Beginning on September 26, 2017, representatives of Orexigen Therapeutics, Inc. (the “Company” or “Orexigen”) will begin presenting to and conducting meetings with investors, analysts and others. During these presentations and meetings, the Company will present the slides that are attached as Exhibit 99.1 to the Current Report on Form 8-K, which are incorporated herein by reference.

The information in this Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1, is being furnished pursuant to Item 7.01 and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and it shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or under the Exchange Act, whether made before or after the date hereof, except as expressly set forth by specific reference in such filing to this item of this report.

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By filing this Current Report on Form 8-K, including Exhibit 99.1, and furnishing this information, the Company makes no admission as to the materiality of any information in this report. The information contained in this report is intended to be considered in the context of the Company’s filings with the Securities and Exchange Commission (“SEC”) and other public announcements that the Company makes, by press release or otherwise, from time to time. The Company undertakes no duty or obligation to publicly update or revise the information contained in this report, although it may do so from time to time as its management believes is appropriate. Any such updating may be made through the filing of other reports or documents with the SEC, through press releases or through other public disclosure.

Orexigen cautions you that statements included in this report that are not a description of historical facts are forward-looking statements. Words such as “believes,” “anticipates,” “plans,” “expects,” “indicates,” “will,” “should,” “intends,” “potential,” “suggests,” “assuming,” “designed” and similar expressions are intended to identify forward-looking statements. These statements are based on the Company’s current beliefs and expectations. These forward-looking statements include statements regarding: the potential success of marketing and commercialization efforts for Contrave ^® in the United States; the potential for Contrave and Mysimba ^TM to achieve commercial success globally, including through potential partnership arrangements outside the United States, and the potential timing of related regulatory filings; the Company’s future financial and sales projections, including future expectations regarding net sales, cash operating expense and market share, its expectation for profitable operations by 2019 and its sales growth projections through 2019; and the status of various strategic plans and initiatives. The inclusion of financial modeling, forward-looking statements and potential financing and transaction plans and terms should not be regarded as a representation by Orexigen that any of its plans will be achieved. Actual results may differ materially from those expressed or implied in this report due to the risk and uncertainties inherent in the Orexigen business, including, without limitation: the potential that the marketing and commercialization of Contrave/Mysimba will not be successful; the Company’s ability to obtain and maintain partnerships and the ability of it or its partners to maintain marketing authorization globally; the Company’s ability to adequately inform consumers about Contrave; the Company‘s ability to successfully commercialize Contrave with a specialty sales force in the United States; the capabilities and performance of various third parties on which it relies for a number of activities related to the manufacture, development and commercialization of Contrave/Mysimba; the estimates of the capacity of manufacturing and the Company’s ability to secure additional manufacturing capabilities; the Company’s ability to successfully complete the post-marketing requirement studies for Contrave; the therapeutic and commercial value of Contrave/Mysimba; competition in the global obesity market, particularly from existing therapies; the Company’s failure to successfully acquire, develop and market additional product candidates or approved products; the Company’s ability to obtain and maintain global intellectual property protection for Contrave and Mysimba; the potential for a Delaware court to determine that one or more of the Company’s patents is not valid or that Actavis’ proposed generic product is not infringing each of the patents at issue; other legal or regulatory proceedings

against Orexigen, as well as potential reputational harm, as a result of misleading public claims about Orexigen; the Company’s ability to maintain sufficient capital to fund its operations for the foreseeable future; the Company’s ability to satisfy covenants in the indentures for its outstanding indebtedness, including one requirement that the Company generate consolidated net product sales of least $100 million for fiscal 2017; the Company’s ability to satisfy the applicable listing standards of the NASDAQ Global Market; and other risks described in Orexigen’s filings with the Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Orexigen undertakes no obligation to revise or update this report to reflect events or circumstances after the date hereof. Further information regarding these and other risks is included under the heading “Risk Factors” in Orexigen’s Quarterly Report on Form 10-Q, which was filed with the Securities and Exchange Commission on August 9, 2017 and its other reports, which are available from the SEC’s website (www.sec.gov) and on Orexigen’s website (www.orexigen.com) under the heading “Investors.” All forward-looking statements are qualified in their entirety by this cautionary statement. This caution is made under the safe harbor provisions of Section 21E of the Private Securities Litigation Reform Act of 1995.