Valeant has been under significant pressure from lawmakers and shareholders after the company hiked prices for certain drugs. On Sunday, The Wall Street Journal reported that Pearson was key in making those decisions. Valeant's board ousted Pearson in March. Last week, Valeant named Joseph Papa to succeed Pearson.
Valeant declined CNBC's request for comment. CNBC could not immediately locate Pearson for comment.