Important Notice Regarding the Availability of Proxy Materials for Annual Meeting of Stockholders

To Be Held on June 7, 2017:

The Notice of 2017 Annual Meeting of Stockholders, Proxy Statement, and 2016 Annual Report on Form 10-K are

available at the following website: www.proxyvote.com.

Corporate Governance Practices

We strive to maintain effective corporate governance practices to ensure that our company is managed for the long-term benefit of our stockholders. We review our corporate governance principles and practices on a regular basis. A description of our corporate governance highlights is set forth in the “Proxy Statement Summary” above.

We believe that our Board’s primary functions are to appoint, evaluate and hold accountable management, as well as assuring optimal capital allocation and strategic decisions such that long-term shareholder value is maximized.

We believe part of effective corporate governance includes active engagement with our stockholders. We value the views of our stockholders and other stakeholders, and we communicate with them regularly and solicit input on a number of topics such as business strategy, capital allocation, corporate governance, executive compensation, sustainability, and corporate social responsibility initiatives.

Director Independence

Board of Directors. All of our directors and nominees for director, other than Mr. Vounatsos, our Chief Executive Officer, satisfy the independence requirements of The NASDAQ Stock Market (NASDAQ). In determining that Stelios Papadopoulos, the Chairman of our Board of Directors, is independent, our Board of Directors considered that Dr. Papadopoulos is a director or advisor to certain companies with which we collaborate.

Committees.

Leadership Structure. We currently separate the roles of Chairman of the Board of Directors and Chief Executive Officer. Dr. Papadopoulos, an independent director, is Chairman of our Board. Among other responsibilities, our Chairman:

We believe that having an independent Chairman promotes a greater role for the independent directors in the oversight of the Company, including oversight of material risks facing the Company, encourages active participation by the independent directors in the work of our Board of Directors, enhances our Board of Directors’ role of representing stockholders’ interests, and improves our Board of Directors’ ability to supervise and evaluate our Chief Executive Officer and other executive officers.

Nominating Processes

Our Corporate Governance Committee is responsible for identifying individuals qualified to become members of our Board of Directors and reviewing candidates recommended by stockholders. Stockholders may recommend nominees for consideration by our Corporate Governance Committee by submitting the names and supporting information to our Secretary, Biogen Inc., 225 Binney Street, Cambridge, Massachusetts 02142. Any such recommendation should include at a minimum the name(s) and address(es) of the stockholder(s) making the recommendation and appropriate biographical information for the proposed nominee(s). Candidates who are recommended by stockholders will be considered in the same manner as candidates from other sources. For all potential candidates, our Corporate Governance Committee will consider all factors it deems relevant, including at a minimum those listed below in the subsection titled “Director Qualifications, Standards, and Diversity.” Director nominations are recommended by our Corporate Governance Committee to our Board of Directors and must be approved by a majority of independent directors.

In addition, our Bylaws contain provisions that address the process by which a stockholder may nominate an individual to stand for election to our Board of Directors at an annual meeting of stockholders.

The number of stockholder-nominated candidates appearing in any annual meeting proxy statement can equal up to 25% of the number of directors then serving on our Board. If 25% is not a whole number, the maximum number of stockholder-nominated candidates would be the closest whole number below 25%, subject to a minimum of one. A nominee will be counted in determining whether the 25% maximum has been reached if the nominee was submitted under the proxy access procedures and later withdrawn, the nominee was included in the proxy materials as a Board-nominated candidate, or the nominee was nominated in any of the Company’s three preceding annual meetings and is being recommended by our Board for reelection.

The nominating stockholder or group of stockholders also must deliver the information required by our Bylaws, and each nominee must meet the qualifications required by our Bylaws.

Requests to include stockholder-nominated candidates in our proxy materials for next year’s annual meeting must be received by our Secretary no earlier than 150 days and no later than 120 days before the anniversary of the date that we issued our proxy statement for the previous year’s annual meeting of stockholders.

