A new drug that could save the US billions just got one step closer to an approval

REUTERS/Karoly Arvai

The panel voted unanimously in favor of licensing ABP-501, the version of Humira that's made by Amgen.

The drug is called a "biosimilar," which is like a generic version of a biologic medication, a medicine produced by living cells.

Biosimilars are a bit more complicated than your average competing medicine: unlike generics for chemical-based drugs like antibiotics, which can be interchangeable with branded versions, the copycats of biologic medications, produced using living cells, have a few more caveats.

So far, the US Food and Drug Administration (FDA) has approved two: a version of Remicade, or infliximab, a drug used to treat autoimmune diseases like Crohn's disease and rheumatoid arthritis. Another one, called Zarxio was approved in 2015. An FDA panel is also evaluating a biosimilar version of Amgen's Enbrel, another drug used to treat autoimmune diseases including RA, psoriatic arthritis, and plaque psoriasis.

The FDA doesn't necessarily have to follow the panel's recommendation, and a final decision on the approval of the drug will be made by September.

Having more biosimilars in the US will be a big deal: It might be the best way to drive down the cost of biologic medications that have been around for a while. The savings of putting people on far less costly biosimilars - even just new patients who have never taken the original - are estimated to be billions of dollars.

What makes biosimilars different from generics

Developing a biosimilar is not as easy as creating a generic knockoff: Because you're working with complex living things, making a copy isn't so simple.

"When you have a small molecule like Lipitor, you know where every single atom is," Dennis Lanfear, CEO of biosimilar company Coherus Biosciences, told Business Insider in April. That's not the case with something like a monoclonal antibody - a type of lab-produced protein that can go after certain cells like your immune system would - which can vary widely. This means that you have to run the biosimilar through a whole bunch of studies to prove that it does the same thing that the original drug does.

Coherus is developing biosimilar versions to drugs for autoimmune diseases and cancer treatment, including biosimilar versions of Humira and Enbrel. They plan to file a biologic-license application to the FDA for their version of pegfilgrastim, a bone-marrow stimulant, in 2016.

"Biosimilars are here," Lanfear said. "They are now here today. The simple ones have been approved like Zarxio, and the complex ones have also been approved."