Atezolizumab

Cancer Treatment

Atezolizumab is an immunotherapy used to treat several types of cancer. It works by helping the immune system identify and attack cancer cells. It is often prescribed when cancer is advanced, has spread to other parts of the body (metastatic), or cannot be removed by surgery.

Lung Cancer

• Non-Small Cell Lung Cancer (NSCLC): This medication is used as a primary treatment for advanced NSCLC or as a follow-up treatment after surgery and chemotherapy to reduce the risk of the cancer returning.
• Small Cell Lung Cancer (SCLC): It is used in combination with chemotherapy for the initial treatment of advanced-stage SCLC.

Liver and Bladder Cancers

• Hepatocellular Carcinoma: It is used to treat liver cancer that has spread or cannot be surgically removed, usually in combination with other specific medications.
• Urothelial Carcinoma: It is used for advanced cancer of the bladder or urinary tract.

Other Indications

• Melanoma: It is used for certain types of advanced skin cancer that have specific genetic markers, often used alongside other targeted therapies.
• Alveolar Soft Part Sarcoma: It is used for adults and children aged 2 years and older with this rare type of soft tissue cancer when it is advanced or cannot be removed by surgery.

How Atezolizumab Works

Atezolizumab is a type of medication called a monoclonal antibody. It is designed to target a specific protein known as programmed death-ligand 1 (PD-L1), which is found on the surface of some cancer cells and certain immune cells.

In a healthy body, the PD-L1 protein helps keep the immune system from attacking normal cells. However, some cancer cells use this protein to avoid being detected. When PD-L1 binds to receptors on T-cells (a type of white blood cell that fights disease), it sends a signal that tells the T-cells to stay inactive. This prevents the immune system from attacking the cancer.

Atezolizumab works by attaching to the PD-L1 protein and blocking it from connecting with the receptors on T-cells. By interfering with this process, the medication:

• Restores the immune response by allowing T-cells to recognize cancer cells as a threat.
• Enables the immune system to find and attack the tumor cells.
• Slows or stops the growth and spread of the cancer.

Because this treatment uses the body's own immune system to fight the disease, it is classified as a type of immunotherapy.

Common Side Effects

Many people receiving atezolizumab experience mild to moderate side effects. These may include:

• Feeling tired or weak
• Loss of appetite
• Nausea or vomiting
• Constipation or diarrhea
• Cough or shortness of breath
• Rash or itchy skin
• Joint, muscle, or back pain
• Fever
• Swelling in the hands, feet, or ankles
• Urinary tract infections

Serious Side Effects

Atezolizumab works by stimulating the immune system, which can sometimes cause the body to attack its own healthy tissues. These immune-mediated reactions can be severe or life-threatening and may occur in various organs:

• Lung problems: New or worsening cough, chest pain, or shortness of breath.
• Liver problems: Yellowing of the skin or eyes (jaundice), dark urine, or severe pain on the right side of the stomach area.
• Intestinal problems: Severe diarrhea, blood in the stool, or intense stomach pain.
• Hormone gland problems: Changes in mood or behavior, headaches, extreme tiredness, weight changes, or increased thirst and urination.
• Kidney problems: Changes in the amount or color of urine.
• Skin reactions: Severe rash, blistering, or peeling.
• Nervous system problems: Confusion, muscle weakness, numbness, or tingling in the hands or feet.

Some patients may also experience reactions during or shortly after the infusion or injection, such as chills, shaking, dizziness, or flushing. If the medication is given as a subcutaneous injection, redness or pain at the injection site may occur.

Immune-Mediated Reactions

Atezolizumab works by stimulating the immune system to attack cancer cells, but it can also cause the immune system to attack healthy parts of the body. These reactions can happen in any organ or tissue and may occur during treatment or after the medication has been stopped. Serious inflammation may affect the following areas:

• Lungs: Inflammation (pneumonitis) can cause new or worsening cough, chest pain, or shortness of breath.
• Intestines: Colitis can lead to severe diarrhea, stomach pain, or blood in the stool.
• Liver: Hepatitis can cause yellowing of the skin or eyes, dark urine, or severe nausea and vomiting.
• Hormone Glands: Problems can occur in the thyroid, adrenal glands, pituitary gland, or pancreas (including Type 1 diabetes).
• Kidneys: Nephritis can cause changes in the amount or color of urine.
• Skin: Severe rashes, itching, blistering, or peeling may occur.

