Morgan Stanley analyst Matthew Harrison noted that Alexion shares dropped on Friday following news that Brazil's Attorney General revoked Alexion's Soliris patent in Brazil. The company subsequently issued a statement noting that the Brazil court decision related to a "mailbox" patent that expired in 2015, and Harrison pointed out that his is not a Soliris specific issue and relates to a long-time legal battle by many companies on how to interpret Brazilian law related to mailbox patents. The analyst, who noted that Alexion shares came off their lows prior to Friday's close, expects the stock to further recover on Monday as the details of this patent fight are more fully understood. Harrison maintains an Overweight rating on Alexion.