Zai Lab Ltd

1. Organization and Principal Activities

Zai Lab Limited was incorporated on March 28, 2013 in the Cayman Islands as an exempted company with limited liability under the Companies Act of the Cayman Islands (as amended). Zai Lab Limited and its subsidiaries (collectively referred to as the “Company”) are focused on discovering, developing, and commercializing products that address medical conditions with significant unmet needs in the areas of oncology, immunology, neuroscience, and infectious disease.

The Company’s principal operations and geographic markets are in Greater China. The Company has a substantial presence in Greater China and the United States.

2. Basis of Presentation and Consolidation and Significant Accounting Policies

(a)Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”), and applicable rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”), regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this report should be read in conjunction with the consolidated financial statements and accompanying notes included in the Annual Report on Form 10-K for the year ended December 31, 2025 (the “2025 Annual Report”). The December 31, 2025 condensed consolidated balance sheet data included in this report were derived from the audited financial statements in the 2025 Annual Report.

The accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments that are necessary to present fairly the results for the interim periods presented. Interim results are not necessarily indicative of the results for the year ending December 31, 2026.

(b)Principles of Consolidation

The unaudited condensed consolidated financial statements include the accounts of Zai Lab Limited and its subsidiaries, which are wholly owned. All intercompany transactions and balances are eliminated upon consolidation.

(c)Use of Estimates

The preparation of the unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates, judgments, 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 revenues and expenses during the period. Areas where management uses subjective judgment include, but are not limited to, accrual of rebates, recognition of research and development expenses based on the Company’s estimates of the actual services performed by CROs and CMOs, fair value of share-based compensation expenses, recoverability of deferred tax assets, and useful life of intangible assets for commercial products. These estimates, judgments, and assumptions can affect the reported amounts of assets and liabilities as of the date of the financial statements as well as the reported amounts of revenues and expenses during the periods presented. Actual results could differ from these estimates.

(d)Fair Value Measurements

Financial instruments of the Company primarily include cash and cash equivalents, current restricted cash, short-term investments, accounts receivable, notes receivable, prepayments and other current assets, non-current restricted cash, accounts payable, short-term debt, and other current liabilities. As of September 30, 2026 and December 31, 2025, the carrying values of cash and cash equivalents, current restricted cash, short-term investments, accounts receivable, prepayments and other current assets, accounts payable, short-term debt, and other current liabilities approximated their fair value due to the short-term maturity of these instruments, and the carrying value of notes receivable and non-current restricted cash approximated their fair value based on the assessment of the ability to recover these amounts.

(e)Recent Accounting Pronouncements

Recently Issued Accounting Pronouncements Not Yet Adopted

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This ASU requires disclosure in the notes to the financial statements of specified information about certain costs and expenses. This ASU will be effective for annual reporting periods beginning after December 15, 2026 and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. This ASU will result in the required additional disclosures being included in the notes to consolidated financial statements, once adopted. The Company is currently evaluating the impact of this ASU and expects to adopt it for the year ending December 31, 2027.

For additional information on the Company’s significant accounting policies, refer to the notes to the consolidated financial statements in the 2025 Annual Report.

3. Cash and Cash Equivalents

The following table presents the Company’s cash and cash equivalents ($ in thousands):

(i)Cash equivalents represent short-term and highly liquid investments in a money market fund.

(ii)Certain cash and bank balances denominated in RMB were deposited with banks in mainland China. The conversion of these RMB-denominated balances into foreign currencies is subject to the rules and regulations of foreign exchange control promulgated by the Chinese government.

4. Inventories, Net

The following table presents the Company’s inventories, net ($ in thousands):

The Company writes down inventory for any excess or obsolete inventory or when the Company believes that the net realizable value of inventory is less than the carrying value. The Company recorded write-downs in inventory, which were included in cost of product revenue, of $7.5 million and $13.6 million in the three and nine months ended September 30, 2026, respectively, and $0.6 million and $0.9 million in the three and nine months ended September 30, 2025, respectively. The inventory write-down in the three and nine months ended September 30, 2026 was mainly related to VYVGART Hytrulo.

5. Property and Equipment, Net

The following table presents the components of the Company’s property and equipment, net ($ in thousands):

Depreciation expense was $2.3 million and $7.0 million in the three and nine months ended September 30, 2026, respectively, and $2.4 million and $6.7 million in the three and nine months ended September 30, 2025, respectively.

6. Intangible Assets, Net

The following table presents the components of the Company’s intangible assets, net ($ in thousands):

(i) The increase in the net carrying value is primarily driven by $10.0 million of regulatory milestone fees for Tisotumab Vedotin (see Note 14).

Intangible assets for commercial products include capitalized post-approval milestone fees and acquired commercial manufacturing know-how and related development costs. The Company is amortizing intangible assets for commercial products as cost of product revenue over the estimated remaining useful life of the related products. Intangible assets for externally purchased software are amortized over three tofive years on a straight-line basis.

