I-Mab INDEX TO CONSOLIDATED FINANCIAL STATEMENTS Unaudited Interim Condensed Consolidated Financial Statements for the Nine Months Ended

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Unaudited Interim Condensed Consolidated Financial Statements for the Nine Months Ended September 30, 2019 and 2020

Consolidated Balance Sheet as of December 31, 2019 and

Unaudited Interim Condensed Consolidated Balance Sheet

as of September 30, 2020

(All amounts in thousands, except for share and per share data, unless otherwise noted)

Consolidated Balance Sheet as of December 31, 2019 and

Unaudited Interim Condensed Consolidated Balance Sheet

as of September 30, 2020 (Continued)

(All amounts in thousands, except for share and per share data, unless otherwise noted)

The accompanying notes are an integral part of these unaudited interim condensed consolidated financial statements.

Unaudited Interim Condensed Consolidated Statements of Comprehensive Loss

For the Nine Months Ended September 30, 2019 and 2020

(All amounts in thousands, except for share and per share data, unless otherwise noted)

The accompanying notes are an integral part of these unaudited interim condensed consolidated financial statements.

Unaudited Interim Condensed Consolidated Statements of Changes in Shareholders' Equity (Deficit)

For the Nine Months Ended September 30, 2019 and 2020

(All amounts in thousands, except for share and per share data, unless otherwise noted)

The accompanying notes are an integral part of these unaudited interim condensed consolidated financial statements.

Unaudited Interim Condensed Consolidated Statements of Cash Flows

For the Nine Months Ended September 30, 2019 and 2020

(All amounts in thousands, except for share and per share data, unless otherwise noted)

Unaudited Interim Condensed Consolidated Statements of Cash Flows (Continued)

For the Nine Months Ended September 30, 2019 and 2020

(All amounts in thousands, except for share and per share data, unless otherwise noted)

The accompanying notes are an integral part of these unaudited interim condensed consolidated financial statements.

Notes to the Unaudited Interim Condensed Consolidated Financial Statements

(All amounts in thousands, except for share and per share data, unless otherwise noted)

1. Principal Activities and Organization

(the "Company") was incorporated in the Cayman Islands on June 30, 2016 as an exempted company with limited liability under the Companies Act of the Cayman Islands. The Company and its subsidiaries (together the "Group") are principally engaged in discovering and developing transformational biologics in the fields of immuno-oncology and immuno-inflammation diseases in the People's Republic of China (the "PRC") and other countries and regions.

Prior to the incorporation of the Company, the Group carried out its operation in the PRC since November 2014 mainly through Third Venture Biopharma (Nanjing) Co., Ltd. ("Third Venture"), which was incorporated on November 17, 2014 in the PRC. For the purpose of introduction of overseas investors and in preparation for a listing of the Company's shares on the overseas capital markets, the Group underwent a reorganization (the "Reorganization") in 2016. The Reorganization was approved by the Board of Directors and a restructuring framework agreement was entered into by Third Venture, the Company, and the shareholders of the Company based on Reorganization framework agreement, pursuant to which on July 7, 2016, Third Venture transferred all of its assets and operations to the Company's wholly owned subsidiary, I-Mab

Biopharma Co., Ltd. ("I-Mab

Shanghai"), which was a transaction in which shareholders had identical ownership interests before and after the transaction and was accounted for in a manner similar to a common control transaction.

The Reorganization, as described above has been accounted for at historical cost. That Reorganization was reverse merger of Third Venture and Third Venture is the predecessor of the Company. As such, the assets and liabilities of Third Venture are consolidated in the Company's financial statements at historical cost.

On January 17, 2020, the Company consummated its IPO on the Nasdaq Global Market, where 7,407,400 American Depositary Shares ("ADSs") were issued at the price of US$14.00 per ADS for total gross proceeds of US$103.7 million. On February 10, 2020, the underwriters of the IPO have exercised their over-allotment option to purchase an additional 768,350 ADSs of the Company at the IPO price of US$14.00 per ADS. After giving effect to the exercise of the over-allotment option, the Company has issued and sold a total of 8,175,750 ADSs in the IPO, for total gross proceeds of US$114.5 million. Each ten ADSs represents twenty-three ordinary shares of the Company.

