Monoclonal Antibodies: Uses, Types & Contraindications

Monoclonal antibodies are lab-made proteins, such as trastuzumab, rituximab, or adalimumab. They work by binding to specific parts of viruses, bacteria, or certain cancer cells.

This helps the immune system recognize foreign or abnormal cells more easily. It can also help the body fight some diseases more effectively.

Depending on the type used, monoclonal antibodies may be recommended for conditions such as osteoporosis, leukemia, plaque psoriasis, breast cancer, bone cancer, or COVID-19 prevention in certain people. These medications are usually given in hospitals or specialized clinics.

Main uses

Monoclonal antibodies are indicated for the treatment of conditions such as:

• Cancer

• Rheumatoid arthritis

• Multiple sclerosis

• Lupus

• Crohn’s disease

• Ulcerative colitis

• Psoriasis

• Ankylosing spondylitis

• Osteoporosis

• Transplant rejection

Treatment with monoclonal antibodies is also called immunotherapy or targeted therapy. This is because each type of monoclonal antibody targets specific parts of cells involved in certain diseases, or microorganisms such as viruses or bacteria.

Monoclonal antibodies and COVID-19

Some monoclonal antibodies were previously used for COVID-19 because they worked by binding to specific proteins on the surface of the coronavirus. This could help prevent the virus from infecting the body’s cells or help the immune system fight the infection.

A monoclonal antibody called pemivibart (Pemgarda) is authorized by the FDA for COVID-19 pre-exposure prevention in certain adults and adolescents who are moderately or severely immunocompromised and may not have an adequate response to vaccination, when they meet FDA-authorized conditions.

Main types

The main types of monoclonal antibodies include:

1. Recombinant monoclonal antibodies

Recombinant monoclonal antibodies are the most commonly used type and are developed through genetic engineering.

Some examples of recombinant monoclonal antibodies are:

• Trastuzumab (Herceptin): indicated for the treatment of HER2-positive breast cancer or stomach cancer. It may be used alone or combined with chemotherapy, depending on the stage of the tumor and the doctor’s recommendation.

• Rituximab (Rituxan): indicated for the treatment of CD20-positive non-Hodgkin lymphoma, rheumatoid arthritis, or chronic lymphocytic leukemia, for example.

• Denosumab (Prolia or Xgeva): indicated for the treatment of osteoporosis in postmenopausal women or men with prostate cancer who have a higher risk of bone fractures. It may also be used for bone cancer or advanced cancer with bone metastases

• Adalimumab (Humira): indicated for the treatment of rheumatoid arthritis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis, or psoriasis, for example. It works by blocking a specific protein called TNF-α, which is found at high levels in inflammatory diseases.

• Pemivibart (Pemgarda): authorized for COVID-19 pre-exposure prevention in certain people who are moderately or severely immunocompromised and meet FDA-authorized conditions.

This type of monoclonal antibody targets specific proteins on foreign, abnormal, or diseased cells. According to the National Cancer Institute, some monoclonal antibodies used in cancer treatment can help the immune system attack cancer cells or interfere with signals that help cancer cells grow.

These medications should be used only as prescribed and for the length of time recommended by a doctor. Doses are individualized according to each condition and treatment goal.

2. Conjugated monoclonal antibodies

The main conjugated monoclonal antibodies are:

• Ado-trastuzumab emtansine (Kadcyla): indicated for the treatment of HER2-positive metastatic breast cancer. It works by binding to the HER2 protein on the surface of tumor cells and releasing the chemotherapy drug DM1 inside these cells.

• Brentuximab vedotin (Adcetris): indicated for the treatment of CD30-positive Hodgkin lymphoma or systemic anaplastic large cell lymphoma. It works by releasing chemotherapy inside tumor cells that have the CD30 protein on their surface.

Conjugated monoclonal antibodies are designed to carry substances, such as chemotherapy drugs or radioactive agents. These substances are released into specific cells in the body, leading to their destruction.

3. Bispecific monoclonal antibodies

Bispecific monoclonal antibodies contain two different antibodies. One example is blinatumomab (Blincyto), which works by activating the immune system to attack and destroy cancerous white blood cells, and is indicated for the treatment of acute lymphoblastic leukemia.

How to use

Monoclonal antibody treatments are given only in hospitals or specialized clinics, by a nurse or other trained healthcare professional, and always with a doctor’s prescription. The specific antibody used and the dose depend on the illness being treated and how severe it is.

In many cases, monoclonal antibodies are used to treat cancer. They may be used alone or combined with chemotherapy, according to the doctor’s specific recommendations.

Possible side effects

The most common side effects that monoclonal antibodies can cause include diarrhea or constipation, nausea, vomiting, insomnia, abdominal pain or discomfort, excessive tiredness, and muscle or joint pain, for example.

In addition, monoclonal antibodies can cause severe allergic reactions or anaphylaxis. Symptoms may start immediately after the injection and can include difficulty breathing, chills, fever, cough, a tight feeling in the throat, swelling of the mouth, tongue, or face, or hives.

For this reason, monoclonal antibodies should be given in hospitals or specialized clinics so that immediate medical care can be provided if needed.

Contraindications for use

Monoclonal antibodies should only be used during pregnancy, breastfeeding, or in children when prescribed by a doctor after carefully evaluating the risks and benefits of the medication.

People who are allergic to any ingredient in the formulation should not use these medications.