You may be able to find other antibodies on the market, but they will not be therapeutic, meaning that their effectiveness against human disease has not been scientifically proven. Typically, you will find antibodies on the market that have been produced from a clone similar to the original antibodies. Since the actual sequence of an expression clone is part of the patent of a drug, the vast majority of primary sequences are not published. Therefore, most RUO molecules – including antibodies – are produced on the basis of a sequence that is close to, but not identical to, the therapeutic molecule.
Furthermore, therapeutic molecules/antibodies are only a part of the final drug: the Active Pharmaceutical Ingredient (API). Forumulation of the buffer of a drug is another important component of therapeutic molecules and therapeutic antibodies. Therefore, all drug aliquots from Evidentic contain the API of the drug and other components that are critical for some analysis purposes.
After all, nowhere else will you find different batches of the same API.