Annual Elections and Majority Voting

Our directors are elected annually to serve until the next annual meeting of stockholders and until their successors are duly elected and qualified. Our directors must be elected by a majority of votes cast in uncontested elections (meaning any election for which the number of directors nominated does not exceed the number of directors to be elected at such meeting), and by a plurality of votes cast in contested elections (meaning any election for which the number of directors nominated exceeds the number of directors to be elected at such meeting, regardless of whether such nominees were proposed by the Company or by stockholders). In addition, following their appointment or election by stock-

holders to our Board of Directors, directors must submit an irrevocable resignation that will be effective upon (1) the failure to receive the required number of votes for reelection at the next annual meeting of stockholders at which they face reelection and (2) acceptance of such resignation by our Board of Directors. If an incumbent director fails to receive the number of votes required for reelection, our Board of Directors (excluding the director in question) will, within 90 days after certification of the election results, decide whether to accept the director’s resignation taking into account such factors as it deems relevant. Such factors may include the stated reasons why stockholders voted against such director’s reelection, the qualifications of the director, and whether accepting the resignation would cause us to fail to meet any applicable listing standards or would violate state law. Our Board of Directors will promptly disclose its decision in a filing with the SEC.

Director Qualifications, Standards, and Diversity

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE FOR THE ELECTION OF EACH DIRECTOR NOMINEE NAMED ABOVE.

Our non-employee directors are also eligible to be paid a fee of $1,000 for each full day of service to the Company other than in connection with meetings of our Board of Directors or its committees.

Our non-employee directors may defer all or part of their cash compensation under our Voluntary Board of Directors Savings Plan, which is similar to our Supplemental Savings Plan described in the narrative preceding the 2016 Non-Qualified Deferred Compensation Table in Part 5 – Executive Compensation Matters of this Proxy Statement, but without any Company matching contributions. If non-employee directors choose to defer compensation under our Voluntary Board of Directors Savings Plan, their notional accounts under the plan will periodically be credited with amounts of deemed investment earnings as if their deferred compensation was actually invested in the

notional investment(s) selected by the director or in a default investment if the director does not make a selection. These notional investment options include the mutual funds available under our 401(k) plan as well as a fixed rate option which earns a rate of return determined each year by the Company’s retirement committee. For non-employee director contributions notionally invested in the fixed rate option in 2016, this rate of return was set at 5.50%. Contributions notionally invested in the fixed rate option continue to be credited with the rate of return that was in effect during the year of contribution.

Non-employee directors are also reimbursed for actual expenses incurred in attending meetings of our Board of Directors and its committees, as well as service to our Board of Directors unrelated to such meetings.

Equity Awards

Awards Under Our Non-Employee Directors Equity Plan

Our non-employee directors receive awards under our 2006 Non-Employee Directors Equity Plan (the Non-Employee Directors Equity Plan). The Non-Employee Directors Equity Plan was initially approved by stockholders at our 2006 Annual Meeting of Stockholders. In 2015, our stockholders approved an amendment to extend the term of the plan until June 10, 2025.

General Provisions of the Non-Employee Directors Equity Plan

Non-employee directors receive annual grants under the Non-Employee Directors Equity Plan effective on the date of each annual meeting of stockholders (or a pro rata grant upon election other than at an annual meeting of stockholders). Under the Non-Employee Directors Equity Plan, a maximum of 17,500 shares of our common stock (or 30,000 shares for the independent Chairman of the Board) may be granted to a non-employee director pursuant to such annual grants each calendar year. Annual grants vest on the one-year anniversary of the date of grant or over a longer period in the discretion of our Compensation Committee.

Grants to non-employee directors are recommended by our Compensation Committee and approved by our Board of Directors, with the independent Chairman recused from discussion and voting upon his awards.

Awards granted under the Non-Employee Directors Equity Plan are subject to accelerated vesting upon termination of a director’s service by reason of death, disability, or retirement and upon a change in control (as such terms are defined in the plan). In addition, non-employee director awards will become fully vested upon an involuntary termination of a director’s service within two years following certain mergers or other corporate transactions, as defined in the plan.

Grants During 2016

In June 2016, our Compensation Committee recommended, and our Board of Directors approved, annual grants to non-employee directors with a grant date fair value of approximately $270,000 for each director and an additional grant of approximately $135,000 for the independent Chairman. These amounts were consistent with those approved in 2015 and were below the limits set forth in the

Non-Employee Directors Equity Plan described above. The June 2016 annual grants were awarded in the form of restricted stock units (RSUs) vesting in full on the first anniversary of the grant date, generally subject to the director’s continued service.