Infusion and Injection Reactions

Some patients experience reactions while receiving the medication or shortly after. These reactions can be severe or life-threatening. Symptoms may include chills, shaking, dizziness, fever, itching, or difficulty breathing. Healthcare providers typically monitor patients closely during and after administration.

Pregnancy and Breastfeeding

Atezolizumab can cause harm to an unborn baby. Effective birth control is recommended for females of reproductive potential during treatment and for at least five months after the final dose. It is generally recommended that breastfeeding be avoided during treatment and for five months following the last dose.

Stem Cell Transplant Risks

There are potential risks for patients who have had or will have an allogeneic stem cell transplant (using donor cells). Complications, such as graft-versus-host disease, may occur if atezolizumab is used before or after the transplant procedure.

Pregnancy

Based on its mechanism of action and animal studies, atezolizumab can cause fetal harm when administered to a pregnant woman. It may increase the risk of pregnancy loss or cause birth defects. Healthcare providers typically advise against starting this treatment if you are pregnant unless the potential benefit justifies the potential risk to the fetus.

Females who are able to become pregnant should have a pregnancy test before starting treatment. It is recommended to use effective birth control during treatment and for at least 5 months after the final dose of atezolizumab.

Breastfeeding

There is no information available regarding the presence of atezolizumab in human breast milk, its effects on the breastfed child, or its effects on milk production. Because of the potential for serious adverse reactions in a nursing infant, breastfeeding is not recommended during treatment and for at least 5 months after the last dose.

Available Forms

Atezolizumab is provided in the following administration formats:

• Intravenous Infusion: This form is a concentrated, preservative-free solution supplied in single-dose vials. It must be diluted by a healthcare provider before being administered into a vein.
• Subcutaneous Injection: This form is a solution for injection under the skin, typically in the thigh. This version is a combination product that includes an enzyme to assist the body in absorbing the medication.

FDA Approval and Indications

Atezolizumab is approved by the U.S. Food and Drug Administration (FDA) for the treatment of several types of cancer. It is used in adults and, in some cases, pediatric patients for conditions including:

• Non-small cell lung cancer
• Small cell lung cancer
• Hepatocellular carcinoma (a type of liver cancer)
• Melanoma
• Alveolar soft part sarcoma

The FDA has approved two methods of administration: an intravenous infusion and a subcutaneous injection. The subcutaneous version, which includes the enzyme hyaluronidase to aid absorption, was approved in 2024 for use in all adult indications previously established for the intravenous form.

Regulatory Status

Atezolizumab is available only by prescription. It belongs to a class of drugs known as PD-L1 blocking antibodies. While it carries significant warnings regarding immune-mediated side effects, it does not currently have a Boxed Warning or a Risk Evaluation and Mitigation Strategy (REMS) program required by the FDA.

Factors Affecting Price

Atezolizumab is a specialized biologic medication administered by healthcare professionals. The total cost of therapy is influenced by:

• Administration Method: Costs may vary depending on whether the drug is given as an intravenous (IV) infusion or a subcutaneous injection.
• Treatment Setting: The price can differ based on whether the medication is received in a hospital, a specialized infusion center, or a doctor's office.
• Dosage and Frequency: The amount of medication required and how often it is administered (such as every two, three, or four weeks) will impact the overall expense.

Insurance and Financial Support

Most insurance plans, including Medicare and private insurers, typically cover atezolizumab when it is used for approved medical conditions. However, patients may still be responsible for out-of-pocket expenses like deductibles or coinsurance. Because it is a high-cost specialty drug, some patients may be eligible for financial assistance programs or co-pay support offered by the manufacturer.

Biosimilar Status

Currently, there are no FDA-approved biosimilar versions of atezolizumab. It is only available as a brand-name product, which generally means the cost remains higher than it would be if generic or biosimilar alternatives were available on the market.