Zai Lab Limited Index to Consolidated Financial Statements ​ ​ ​ ​ Page ​ ​ ​ Report of Independent Registered Public Accounting Firm ​ F- 2 Consolidated Balance Sh

2020-12-312029-12-316823724774882338P1YP5YP5Y0.200.20P1Y0.250.25

Index to Consolidated Financial Statements

Report of independent registered public accounting firm

To the shareholders and Board of Directors of Zai Lab Limited

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Zai Lab Limited and its subsidiaries (collectively referred to as the "Company") as of June 30, 2020 and December 31, 2019, the related consolidated statement of operations, comprehensive loss, changes in shareholders' equity, and cash flow, for the six months ended June 30, 2020, and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of June 30, 2020 and December 31, 2019, and the results of its operations and its cash flows for the six months in the period ended June 30, 2020, in conformity with accounting principles generally accepted in the United States of America.

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud.

Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matter does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Research and development expenses- Cut-off Refer to Note 2(t) to the financial statements

Critical Audit Matter Description

As disclosed in the consolidated statements of operations, for the six months ended June 30, 2020, the Company incurred significant research and development ("R&D") expenses, which amounted to approximately US$102 million. A large amount of the Company's R&D expenses are service fees paid to contract research organizations ("CROs") and contract manufacturing organizations ("CMOs") (collectively referred as "Outsourced Service Providers").

The R&D activities with these Outsourced Service Providers are documented in detailed agreements and are typically performed over an extended period. There are typically several milestones of the services in one agreement, therefore

allocation of the service expenses to the appropriate financial reporting period based on the progress of the R&D projects involved judgement and estimation.

We identified cut-off of R&D expenses as a critical audit matter due to the potential significance of misstatements to the financial statements that could arise from not accruing R&D expenses incurred for services provided by the Outsourced Service Providers in the appropriate reporting period.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to the cut-off of research and development expenses included the following, among others:

/s/ Deloitte Touche Tohmatsu Certified Public Accountants LLP

We have served as the Company's auditor since 2017.

Consolidated balance sheets

(In thousands of U.S. dollars ("$") except for number of shares and per share data)

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

Consolidated statements of operations

(In thousands of U.S. dollars ("$") except for number of shares and per share data)

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

Consolidated statements of comprehensive loss

(In thousands of U.S. dollars ("$") except for number of shares and per share data)

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

Consolidated statements of shareholders' equity

(In thousands of U.S. dollars ("$") except for number of shares and per share data)

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

"0" in above table means less than 1,000 dollars.

Consolidated statements of cash flows

(In thousands of U.S. dollars ("$") except for number of shares and per share data)

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

Notes to the consolidated financial statements

(In thousands of U.S. dollars ("$") and Renminbi ("RMB") except for number of shares and per share data)

1.Organization and principal activities

Zai Lab Limited (the "Company") was incorporated on March 28, 2013 in the Cayman Islands as an exempted company with limited liability under the Companies Law of the Cayman Islands. The Company and its subsidiaries (collectively referred to as the "Group") are principally engaged in discovering or licensing, developing and commercializing proprietary therapeutics that address areas of large unmet medical needs in the China market and the global markets, including in the fields of oncology, infectious and autoimmune diseases.

The Group's principal operations and geographic markets are in the People's Republic of China ("PRC" or "China"). The accompanying consolidated financial statements include the financial statements of the Company and its subsidiaries.

As of June 30, 2020, the Group's significant operating subsidiaries are as follows:

2.Summary of significant accounting policies

(a) Basis of presentation

The consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP"). Significant accounting policies followed by the Group in the preparation of the accompanying consolidated financial statements are summarized below.

(b) Principles of consolidation

The consolidated financial statements include the financial statements of the Company and its subsidiaries. All intercompany transactions and balances among the Group and its subsidiaries are eliminated upon consolidation.

(c) 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 disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the period. Areas where management uses subjective judgment include, but are not limited to, estimating the useful lives of long-lived assets, estimating the current expected credit losses for financial assets, assessing the impairment of long-lived assets, discount rate of operating lease liabilities, revenue recognition, allocation of the research and development service expenses to the appropriate financial reporting period based on the progress of the research and development projects, share-based compensation expenses, recoverability of deferred tax assets and the fair value of the financial instruments. Management bases the estimates on historical experience 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 these estimates.

