The Department of Justice has closed its investigation into the Plato trials which supported the approval of AstraZeneca’s  anti-clotting drug, Brilinta (ticagrelor). The company announced the end of the investigation Tuesday.

The drug was of note during the company’s bid to fend off Pfizer’s proposed takeover. The firm projected that the anti-clotting drug had the potential to hit $3.5 billion in sales by 2023 if it pursued “broader opportunities.”

The FDA approved Brilinta for the treatment of patients with acute coronary syndrome in 2011, but in 2013 the DOJ asked the drugmaker to submit documents about the head-to-head Plato trial which compared Brilinta to clopidogrel, which is also known by the BMS/Sanofi brand name Plavix. Allegations that the data had been manipulated surfaced when adjunct medical professor Victor Serebruney at Johns Hopkins Hospital said the numbers did not add up, and filed a complaint under the False Claims Act.

The Wall Street Journal noted at the time that although the professor specialized in these types of drugs but “didn’t assert direct personal knowledge of any wrongdoing.”

The Journal also noted at the time that the complaint was not the only allegation that shadowed the trial. Thomas Marciniak, who headed up the FDA’s drug review said the review application was a mess of poor record keeping and was “the worst submission I have encountered for collecting—or at least submitting—information on SAEs,” with SAEs referring to serious adverse events.