5000ish pages of TPPA text recently made public after years of top secret negotiations, was written by a group of 600ish US-based multinational corporate lobbyists and lawyers for the benefit of their clients.
Though inaccurately promoted as a Free Trade Agreement, the TPPA is primarily designed to streamline and "harmonise" national policies to make it easier for mercurial multinational corporations to maximise their shareholder value, their only priority, by playing countries off one another more efficiently.
It gives them the ability to magically build things in the places with the lowest wages, fewest environmental protections and government compliance requirements. To pay tax (or not) in the lowest tax jurisdictions, and maximise revenue by having unfettered access to the biggest, wealthiest markets.
In short, the TPPA, along with its siblings TTIP and TISA, exist to get nations to agree to the rules of a globalised game in which they can no longer play an active part. The game is focused on maximising exploitation of the Commons - privatising profits - and socialising liabilities. Give the 1% the gains, and let the 99% clean up after them (and bear the cost of doing so).
One statement about the TPPA we can make without fear of contraction is this: the TPPA was not written with the benefit or best interests of the citizens of the 12 participating nations in mind.