Drug Guide: Biologics

Everything you need to know about biologic response modifiers

By Donna Rae Siegfried

What are biologics?

In general, biologics are genetically engineered medication made from a living organism, such as a virus, gene or protein, and then used to treat a problem occurring in a different organism, such as a human. Vaccines are one type of biologic agent. In contrast, other drugs are synthesized chemicals.

What conditions do biologics treat?

Because the biologics block triggers of inflammation, they are used to treat autoimmune forms of arthritis, such as rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), ankylosing spondylitis or psoriasis/psoriatic arthritis. Inflammation is the result of the immune system’s errant attack on the body’s tissues, causing joint pain and destruction, as well as other systemic effects, such as fatigue and heart and lung damage. Some biologics approved for rheumatoid arthritis are approved for, or are in development for, other conditions, ranging from Crohn’s disease to cancer.

How are biologics used?

Some biologics are used after a patient has “failed,” or not responded adequately to, traditional disease-modifying anti-rheumatic drugs (DMARDs) or other biologics. When a biologic drug is used for treatment, it is used often in combination with a traditional DMARD, such as methotrexate, for greater effectiveness.

Will biologics cure RA or other conditions?

Unfortunately, no! But the biologics, which work for about two-thirds of people who have rheumatoid arthritis, can induce remission in most people who respond favorably. A clinical remission is defined as fewer than 15 minutes of morning stiffness, and no tender or swollen joints for at least three months. Treating rheumatoid arthritis and other inflammatory forms of arthritis aggressively with DMARDs, including biologics, as soon as possible after diagnosis increases the chance of remission, as well as minimizes the risk of limited function due to permanent joint destruction.

Why can’t two biologics be taken together?

Biologics and other DMARDs decrease inflammation and disease activity by impairing the immune system’s activity. But suppress the immune system too much, and an overwhelming infection could take hold. Limited studies suggest that taking two biologics at the same time would increase the risk of infection markedly, without an increase in therapeutic benefit.

Why are biologics so expensive?

The materials required to create these agents are more expensive, and the manufacturing processes using live organisms are more complex than are required for traditional chemical pharmaceuticals. Other factors include the high cost of research and development. 

All of the current biologics are still under patent protection. After a traditional drug patent expires (20 years from the date the company applies for it), other companies can produce generic versions that cost less.

It’s not clear yet how generic biologics – frequently called “follow-on biologics” – will be handled. The unique process of producing copies of biologic agents presents issues of consistency, as well as proof of safety and effectiveness. The U.S. Food and Drug Administration (FDA) currently has no authority to approve a follow-on biologic for the marketplace, but there are bills in Congress to change this.

Why can’t biologics be taken in pill form?

The biologics currently approved by the FDA must be injected or infused (that is, given intravenously) because they are made up of large protein molecules that cannot be absorbed if taken orally. Seven oral rheumatoid arthritis drugs made from small molecules are now in early stages of development and testing. 

Do all biologics work the same way?

Although the goal of biologics is the same – to stop damaging inflammation – they interrupt the complex cascade of cellular events that drive inflammation at different stages.

For instance, adalimumab (Humira), etanercept (Enbrel) and infliximab (Remicade) each prevent the production of tumor necrosis factor alpha (TNF-a) – a protein produced by cells of the immune system to induce inflammation.

Anakinra (Kineret), on the other hand, inhibits production of the chemical called interleukin-1 (IL-1), which is involved in the bone damage that occurs when joints are damaged by RA. As an IL-1 inhibitor, it can help prevent erosion of bones.

Rituximab (Rituxan) stops the activation of a certain type of white blood cell called B cells. With fewer B cells, the overactivity of the immune system decreases.

Abatacept (Orencia) is a selective costimulation modulator that blocks a particular chemical that triggers the overproduction of T cells.

Other biologics are being developed against other targets. These future biologics, which may block not only TNF-a, but also other inflammatory proteins, such as interleukin-6, will expand treatment options.