Biosimilars are here, and here to stay.
In the US drug costs make up half of the total cost of MS care, and over the last couple of years MS drug prices have increased more than any other therapeutic area. According to the NMSS (National Multiple Sclerosis Society) the average annual cost for medications in 2016 was $78,000, up 400% from the $16,000 annual cost in 2004.
The prospect of dug cost savings with the introduction of copy drugs is attractive for providers.
However, it is a mistake to assume that since these newer versions are a copy of the original that they are identical. A generic/biosimilar is not required to be identical to the "brand" drug but only comparable. In essence not interchangeable, but equivalent. A copy drug, therefore can be deemed to be therapeutically equivalent to the "brand" drug, by demonstrating the same active ingredient, purity, strength, dosing and route of delivery (pharamceutical equivalence), and by having similar pharmacokinetics to the "brand" drug with a similar rate and extent of absorption into the body (bioequivalence).
The development of generics/biosimilars is therefore a compromise and their success depends on their ability to offer a similar, safe and efficacious product. Make the requirements for developing a copy drug too stringent, it would dis-incentivize the drug producers. An appropriate trade-off is therefore needed.
If a copy drug is deemed interchangeable (based on clinical trail data) then it may be substituted for a "brand" drug without the authorization of the physician.
Compared to other areas in medicine, for example in rheumatology; the development of copy drugs in MS has been slow. Currently, copaxone, interferon beta, and natalizumab have been the primary targets. Gilenya's (fingolimod) composition of matter patent protection, for instance, expires in 2019 within the US, and 2018 outside of the US.
Interesting times.