Aclaris Therapeutics Inc

Report of Independent Registered Public Accounting Firm

To the Board of Directors and Stockholders of Aclaris Therapeutics, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Aclaris Therapeutics, Inc. and its subsidiaries (the “Company”) as of December 31, 2024 and 2023, and the related consolidated statements of operations and comprehensive loss, of stockholders’ equity and of cash flows for the years then ended, including the related notes (collectively referred to as 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, 2024 and 2023, and the results of its operations and its cash flows for the years then ended in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s 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 of these consolidated financial statements in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits 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 Matters

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 (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters 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.

Fair Value of the Contingent Consideration Liability

As described in Notes 2 and 3 to the consolidated financial statements, the Company’s contingent consideration balance was $8.7 million as of December 31, 2024. The Company records a contingent consideration liability related to future potential payments resulting from the acquisition of Confluence based upon significant unobservable inputs including the achievement of regulatory and commercial milestones, as well as estimated future sales levels and the discount rates applied to calculate the present value of the potential payments. Management evaluates fair value estimates of the contingent consideration liability on a quarterly basis using a probability-weighted expected payment model for regulatory milestone payments and a Monte Carlo simulation model for commercial milestone and royalty payments and then applying a risk-adjusted discount rate to calculate the present value of the potential payment. Changes in the fair value of the contingent consideration are recorded as income or expense in the Company’s consolidated statement of operations and comprehensive loss. Significant assumptions used in management’s estimates include the probability of achieving

regulatory milestones and commencing commercialization, which are based upon an asset’s current stage of development and review of existing clinical data.

The principal considerations for our determination that performing procedures relating to the fair value of the contingent consideration liability is a critical audit matter are (i) the significant judgment by management when developing the fair value estimate, which in turn led to (ii) a high degree of auditor judgment, subjectivity and effort in performing procedures and evaluating management’s significant assumptions related to the probability of achieving regulatory milestones and commencing commercialization. In addition, the audit effort involved the use of professionals with specialized skill and knowledge.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included, among others, (i) testing management’s process for developing the fair value of the contingent consideration liability, (ii) evaluating the appropriateness of the probability weighted expected payment and Monte Carlo simulation valuation models, (iii) testing the completeness and accuracy of the underlying data used in the models, and (iv) evaluating the reasonableness of the significant assumptions used by management related to the probability of achieving regulatory milestones and commencing commercialization. Evaluating management’s assumptions related to the probability of achieving regulatory milestones and commencing commercialization involved evaluating whether the assumptions were reasonable considering the agreements associated with the transaction as well as the consistency with industry information, the stage of product development and whether the assumptions were consistent with evidence obtained in other areas of the audit. Professionals with specialized skill and knowledge were used to assist in the evaluation of the Company’s probability-weighted expected payment and Monte Carlo simulation valuation models.

/s/PricewaterhouseCoopers LLP

Philadelphia, Pennsylvania

February 27, 2025

We have served as the Company’s auditor since 2015.