September 30, 2020, the Company's principal subsidiaries are as follows:

Notes to the Unaudited Interim Condensed Consolidated Financial Statements

(All amounts in thousands, except for share and per share data, unless otherwise noted)

2. Principal Accounting Policies

2.1 Basis of presentation

The accompanying unaudited interim condensed consolidated financial statements of the Group have been prepared in accordance with the accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information. Accordingly, they do not include all of the information and footnotes normally included in the annual financial statements prepared in accordance with U.S. GAAP. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted consistent with Article 10 of Regulation S-X.

In the opinion of management, the Group's unaudited interim condensed consolidated financial statements and accompanying notes include all adjustments (consisting of normal recurring adjustments) considered necessary for the fair statement of the Group's financial position as of September 30, 2020, and results of operations and cash flows for the nine months ended September 30, 2019 and 2020. Interim results of operations are not necessarily indicative of the results for the full year or for any future period. These unaudited interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements as of and for the year ended December 31, 2019, and related notes included in the Group's audited consolidated financial statements. The financial information as of December 31, 2019 presented in the unaudited interim condensed consolidated financial statements is derived from the audited consolidated financial statements as of December 31, 2019.

Significant accounting policies followed by the Group in the preparation of the accompanying consolidated financial statements are summarized below.

2.2 Basis of consolidation

The accompanying consolidated financial statements reflect the accounts of the Company and all of its subsidiaries in which a controlling interest is maintained. All inter-company balances and transactions have been eliminated in consolidation.

2.3 Use of estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Estimates are used when accounting for amounts recorded in connection with acquisitions, including initial fair value determinations of assets and liabilities and other intangible assets as well as subsequent fair value measurements. Additionally, estimates are used in determining items such as fair value measurements of wealth management products, impairment of other receivables, long-lived assets, intangible assets and goodwill, useful lives of property, equipment and software, recognition of right-of-use

assets and lease liabilities, fair value measurements of warrants, variable consideration in collaboration revenue arrangements, determination of the standalone selling price of each performance obligation in the Company's revenue arrangements, valuation of share-based compensation arrangements, deferred tax assets valuation allowances and fair value of put right liabilities. Management bases the estimates on historical experience, known trends and various other assumptions that are believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ from those estimates.

Notes to the Unaudited Interim Condensed Consolidated Financial Statements

(All amounts in thousands, except for share and per share data, unless otherwise noted)

2. Principal Accounting Policies (Continued)

2.4 Fair value measurements

Financial assets and liabilities of the Group primarily comprise of cash and cash equivalents, restricted cash, short-term investments, other financial assets, contract assets, other receivables, short-term borrowings, accruals and other payables and put right liabilities. As of December 31, 2019, and September 30, 2020, except for short-term investments and put right liabilities, the carrying values of these financial assets and financial liabilities approximated their fair values because of their generally short maturities. The Group reports short-term investments and put right liabilities at fair value at each balance sheet date and changes in fair value are reflected in the consolidated statements of comprehensive loss.

The Group measures its financial assets and liabilities using inputs from the following three levels of the fair value hierarchy. The three levels are as follows:

Level 1 inputs are unadjusted quoted prices in active markets for identical assets that the management has the ability to access at the measurement date.

Level 2 inputs include quoted prices for similar assets in active markets, quoted prices for identical or similar assets in markets that are not active, inputs other than quoted prices that are observable for the asset (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs).

Level 3 includes unobservable inputs that reflect the management's assumptions about the assumptions that market participants would use in pricing the asset. The management develops these inputs based on the best information available, including the own data.

Assets and liabilities measured at fair value on a recurring basis

The Group measured its short-term investments and put right liabilities at fair value on a recurring basis. As the Group's short-term investments and put right liabilities are not traded in an active market with readily observable prices, the Group uses significant unobservable inputs to measure the fair value of short-term investments and put right liabilities. These instruments are categorized in the Level 3 valuation hierarchy based on the significance of unobservable factors in the overall fair value measurement.