Amortization expense was $2.1 million and $5.5 million in the three and nine months ended September 30, 2026, respectively, and $1.5 million and $4.4 million in the three and nine months ended September 30, 2025, respectively. The weighted-average remaining amortization period for intangible assets for commercial products and software was 8.5 years and 1.8 years, respectively.

7. Revenues

Product Revenue, Net

The Company’s product revenue is derived from the sales of its commercial products in Greater China. The table below presents the Company’s gross and net product revenue ($ in thousands):

Sales rebates are offered to distributors in mainland China, and the amounts are recorded as a reduction of product revenue. Estimated rebates are determined based on contracted rates, sales volumes, and level of distributor inventories.

The following table presents the Company’s net revenue by commercial program ($ in thousands):

(i)Other includes product candidates sold in patient programs prior to commercialization.

Collaboration Revenue

Collaboration revenue was $0.6 million and $5.2 million in the three and nine months ended September 30, 2026, respectively, and $0.7 million and $2.5 million in the three and nine months ended September 30, 2025, respectively, and mainly related to a regional license and collaboration arrangement and promotional activities in mainland China.

8. Income Tax

Income tax benefit was $1.9 million and $1.5 million in the three and nine months ended September 30, 2026, respectively, primarily due to the deferred tax benefit related to the inventory provision. Income tax expense wasnil in both the three and nine months ended September 30, 2025 as the Company’s subsidiaries were in cumulative loss positions.

9. Loss Per Share

The following table presents the computation of the basic and diluted net loss per share ($ in thousands, except share and per share data):

As a result of the Company’s net loss in the three and nine months ended September 30, 2026 and 2025, share options and non-vested restricted shares outstanding in the respective periods were excluded from the calculation of diluted loss per share as their inclusion would have been anti-dilutive.

10. Borrowings

The Company has debt arrangements with the Bank of China, SPD Bank, CMB, BOCOM, Ningbo Bank, and CIB to support its working capital needs in mainland China. The following table presents the Company’s short-term debt and weighted-average interest rate per annum ($ in thousands):

Bank of China Working Capital Loan Facility

The Company has an uncommitted facility letter with the Bank of China (Hong Kong) Limited (“BOC HK”) pursuant to which BOC HK will provide standby letters of credit in favor of the Bank of China Pudong Development Zone Branch (“BOC Pudong Branch”) for loans of up to $100.0 million, which are or may become payable by the Company’s wholly-owned subsidiary, Zai Lab (Shanghai) Co., Ltd. (“Zai Lab Shanghai”). BOC HK and BOC Pudong Branch are collectively referred to as Bank of China. In accordance with this agreement, the Company also maintained restricted deposits of $100.0 million, which are presented as restricted cash-current on the unaudited condensed consolidated balance sheet, to secure the standby letters of credit. Each working capital loan has aone-year term and is subject to a floating interest rate, which is subject to adjustment everysix months.

SPD Bank Working Capital Loan Facility

In February 2024, the Company entered into a maximum-amount guarantee contract with the Shanghai Pudong Development Bank Co., Ltd. Zhangjiang Hi-Tech Park Sub-Branch (“SPD Bank”) pursuant to which the Company will guarantee working capital loans of up to RMB 300.0 million (approximately $42.0 million) from SPD Bank to Zai Lab Shanghai over athree-year period. Each working capital loan has aone-year term and is subject to a fixed interest rate.

China Merchants Bank Working Capital Loan Facility

In August 2025, the Company issued a maximum-amount irrevocable letter of guarantee to China Merchants Bank Co., Ltd., Shanghai Branch (“CMB”) pursuant to which the Company will guarantee working capital loans of up to RMB 500.0 million (approximately $69.6 million) from CMB to Zai Lab Shanghai, and Zai Lab Shanghai entered into a Credit Agreement with CMB with respect to the RMB 500.0 million facility. The guarantee and credit facility include the outstanding working capital loans with CMB. The credit facility will be available fortwo years. Each working capital loan has aone-year term and is subject to a floating interest rate, which is subject to adjustment every three months.

Bank of Communications Working Capital Loan Facility

In January 2025, the Company entered into a guarantee contract with Bank of Communications Co., Ltd. Shanghai Zhangjiang Sub-Branch (“BOCOM”) pursuant to which the Company will guarantee working capital loans from BOCOM to Zai Lab Shanghai, and Zai Lab Shanghai entered into a working capital loan contract with BOCOM with respect to a revolving credit facility that expired in September 2025. In February 2026, the Company replaced the expired credit facility with a new revolving credit facility of up to RMB 300.0 million (approximately $43.6 million) with BOCOM that will expire in February 2029, and entered into a new guarantee contract with BOCOM pursuant to which the Company will provide a maximum-amount guarantee of RMB 330.0 million (approximately $47.9 million). Each working capital loan has aone-year term and is subject to a floating interest rate, which is subject to adjustment every three months.

