Oppenheimer analyst Derek Archila downgraded Mallinckrodt (MNK) to Perform saying he's been "flat out wrong" on the shares.

The thesis of branded growth and material margin expansion has not and is unlikely to play out within the next 12-18 months, Archila tells investors in a research note. He sees "little-to-no visibility" on Acthar growth outside of management's remarks on the payer pushback/patient abandonment issues. Further, Archila is not certain whether the company can remedy the Acthar growth issue in a timely manner.

He pulled his price target for Mallinckrodt shares.