Scholar Rock Holding Corp

To the Stockholders and the Board of Directors of Scholar Rock Holding Corporation

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheet of Scholar Rock Holding Corporation and subsidiaries (the "Company") as of December 31, 2025, the related consolidated statements of operations and other comprehensive loss, stockholders' equity, and cash flows, for the year 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 the results of its operations and its cash flows for the year ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

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 audit. 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 audit 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. 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 audit, 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 audit 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 audit 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 audit provides 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 were 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.

External Prepaid and Accrued Research and Development Expenses– Refer to Notes 2, 5 and 7 to the financial statements

Critical Audit Matter Description

As shown in Notes 5 and 7 to the financial statements, the Company’s prepaid and accrued external research and development expenses totaled $6.5 million and $14.2 million, respectively, at December 31, 2025. As discussed in Note 2 to the consolidated financial statements, the Company’s prepaid and accrued external research and development expenses are recognized based on various inputs, including open contracts and purchase orders, the level of service performed, contracted costs, invoices received, and progress of studies, clinical trials or other activities based on

communication with internal and/or external personnel. Payments for the external research and development activities are due based on the terms of individual arrangements, which may differ from the pattern of costs incurred. Accrued expenses are reflected on the consolidated balance sheet when costs incurred exceed payments made, while prepaid expenses are reflected on the consolidated balance sheet when payments made exceed the costs incurred.

We identified prepaid and accrued external research and development expenses as a critical audit matter because of the significant judgment required by management in estimating the progress of the research and development activities conducted, as the progress is not directly observable. This required a high degree of auditor judgment and an increased extent of effort when performing procedures to audit management's estimates of progress and evaluating the results of those procedures.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to external prepaid and accrued research and development expenses included the following, among others:

/s/Deloitte & Touche LLP

Boston, Massachusetts

March 3, 2026

We have served as the Company’s auditor since 2025.

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Stockholders and the Board of Directors of Scholar Rock Holding Corporation

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheet of Scholar Rock Holding Corporation (the Company) as of December 31, 2024 and the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for the year ended December 31, 2024, and 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 at December 31, 2024, and the results of its operations and its cash flows for the year ended December 31, 2024, in conformity with U.S. generally accepted accounting principles.

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 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. 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 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.

/s/Ernst & Young LLP

We served as the Company’s auditor from 2015 to 2025.

Boston, Massachusetts

February 27, 2025