Periodically we review our compensation program for our non-employee directors in relation to those of the peer group used for compensation purposes (as described below in our Compensation Discussion and Analysis) to assess its competitiveness and appropriateness. While the grant date fair values of the equity awards granted in 2016 were above the median of our peer group, the annual cash retainer for directors was at or below the 25^th percentile of that same peer group. Overall, the total compensation levels were market competitive. Our Compensation Committee and our Board of Directors believe that a somewhat heavier reliance on equity awards than that of our peer group companies is appropriate because it will further align the interests of our directors with those of our stockholders.

10b5-1 Trading Plans

Our directors must use pre-established trading plans to sell shares of our common stock. Trading plans may only be entered into during an open trading window and when the director is not in possession of material non-public information about the Company. We require a waiting period following the establishment of a trading plan before any trades may be executed. Our policy is designed to provide safeguards that will allow our directors to have an opportunity to realize the value intended by the Company in granting equity-based awards.

Non-Employee Director Share Ownership Guidelines

We maintain the following share ownership guidelines for our non-employee directors:

Our Audit Committee is directly responsible for the appointment, compensation, retention, and oversight of the independent registered public accounting firm retained to audit our consolidated financial statements. Our Audit Committee has selected PricewaterhouseCoopers LLP (PwC) as our independent registered public accounting firm for the fiscal year ending December 31, 2017. PwC has served as our independent registered public accounting firm since 2003.

In order to assure continuing auditor independence, our Audit Committee periodically considers whether there should be a rotation of the independent registered public accounting firm. Further, in conjunction with the rotation of the auditing firm’s lead engagement partner required by applicable SEC rules, our Audit Committee and its Chair has in the past been and in the future will be directly involved in the selection of PwC’s new lead engagement partner.

Our Audit Committee believes at this time that the continued retention of PwC to serve as our independent registered public accounting is in the best interest of Biogen and its stockholders.

Although stockholder approval of our Audit Committee’s selection of PwC is not required, our Board of Directors believes that it is a matter of good corporate practice to solicit stockholder ratification of this selection. If our stockholders do not ratify the selection of PwC as our independent registered public accounting firm, our Audit Committee will reconsider its selection. Even if the selection is ratified, our Audit Committee always has the ability to change the engagement of PwC if it considers that a change is in Biogen’s best interest. Representatives of PwC will participate in the Annual Meeting, have the opportunity to make a statement if they so desire, and be available to respond to appropriate questions.

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE FOR THE RATIFICATION OF

THE SELECTION OF PRICEWATERHOUSECOOPERS LLP AS OUR INDEPENDENT REGISTERED PUBLIC

ACCOUNTING FIRM FOR THE FISCAL YEAR ENDING DECEMBER 31, 2017.

The Audit Committee’s role is to act on behalf of our Board of Directors in the oversight of Biogen’s financial reporting, internal control, and audit functions. The roles and responsibilities of the Audit Committee are set forth in the written charter adopted by our Board of Directors, which is posted on our website, www.biogen.com, under the “Governance” subsection of the “About Us” section of the site. Management has primary responsibility for the financial statements and the reporting process, including the systems of internal controls.

In fulfilling its oversight responsibilities, the Audit Committee, among other things:

In reliance on these reviews and discussions, the Audit Committee recommended to our Board of Directors that the audited consolidated financial statements be included in Biogen’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016 for filing with the SEC.

The Audit Committee of our Board of Directors:

Caroline D. Dorsa (Chair)

Nancy L. Leaming

Stelios Papadopoulos

Brian S. Posner

The following table shows fees for professional audit services billed to us by PwC for the audit of our annual consolidated financial statements for the years ended December 31, 2016 and December 31, 2015, and fees billed to us by PwC for other services provided during 2016 and 2015:

Audit fees are fees for the audit of our 2016 and 2015 consolidated financial statements included in our Annual Reports on Form 10-K, reviews of our condensed consolidated financial statements included in our Quarterly Reports on Form 10-Q, review of the consolidated financial statements incorporated by reference into our outstanding registration statements, and statutory audit fees in overseas jurisdictions.

Audit-related fees are fees that principally relate to assurance and related services that are also performed by our independent registered public accounting firm. More specifically, these services include audits of employee benefit plan information, accounting consultations, due diligence, and audits in connection with business development activity, internal control reviews, and attest services related to financial reporting that are not required by statute or regulation. The increase in fees in 2016 over 2015 was primarily due to audit-related services provided in relation to the spin-off of Bioverativ Inc. (Bioverativ), a wholly-owned subsidiary of the Company, as an independent publicly traded company on February 1, 2017.

