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.
