Replies to post #120053 on Biotech Values

[biomaven0]

The closer two molecules are to each other the greater the chance of cross-reactivity. So I wouldn't expect to see much impact when patients switch from one of the existing drugs to another as they are generally fairly different from each other.

Here's what Woodcock had to say back in 2007:

"The ability to predict immunogenicity of a protein product, particularly the more complex proteins, is extremely limited. Therefore, some degree of clinical assessment of a new product’s immunogenic potential will ordinarily be needed. The extent of independent testing needed will again depend on a variety of scientific factors such as the indication, whether the product is to be administered chronically, the overall assessment of the product’s immunogenic potential, and whether there is the possibility of generating a cross-reaction with an important endogenous molecule.

A finding by the Agency that a follow-on protein product may be approved as safe and effective is distinct from a determination that the follow-on protein product would be substitutable for the referenced protein product. To establish that two protein products would be substitutable, the sponsor of a follow-on product would need to demonstrate through additional clinical data that repeated switches from the follow-on product to the referenced product (and vice versa) would have no negative effect on the safety and/or effectiveness of the products as a result of immunogenicity. For many follow-on protein products — and in particular, the more complex proteins – there is a significant potential for repeated switches between products to have a negative impact on the safety and/or effectiveness. Therefore, the ability to make determinations of substitutability for follow-on protein products may be limited."

(emphasis added).

I don't know if this is a real issue or a hypothetical concern, but so long as the FDA thinks its real, those are going to be the ground rules for a while.

Peter