ANDA: Proving Sameness Instead of Proving Safety

An ANDA is the application for a generic drug. It is abbreviated because it omits the thing that makes an NDA expensive: preclinical and clinical studies establishing safety and effectiveness.

The reasoning is that those questions were answered once, for the reference listed drug. You do not re-answer them. You prove your product is the same.

What sameness means

An ANDA has to establish that the proposed product is the same as the RLD in:

• Active ingredient
• Dosage form
• Route of administration
• Strength
• Conditions of use, meaning the labelling

And that it is bioequivalent: the rate and extent of absorption are not significantly different when administered at the same dose under similar conditions.

Inactive ingredients may differ, within limits, and for some dosage forms those limits are tight.

What is not abbreviated

The CMC section. Everything in Module 3 still applies: manufacture, controls, stability, specifications. A generic applicant carries the same manufacturing obligations as a brand applicant, faces the same pre-approval inspection, and is subject to the same data integrity expectations.

This is where most ANDAs actually get delayed. The bioequivalence study is rarely the problem.

Patent certification

The applicant must certify against each patent listed in the Orange Book for the RLD, in one of four ways:

• Paragraph I: no patent information has been filed.
• Paragraph II: the patent has expired.
• Paragraph III: the applicant will wait until the patent expires.
• Paragraph IV: the patent is invalid, unenforceable, or will not be infringed.

A Paragraph IV certification is a litigation position. The applicant notifies the patent holder, and if suit is filed within 45 days, FDA's approval is stayed for up to 30 months or until the case resolves.

The first substantially complete Paragraph IV applicant can earn 180 days of generic exclusivity, which is why the filings cluster on the earliest possible date.

Suitability petitions

If you want to change something an ANDA cannot ordinarily change, such as dosage form or strength, you file a suitability petition asking FDA to permit an ANDA for that variation. If it is refused, the route is a 505(b)(2) rather than an ANDA.