New FDA Approval: Inflectra
Drug
Infliximab-dyyb [Inflectra]
Indication
It’s a biosimilar to infliximab [Remicade], so it has the same indications. Primarily, you’re going to see it used for Crohn’s disease, ulcerative colitis, and rheumatoid arthritis. But you’ll also see it occasionaly used for ankylosing spondylitis and psoriasis.
What the Crap is “dyyb”?
The FDA has mandated that biosimilar product names will be followed by 4 nonsense letters with no meaning.
The purpose of these nonsense letters is to distinguish the biosimilar from the original brand product. Biosimilars are pretty different than your run of the mill generic drugs. We’ll talk about that more below.
How it Works
It’s a chimeric monoclonal antibody against Tumor Necrosis Factor alpha (TNF-a). To learn what the hell a chimeric monoclonal antibody is, check out our tutorial.
What does TNF-alpha do? It’s a part of your immune system that basically goes around your body acting like a signal flare. It causes the production of inflammatory cytokines / interleukins. It causes immune cells (WBCs) to flock to it and activate--trashing the lights of any potential infections.
Autoimmune disorders like Crohn’s and rheumatoid arthritis have been found to show TNFa levels that are too high. So, we have a whole class of drugs that inhibit it. Infliximab is one such drug, and now it has a “generic” in infliximab-dyyb.
Notable Adverse Effects
Any time you inhibit part of the immune system, bad things can happen. To name a few:
Black Box Warning for serious infections (TB, invasive fungal infections like aspergillosis, and opportunistic microbes like Listeria)
Black Box Warning for lymphoma and other malignancies
Increased liver enzymes
Respiratory issues (URTI, cough, pharyngitis)
Oh, and because it’s a foreign protein (and a chimeric one at that), there is a pretty high rate of infusion reactions (~18%).
Current Place in Therapy
For starters, infliximab is NOT a first line treatment for anything. It’s reserved for “moderate to severe” cases that have not responded to other therapies. For every indication.
That being said, this is a big deal. Infliximab works very well for a lot of people, despite the risks of infection and cancer. It’s also very expensive. Current estimates have a year’s worth of treatment with Remicade roughly costing Texas with a dollar sign ($Texas).
Opening up the floor for biosimilars (generics) is huge. Biosimilars don’t have the same approval process as drugs. In fact, this is only the second biosimilar approved. Ever. The first one was for filgrastim [Neupogen], which stimulates white blood cell production (usually used in chemotherapy patients).
The process to create a biosimilar is difficult. It uses living organisms. It isn’t a copy of the original product (as in generic drugs). It’s just a similar product, made by a DIFFERENT process, that has no clinically meaningful differences. It’ll work the same way as the reference biologic, but it’s not the same thing.
There will be more biosimilars coming soon. And that’s a good thing, because the originals are all cripplingly expensive. Stay tuned...