(d) Foreign currency translation

The functional currency of Zai Lab Limited and Zai Lab (Hong Kong) Limited are the United States dollar ("$"). The Group's PRC subsidiaries determined their functional currency to be Chinese Renminbi ("RMB"). The Group's Australia subsidiary determined its functional currency to be Australia dollar ("A$"). The determination of the respective functional currency is based on the criteria of Accounting Standard Codification ("ASC") 830, Foreign Currency Matters. The Group uses the United States dollar as its reporting currency.

Assets and liabilities are translated from each entity's functional currency to the reporting currency at the exchange rate on the balance sheet date. Equity amounts are translated at historical exchange rates, and expenses, gains and losses are translated using the average rate for the period. Translation adjustments are reported as cumulative translation adjustments and are shown as a separate component of other comprehensive loss in the consolidated statements of changes in shareholders' equity and comprehensive loss.

Monetary assets and liabilities denominated in currencies other than the applicable functional currencies are translated into the functional currencies at the prevailing rates of exchange at the balance sheet date. Non-monetary assets and liabilities are translated into the applicable functional currencies at historical exchange rates. Transactions in currencies other than the applicable functional currencies during the period are converted into the functional currencies at the applicable rates of exchange prevailing at the transaction dates. Transaction gains and losses are recognized in the consolidated statements of operations.

(e) Cash, cash equivalents and restricted cash

Cash and cash equivalents

The Group considers all highly liquid investments purchased with original maturities of three months or less to be cash equivalents. Cash and cash equivalents consist primarily of cash on hand, demand deposits and highly liquid investments with maturity of less than three months and are stated at cost plus interests earned, which approximates fair value.

Restricted cash mainly consists of the bank deposits held as collateral for issuance of letters of credit.

(f) Short-term investments

Short-term investments are time deposits with original maturities more than three months. Short-term investments are stated at cost, which approximates fair value. Interest earned is included in interest income.

(g) Accounts receivable

From January 1, 2020, the Group adopted the ASU 2016-13, Credit Losses, Measurement of Credit Losses on Financial Instruments. Accounts receivable are recorded at the amounts due from customers and net of allowances for credit losses. The allowance for credit losses reflects the Group's current estimate of credit losses expected to be incurred over the life of the receivables. The Group considers various factors in establishing, monitoring, and adjusting its allowance for credit losses including the aging of receivables and aging trends, customer creditworthiness and specific exposures related to particular customers. The Group also monitors other risk factors and forward-looking information, such as country specific risks and economic factors that may affect a customer's ability to pay in establishing and adjusting its allowance for credit losses. Accounts receivable are written off when deemed uncollectible.

Inventories are stated at the lower of cost or net realizable value, with cost determined on a weighted average basis. The Group periodically reviews the composition of inventory and shelf life of inventory in order to identify obsolete, slow-moving or otherwise non-saleable items. The Group will record a write-down to its net realizable value in cost of sales in the period that the decline in value is first identified. Nil and $7 inventory write-down was recorded as of December 31, 2019 and June 30, 2020.

(i) Investments in equity investees

The Group uses the equity method to account for an equity investment over which it has significant influence but does not own a majority equity interest or otherwise control. The Group records equity method adjustments in share of earnings and losses. Equity method adjustments include the Group's proportionate share of investee income or loss, adjustments to recognize certain differences between the Group's carrying value and its equity in net assets of the investee at the date of investment, impairments, and other adjustments required by the equity method. Dividends received are recorded as a reduction of carrying amount of the investment. Cumulative distributions that do not exceed the Group's cumulative equity in earnings of the investee are considered as a return on investment and classified as cash inflows from operating activities. Cumulative distributions in excess of the Group's cumulative equity in the investee's earnings are considered as a return of investment and classified as cash inflows from investing activities.

The Group is required to perform an impairment assessment of its investments whenever events or changes in business circumstances indicate that the carrying value of the investment may not be fully recoverable. An impairment loss is recorded when there has been a loss in value of the investment that is other than temporary. No impairment was recorded for the six months ended June 30, 2020.

(j) Prepayments for equipment

The prepayments for equipment purchase are recorded in long term prepayments considering the prepayments are all related to property and equipment.

(k) Property and equipment

Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the respective assets as follows:

Construction in progress represents property and equipment under construction and pending installation and is stated at cost less impairment losses if any.

