Drug Overview

Sintilimab is a modern cancer medication that helps your body’s own immune system find and destroy cancer cells. It belongs to a group of advanced treatments known as “checkpoint inhibitors.” Because it works by boosting the immune system’s natural ability to fight disease, it is a primary example of Immunotherapy and Targeted Therapy.

This medication is specifically designed to be highly precise, acting like a “Smart Drug” to unlock the body’s natural defenses that the cancer has tried to shut down. It is used internationally to treat various aggressive cancers that have not responded well to traditional chemotherapy.

• Generic name: Sintilimab (also known as IBI308)
• US Brand names: Tyvyt (Note: Primarily approved and marketed in China; available through specific clinical pathways or international markets)
• Drug Class: PD-1 Blocking Antibody (Immune Checkpoint Inhibitor)
• Route of Administration: Intravenous (IV) infusion
• FDA Approval Status: Investigational in the US (Currently undergoing review and clinical trials for US market entry)

What Is It and How Does It Work? (Mechanism of Action)

Sintilimab is a monoclonal antibody that acts on the communication system between your immune cells and cancer cells. To understand how it works at the molecular level, imagine your immune system’s T-cells as soldiers looking for enemies.

Cancer cells are very sneaky. They often use a “secret handshake” to trick the T-cells into thinking they are healthy. This is done through a protein on the T-cell called Programmed Cell Death Protein 1 (PD-1). When a cancer cell connects to this PD-1 receptor, it sends a signal that tells the T-cell to “turn off” and stop attacking.

Sintilimab works by stepping in between the T-cell and the cancer cell. It physically binds to the PD-1 receptor on the T-cell, acting like a protective cap. Because the receptor is covered, the cancer cell can no longer perform the “secret handshake.” This shuts down the inhibitory signaling pathway. As a result:

1. The T-cells stay “turned on.”
2. The immune system recognizes the cancer as a threat.
3. The T-cells multiply and begin to actively destroy the tumor.

FDA Approved Clinical Indications

While sintilimab is widely used and approved by several international health authorities (such as the NMPA), its status with the US FDA is currently as an investigational drug for specific uses.

Oncological uses

• Relapsed or refractory classical Hodgkin lymphoma (after at least two lines of chemotherapy).
• First-line treatment for advanced Non-Small Cell Lung Cancer (NSCLC) in combination with chemotherapy.
• Advanced Gastric (stomach) or Gastroesophageal Junction cancers.
• Advanced Hepatocellular Carcinoma (liver cancer) in combination with other targeted drugs.
• Esophageal Squamous Cell Carcinoma.

Non-oncological uses

• There are currently no non-oncological uses for this medication.

Dosage and Administration Protocols

Sintilimab is given as a liquid through a needle into a vein by a healthcare professional in a hospital or clinic.

Dose Adjustments

For patients with mild renal (kidney) or hepatic (liver) insufficiency, no starting dose adjustment is typically required. However, if a patient develops severe “immune-related adverse events,” the doctor may pause the treatment or stop it entirely. There is no “dose reduction” for sintilimab; you either receive the full dose or you hold the dose until your immune system calms down.

Clinical Efficacy and Research Results

Clinical research data from 2020 to 2025 has shown that sintilimab is very effective across several types of cancer.

Numerical data from the ORIENT-11 trial showed that in patients with advanced lung cancer, adding sintilimab to chemotherapy significantly improved the “progression-free survival.” Patients receiving the drug lived longer without their cancer getting worse compared to those receiving only chemotherapy. In trials for Hodgkin lymphoma, the “objective response rate” was reported to be approximately 80 percent, meaning 8 out of 10 patients saw their tumors shrink significantly. Recent results from 2024 studies also indicate that for stomach cancer, combining sintilimab with chemotherapy reduced the risk of death by approximately 30 percent compared to chemotherapy alone.

Safety Profile and Side Effects

Because sintilimab makes the immune system more active, side effects usually happen when the immune system starts attacking healthy parts of the body.

Black Box Warning

There is no official US Black Box Warning for sintilimab, but it carries a general warning for all checkpoint inhibitors regarding severe “Immune-Mediated Adverse Reactions.”

Common side effects

These effects occur in more than 10 percent of patients:

• Feeling very tired (fatigue)
• Fever or chills
• Skin rash or itching
• Decreased appetite
• Nausea or diarrhea
• Cough

Serious adverse events

• Immune-mediated Pneumonitis (inflammation of the lungs)
• Immune-mediated Colitis (severe inflammation of the intestines)
• Immune-mediated Hepatitis (liver inflammation)
• Hormone gland problems (thyroid, adrenal, or pituitary gland issues)
• Infusion reactions (allergic response during the drip)

Management strategies

If you develop a side effect, it is vital to tell your doctor immediately. Most immune-related side effects are managed with steroid medications (like prednisone) to calm the immune system. If the reaction is severe, the treatment must be stopped to prevent permanent organ damage.

Research Areas

Sintilimab is a major focus in Research Areas involving “Combination Immunotherapy.” Scientists are currently studying how this drug can be used alongside stem cell therapies to help “reboot” the immune system after high-dose chemotherapy. There is also active research looking at using sintilimab before surgery (neoadjuvant therapy) to shrink tumors and make them easier to remove. By combining this “Smart Drug” with other targeted treatments, researchers hope to create long-lasting “immune memory” so the cancer does not return.

Patient Management and Practical Recommendations

Pre-treatment tests to be performed

• Blood tests to check baseline liver and kidney function.
• Thyroid function tests (TSH, Free T4).
• A physical exam and baseline oxygen level check.
• Pregnancy test for women of childbearing age.

Precautions during treatment

The most important rule is that “new symptoms are important.” Because the immune system can attack any organ, a simple cough or a mild stomach ache could be a sign of a serious reaction.

Do’s and Don’ts list

• Do carry a “Patient Wallet Card” stating you are on immunotherapy in case of an emergency.
• Do report any new shortness of breath or diarrhea to your doctor within 24 hours.
• Do keep all follow-up appointments for blood work.
• Don’t take new herbal supplements without asking your oncologist, as they may interfere with the immune response.
• Don’t ignore a fever; even a low-grade fever should be reported.
• Don’t stop taking your other medications unless directed by your cancer care team.

Legal Disclaimer

This guide is for informational purposes only and does not constitute medical advice. Sintilimab is a powerful prescription medication that must be managed by a specialized oncologist. Always consult with your healthcare provider for diagnosis and treatment.