The accompanying condensed consolidated financial statements reflect the operations of Merrimack Pharmaceuticals, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated.

The condensed consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

The accounting policies followed in the preparation of the interim condensed consolidated financial statements are consistent in all material respects with those presented in Note 1 to the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018.

The accompanying condensed consolidated financial statements reflect Merrimack Pharmaceuticals, Inc. and its wholly owned subsidiaries.

The condensed consolidated balance sheet as of December 31, 2018 was derived from audited financial statements, but does not include all disclosures required by GAAP. The condensed consolidated balance sheet as of June 30, 2019, the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2019 and 2018, the condensed consolidated statements of stockholders’ equity for the three and six months ended June 30, 2019 and 2018 and the condensed consolidated statements of cash flows for the six months ended June 30, 2019 and 2018 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of June 30, 2019, the results of its operations for the three and six months ended June 30, 2019 and 2018, its statements of stockholders’ equity for the three and six months ended June 30, 2019 and 2018 and its statements of cash flows for the six months ended June 30, 2019 and 2018. The financial data and other information disclosed in the notes related to the three and six months ended June 30, 2019 and 2018 are unaudited. The results for the three and six months ended June 30, 2019 and 2018 are not necessarily indicative of results to be expected for the year ending December 31, 2019, any other interim periods, or any future year or period.

The unaudited interim financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 filed with the SEC on March 6, 2019.

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statement of financial position that sum to the total of the same such amounts shown in the statement of cash flows:

(in thousands)	June 30, 2019		June 30, 2018
Cash and cash equivalents	$	36,917	$	22,460
Restricted cash in prepaid expenses and other current assets		—		192
Restricted cash (short-term)		584		—
Restricted cash (long-term)		—		584
Total cash, cash equivalents and restricted cash shown in the condensed consolidated statement of cash flows	$	37,501	$	23,236

Restricted cash on the statement of financial position for 2019 and 2018 primarily represents amounts pledged as collateral for operating lease obligations as contractually required.

The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates, assumptions and judgments reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.

Marketable debt securities consist of investments with original maturities greater than 90 days at their acquisition date. The Company classifies all of its marketable debt securities as available-for-sale securities. The Company’s marketable debt securities are measured and reported at fair value using quoted prices in active markets for similar securities. Unrealized gains and losses on available-for-sale securities are reported as accumulated other comprehensive loss, which is a separate component of stockholders’ equity. The cost of securities sold is determined on a specific identification basis, and realized gains and losses are included in other income and expenses, net in the consolidated statements of operations and comprehensive loss.

The Company evaluates its marketable debt securities with unrealized losses for other-than-temporary impairment. When assessing marketable debt securities for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the statement of operations and comprehensive loss. No such adjustments were necessary during the periods presented.