointestinal issues
All patients should be closely monitored for organ function and inflammatory markers during treatment.
Recovery and Aftercare
While not curative for most advanced cases, these therapies significantly improve the quality of life and progression-free survival.
During treatment:
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Blood tests to monitor organ function
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Tumor marker tests (CEA, CA 19-9)
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Imaging every 2–3 months
After treatment:
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Continued monitoring for disease progression
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Nutritional and psychological support
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Long-term surveillance for side effects
Patients on immunotherapy may require extended follow-up due to the potential for delayed immune-related toxicities.
Cost and Availability
Immunotherapy and targeted therapies are costly but increasingly available in major cancer centers worldwide.
In India:
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Trastuzumab: ₹50,000 – ₹80,000 ($600 – $960) per dose
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Nivolumab/Pembrolizumab: ₹1.5 – ₹2.5 lakhs ($1,800 – $3,000) per cycle
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Ramucirumab: ₹90,000 – ₹1.2 lakhs ($1,100 – $1,400) per cycle
In China:
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Immunotherapy: ¥15,000 – ¥25,000 ($2,000 – $3,500) per cycle
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Targeted therapy: ¥10,000 – ¥20,000 ($1,400 – $2,800) per dose
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Government insurance and patient assistance programs reduce costs for eligible patients
Patient Experiences
Real patient stories reflect the positive impact of these therapies:
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“Nivolumab gave me new hope after chemo failed.”
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“With Trastuzumab, my scans showed tumor shrinkage in just a few cycles.”
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“Side effects were manageable, and I felt stronger than during chemo.”
Patients also emphasized the importance of genetic testing and biomarker analysis before starting treatment.
Cost in Countries Like China, India, Israel, Malaysia, Korea, Thailand, Turkey, and USA
| Country | Average Cost per Cycle (USD) | Annual Treatment Cost (USD) |
|---|---|---|
| China | $2,000 – $3,500 | $20,000 – $40,000 |
| India | $1,000 – $3,000 | $15,000 – $30,000 |
| Israel | $4,000 – $7,000 | $40,000 – $60,000 |
| Malaysia | $2,500 – $5,000 | $30,000 – $50,000 |
| South Korea | $3,000 – $6,000 | $35,000 – $60,000 |
| Thailand | $2,500 – $5,500 | $30,000 – $55,000 |
| Turkey | $2,000 – $4,500 | $25,000 – $50,000 |
| USA | $6,000 – $10,000 | $60,000 – $100,000 |
Prices vary depending on dose, drug combination, and insurance.
List of Ongoing Clinical Trials in China
China is leading global clinical research in targeted and immunotherapies for stomach cancer. Key trials include:
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Nivolumab + FLOT Regimen
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Neoadjuvant use before surgery
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Status: Phase III
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Claudin 18.2 Targeted Antibody Trials (e.g., Zolbetuximab)
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Focus: Claudin-positive gastric cancers
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Status: Phase II/III
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PD-1 Inhibitors + Ramucirumab
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Dual targeting of immune and angiogenesis pathways
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Status: Phase II
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Tislelizumab + Chemotherapy
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PD-1 inhibitor developed in China
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Status: Phase III
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Next-generation HER2-targeted ADCs
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Antibody-drug conjugates for HER2-positive tumors
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Status: Early Phase I/II
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Top trial centers: Fudan University Cancer Hospital, Sun Yat-sen University Cancer Center, National Cancer Center of China.
FAQ
Is immunotherapy approved for stomach cancer?
Yes, especially for MSI-H, PD-L1-positive, and HER2-positive advanced stomach cancers.
Do I need genetic testing before these treatments?
Yes. Testing for HER2, MSI, and PD-L1 expression is essential to determine eligibility.
Are side effects less than chemotherapy?
Usually, yes. Immunotherapy and targeted therapy are often better tolerated but require ongoing monitoring.
Can these therapies cure stomach cancer?
In advanced stages, they control the disease rather than cure it. They improve survival and quality of life.
Is it covered by insurance?
Partially. Some policies in India and China cover portions of the cost. Assistance programs also exist.