The offer marked a considerable increase from the 694 billion earlier this month, which was turned down in a matter of hours by AstraZenenca.
Pfizer's new and revised deal promised 606 kronor per share, 55 kronor higher than the previous offer.
However, on early Monday morning, AstraZeneca head Leif Johansson announced that the Anglo-Swedes were not interested.
“We have rejected Pfizer’s final proposal because it is inadequate and would present significant risks for shareholders, while also having serious consequences for the company, our employees and the life-sciences sector in the UK, Sweden and the US,” he said in a statement.
Pfizer's head, Ian Read, had warned on Sunday that "time was running out" for a bargain to be struck, adding that the move would create a "scientific powerhouse".
"Following a conversation with AstraZeneca earlier today, we do not believe that the AstraZeneca board is currently prepared to recommend a deal at a reasonable price. We remain ready to engage in a meaningful dialogue but time for constructive engagement is running out," he said.