Generic medications play an important role in healthcare cost savings.  For FDA approval, a generic drug must be identical in strength, dosage form, and route of administration and be bioequivalent.  In other words, the generic drug for all intents and purposes must be the same as the brand reference drug.  A biosimilar, on the other hand is approved if it shows that it is highly similar to an FDA-approved biologic product known as a reference product.  In addition, a biosimilar is not labeled as bioequivalent to the reference drug.  Thus, unlike a generic medication, a biosimilar is not interchangeable with the reference drug without the prescriber’s approval.

So how does a biosimilar fit into the healthcare spending equation?  Biosimilar are expected to be 15-30% less expensive than the originator drugs.  However, to benefit fully from this potential cost savings, the biosimilar needs to be interchangeable with its reference drug.   The ability to interchange a biosimilar with its reference drug allows the pharmacist to dispense a biosimilar when the prescription is written for the reference drug, much similar to how generics are dispensed for brand name products.  If a biosimilar is not interchangeable with its reference drug, it will certainly not be as readily dispensed since each request to change to a biosimilar will require the prescriber’s approval.

Currently, there are 2 biosimilars approved in the United States.  Zarxio, a biosimilar version of filgrastim and Inflextra, a biosimilar to Remicade.  Biosimilar for a few other blockbuster drugs such as Enbrel and Humira are expected to be approved by the FDA later this year.  Experts believe biosimilars will lead to a $40 billion dollars savings over the next 10 years.  To see this savings, doctors, patients, payors, and legislators will need to have a better understanding of biosimilars and how best to expand its access to patients.  With the skyrocketing cost of biologic medications, biosimilars may be our knight in shining armor to rescue us from this specialty drug distress.

Submitted by Stan Leung PharmD, PHC Director of Pharmcy