Supernus Pharmaceuticals to Acquire Adamas Pharmaceuticals Strengthening its CNS Product Portfolio

Supernus Pharmaceuticals

to Acquire Adamas Pharmaceuticals Strengthening its CNS Product Portfolio

and EMERYVILLE, CA, October 11, 2021 - Supernus Pharmaceuticals, Inc. (Nasdaq: SUPN) and Adamas Pharmaceuticals, Inc.

(Nasdaq: ADMS), today announced a definitive agreement for Supernus to acquire Adamas through a tender offer for $8.10 per share in cash

(or an aggregate of approximately $400 million), payable at closing plus two non-tradable contingent value rights (CVR) collectively

worth up to $1.00 per share in cash (or an aggregate of approximately $50 million), for a total consideration of $9.10 per share in cash

(or an aggregate of approximately $450 million). The first CVR, worth $0.50 per share, is payable upon achieving net sales of GOCOVRI

of $150 million in any four consecutive quarters between closing and the end of 2024. The second CVR, worth $0.50 per share, is

payable upon achieving net sales of GOCOVRI of $225 million in any four consecutive quarters between closing and the end of 2025. The

transaction is expected to close in late fourth quarter 2021 or in early first quarter 2022.

will provide Supernus with two marketed products: GOCOVRI (amantadine) extended release capsules, the first and only U.S. Food and Drug

Administration (FDA)-approved medicine indicated for the treatment of both OFF and dyskinesia in patients with Parkinson's disease

receiving levodopa-based therapy; and Osmolex ER (amantadine) extended release tablets, approved for the treatment of

Parkinson's disease and drug-induced extrapyramidal reactions in adult patients.

represents a significant step to further build a strong and diverse Parkinson's disease portfolio, and aligns with our focus of

acquiring value-enhancing, clinically-differentiated medicines to treat CNS diseases," said Jack Khattar, President and CEO of

Supernus Pharmaceuticals. "We have a proven track record of strong commercial execution, and look forward to building on GOCOVRI's

growth momentum so that more patients can benefit from access to Adamas' innovative neurological therapies."

that Supernus recognized the value created at Adamas and firmly believe this path forward is an excellent outcome for not only our shareholders,

but all our stakeholders," said Neil F. McFarlane, Chief Executive Officer of Adamas Pharmaceuticals, Inc. "With their

shared commitment to helping patients affected by neurological diseases and their extensive resources, Supernus can continue to advance

our mission and reach. I am extremely proud of Team Adamas for their hard work and dedication to get us to this point and am confident

that partnering with Supernus will maximize the potential of our innovative therapies."

of the agreement, Supernus will commence a tender offer to acquire all outstanding shares of Adamas Pharmaceuticals, Inc. for a

purchase price of $8.10 per share in cash (or an aggregate of approximately $400 million) payable at closing plus two non-tradable CVRs.

All cash consideration will be funded through existing balance sheet cash.

Adamas stockholders to receive up to an additional $1.00 per share in cash (or an aggregate of approximately $50 million) payable upon

GOCOVRI achieving certain net sales milestones within specified periods (subject to the terms and conditions contained in a Contingent

Value Rights Agreement detailing the terms of the CVRs). These milestones include (i) $0.50 per share payable if in any four consecutive

quarters between closing and the end of 2024, net sales of GOCOVRI achieving $150 million, and (ii) another $0.50 per share payable

if in any four consecutive quarters between closing and the end of 2025, net sales of GOCOVRI achieving $225 million. There can be no

assurance any payments will be made with respect to the CVR.

which has been approved by the boards of directors of both companies, is expected to close in late fourth quarter 2021 or in early first

quarter 2022, subject to customary closing conditions, including receipt of required regulatory approvals and the tender of a majority

of the outstanding shares of Adamas' common stock. Following the successful closing of the tender offer, Supernus will acquire any shares

of Adamas that are not tendered in the tender offer through a second-step merger at the same consideration as paid in the tender offer.

Supernus will provide

full year 2022 financial guidance during the Company's fourth quarter 2021 financial results conference call in February 2022.

acting as the exclusive financial advisor to Supernus. Lazard is acting as the exclusive financial advisor to Adamas. Saul Ewing Arnstein &

Lehr LLP is serving as legal counsel and Grant Thornton is providing due diligence services to Supernus, and Cooley LLP is serving as

legal counsel to Adamas.

and Webcast today, October 11 at 8:30 a.m. ET

and a live webcast will be hosted today, October 11, at 8:30 a.m. ET, to discuss this transaction. Presentation slides will

be available via this webcast link. A question and answer session with the Supernus management team will follow the company's remarks.

the information below for conference call dial-in information and webcast registration. Callers should dial in approximately 10 minutes

prior to the start of the call.

call, a replay will be available on the Company's website, www.supernus.com, under "Investor Relations".