Ningbo Bank Working Capital Loan Facility

In February 2024, the Company’s wholly-owned subsidiary, Zai Lab (Suzhou) Co., Ltd. (“Zai Lab Suzhou”), entered into a maximum credit contract with Bank of Ningbo Co., Ltd. Suzhou Sub-branch (“Ningbo Bank”) as well as an Electronic Commercial Draft Discounting Master Agreement and Online Working Capital Loan Master Agreement (collectively, the “Ningbo Bank Agreements”). The Ningbo Bank Agreements permit Zai Lab Suzhou to utilize, including through discounting or working capital loan agreements and subject to the terms and conditions in related master agreements, up to RMB 230.3 million (approximately $32.4 million), of which Zai Lab Suzhou is authorized to utilize up to RMB 160.0 million (approximately $22.5 million). The cash proceeds from the discounting arrangement were classified as short-term debt. Each discounted bill has a 6-month term.

Industrial Bank Working Capital Loans

On October 13, 2025, the Company entered into a maximum amount guarantee contract with Industrial Bank Co., Ltd., Shanghai Gubei Branch (“CIB”) pursuant to which the Company will guarantee working capital loans of up to RMB 300.0 million (approximately $42.1 million) from CIB to its wholly-owned subsidiary, Zai Lab Shanghai, and Zai Lab Shanghai entered into a credit line contract with CIB with respect to the RMB 300.0 million revolving credit facility. The credit facility expired in May 2026. Each working capital loan has aone-year term and is subject to a fixed interest rate.

11. Other Current Liabilities

The following table presents the Company’s other current liabilities ($ in thousands):

(i)Other primarily includes accrued travel, business-related expenses, and advance payments from partners.

12. Related Party Transactions

In January 2025, the Company entered into a license agreement with Zenas BioPharma (HK) Limited, a subsidiary of Zenas BioPharma, Inc. (“Zenas”), pursuant to which the Company obtained a license under certain patents and know-how of Zenas to develop and commercialize products containing a differentiated humanized monoclonal antibody targeting IGF-1R as an active ingredient in Greater China. One of the members of the Company’s Board of Directors, Mr. Moulder, is also the Chairman of the Board of Directors and Chief Executive Officer of Zenas. The Company recorded a $10.0 million upfront fee into research and development expenses in the first quarter of 2025. As of September 30, 2026, the Company may be required to pay an additional aggregate amount of up to $117.0 million in development and sales-based milestones as well as certain royalties at tiered percentage rates ranging from high-single digits to mid-teens on annual net sales of the licensed products in the licensed territories.

13. Share-Based Compensation

During the nine months ended September 30, 2026, the Company granted share options to purchase up to 11,439,690 ordinary shares and restricted shares representing 12,722,240 ordinary shares under its equity incentive plans. The share options granted have a contractual term often years. Share options granted since April 2023 generally vest ratably over afour-year period, and share options granted prior to April 2023 generally vest ratably over afive-year period, with 25% or 20% of the awards vesting on each anniversary of the grant date, respectively, subject to continued employment/service with the Company on the vesting date. The restricted shares granted generally vest ratably over a specified period on the anniversary of the grant date, subject to continued employment/service with the Company on the vesting date. For a description of the Company’s equity incentive plans and more details on the terms of the share-based awards, see Note 15 in the 2025 Annual Report.

During the nine months ended September 30, 2026, the Company also granted cash-settled performance-based restricted shares representing 1,169,170 ordinary shares under its equity incentive plans. These awards will vest on the third anniversary of the grant date and will be settled in cash based on value of the Company’s ordinary shares on the vesting date. These awards are accounted for as liability awards and their fair value is measured at the end of each reporting period. The related liability of $0.6 million is recorded in other non‑current liabilities in the unaudited condensed consolidated balance sheet as of September 30, 2026, and the related compensation expense of $0.3 million and $0.6 million were recorded in stock‑based compensation in the unaudited condensed consolidated statements of operations in the three and nine months ended September 30, 2026.

The following table presents the share-based compensation expense that has been reported in the Company’s unaudited condensed consolidated statements of operations and comprehensive loss as follows ($ in thousands):

14. License and Collaboration Agreements

The Company has entered into various license and collaboration agreements with third parties to develop and commercialize product candidates.

Significant License and Collaboration Arrangements

For a description of the material terms of the Company’s significant license and collaboration agreements, see Note 16 in the 2025 Annual Report. In the nine months ended September 30, 2026, the Company did not enter into any new significant license or collaboration agreements. The following includes a description of milestone fees incurred in the nine months ended September 30, 2026 under the Company’s significant license and collaboration agreements.