Tax fees are fees for tax compliance and planning services.

All other fees include license fees for a web-based accounting research tool, which totaled $7,110 and $7,470 in 2016 and 2015, respectively. All other fees in 2015 also include $6,077 of fees incurred for services provided in assessing the technical structure and format of reports submitted to government authorities to ensure compliance with applicable regulations.

Our Audit Committee has the sole authority to approve the scope of the audit and any audit-related services as well as all audit fees and terms. Our Audit Committee must pre-approve any audit and non-audit services provided by our independent registered public accounting firm. Our Audit Committee will not approve the engagement of the independent registered public accounting firm to perform any services that the independent registered public accounting firm would be prohibited from providing under applicable securities laws, NASDAQ requirements, or Public Company Accounting Oversight Board rules. In assessing whether to approve the use of our independent registered public accounting firm to provide permitted non-audit services, our Audit Committee tries to minimize relationships that could appear to impair the objectivity of our independent registered public accounting firm. Our Audit Committee will approve permitted non-audit services by our independent registered public accounting firm only when it will be more effective or economical to have such services provided by our independent registered public accounting firm than by another firm.

Our Audit Committee annually reviews and pre-approves the audit, audit-related, tax, and other permissible non-audit services that can be provided by the independent registered public accounting firm. After the annual review, any proposed services exceeding pre-set levels or amounts or additional services not previously approved requires separate pre-approval by our Audit Committee or the Chair of our Audit Committee. Any pre-approval decision made by the Chair of our Audit Committee is reported to our Audit Committee at the next regularly scheduled Audit Committee meeting. Our Chief Accounting Officer and Chief Financial Officer can approve up to an additional $50,000 in the aggregate per calendar year for categories of services that our Audit Committee (or the Chair through its delegated authority) has pre-approved.

All of the services provided by PwC during 2016 and 2015 were pre-approved in accordance with this policy, except for $6,077 of fees incurred in 2015 for technical compliance services described under the caption “All other fees”, which were subsequently ratified by our Audit Committee.

Our Compensation Discussion and Analysis, which appears below, describes our executive compensation programs and the compensation decisions that our Compensation Committee and our Board of Directors made with respect to the 2016 compensation of our named executive officers (listed in the Summary Compensation Table). As required pursuant to Section 14A of the Securities Exchange Act, our Board of Directors is asking that stockholders cast a non-binding, advisory vote FOR the following resolution:

“RESOLVED, that the compensation paid to the Company’s named executive officers, as disclosed pursuant to Item 402 of Regulation S-K, including the Compensation Discussion and Analysis, compensation tables, and narrative discussion, is hereby APPROVED.”

Our Board of Directors is asking that our stockholders support this proposal. Although the vote you are being asked to cast is non-binding, we value the views of our stockholders, and our Compensation Committee and our Board of Directors will consider the outcome of the vote when making future compensation decisions for our named executive officers.

As we describe in our Compensation Discussion and Analysis, our executive compensation programs embody a pay-for-performance philosophy that supports our business strategy and aligns the interests of our executives with those of our stockholders. In particular, our compensation programs reward financial, strategic, and operational performance and the goals set for each performance category support our long-range plans. In addition, to discourage excessive risk taking, we maintain policies for share ownership and recoupment of compensation, we cap payments under our annual bonus plan, and we require multi-year vesting of long-term incentive awards.

OUR BOARD OF DIRECTORS RECOMMENDS THAT STOCKHOLDERS VOTE FOR THE APPROVAL OF THE RESOLUTION SET FORTH ABOVE.

2016 Highlights

In 2016, we experienced solid performance across our portfolio of multiple sclerosis and hemophilia therapies and received marketing approval of SPINRAZA. We also strengthened our research and development and leadership teams, and made significant progress in building and advancing our pipeline.

We provided value to our stockholders through the return of approximately $1.0 billion in capital, and we continued our leading efforts in environmental, sustainability, and diversity matters.

Our executive compensation programs for 2016 were similar to past years, remaining closely-linked to the achievement of our corporate performance goals and aligned with stockholder interests.