Pharmaceuticals, Inc.

Supernus Pharmaceuticals

is a biopharmaceutical company focused on developing and commercializing products for the treatment of central nervous system (CNS) diseases.

Our diverse neuroscience

portfolio includes approved treatments for epilepsy, migraine, ADHD, hypomobility in Parkinson's disease, cervical dystonia and

chronic sialorrhea. We are developing a broad range of novel CNS product candidates including new potential treatments for hypomobility

in Parkinson's disease, epilepsy, depression and rare CNS disorders.

For more information,

please visit www.supernus.com

At Adamas our vision

is clear - to deliver innovative medicines that reduce the burden of neurological diseases on patients, caregivers and society.

We are a fully integrated company focused on growing a portfolio of therapies to address a range of neurological diseases.

For more information,

please visit www.adamaspharma.com.

For more information

about GOCOVRI, please visit www.Gocovri.com.

For more information

about Osmolex ER, please visit www.Osmolex.com.

Additional Information

About the Tender Offer and Where to Find It

for the outstanding common stock of Adamas Pharmaceuticals, Inc. ("Adamas") has not been commenced. This filing does

not constitute a recommendation, an offer to purchase or a solicitation of an offer to sell Adamas securities. At the time the tender

offer is commenced, Supernus Pharmaceuticals, Inc. ("Supernus") and Supernus Reef, Inc., a direct wholly owned

subsidiary of Supernus ("Purchaser"), will file a Tender Offer Statement on Schedule TO (including an Offer to Purchase)

with the Securities and Exchange Commission (the "SEC") and thereafter, Adamas will file a Solicitation/Recommendation Statement

on Schedule 14D-9 with the SEC, in each case, with respect to the tender offer. The solicitation and offer by Supernus to purchase shares

of Adamas common stock will only be made pursuant to such Offer to Purchase and related materials. Once filed, investors and security

holders are urged to read these materials (including the Offer to Purchase, a related Letter of Transmittal and certain other tender

offer documents, as each may be amended or supplemented from time to time) carefully since they will contain important information that

Adamas investors and security holders should consider before making any decision regarding tendering their common stock, including the

terms and conditions of the tender offer. The Tender Offer Statement, Offer to Purchase, Solicitation/Recommendation Statement and related

materials will be filed with the SEC, and Adamas investors and security holders may obtain a free copy of these materials (when available)

and other documents filed by Supernus, Purchaser and Adamas with the SEC at the website maintained by the SEC at www.sec.gov. In addition,

the Tender Offer Statement and other documents that Supernus and Purchaser file with the SEC will be made available to all investors

and security holders of Adamas free of charge from the information agent for the tender offer. Investors may also obtain, at no charge,

the documents filed with or furnished to the SEC by (i) Supernus under the "Investor Relations" section of Supernus's

website at https://www.supernus.com and (ii) Adamas under the "Investors & Media" section of Adamas's

website at https://www.adamaspharma.com.

Supernus Forward-Looking

includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements do not

convey historical information but relate to predicted or potential future events that are based upon management's current expectations.

These statements are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or

implied by such statements. In addition to the factors mentioned in this press release, such risks and uncertainties include, but are

not limited to, the risk that the proposed acquisition of Adamas by Supernus may not be completed; the possibility that competing offers

or acquisition proposals for Adamas will be made; the delay or failure of the tender offer conditions to be satisfied (or waived), including

insufficient shares of Adamas common stock being tendered in the tender offer; the failure (or delay) to receive the required regulatory

approvals of the proposed acquisition; the possibility that prior to the completion of the transactions contemplated by the acquisition

agreement, Supernus's or the Adamas's business may experience significant disruptions due to transaction related uncertainty;

the effects of disruption from the transactions of Adamas's business and the fact that the announcement and pendency of the transactions

may make it more difficult to establish or maintain relationships with employees, manufactures, suppliers, vendors, business partners

and distribution channels to patients; the occurrence of any event, change or other circumstance that could give rise to the termination

of the acquisition agreement; the risk that stockholder litigation in connection with the proposed transaction may result in significant