If a generic drug product is ready for approval before the expiration of any patents or exclusivities accorded to the reference listed drug product, FDA issues a tentative approval letter to the applicant. The tentative approval letter details the circumstances associated with the tentative approval. FDA delays final approval of the generic drug product until all patent or exclusivity issues have been resolved. A tentative approval does not allow the applicant to market the generic drug product.
Therapeutic Biological Product
A therapeutic biological product is a protein derived from living material (such as cells or tissues) used to treat or cure disease.
Therapeutic Equivalence (TE)
Drug products classified as therapeutically equivalent can be substituted with the full expectation that the substituted product will produce the same clinical effect and safety profile as the prescribed product. Drug products are considered to be therapeutically equivalent only if they meet these criteria:
- they are pharmaceutical equivalents (contain the same active ingredient(s); dosage form and route of administration; and strength.)
- they are assigned by FDA the same therapeutic equivalence codes starting with the letter "A ." To receive a letter "A", FDA
- designates a brand name drug or a generic drug to be the Reference Listed Drug (RLD).
- assigns therapeutic equivalence codes based on data that a drug sponsor submits in an ANDA to scientifically demonstrate that its product is bioequivalent (i.e., performs in the same manner as the Reference Listed Drug).
Therapeutic Equivalence (TE) Codes
The coding system for therapeutic equivalence evaluations allows users to determine whether FDA has evaluated a particular approved product as therapeutically equivalent to other pharmaceutically equivalent products (first letter) and to provide additional information on the basis of FDA's evaluations (second letter). Sample TE codes: AA, AB, BC (More on TE Codes4)
FDA assigns therapeutic equivalence codes to pharmaceutically equivalent drug products. A drug product is deemed to be therapeutically equivalent ("A" rated) only if:
- a drug company's approved application contains adequate scientific evidence establishing through in vivo and/or in vitro studies the bioequivalence of the product to a selected reference listed drug.
- those active ingredients or dosage forms for which no in vivo bioequivalence issue is known or suspected.
Some drug products have more than one TE Code.
Those products which the FDA does not deem to be therapeutically equivalent are "B" rated.
Over-the-counter drugs are not assigned TE codes.
No bioequivalence problems in conventional dosage forms
Meets necessary bioequivalence requirements
Meets bioequivalence requirement to AB1 rated reference drug
Meets bioequivalence requirement to AB2 rated reference drug
Meets bioequivalence requirement to AB3 rated reference drug
Meets bioequivalence requirement to AB4 rated reference drug
Solution or powder for aerosolization
Injectable oil solution
Injectable aqueous solution