We achieved the majority of our corporate performance goals that we set in the beginning of the year under our incentive compensation plans and, accordingly, the payouts under these plans for 2016 were moderately above target payout amounts.

A brief summary of our 2016 business, financial, and executive compensation highlights follow:

Roles & Responsibilities

Role of our Compensation Committee

Our Compensation Committee, which is composed of four independent directors, oversees and administers our executive compensation programs. In making executive compensation decisions, our Compensation Committee considers a variety of factors and data, most importantly our performance and individual executives’ performance, and takes into account the totality of compensation that may be paid. In addition, our Compensation Committee administers our annual bonus plan and our 2008 Omnibus Equity Plan, reviews business achievements relevant to compensation levels, makes recommendations to our Board of Directors with respect to compensation policies and practices, and seeks to ensure that total compensation paid to our executive officers is fair and aligned with stockholder interests. Our Compensation Committee retains the right to hire outside advisors as needed to assist it in reviewing and revising our executive compensation programs.

The duties and responsibilities of our Compensation Committee are described on page 18 and can be found in our Compensation Committee’s written charter adopted by our Board of Directors, which can be found on our website, www.biogen.com, under the “Governance” subsection of the “About Us” section of the site.

Role of the Independent Compensation Consultant

Our Compensation Committee believes that independent advice is important in developing Biogen’s executive compensation programs. Frederic W. Cook & Co., Inc. (FW Cook) is currently engaged as our Compensation Committee’s independent compensation consultant. FW Cook does not provide any other services to Biogen.

Reporting directly to our Compensation Committee, FW Cook provides guidance on trends in CEO, executive, and non-employee director compensation, the development of specific executive compensation programs, and the composition of the Company’s compensation peer group. Additionally, FW Cook prepares a report on CEO pay that compares each element of compensation to that of CEOs in comparable positions at companies in our peer group. Using this and other similar information, our Compensation Committee recommends, and our Board of Directors approves, the elements and target levels of our CEO’s compensation. FW Cook also engages in other matters as needed and as directed solely by our Compensation Committee.

During 2016, the Company paid FW Cook approximately $246,252 in consulting fees directly related to these serv-

ices. Our Compensation Committee assesses FW Cook’s independence annually and, in accordance with applicable SEC and NASDAQ rules, confirmed in December 2016 that FW Cook’s work did not raise any conflicts of interest and that FW Cook remains independent under applicable rules.

Role of our CEO

Each year our CEO provides an assessment of performance of each executive officer, other than himself, during the prior year and recommends to our Compensation Committee the compensation to be awarded to each executive. Our CEO’s recommendations are based on numerous factors including:

To understand the external market competitiveness of the compensation for our executive officers, our CEO and our Compensation Committee review a report analyzing publicly-available information and surveys prepared by our internal compensation group and reviewed by FW Cook. The report compares the compensation of each executive officer, other than our CEO, relative to data for comparable positions at companies in our peer group, by compensation element (see “External Market Competitiveness and Peer Group” below for further details). Our Compensation Committee considers all of the information presented, discusses the recommendations with our CEO and with FW Cook, and applies its judgment to determine the elements of compensation and target compensation levels for each executive officer other than the CEO.

Our CEO also provides a self-assessment of his achievements for the prior year. Our Compensation Committee reviews and considers this in analyzing the CEO’s performance, and in recommending for approval by our Board of Directors, the compensation of our CEO. Our CEO does not participate in any deliberations regarding his own compensation.

Executive Compensation Philosophy and Objectives

Our executive compensation programs are designed to drive the creation of long-term stockholder value by delivering performance-based compensation that is competitive with our peer group in order to attract and retain extraordinary leaders who can perform at high levels and suc-

ceed in a demanding business environment. We aim to achieve this by designing programs that are:

External Market Competitiveness and Peer Group

Market practices are one of our considerations when determining executive compensation levels and program

designs at Biogen. We do not target a specific market percentile or simply replicate the market practice. Instead, we review external market practices as a reference point to assist us in providing programs designed to attract, retain, and inspire extraordinary talent. Our Compensation Committee also uses a peer group to provide context for its executive compensation decision-making. Each year our compensation consultant reviews the external market landscape and evaluates the composition of our peer group for appropriateness.

