BIIB

SEC source: 0001127602-17-033939 · form4.xml · nonDerivative · entry 1

Guindo Chirfi · CIK 0001722753 · EVP Glob. Mkt Acc & Cust Innov

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,350

SEC source: 0001127602-17-033936 · form4.xml · nonDerivative · entry 2

COVINO GREGORY F · CIK 0001224116 · VP, Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,439.3601

SEC source: 0001127602-17-033936 · form4.xml · nonDerivative · entry 1

COVINO GREGORY F · CIK 0001224116 · VP, Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,542.3601

F1 · balance_after: Includes 86.155 shares and 5.382 shares acquired under the Biogen Inc. employee stock purchase plan on 3/31/2017 and 6/30/2017, respectively.

SEC source: 0001127602-18-001380 · form4a.xml · derivative · entry 1

Guindo Chirfi · CIK 0001722753 · EVP Glob. Mkt Acc & Cust Innov

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,510

Underlying: Common Stock · 3,510 shares

Expires 2020-12-01

F1 · shares: In the original Form 4, the number of Restricted Stock Units acquired was reported at the target payout and should have been reported at the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout.

F2 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

SEC source: 0000899243-17-027610 · doc4.xml · nonDerivative · entry 2

DENNER ALEXANDER J · CIK 0001361754 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 413,858

F1 · ownership.nature: On November 28, 2017 and November 29, 2017, funds managed by Sarissa Capital Management LP (such funds, the "Sarissa Funds") purchased an aggregate of 20,000 shares and 10,000 shares, respectively, of common stock of Biogen Inc. All of the shares reported herein as being indirectly beneficially owned by Dr. Denner are directly beneficially owned by the Sarissa Funds.

F2 · ownership.nature: Dr. Denner is the Chief Investment Officer of Sarissa Capital Management LP and the managing member of the general partner of the Sarissa Funds. By virtue of the foregoing, Dr. Denner may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 of the Securities Exchange Act of 1934, as amended) the shares that the Sarissa Funds directly beneficially own. Dr. Denner disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.

SEC source: 0001127602-17-033932 · form4.xml · nonDerivative · entry 3

SHERWIN STEPHEN A · CIK 0001079462 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,134

SEC source: 0001127602-17-033932 · form4.xml · nonDerivative · entry 2

SHERWIN STEPHEN A · CIK 0001079462 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,534

SEC source: 0001127602-17-033932 · form4.xml · nonDerivative · entry 1

SHERWIN STEPHEN A · CIK 0001079462 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,734

SEC source: 0000899243-17-027610 · doc4.xml · nonDerivative · entry 1

DENNER ALEXANDER J · CIK 0001361754 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 403,858

F1 · ownership.nature: On November 28, 2017 and November 29, 2017, funds managed by Sarissa Capital Management LP (such funds, the "Sarissa Funds") purchased an aggregate of 20,000 shares and 10,000 shares, respectively, of common stock of Biogen Inc. All of the shares reported herein as being indirectly beneficially owned by Dr. Denner are directly beneficially owned by the Sarissa Funds.

F2 · ownership.nature: Dr. Denner is the Chief Investment Officer of Sarissa Capital Management LP and the managing member of the general partner of the Sarissa Funds. By virtue of the foregoing, Dr. Denner may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 of the Securities Exchange Act of 1934, as amended) the shares that the Sarissa Funds directly beneficially own. Dr. Denner disclaims beneficial ownership of these shares except to the extent of his pecuniary interest therein.

SEC source: 0001140361-17-034050 · doc1.xml · nonDerivative · entry 1

DENNER ALEXANDER J · CIK 0001361754 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 383,858

F1 · shares: On August 31, 2017, in connection with a private transaction with Sarissa Capital Master Offshore Fund LP, a Cayman Island exempted limited partnership ("Sarissa Offshore"), and Sarissa Capital Domestic Fund LP, a Delaware limited partnership ("Sarissa Domestic"), Dr. Alexander Denner increased his pecuniary interest in shares of common stock of Biogen Inc. through his direct interest in Sarissa Domestic and his indirect interest in Sarissa Offshore.

F1 · ownership.nature: On August 31, 2017, in connection with a private transaction with Sarissa Capital Master Offshore Fund LP, a Cayman Island exempted limited partnership ("Sarissa Offshore"), and Sarissa Capital Domestic Fund LP, a Delaware limited partnership ("Sarissa Domestic"), Dr. Alexander Denner increased his pecuniary interest in shares of common stock of Biogen Inc. through his direct interest in Sarissa Domestic and his indirect interest in Sarissa Offshore.

