Finally, FDA has come out with its interchangeability guidelines. The US drug regulatory agency has presented its recommendations for the data requirement for a biologic product to be interchangeable to a reference product. You may go through the draft guidance upon following the link.
As per the FDA guidelines, an interchangeable biological product may be substituted for the reference product without the intervention of the health care provider who prescribed the reference product, leading to pharmacy-level substitution. Interchangeable approval is a two-step process. Step 1 is to establish biosimilarity and step 2 is to establish product’s substitutability. Due to the complex nature of the biologic product, FDA will look at the data presented by the applicant on a case-by-case basis. The regulators expect data ensuring same clinical results as reference biologic in any patient (extension study, real world evidence, etc.), a switching study (crossover study to establish safety and efficacy when patients are switched between biosimilar and reference biologic), and data demonstrating similar effects in all indications for which approval is sought.
For a cost-effective alternative of the already marketed biologics, FDA is looking for a “twin”. The guidance hints towards the requirement of US-licensed comparator to avoid subtle differences and safety concerns regarding immune responses. Different product presentations including the delivery device and container closure system may also influence FDA’s decision for interchangeability.
A biosimilar product with interchangeable status is expected to be warmly received by both the physicians and the payer community. The possibility of pharmacy-level substitution is likely to increase access and uptake of the biosimilar product. It is therefore in the interest of the biosimilar developer to collaborate with FDA in the early stages of development for an approval with interchangeability designation. It will be interesting to see how industry responds to these guidelines and how US biosimilar market is affected with the same.