The firm also raised its price target on the Crestwood, Ky., company to $49 a share from $35. The new price target represents a potential 88% upside from the stock's Thursday closing price of $26.12.
Apellis shares were trading at $27.71 Friday.
JP Morgan analysts see promising opportunities in the company's later-stage blood-disease drug, calling the asset underappreciated.
Late last month, Apellis said it had completed the enrollment process for the Phase 3 trial of its paroxysmal nocturnal hemoglobinuria treatment candidate.
The company said it planned to release top-line data from the study in December.
Apellis says on its website that some 4,700 people in the U.S. suffer from PNH. Symptoms of the blood disorder include, among many others, severe anemia, abdominal pain and headaches.
If left untreated PNH kills 35% of patients within five years of diagnosis, mostly due to blood clots, Apellis said.
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