BIOGEN INC. — Director's Dealing 2012

Feb 3, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN IDEC INC. (BIIB)
CIK: 0000875045
Period of Report: 2012-02-01

Reporting Person: LEAMING NANCY (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-02-01	Common Stock	M	5700	$59.17	Acquired	12035	Direct
2012-02-01	Common Stock	S	5700	$120.00	Disposed	6335	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-02-01	Stock Option (Right to Buy)	$59.17	M	5700	Disposed	2018-06-18	Common Stock (5700)	Direct

Footnotes

F1: Exercise/sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities and Exchange Act of 1934.