Bioequivalence and Bioavailability Forum

Hi Brus,

❝ We are developing a generic of an RLD with two strengths (100 mg and 50 mg).

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❝ But viewing the dosage regimen of reference drug product, it would make sense to develop a 150 mg strength even though the reference product does not have it. So, our generic drug product will have 3 strengths (150, 100 and 50 mg).

❝

❝ PK linearity has been demonstrated in the range of that doses.

So far so good. Since you are mentioning RLD you are targeting the FDA, right?
Is a single (not daily) 150 mg dose approved?

❝ Should RLD 100mg VS Generic 100mg be done …

Yes. If a proportionality biowaiver (in vitro similarity) of the 50 mg strength works, fine. Check the product-specific guidance for the recommended conditions. If that fails, you need to perform a biostudy of the 50 mg strength as well.

❝ … or RLD 100mg + RLD 50mg VS generic 150mg?

For the FDA that’s an 505(b)(2) NDA (the guidance is quite old and not very specific); you can’t get an approval of the 150 mg via an ANDA since it not a generic (no 150 mg RLD). The study 150 mg (T) vs. 100 mg (RLD) + 50 mg (RLD) is just part of the story.
In Europe that’s the hybrid pathway. Additionally to this study generally clinical studies are required as well.