F2 · ownership.nature: All shares reported herein as of August 31, 2017 are beneficially owned by Sarissa Offshore. Sarissa Capital Management GP LLC, a Delaware limited liability company ("Sarissa Capital GP"), is the general partner of Sarissa Capital Management LP, a Delaware limited partnership ("Sarissa Capital"), the investment advisor to Sarissa Offshore. Dr. Denner is the Chief Investment Officer of Sarissa Capital and the managing member of Sarissa Capital GP. By virtue of the foregoing, Dr. Denner may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 of the Securities Exchange Act of 1934, as amended) the shares that Sarissa Offshore directly beneficially owns. Dr. Denner disclaims beneficial ownership of these shares except to the extent of any pecuniary interest therein.

SEC source: 0001127602-17-024875 · form4.xml · derivative · entry 2

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,280

Underlying: Common Stock · 1,280 shares

Expires 2020-08-01

F1 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

SEC source: 0001127602-17-024875 · form4.xml · nonDerivative · entry 1

Gregory Ginger · CIK 0001545716 · EVP, Human Resources

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 860

SEC source: 0001127602-17-024164 · form4.xml · nonDerivative · entry 1

ALEXANDER SUSAN H · CIK 0001263839 · EVP Chief Legal Corp Svc & Sec

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 22,258

F1 · kind: Sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-17-023953 · form4.xml · nonDerivative · entry 1

ALEXANDER SUSAN H · CIK 0001263839 · EVP Chief Legal Corp Svc & Sec

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,232

F1 · kind: Sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-17-023131 · form4.xml · derivative · entry 1

Kress Jean-Paul · CIK 0001654979 · EVP Pres Int'l & Global Hd GTO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,660

Underlying: Common Stock · 4,660 shares

Expires 2020-07-03

F1 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

SEC source: 0001127602-17-021193 · form4.xml · nonDerivative · entry 1

Posner Brian S · CIK 0001372455 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,330

F1 · kind: Sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-17-021106 · form4.xml · nonDerivative · entry 1

Rowinsky Eric K · CIK 0001318886 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,144

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,060 shares. This award was adjusted to 1,084 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021105 · form4.xml · nonDerivative · entry 1

DORSA CAROLINE · CIK 0001181174 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,172

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,060 shares. This award was adjusted to 1,084 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021103 · form4.xml · nonDerivative · entry 1

Mulligan Richard · CIK 0001376247 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,029

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,060 shares. This award was adjusted to 1,084 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021101 · form4.xml · nonDerivative · entry 1

SHERWIN STEPHEN A · CIK 0001079462 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,984

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,060 shares. This award was adjusted to 1,084 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021099 · form4.xml · nonDerivative · entry 1

PAPADOPOULOS STELIOS · CIK 0001202098 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,946

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,590 shares. This award was adjusted to 1,626 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021095 · form4.xml · nonDerivative · entry 1

SCHENK LYNN · CIK 0001236534 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,029

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,060 shares. This award was adjusted to 1,084 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021096 · form4.xml · nonDerivative · entry 1

Posner Brian S · CIK 0001372455 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,414

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,060 shares. This award was adjusted to 1,084 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021098 · form4.xml · nonDerivative · entry 1

PANGIA ROBERT W · CIK 0001236188 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,707

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,060 shares. This award was adjusted to 1,084 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021097 · form4.xml · nonDerivative · entry 1

LEAMING NANCY · CIK 0001265751 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,063

F1 · balance_after: On 6/8/16 an RSU was awarded for 1,060 shares. This award was adjusted to 1,084 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-021094 · form4.xml · nonDerivative · entry 1

DENNER ALEXANDER J · CIK 0001361754 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,029

SEC source: 0001127602-17-020555 · form4.xml · derivative · entry 5

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,996

Underlying: Common Stock · 1,235 shares

Expires 2019-06-01

F4 · shares: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F3 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

F4 · derivative.underlying_shares: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

SEC source: 0001127602-17-020555 · form4.xml · derivative · entry 4

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,231

Underlying: Common Stock · 1,259 shares

Expires 2019-06-01

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · shares: This award was previously reported as covering 7,320 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017

F3 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

F2 · derivative.underlying_shares: This award was previously reported as covering 7,320 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017

