Company: SUPN
Filing Date: 2025-06-16
Form Type: SC TO-C
Source: 0001104659-25-059761
Chunk: 7

Company: SUPERNUS PHARMACEUTICALS, INC.
Filing Date: 2025-06-16
Form: SC TO-C
Chunk 7
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 (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 Sage 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 Sage investors and security holders may obtain a free copy of these materials (when available) and other documents filed by Supernus,
Purchaser and Sage 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 Sage 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 Supernus under the “Investor Relations” section of Supernus’s website at https://www.supernus.com.

| Item 9.01 | Financial Statements and Exhibits. |

| (d) | Exhibits |

Exhibit 2.1* — Agreement and Plan of Merger, dated as of June 13, 2025, by and among Supernus Pharmaceuticals, Inc., Sage Therapeutics, Inc. and Saphire Inc.

Exhibit 99.1 — Joint Press Release of Supernus Pharmaceuticals, Inc. and Sage Therapeutics, Inc., dated June 16, 2025.

Exhibit 99.2 — Investor Presentation dated June 16, 2025.

Exhibit 104 — The cover page from
this Current Report on Form 8-K, formatted in Inline XBRL.

* Scheduled omitted pursuant to Item 601 of Regulation S-K.
The Company agrees to furnish supplementally a copy of any omitted schedule to the SEC upon request.

<div align='center'>4

SIGNATURES</div>

Pursuant to the requirements of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

| DATED: June 16, 2025 | SUPERNUS PHARMACEUTICALS, INC. 
 By:                            | /s/                                               
 Timothy C. Dec                                    |
|:---------------------|:-------------------------------