The Patent Doc blog covered a recent FDA presentation (Dr. Rachel Sherman, Feb 15th) on the biosimilar guidance documents issued earlier this month.
This FDA used entertaining analogy to demonstrate the thinking process in this determination. The presentation contains a line drawing of an elephant (below), where each line represents an analytical or clinical study performed by the biosimilar applicant. The FDA will have to compare the reference product (figure A) with the biosimilar products (figures B-E) to determine what level of detail is required for a determination of biosimilarity (whether the drawing is an elephant or not). The biosimilar applicant will attempt to draw the minimum amount of lines such that the FDA can make a finding that the biological product is biosimilar to the reference product (elephant). The FDA will not permit any "tracing" of the lines in the drawing, as these attributes of the biosimilar are already known. Each test or study must add something to the whole body of evidence. This elephant analogy is also used to define "fingerprint" studies, which may tell the biosimilar applicant at an early stage that its product will not qualify for approval under 351(k) (e.g., if early lines in the drawing show a beak or fins).
This got me to thinking about the old Jain proverb of the Six Blind Men and the Elephant.
The story says that six blind men were asked to determine what an elephant looked like by feeling different parts of the elephant's body. The blind man who feels a leg says the elephant is like a pillar; the one who feels the tail says the elephant is like a rope; the one who feels the trunk says the elephant is like a tree branch; the one who feels the ear says the elephant is like a hand fan; the one who feels the belly says the elephant is like a wall; and the one who feels the tusk says the elephant is like a solid pipe.
A king [FDA] explains to them:
"All of you are right. The reason every one of you is telling it differently is because each one of you touched the different part of the elephant. So, actually the elephant has all the features you mentioned."
This resolves the conflict, and is used to illustrate the principle of living in harmony with different beliefs and that truth can be stated in different ways.
Here's hoping the FDA can harmonize its biosimilar elephants by using a process "where each analytical study required of biosimilar applicants will advance the field of knowledge regarding the molecule of interest."
Posted by Bruce Lehr Feb 28th 2012.