F2 · balance_after: This award was previously reported as covering 7,320 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017

SEC source: 0001127602-17-020555 · form4.xml · nonDerivative · entry 3

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,616

SEC source: 0001127602-17-020555 · form4.xml · nonDerivative · entry 2

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,027

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-17-020555 · form4.xml · nonDerivative · entry 1

Ehlers Michael D · CIK 0001674364 · EVP, Research and Development

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,768

F1 · balance_after: On June 1, 2016 an RSU was awarded for 3,034 shares. This award was adjusted to 3,104 shares pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-016857 · form4.xml · derivative · entry 4

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,496

Underlying: Common Stock · 1,508 shares

Expires 2019-05-02

F3 · shares: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F2 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

SEC source: 0001127602-17-016857 · form4.xml · derivative · entry 3

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 8,004

Underlying: Common Stock · 1,736 shares

Expires 2019-05-02

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: This award was previously reported as covering 9,520 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ, Inc. on February 1, 2017.

F2 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

F1 · derivative.underlying_shares: This award was previously reported as covering 9,520 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ, Inc. on February 1, 2017.

F1 · balance_after: This award was previously reported as covering 9,520 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ, Inc. on February 1, 2017.

SEC source: 0001127602-17-016857 · form4.xml · nonDerivative · entry 2

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,099.458

SEC source: 0001127602-17-016857 · form4.xml · nonDerivative · entry 1

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,663.458

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001127602-17-016342 · form4.xml · nonDerivative · entry 1

Vounatsos Michel · CIK 0001672709 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,927.458

F1 · kind: Purchase pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

F2 · balance_after: Includes 91.527 shares acquired under the Biogen Inc. employee stock purchase plan on 3/31/2017.

SEC source: 0001127602-17-016142 · form4.xml · nonDerivative · entry 2

DENNER ALEXANDER J · CIK 0001361754 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 383,858

F1 · shares: On April 27, 2017, Sarissa Capital Domestic Fund LP, a Delaware limited partnership ("Sarissa Domestic"), purchased an aggregate of 73,858 shares of common stock of Biogen Inc.

F3 · ownership.nature: Alexander Denner is the Chief Investment Officer of Sarissa Capital and the managing member of Sarissa Capital GP. By virtue of the foregoing, Dr. Denner may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 of the Securities Exchange Act of 1934, as amended) the shares that the Sarissa Funds directly beneficially own. Dr. Denner disclaims beneficial ownerhip of these shares except to the extent of his pecuniary interest therein.

F4 · ownership.nature: Includes (i) 264,000 shares beneficially owned by Sarissa Domestic and (ii) 119,858 shares beneficially owned by Sarissa Offshore.

SEC source: 0001127602-17-016142 · form4.xml · nonDerivative · entry 1

DENNER ALEXANDER J · CIK 0001361754 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 325,000

F1 · shares: On April 27, 2017, Sarissa Capital Domestic Fund LP, a Delaware limited partnership ("Sarissa Domestic"), purchased an aggregate of 73,858 shares of common stock of Biogen Inc.

F2 · ownership.nature: Includes (i) 205,142 shares beneficially owned by Sarissa Domestic and (ii) 119,858 shares beneficially owned by Sarissa Capital Offshore Master Fund LP, a Cayman Island exempted limited partnership ("Sarissa Offshore" and together with Sarissa Domestic, the "Sarissa Funds"). Sarissa Capital Management GP LLC, a Delaware limited liability company ("Sarissa Capital GP"), is the general partner of Sarissa Capital Management LP, a Delaware limited partnership ("Sarissa Capital"), the investment advisor to the Sarissa Funds.

F3 · ownership.nature: Alexander Denner is the Chief Investment Officer of Sarissa Capital and the managing member of Sarissa Capital GP. By virtue of the foregoing, Dr. Denner may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 of the Securities Exchange Act of 1934, as amended) the shares that the Sarissa Funds directly beneficially own. Dr. Denner disclaims beneficial ownerhip of these shares except to the extent of his pecuniary interest therein.

