After-hours buzz: HRB, BIIB, ALXN

A trader works on the floor of the New York Stock Exchange (NYSE).
Brendan McDermid | Reuters
A trader works on the floor of the New York Stock Exchange (NYSE).

Check out which companies are making headlines after the bell:

H&R Block shares climbed more than 11 percent in extended trade after the company reported stronger-than-expected earnings and margin improvement for its fourth quarter. The tax preparation company reported earnings of $3.76 a share on revenue of $2.33 billion, beating Wall Street's earnings expectations of $3.53 a share on revenue of 2.32 billion, according to Thomson Reuters consensus estimates. H&R Block also posted a 10 percent improvement in net income and an increase in earnings per share from $0.43 to $1.96.

Shares of Biogen dropped more than 2 percent after hours following an announcement that CFO Paul Clancy will leave after 16 years to join Alexion Pharmaceuticals.

Biogen said Greg Covino will serve as the interim principle financial officer as the company searches for a new CFO. Clancy will remain with Biogen through the second quarter to assist with the transition.

Shares of Alexion rose over 4 percent following an announcement that Clancy will become the company's CFO on July 31. Prior to his role at Biogen, Clancy served as an executive at Pepsi.

Marathon Oil shares fell 2 percent in extended trading, following an increase of more than 3% in the regular session.