License and Collaboration Agreement with MediLink Therapeutics (DLL3-Targeting ADC)

Under the terms of the Company’s license and collaboration agreement with MediLink, the Company recorded an $8.0 million development milestone fee into research and development expenses in the first quarter of 2026. As of September 30, 2026, the Company may be required to pay an additional aggregate amount of up to $584.0 million in development, regulatory, and sales-based milestones as well as certain royalties at tiered percentage rates ranging from high single digits to low-teens on annual net sales of the licensed products in the licensed territory.

Collaboration and License Agreement with Pfizer (Tisotumab Vedotin)

Under the terms of the Company’s license and collaboration agreement with Seagen (a company later acquired by Pfizer), the Company recorded a regulatory milestone fee of $10.0 million as an intangible asset in the second quarter of 2026. As of September 30, 2026, the Company may be required to pay an additional aggregate amount of up to $248.0 million in development, regulatory, and sales-based milestones as well as certain royalties at tiered percentage rates ranging from mid-teens to low-twenties on annual net sales of the licensed products in the licensed territory.

Other License and Collaboration Arrangements That Are Not Individually Significant

The Company recorded upfront and milestone fees of $29.0 million into research and development expenses in the nine months ended September 30, 2026 for license and collaboration agreements that are not individually significant, including $25.0 million in license fees for a pre-clinical program that the Company terminated in the third quarter of 2026.

15. Restricted Net Assets

Chinese laws and regulations restrict the Company’s ability to receive distributions of funds from its Chinese subsidiaries. For example, relevant Chinese laws and regulations permit payments of dividends by the Company’s Chinese subsidiaries only out of its retained earnings, if any, as determined in accordance with Chinese accounting standards and regulations.

In accordance with the Company Law of the People’s Republic of China, each Chinese subsidiary of the Company is required to provide statutory reserves of at least 10% of its annual after-tax profit until such reserve has reached 50% of its respective registered capital based on the enterprise’s Chinese statutory accounts. The reserves can only be used for specific purposes and are not distributable as cash dividends. Foreign exchange and other regulations in mainland China may further restrict the Company’s Chinese subsidiaries from transferring out funds in the form of dividends, loans, and advances.

No appropriation to statutory reserves was made in the three and nine months ended September 30, 2026 and 2025 because the Chinese subsidiaries had substantial losses during such periods. The Company did not receive any distributions from its Chinese subsidiaries; such distributions were not permitted under Chinese laws and regulations due to the reserve requirements discussed above. As of both September 30, 2026 and December 31, 2025, amounts restricted included the paid-in capital of the Company’s subsidiaries in mainland China and were $516.0 million.

16. Commitments and Contingencies

(a) Purchase Commitments

As of September 30, 2026, the Company’s commitments were $0.7 million and related to capital expenditures that are contracted but not yet reflected in the unaudited condensed consolidated financial statements. These commitments were expected to be incurred within one year from September 30, 2026.

(b) Legal Proceedings

The Company is not currently a party to any material legal proceedings.

(c) Indemnifications

In the normal course of business, the Company enters into agreements that indemnify others for certain liabilities that may arise in connection with a transaction or certain events and activities. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations.

17. Segment Information

The Company operates as a single operating segment that is engaged in discovering, developing, and commercializing products that address medical conditions with significant unmet needs in the areas of oncology, immunology, neuroscience, and infectious disease. A global research and development organization and a supply chain organization discover, develop, manufacture, and supply the Company’s products. A global commercial organization markets, distributes, and sells the products. The business is also supported by global corporate staff functions. The Company’s Chief Operating Decision Maker (the “CODM”) is the Chief Executive Officer, who assesses performance and allocates resources based on significant expenses and net income on a consolidated basis. The significant expenses that are regularly provided to the CODM include those amounts that are also reported on the consolidated statement of operations as well as below additional disaggregated measures. The CODM also reviews cash position (which includes cash and cash equivalents, current restricted cash, and short-term investments that are reported on the consolidated balance sheets) when making operating decisions. In accordance with ASC 280, the Company has onlyone reportable segment.

The following tables present disaggregated expenses that are regularly provided to the CODM:

18. Subsequent Events

On October 22, 2026, the Company entered into a securities purchase agreement with certain accredited investors, relating to the sale of 11,340,000 ADSs, each representing ten ordinary shares of the Company with a par value of $0.000006 per share, at an offering price of $22.04 per ADS in a private placement transaction. The private placement closed on October 27, 2026, and the Company received gross proceeds of approximately $250.0 million, resulting in net proceeds to the Company of approximately $241.2 million after deducting placement agent fees and other expenses. The Company intends to use the net proceeds to fund the development of pipeline assets and for working capital and other general corporate purposes.