Most medicines are created by combining chemicals. In the last century, scientists have produced a new breed of drugs that contain human or animal proteins. This class of drugs are called biologics, and have been used in the production of vaccines, cancer drugs and insulin. Over the last decade, biologics have emerged as a promising new treatment for certain forms of arthritis such as Juvenile Idiopathic Arthritis, psoriatic arthritis, rheumatoid arthritis and ankylosing spondylitis.
Biologics can be very effective at improving arthritis but how well they work will vary for each person. For some people, biologic treatments may not work at all. For others, one biologic may not work but another may be effective. This is because the various biologics work by different mechanisms.
In arthritis treatment, biologics are given to lessen inflammation by interfering with biologic substances that cause or worsen inflammation. These new biologic agents can specifically affect some of the abnormalities of the immune system that lead to joint inflammation and other joint abnormalities.
How it works
Biologics are different from other medications because they are designed to block diseases early in their development – in the immune system. It copies the effects of substances naturally made by your body’s immune system.
The action involves the targeting or "going after" over-active immune cells in the body. Some biologics target a type of immune cell called a T cell, while others target TNF-alpha, the chemical messengers released by activated T cells.
T cells are the so-called "generals" of the immune system because they normally recognise bacteria and viruses and coordinate the immune response to eliminate these foreign invaders. In arthritis, however, certain T cells are mistakenly activated and migrate to the joints.
Once in the joints, they begin to act as if they are fighting an infection or healing a wound, which sets off a chain of events that leads to joint inflammation and damage. Certain biologic medications treat arthritis by preventing the activation and/or migration of T cells; by reducing the number of arthritis-involved T cells in the body; or both.
Under normal conditions, TNF-alpha helps fight infections and communicates messages between cells. In people with arthritis, TNF-alpha is produced in excess amounts. The messages communicated by TNF-alpha can lead to the rapid growth of cells, leading to joint pain, stiffness and other arthritis symptoms. Biologics binds to TNF-alpha and prevents it from communicating with other cells.
How are they used?
Biologics have been approved by the US FDA to treat moderate to severe rheumatoid arthritis that has not responded to traditional disease modifying antirheumatic drugs (DMARDs, e.g.- methotrexate, leflunomide, hydroxychloroquine, sulfasalazine) because of side effects or other conditions.
Biologics may be used alone, but are often given in conjunction with other DMARDs, to increase the benefit and limit potential side effects. When patients start biologic agents, they usually also remain on their current dose of nonsteroidal anti-inflammatory (NSAID) and/or corticosteroid (i.e., prednisone) medicines for symptomatic relief until the disease is controlled.
Biologic agents can be given by an injection under the skin or by intravenous (IV) infusion. As they are a kind of protein, these medications must be stored in a refrigerator and warmed to room temperature prior to use.
The injections are self-administered and your doctor or nurse will show you how to inject the medicine in the front of your thighs or abdomen. Injection sites should be rotated so that the same site is not used repeatedly. IV transfusions are done in the doctor’s office and usually take 2-3 hours, during which the patient can rest, read, watch TV without discomfort.
Biologic agents usually work quickly to relieve the symptoms and swelling associated with rheumatoid arthritis. Although studies show that most patients will improve within 4-6 weeks of treatment, most patients will notice marked improvement after the first or second injection.
The side effects for biologic medications vary. Commons side effects for all biologics include respiratory infections, flu-like symptoms and reactions at the site of injections (such as swelling, itch or rash) These are generally mild and, in most cases, do not cease people to stop taking the medication.
People with compromised immune system or active infections may not be eligible for some biologics. If a major infection develops while taking a biologic, it is usually recommended that the medication be temporarily stopped. In addition, screening for tuberculosis, multiple sclerosis and congestive heart failure may be required before biologics treatment is started.
Despite their high level of efficacy, biologics are still not as widely used as they should be because of the high cost of between RM4000-RM5000 a month. This is because biologics are very complex medications to make, and it can take decades of research and development before a biologic is approved and ready for patients to use. Speak to your insurance company to check whether it is covered under your policy.
Reference: American College of Rheumatology, US National Psoriasis Foundation