COLLEGIUM PHARMACEUTICAL, INC

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the shareholders and the Board of Directors of Collegium Pharmaceutical, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Collegium Pharmaceutical, Inc. and subsidiaries (the "Company") as of December 31, 2025 and 2024, the related consolidated statements of operations, comprehensive income, shareholders' equity, and cash flows, for each of the three years in the period ended December 31, 2025, 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 December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 26, 2026, expressed an unqualified opinion on the Company's internal control over financial reporting.

Basis for Opinion

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 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 matters 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.

Revenue Recognition – Product Return Liability– Refer to Note 3 to the Financial Statements

Critical Audit Matter Description

Revenue is recognized when control is transferred to the customer, which occurs upon delivery, and revenue is measured as the amount of consideration the Company expects to receive in exchange for transferring products to a customer (“transaction price”). The transaction price for product sales includes variable consideration related to sales deductions and a refund liability is established for estimated product returns. At the end of each reporting period, the Company updates the estimated transaction price (including updating its assessment of whether an estimate of variable consideration should be constrained). Variable consideration, including the risk of customer concessions, is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty is subsequently resolved. The Company updates the measurement of the returns and the refund liability (the “return provision”) at the end of each reporting period for changes in expectations about the amount of returns and refunds with the corresponding adjustments recognized as revenue (or reductions of revenue).

Estimating the variable consideration and return provision requires significant judgment by management. Given the complexity and significant level of estimation uncertainty involved in calculating the return provision, our audit procedures in this area required a high degree of auditor judgment and an increased extent of effort.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to the return provision included the following, among others:

•We tested the effectiveness of controls over the measurement and recognition of the return provision.

•We evaluated the Company's methodology and significant assumptions made in developing the return provision.

•We tested the completeness and accuracy of the data underlying the measurement of the return provision.

•We tested the mathematical accuracy of management's underlying calculation of the return provision.

•We performed a retrospective review, comparing prior period product return estimates to actual product returns.

•We developed independent estimates of the return provision using historical sales and returns activity, product dating and expiration dates, and other information.

/s/Deloitte & Touche LLP

Boston, Massachusetts

February 26, 2026

We have served as the Company's auditor since 2016.