SBBP Strongbridge Biopharma PLC

Strongbridge Biopharma plc (NASDAQ:SBBP) (the “Company”) today announced the closing of its previously announced underwritten public offering of 4,000,000 ordinary shares. The total net proceeds of the offering are approximately $23.4 million, after deducting the underwriting discounts and commissions and estimated offering expenses payable by the Company.

Cantor Fitzgerald & Co. acted as the sole book-running manager for the offering. Oppenheimer & Co. Inc. and H.C. Wainwright & Co., LLC acted as co-managers for the offering.

The Company intends to use the net proceeds from the offering for investment in expanded commercial infrastructure for Keveyis, continued development of Recorlev and veldoreotide, commercialization expenditures, and for other general corporate purposes, which may include working capital, capital expenditures, acquisition of additional technologies or other forms of intellectual property, acquisition of assets or businesses that are complementary to its existing business, and general and administrative expenses.

The ordinary shares described above were offered by the Company pursuant to its shelf registration statement on Form F-3 previously filed with the Securities and Exchange Commission (the “SEC”) and declared effective on May 8, 2017. A final prospectus supplement and accompanying prospectus relating to the offering was filed with the SEC and is available on the SEC’s website at www.sec.gov. Copies of the final prospectus supplement and accompanying prospectus may also be obtained by sending a request to Cantor Fitzgerald & Co., Attention: Capital Markets, 499 Park Ave., 6th Floor, New York, New York 10022 or by e-mail at prospectus@cantor.com.

About Strongbridge Biopharma plc

Strongbridge Biopharma is a global commercial-stage biopharmaceutical company focused on the development and commercialization of therapies for rare diseases with significant unmet needs. Strongbridge’s first commercial product is KEVEYIS® (dichlorphenamide), the first and only FDA-approved treatment for hyperkalemic, hypokalemic, and related variants of Primary Periodic Paralysis. KEVEYIS has orphan drug exclusivity status in the U.S. through August 7, 2022. In addition to establishing this neuromuscular disease franchise, the Company has a clinical-stage pipeline of therapies for rare endocrine diseases. Strongbridge’s lead compounds include RECORLEV™ (levoketoconazole), a cortisol synthesis inhibitor currently being studied for the treatment of endogenous Cushing’s syndrome, and veldoreotide, a next-generation somatostatin analog being investigated for the treatment of acromegaly, with potential additional applications in Cushing’s syndrome and neuroendocrine tumors. Both RECORLEV and veldoreotide have received orphan designation from the U.S. Food and Drug Administration and the European Medicines Agency.

“Safe Harbor” Statement Under the Private Securities Litigation Reform Act of 1995

This press release contains forward-looking statements within the meaning of the federal securities laws. These statements involve risks and uncertainties that could cause actual results to differ materially, including, but not limited to, the anticipated use of the proceeds of the offering, which could change as a result of market conditions or for other reasons, and the impact of general economic, industry or political conditions in the United States or internationally. Additional risks and uncertainties relating to the proposed offering, Strongbridge and its business can be found under the heading “Risk Factors” in Strongbridge’s annual report on Form 20-F for the year ended December 31, 2016, filed with the SEC on April 4, 2017, its Report on Form 6-K filed with the SEC on August 7, 2017, and in the preliminary prospectus supplement and accompanying prospectus relating to the offering to be filed with the SEC. Strongbridge assumes no duty or obligation to update or revise any forward-looking statements for any reason.

Contacts:

Corporate and Media Relations Elixir Health Public Relations Lindsay Rocco +1 862-596-1304 lrocco@elixirhealthpr.com

Investor RelationsU.S.:The Trout Group Marcy Nanus +1 646-378-2927 mnanus@troutgroup.com

Europe:First HouseMitra Hagen Negård+47 21 04 62 19strongbridgebio@firsthouse.no

USA 900 Northbrook Drive Suite 200 Trevose, PA 19053 Tel. +1 610-254-9200 Fax. +1 215-355-7389