The following table summarizes the Group's financial assets and financial liabilities measured and recorded at fair value on a recurring basis as of December 31, 2019 and September 30, 2020:

Notes to the Unaudited Interim Condensed Consolidated Financial Statements

(All amounts in thousands, except for share and per share data, unless otherwise noted)

2. Principal Accounting Policies (Continued)

2.4 Fair value measurements (Continued)

The roll forward of major Level 3 financial assets and financial liabilities are as follows:

Refer to Note 7 for additional information about Level 3 put right measured at fair value on a recurring basis for the nine months ended September 30, 2020.

2.5 Foreign currency translation

The Group uses Chinese Renminbi ("RMB") as its reporting currency. The United States Dollar ("US$") is the functional currency of the Group's entities incorporated in the Cayman Islands, the United States of America ("U.S.") and Hong Kong, the Australia Dollar ("AUD") is the functional currency of the Group's entity incorporated in Australia and the RMB is the functional currency of the Company's PRC subsidiaries.

Transactions denominated in other than the functional currencies are translated into the functional currency of the entity at the exchange rates prevailing on the transaction dates. Assets and liabilities denominated in other than the functional currencies are translated at the balance sheet date exchange rate. The resulting exchange differences are recorded in the consolidated statements of comprehensive loss.

Notes to the Unaudited Interim Condensed Consolidated Financial Statements

(All amounts in thousands, except for share and per share data, unless otherwise noted)

2. Principal Accounting Policies (Continued)

2.5 Foreign currency translation (Continued)

The unaudited interim condensed consolidated financial statements of the Group are translated from the functional currency to the reporting currency, RMB. Assets and liabilities of the subsidiaries are translated into RMB using the exchange rate in effect at each balance sheet date. Income and expenses are translated at the average exchange rates prevailing for the year. Foreign currency translation adjustments arising from these are reflected in the accumulated other comprehensive income. The exchange rates used for translation on December 31, 2019 and September 30, 2020 were US$1.00 = RMB6.9762 and RMB6.8101 respectively, representing the index rates stipulated by the People's Bank of China.

Translations of balances in the consolidated balance sheets, consolidated statements of comprehensive loss, consolidated statements of changes in shareholders' equity (deficit) and consolidated statements of cash flows from RMB into US$ as of and for the nine months ended September 30, 2020 are solely for the convenience of the readers and were calculated at the rate of US$1.00=RMB6.7896, representing the noon buying rate in The City of New York for cable transfers of RMB as certified for customs purposes by the Federal Reserve Bank of New York on September 30, 2020. No representation is made that the RMB amounts could have been, or could be, converted, realized or settled into US$ at that rate on September 30, 2020, or at any other rate. The US$ convenience translation is not required under U.S. GAAP and all US$ convenience translation amounts in the accompanying consolidated financial statements are unaudited.

2.6 Cash and cash equivalents

Cash and cash equivalents consist of cash on hand and bank deposits, which are unrestricted as to withdrawal and use. The Company considers all highly liquid investments with an original maturity date of three months or less at the date of purchase to be cash equivalents.

Restricted cash consists of the guarantee deposits held in a designated bank account as security deposits under bank borrowing agreements. Such restricted cash was released when the Group repaid the related bank borrowings.

2.8 Short-term investments

Short-term investments represent the investments issued by commercial banks or other financial institutions with a variable interest rate indexed to the performance of underlying assets within one year. These investments are stated at fair value. Changes in the fair value are reflected in the consolidated statements of comprehensive loss.

2.9 Property, equipment and software

Property, equipment and software are stated at cost less accumulated depreciation and amortization. Depreciation and amortization is computed using the straight-line method over the following estimated useful lives, taking into account any estimated residual value:

Notes to the Unaudited Interim Condensed Consolidated Financial Statements

(All amounts in thousands, except for share and per share data, unless otherwise noted)

2. Principal Accounting Policies (Continued)

2.9 Property, equipment and software (Continued)

The Group recognized the gain or loss on the disposal of property, equipment and software in the consolidated statements of comprehensive loss.

2.10 Intangible assets