ANAPTYSBIO INC

To the Stockholders and Board of Directors

AnaptysBio, Inc.:

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of AnaptysBio, Inc. and subsidiary (the Company) as of December 31, 2023 and 2022, the related consolidated statements of operations and comprehensive loss, stockholders’ equity, and cash flows for each of the years in the three-year period ended December 31, 2023, and the related notes (collectively, the consolidated financial statements). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, 2023, in conformity with U.S. generally accepted accounting principles.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on these consolidated 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 consolidated financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risks of material misstatement of the consolidated 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 consolidated 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 consolidated 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 consolidated 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 consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of a critical audit matter does not alter in any way our opinion on the consolidated 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.

Evaluation of Research and Development Costs

As discussed in Note 2 to the consolidated financial statements, the Company has entered into various contracts with third parties to perform research and development, including clinical manufacturing. When billing terms under these contracts do not coincide with the timing of when the work is performed, the Company makes estimates of the costs incurred by third parties during the period and the outstanding obligations to those third parties as of period end. Estimates of costs incurred during the period that are included in period-end prepaid or accrued expense balances are based on a number of factors, including the Company’s knowledge of the research and development programs and clinical manufacturing activities associated with project status and milestones, invoicing to date, and the provisions in the contract. Significant judgments and estimates are made by the Company in determining the costs incurred during the period that are included in prepaid or accrued expense balances at the end of each reporting period.

We identified the evaluation of research and development costs as a critical audit matter. These estimates are based on certain assumptions and inputs that were challenging to assess, including the Company’s knowledge of the status of research and development programs and associated completion status, project milestones achieved, raw materials used in manufacturing, and, for larger clinical trials, per patient costs, patient enrollment status, project costs, and site costs. Significant auditor judgment, subjectivity, and effort were required to evaluate the assumptions and inputs to these estimates.

The following are the primary procedures we performed to address this critical audit matter. On a sample basis, we examined contracts, invoices, and third-party confirmations and compared them to the assumptions and inputs that are described above. We also examined certain invoices received after December 31, 2023 and evaluated whether services received prior to December 31, 2023 were included in the Company’s estimate of costs incurred as of December 31, 2023.

/s/KPMG LLP

We have served as the Company’s auditor since 2009.

San Diego, California

March 11, 2024