Biologic Therapy (DMARDs)

Biologic therapy using DMARDs (Disease-Modifying Anti-Rheumatic Drugs) is a type of treatment that uses medicines made from living cells to calm the immune system and slow down diseases that cause joint and tissue damage.

In conditions like rheumatoid arthritis (a disease where the immune system attacks the body's own joints), the immune system is overactive and sends out proteins called cytokines (chemical messengers) that trigger inflammation (swelling and heat in the tissues). Biologic DMARDs are designed to block specific parts of this process — for example, blocking a cytokine called TNF (tumour necrosis factor) or blocking certain immune cells called B-cells or T-cells. Because they target a very specific step in the process, they work differently from older, broader anti-rheumatic medicines.

Biologic DMARDs are used when the immune system is attacking the body and conventional medicines have not controlled the disease well enough. A rheumatologist (a specialist in joint and immune system diseases) usually considers this therapy when inflammation remains active despite earlier treatment.

• Rheumatoid arthritis (RA) — the most common reason, especially when the disease is moderate to severe
• Psoriatic arthritis — joint inflammation linked to the skin condition psoriasis
• Ankylosing spondylitis — inflammation of the spine that can cause the vertebrae to fuse together
• Juvenile idiopathic arthritis — a form of arthritis that starts in childhood
• Systemic lupus erythematosus (SLE) — a condition where the immune system attacks many organs at once
• Vasculitis — inflammation of blood vessels
• Other inflammatory arthritis conditions that have not responded to conventional DMARDs

This therapy is not suitable for everyone. Doctors will usually avoid it or delay it in certain situations.

• Active serious infection, including active tuberculosis (TB) — biologic medicines reduce the immune response and can make infections much worse
• Certain cancers, especially recent ones, as some biologics may affect the body's ability to fight cancer cells
• Severe heart failure (advanced weakening of the heart's pumping ability)
• Pregnancy or planned pregnancy — the safety of specific biologics in pregnancy varies and is decided case by case
• Known allergy to the specific biologic agent being considered

Biologic DMARDs are powerful medicines and carry real risks that a doctor will weigh carefully against the benefits before starting treatment.

• Increased risk of infection — the most common concern; the immune system is less able to fight bacteria, viruses, and fungi, making everyday infections harder to clear and rare infections more likely
• Reactivation of latent (hidden, inactive) tuberculosis — this is why TB screening is done before starting
• Injection site reactions or infusion reactions — redness, swelling, or itching where the medicine is given; some patients feel flushing, headache, or low blood pressure during an intravenous (through-the-vein) infusion
• Allergic reactions, ranging from mild skin rashes to, rarely, a severe whole-body reaction called anaphylaxis
• Worsening of heart failure in patients who already have heart disease
• Development of autoantibodies (proteins the immune system makes against its own tissues) — in rare cases this can lead to a lupus-like syndrome
• Possible increased risk of certain cancers with long-term use — this is still studied and your doctor will monitor for it
• Liver inflammation (hepatitis reactivation) in patients who carry certain hepatitis viruses
• Low blood cell counts — some biologics can reduce white blood cells, red blood cells, or platelets

Preparing for biologic DMARD therapy involves a series of safety checks that happen over several weeks before the first dose is given. This is not a single-day procedure — the preparation phase is thorough because these medicines affect the immune system.

Before starting, your doctor will usually ask you to do the following. No fasting is generally needed for the medicine itself, but blood tests may have specific instructions. If you take blood thinners or other medicines that affect the immune system, your doctor will review them. Smoking increases the risk of infections and may reduce how well the medicine works; your doctor will likely discuss this with you. Alcohol guidelines vary by the specific biologic and any other medicines you are taking.

Tests that are usually run before the first dose include:

• TB screening — usually a skin test called a Mantoux test (a small injection under the skin to check for past TB exposure) or a blood test called an IGRA (interferon-gamma release assay); a chest X-ray is often done as well
• Blood tests to check liver function, kidney function, and a full blood count (a measure of your red cells, white cells, and platelets)
• Hepatitis B and hepatitis C screening, because these viruses can reactivate when the immune system is suppressed
• HIV test in some cases
• Vaccination review — your doctor will check whether you are up to date with vaccines, because some live vaccines cannot be given once biologic therapy has started
• Imaging of the affected joints (X-ray or MRI) to record the current level of damage as a baseline

What happens when the medicine is given depends on how it is delivered. Your doctor will choose the right form for you. The steps below are a general guide:

• 1. The care team confirms your identity and reviews your screening results one final time.
• 2. If the medicine is given by subcutaneous injection (a small injection just under the skin), the nurse or doctor prepares the pre-filled syringe or auto-injector pen and cleans the injection site — usually the abdomen (belly), thigh, or upper arm.
• 3. If the medicine is given by intravenous infusion (through a drip into a vein), a cannula (a small plastic tube) is placed in a vein, usually in the arm. You sit or lie comfortably for the duration of the infusion, which can range from around thirty minutes to several hours depending on the specific medicine and the dose.
• 4. During an infusion, a nurse monitors you for any early signs of a reaction such as flushing, itching, or changes in blood pressure.
• 5. After the medicine is given, you are observed for a period — usually longer after the first dose — before you are allowed to leave.
• 6. For self-injected biologics, a nurse teaches you (and optionally a family member) how to give the injection safely at home before you leave the clinic.

Biologic DMARD therapy is an ongoing treatment, not a one-time procedure. After each dose, and especially in the weeks and months after starting, regular follow-up is essential to make sure the medicine is working and is not causing harm.

• Monitoring: After an infusion, you are usually observed in the clinic for at least thirty minutes to check for delayed reactions. For self-injected biologics, your first injection is often supervised at the clinic before you take over at home.
• Blood tests: Regular blood tests — typically every few weeks at first, then less often once your condition is stable — check your blood cell counts, liver function, and signs of infection.
• Infection awareness: Tell your doctor immediately if you develop a fever, unusual cough, skin wound that is not healing, or any other sign of infection. Even a common cold can become serious while on this therapy.
• Wound and injection site care: Keep injection sites clean and rotate them as instructed to prevent skin irritation. Report any persistent redness or swelling at injection sites.
• Vaccinations: Certain live vaccines (such as live attenuated influenza vaccine) are usually avoided while on biologic therapy. Your doctor will advise which vaccines are still safe. Annual influenza (flu) vaccination with an inactivated (killed-virus) vaccine is generally encouraged.
• Avoiding contact with infections: In everyday life, careful hand hygiene and avoiding close contact with people who have active infections becomes more important.
• Continued use of other medicines: Biologic DMARDs are often used alongside conventional DMARDs or low-dose steroids (medicines that calm inflammation). Your doctor will decide whether to continue these.
• Activity and lifestyle: Most patients can maintain normal daily activities. Your rheumatologist and, if available, a physiotherapist (a movement and exercise specialist) will guide you on safe levels of exercise for your specific joint condition.
• Follow-up appointments: Regular rheumatology reviews — usually every three to six months once the condition is stable — assess how well the disease is controlled and whether the therapy should continue, be adjusted, or be changed.
• Dental care: Inform your dentist that you are on biologic therapy before any dental procedure, as antibiotics may be recommended to prevent infection.