From January 1, 2019, the Group adopted the ASC Topic 842, Leases ("ASC 842"). The Group adopted the new guidance using the modified retrospective transition approach by applying the new standard to all leases existing at the date of initial application and not restating comparative periods. The Group determines if an arrangement is a lease at inception. The Group classifies the lease as a finance lease if it meets certain criteria or as an operating lease when it does not. The Group has lease agreements with lease and non-lease components, which the Group has elected to account for the components as a single lease component. The Group leases facilities for office, research and development center, and manufacturing facilities in mainland China, Hong Kong and U.S, which are all classified as operating leases with fixed lease payments, or minimum payments, as contractually stated in the lease agreements. The Group's leases do not contain any material residual value guarantees or material restrictive covenants.

At the commencement date of a lease, the Group recognizes a lease liability for future fixed lease payments and a right-of-use ("ROU") asset representing the right to use the underlying asset during the lease term. The lease liability is initially measured as the present value of the future fixed lease payments that will be made over the lease term. The lease term includes periods for which it's reasonably certain that the renewal options will be exercised and periods for which it's reasonably certain that the termination options will not be exercised. The future fixed lease payments are discounted using the rate implicit in the lease, if available, or the incremental borrowing rate ("IBR"). Upon adoption of ASU 2016-02, the Group elected to use the remaining lease term as of January 1, 2019 in the Group's estimation of the applicable discount rate for leases that were in place at adoption. For the initial measurement of the lease liability for leases commencing after January 1, 2019, the Group uses the discount rate as of the commencement date of the lease, incorporating the entire lease term. Additionally, the Group elected not to recognize leases with lease terms of 12 months or less at the commencement date in the consolidated balance sheets.

The ROU asset is measured at the amount of the lease liability with adjustments, if applicable, for lease prepayments made prior to or at lease commencement, initial direct costs incurred by the Group and lease incentives. Under ASC 842, land use rights agreements are also considered to be operating lease contracts. The Group will evaluate the carrying value of ROU assets if there are indicators of impairment and review the recoverability of the related asset group. If the carrying value of the asset group is determined to not be recoverable and is in excess of the estimated fair value, the Group will record an impairment loss in other expenses in the consolidated statements of operations. ROU assets for operating leases are included in operating lease right-of-use assets in the consolidated balance sheets.

Operating leases are included in operating lease right-of-use assets and operating lease liabilities in the consolidated balance sheets. Operating lease liabilities that become due within one year of the balance sheet date are classified as current operating lease liabilities.

Lease expense is recognized on a straight-line basis over the lease term.

All land in the PRC is owned by the PRC government. The PRC government may sell land use rights for a specified period of time. The purchase price of land use rights represents the operating lease prepayments for the rights to use the land in the PRC under ASC 842 and is recorded as land use rights on the balance sheet, which is amortized over the remaining lease term.

In 2019, the Group acquired land use rights from the local Bureau of Land and Resources in Suzhou for the purpose of constructing and operating the research center and biologics manufacturing facility in Suzhou. The land use rights are being amortized over the respective lease terms, which are 30 years.

(n) Long term deposits

Long term deposits represent amounts paid in connection with the Group's long-term lease agreements.

(o) Value added tax recoverable

Value added tax recoverable represent amounts paid by the Group for purchases. The amounts were recorded as long-term assets considering they are expected to be deducted from future value added tax payables arising on the Group's revenues which it expects to generate in the future.

(p) Intangible assets

Intangible assets mainly consist of externally purchased software which are amortized over one to five years on a straight-line basis. Amortization expenses for the six months ended June 30, 2019 and 2020 were $118 (unaudited) and $127, respectively. Amortization expenses of the Group's intangible assets are expected to be approximately $151, $301, $299, $286, $178 and $1 for the remainder of 2020, the years ended December 31, 2021, 2022, 2023, and 2024 and thereafter, respectively.

(q) Impairment of long-lived assets

Long-lived assets are reviewed for impairment in accordance with authoritative guidance for impairment or disposal of long-lived assets. Long-lived assets are reviewed for events or changes in circumstances, which indicate that their carrying value may not be recoverable. Long-lived assets are reported at the lower of carrying amount or fair value less cost to sell. For the six months ended June 30, 2020, there was no impairment of the value of the Group's long-lived assets.

(r) Fair value measurements

The Group applies ASC topic 820 ("ASC 820"), Fair Value Measurements and Disclosures, in measuring fair value. ASC 820 defines fair value, establishes a framework for measuring fair value and requires disclosures to be provided on fair value measurement.

ASC 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

Level 1 - Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.

Level 2 - Include other inputs that are directly or indirectly observable in the marketplace.

Level 3 - Unobservable inputs which are supported by little or no market activity.