Our Compensation Committee reviews the information provided from internal sources as well as the information provided by our compensation consultant to select our peer group based on comparable companies that approximate (1) our scope of business, including revenue and market capitalization, (2) our global geographical reach, (3) our research-based business with multiple marketed products, and (4) a comparable pool of talent for which we compete.

The peer group for determining our February 2016 compensation decisions primarily consisted of biotechnology and pharmaceutical companies, as we compete with companies in both of these sectors for executive talent.

For each of the companies in our peer group, where available we analyze the company’s Compensation Discussion and Analysis and other data publicly filed during the prior year to identify the executives at such companies whose positions are comparable to those held by our executive officers. We then compile and analyze the data for each comparable position. Our competitive analysis includes the structure and design of the compensation programs as well as the targeted value of the compensation under these programs.

For our NEOs other than our CEO, we may supplement the data for our peer group with published compensation surveys where appropriate. For 2016, consistent with past

years, we used the Towers Watson U.S. CDB Pharmaceutical and Health Sciences Executive Compensation Database survey (which we refer to as the Towers Watson survey). We chose this survey because of the number of companies in our peer group that participate in it, the number of positions reported by the survey that continue to be comparable to our executive positions, and the high standards under which we understand the survey is conducted (including data collection and analysis methodologies). All of the companies in our peer group are represented in a special cross-section of the survey focused on our peer group, other than Valeant Pharmaceuticals Incorporated who did not participate in the survey.

Compensation Elements

Our Compensation Committee determines the elements of compensation we provide to our executive officers. The elements of our executive compensation programs and their objectives are as follows:

Compensation Pay Mix

Our Compensation Committee determines the general mix of the elements of our executive compensation programs. It does not target a specific mix of value for the compensation elements within these programs in either the program design or pay decisions. Rather, our Compensation Committee reviews the pay mix to ensure an appropriate level of performance-based compensation is apportioned to the short-term and even more to the long-term to ensure alignment with our business goals and performance.

Additionally, our Compensation Committee believes the greater the leadership responsibilities, the greater the potential impact an individual will have on Biogen’s future strategic direction. Therefore, for our executive officers, including our NEOs, additional emphasis is placed on performance-based compensation, with a particular emphasis on long-term incentives.

The 2016 pay mix for Dr. Scangos and our other NEOs was highly performance-based and at-risk; 91% of 2016 compensation was performance-based for Dr. Scangos and 84% of 2016 compensation was performance-based for our other full-year active NEOs serving at the end of 2016, assuming target level achievement of applicable corporate performance goals and with long-term incentive awards measured at planned approximate grant date values.

Arrangements with Mr. Vounatsos and Dr. Ehlers

In April 2016, we hired Mr. Vounatsos as our Executive Vice President, Chief Commercial Officer and, in May 2016, we hired Dr. Ehlers as our Executive Vice President, Research and Development. Mr. Vounatsos was appointed as our Chief Executive Officer effective in January 2017.

In determining annual and long-term compensation for Mr. Vounatsos and Dr. Ehlers, our Compensation Committee followed the same compensation philosophy and objectives described in this CD&A and also took into consideration the value of compensation that Mr. Vounatsos and Dr. Ehlers would have been eligible to earn had they remained employed by their prior employers. After considering the compensation opportunities that Mr. Vounatsos and Dr. Ehlers would be required to forfeit in order to join us, and in order to incentivize them to do so, our Compensation Committee granted Mr. Vounatsos a one-time cash sign-on bonus of $1,500,000, a long-term incentive award of Cash-Settled Performance Units (CSPUs) with a grant date fair value of $1,550,454, and a long-term incentive award of Market Stock Units (MSUs) with a grant date fair value of $1,600,745 and granted Dr. Ehlers a one-time cash sign-on bonus of $1,170,177, a long-term incentive award of CSPUs with a grant date fair value of $1,250,535, a long-term incentive award of MSUs with a grant date fair value of $1,289,903, and a long-term incentive award of RSUs with a grant date fair value of $870,212. These amounts represent a portion of the compensation that Mr. Vounatsos and Dr. Ehlers would have been eligible to receive had they remained employed with their prior employer as well as, for Dr. Ehlers, compensation that was recouped by Dr. Ehlers’ former employer in connection with his departure.

