Exhibit 99.1

UNITED STATES BANKRUPTCY COURT

FOR THE DISTRICT OF DELAWARE

MONTHLY OPERATING REPORT

File with Court and submit copy to United States Trustee within 20 days after end of month.

Submit copy of report to any official committee appointed in the case.

I declare under penalty of perjury (28 U.S.C. Section 1746) that this report and the attached documents are true and correct to the best of my knowledge and belief.

Notes:

The last four digits of Debtor’s federal tax identification number are (8822). The Debtor’s mailing address for purposes of this chapter 11 case is 3344 North Torrey Pines Court, Suite 200, La Jolla, CA, 92037.

UNITED STATES BANKRUPTCY COURT

FOR THE DISTRICT OF DELAWARE

CERTIFICATION REGARDING POST-PETITION BANK ACCOUNT

RECONCILIATIONS, CASH DISBURSEMENT JOURNALS AND

COMPLIANCE AND PAYMENT OF POST-PETITION TAXES

I, Thomas Lynch, Chief Administrative Officer & General Counsel, of Orexigen Therapeutics, Inc. (the “Debtor”) hereby certify the following:

1. Attached to MOR-1 is a listing of the Debtor’s bank accounts, by account number, and the opening and closing balances. These accounts are reconciled monthly in accordance with the Debtor’s ordinary course accounting practices and are available to the United States Trustee upon request.

2. Cash disbursement journals are maintained in accordance with the Debtor’s ordinary course accounting practices and are available to the United States Trustee upon request.

3. To the best of my knowledge and belief, the Debtor is current on all post-petition taxes, and no post-petition tax amounts are past due.

UNITED STATES BANKRUPTCY COURT

FOR THE DISTRICT OF DELAWARE

Notes to Monthly Operating Report

Debtor in Possession Financial Statements

The financial statements and supplemental information presented in this Monthly Operating Report (“MOR”) have been prepared using the Debtor’s books and records solely to comply with the monthly reporting requirements under the United States Bankruptcy Code and those of the United States Trustee for Region Three.

The financial statements and supplemental information presented herein are unaudited, preliminary in nature, and may not comply with generally accepted accounting principles in the United States of America (“U.S. GAAP”) in all material respects. These preliminary unaudited financial statements and other information represent the Debtor’s good faith attempt to comply with the requirements of the United States Bankruptcy Code and those of the United States Trustee using the resources available. This information is limited in scope to the requirements of this report.

These preliminary unaudited financial statements have not been subject to procedures that would typically be applied to financial information presented in accordance with U.S. GAAP, and upon application of such procedures, the Debtor believes that the financial information could be subject to changes, which could be material. Certain totals may not sum due to rounding.

All related tax implications are not currently reflected in the preliminary unaudited financial statements herein. The financial impact of potential tax and other adjustments on the accompanying preliminary unaudited financial statements cannot be determined at this time.

There may be adjustments to the opening balance sheet as of March 12, 2018 that will impact these accompanying preliminary unaudited financial statements. ASC 805 permits a one-year measurement period in which the opening balance sheet can be adjusted if additional information becomes available.

Liabilities Subject to Compromise

As a result of the commencement of the Debtor’s chapter 11 case, the payment of certain prepetition indebtedness of the Debtor is subject to compromise or other treatment under a plan of reorganization.

Reorganization Items

ASC 852 requires expenses and income directly associated with the Debtor’s chapter 11 cases to be reported separately in the income statement as reorganization items. Reorganization items include expenses related to legal advisory and representation services, and other professional consulting and advisory services. Reorganization costs also include adjustment to record debt at the estimated amount of the claim and an estimate of the loss on sale of assets which is pending a valuation.

Litigation

The Debtor is subject to lawsuits and claims that arise out of its operations in the normal course of business.

Prior to the petition date, the Debtor was the defendant to various legal proceedings, described in detail in the most recent publicly filed financial statements, which are stayed during the course of the chapter 11 bankruptcy proceedings.

There are uncertainties inherent in any litigation and appeal and the Debtor cannot predict the outcome. At this time the Debtor is unable to estimate possible losses or ranges of losses that may result from such legal proceedings described in detail in the most recent publicly filed financial statements, and it has not accrued any amounts in connection with such legal proceedings in the financial statements herein, other than attorney’s fees accrued prior to the petition date.

Sale Transaction

On April 23, 2018, the Debtor entered into an asset purchase agreement with Nalpropion Pharmaceuticals, Inc. (the “Buyer”) for the sale of substantially all of its assets through section 363 of the Bankruptcy Code. This transaction was subsequently approved by the Bankruptcy Court on June 28, 2018. On July 27, 2018, the Debtor closed the sale and transferred substantially all of its assets to the Buyer. As part of the sale, the Debtor entered into a transition services agreement for the post-closing period through the effective date of a Plan of Liquidation. The Debtors are currently in discussions with their stakeholders to develop and file a Plan of Liquidation in the near term.

MOR—1

Consolidated Schedule of Cash Receipts and Disbursements ⁽¹⁾

For the Period: October 1, 2018 - October 31, 2018

(Unaudited)

Notes:

MOR—1a

Schedule of Disbursements by Debtor Entity ⁽¹⁾

For the Period: October 1, 2018 - October 31, 2018

(Unaudited)

Notes:

MOR—1b

Schedule of Debtor Bank Account Balances ⁽¹⁾

For the Period: October 1, 2018 - October 31, 2018

(Unaudited)

Notes:

MOR—1c

Schedule of Professional Fees and Expenses Paid

For the Period: October 1, 2018 - October 31, 2018

(Unaudited)

MOR—2

Statement of Operations

For the Period: October 1, 2018 - October 31, 2018

(Unaudited)

Notes:

MOR—3

Balance Sheet

(Unaudited)

Notes:

MOR—4

Summary of Unpaid Post Petition Accounts Payables

As of October 31, 2018

(Unaudited)

Notes:

MOR—5

Accounts Receivable Aging

As of October 31, 2018

(Unaudited)

CERTIFICATE OF SERVICE

I, Tamara K. Mann, certify that I am not less than 18 years of age, and that service of the foregoing Monthly Operating Report for the Reporting Period October 1, 2018 – October 31, 2018, was caused to be made on November 30, 2018, in the manner indicated upon the party identified below.

VIA HAND DELIVERY

Attn: Timothy Fox, Esq.

Office of the United States Trustee

J. Caleb Boggs Federal Building

844 North King Street, Suite 2207

Wilmington, DE 19801