SEC source: 0001127602-17-015712 · form4.xml · nonDerivative · entry 1

Clancy Paul J · CIK 0001409601 · Executive VP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,813

F1 · kind: Sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-17-013898 · form4.xml · nonDerivative · entry 1

Sandrock Alfred · CIK 0001577061 · EVP CMO Neuro & Neurodegenerat

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,059.8551

F1 · kind: Sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-17-011701 · form4.xml · nonDerivative · entry 1

Clancy Paul J · CIK 0001409601 · Executive VP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,705

F1 · kind: Sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-17-010297 · form4.xml · nonDerivative · entry 1

Sandrock Alfred · CIK 0001577061 · EVP CMO Neuro & Neurodegenerat

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,040.8551

F1 · kind: Sale pursuant to a trading plan intended to comply with Rule 10b5-1 of the Securities Exchange Act of 1934.

SEC source: 0001127602-17-010305 · form4.xml · derivative · entry 5

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,692

Underlying: Common Stock · 363 shares

Expires 2019-03-01

F4 · shares: This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

F3 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

SEC source: 0001127602-17-010305 · form4.xml · derivative · entry 4

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,055

Underlying: Common Stock · 481 shares

Expires 2019-03-01

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · shares: This award was previously reported as covering 2,480 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ, Inc. on February 1, 2017

F3 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

F2 · derivative.underlying_shares: This award was previously reported as covering 2,480 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ, Inc. on February 1, 2017

F2 · balance_after: This award was previously reported as covering 2,480 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ, Inc. on February 1, 2017

SEC source: 0001127602-17-010305 · form4.xml · nonDerivative · entry 3

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,291.443

SEC source: 0001127602-17-010305 · form4.xml · nonDerivative · entry 2

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 561.443

SEC source: 0001127602-17-010305 · form4.xml · nonDerivative · entry 1

McKenzie Paul · CIK 0001677903 · EVP Pharmaceutical Oper & Tech

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 718.443

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · balance_after: Includes 27.114 shares acquired under the Biogen Inc. employee stock purchase plan on 9/30/2016 and 12/30/2016.

SEC source: 0001127602-17-009829 · form4.xml · derivative · entry 15

Clancy Paul J · CIK 0001409601 · Executive VP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,873 shares

Expires 2017-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · date: This award vested on 2/12/2017 and the actual number of shares that vested was determined in accordance with the terms of such award. Due to adjustments to the award to account for the Bioverativ Inc. spin-off, the number of vested shares was not determinable until 2/28/2017. Such adjusted number of vested shares was distributed to the reporting person on 2/28/2017.

F10 · shares: This award was previously reported as covering 2,808 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

F11 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 150% of the number of shares at target payout. One-fourth of these RSUs are eligible to vest on each of the first four anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen Idec common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the average 60 calendar-day closing stock price ending on the vesting date divided by the average 60 calendar-day closing stock price on the grant date]).

F10 · derivative.underlying_shares: This award was previously reported as covering 2,808 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

F10 · balance_after: This award was previously reported as covering 2,808 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-009829 · form4.xml · derivative · entry 14

Clancy Paul J · CIK 0001409601 · Executive VP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,152 shares

Expires 2017-02-12

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · date: This award vested on 2/12/2017 and the actual number of shares that vested was determined in accordance with the terms of such award. Due to adjustments to the award to account for the Bioverativ Inc. spin-off, the number of vested shares was not determinable until 2/28/2017. Such adjusted number of vested shares was distributed to the reporting person on 2/28/2017.

F9 · shares: This award was previously reported as covering 2,448 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

F5 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

F9 · derivative.underlying_shares: This award was previously reported as covering 2,448 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

F9 · balance_after: This award was previously reported as covering 2,448 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

SEC source: 0001127602-17-009829 · form4.xml · derivative · entry 13

Clancy Paul J · CIK 0001409601 · Executive VP and CFO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,546

Underlying: Common Stock · 2,092 shares

Expires 2019-02-22

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · date: This award vested on 2/22/2017 and the actual number of shares that vested was determined in accordance with the terms of such award. Due to adjustments to the award to account for the Bioverativ Inc. spin-off, the number of vested shares was not determinable until 2/28/2017. Such adjusted number of vested shares was distributed to the reporting person on 2/28/2017.

F8 · shares: This award was previously reported as covering 11,060 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

F6 · derivative.exercise_date: The number of RSUs reported represents the maximum possible number of shares that are eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price on the grant date]).

F8 · derivative.underlying_shares: This award was previously reported as covering 11,060 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.

F8 · balance_after: This award was previously reported as covering 11,060 shares, but was adjusted pursuant to the anti-dilution provisions of the award in connection with the spin-off of Bioverativ Inc. on February 1, 2017.