Mr. Vounatsos’ one-time cash sign-on bonus is subject to recoupment by the Company as follows: 100% of his cash sign-on bonus is subject to recoupment if Mr. Vounatsos voluntarily resigns within the first two years of his employment; 50% of his cash sign-on bonus is subject to recoupment if Mr. Vounatsos voluntarily resigns within the third year of his employment; and 25% of his cash sign-on bonus is subject to recoupment if Mr. Vounatsos voluntarily resigns within the fourth year of his employment. Dr. Ehlers’ one-time cash sign on bonus is subject to recoupment by the Company as follows: $300,000 of his cash sign-on bonus is subject to recoupment if Dr. Ehlers voluntarily

resigns within the first year of his employment and $150,000 of his cash sign-on bonus is subject to recoupment if Dr. Ehlers voluntarily resigns within the second year of his employment. The terms of the CSPUs and MSUs awards granted to Mr. Vounatsos and Dr. Ehlers are described below in the section entitled “Long-Term Incentives (LTI).” The RSUs granted to Dr. Ehlers vest ratably over three years, subject to Dr. Ehlers’ continued employment. The payments that Dr. Ehlers will be eligible to receive in connection with certain terminations of employment are described in further detail under the heading “Potential Payments Upon Termination or Change in Control” below.

In connection with Mr. Vounatsos’ appointment as Chief Executive Officer in January 2017, in December 2016 our Compensation Committee approved, as part of the employment agreement he entered into with us, an increase in his annual base salary to $1.1 million and a target bonus of 125% of his base salary under our annual bonus plan. In addition, on February 15, 2017, he received a long-term incentive award of CSPUs with a grant date fair value of $4,999,754 and a long-term incentive award of MSUs with a grant date fair value of $4,999,754. The payments that Mr. Vounatsos will be eligible to receive in connection with certain terminations of employment are described in further detail under the heading “Potential Payments Upon Termination or Change in Control” below. Our Compensation Committee approved these terms after reviewing peer group data provided by FW Cook.

Arrangement with Mr. Cox

Prior to Mr. Vounatsos’ hiring, Mr. Cox served as our interim Executive Vice President, Global Therapeutic Operations, while concurrently serving as our Executive Vice President, Pharmaceutical Operations and Technology. In recognition of the substantial additional responsibilities that Mr. Cox assumed, and his exceptional contributions to the Company, our Compensation Committee granted Mr. Cox a one-time special recognition award consisting of time-based RSUs having a grant date fair value of $2.2 million. These RSUs vest in three equal annual installments beginning on the first anniversary of the date of grant. In connection with the Bioverativ spin-off, these RSUs were converted into RSUs for Bioverativ common stock and will continue to vest in accordance with the terms of his original grant. Our Compensation Committee believes this one-time special recognition award was appropriate in light of Mr. Cox’s exceptional contributions to the Company

and the additional responsibilities he assumed throughout the year, and that the value of the award was commensurate with such contributions and responsibilities.

Dr. Scangos’ Arrangements

On January 6, 2017, Dr. Scangos ceased to be our Chief Executive Officer (which was considered a termination without cause under his employment agreement) and the Company paid him the severance benefits payable under his employment agreement, consisting of a lump sum cash payment in the amount $7.2 million (two times his annual base salary and target annual bonus), provided him with up to nine months of executive-level outplacement services at our cost, and continuation of certain subsidized medical and dental benefits until the earlier of (1) January 8, 2019, (2) the date on which he becomes eligible to receive substantially comparable benefits through another employer, or (3) the date he is eligible for Medicare. In addition, pursuant to the terms of his employment agreement, all of his outstanding MSUs, CPSUs and stock options will continue to vest as if he had remained employed by the Company for the duration of the respective award’s vesting period and all awards that require exercise by him will remain exercisable until the earlier of January 7, 2020 or their expiration date.

2016 Base Salary

In 2016, in determining Dr. Scangos’ base salary, our Board of Directors reviewed the base salaries of comparable chief executive officers in our peer group and considered Dr. Scangos’ pay mix, capabilities, performance, and future expected contributions. Based on its review, Dr. Scangos’ base salary was held constant as compared to 2015, which positioned him at or around the market median when compared to the chief executive officers of our peer group.

Our Compensation Committee undertook a similar review when approving the base salaries for Messrs. Clancy and Cox, which positioned them, on average, slightly below the market median compared to persons with comparable jobs within our peer group.

The base salary of each of our NEOs in 2016 compared to 2015 was as follows: