Basis of Presentation

The unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). AlloVir and its subsidiaries’ operating results are included in the Company’s condensed consolidated financial statements from the Closing Date of the Merger. All other accompanying financial data as of December 31, 2025, and for the three months ended March 31, 2025, include only the accounts and disclosures of Legacy Kalaris. All intercompany transactions and balances have been eliminated upon consolidation.

These unaudited condensed consolidated financial statements and the notes accompanying them should be read in conjunction with Legacy Kalaris' audited financial statements as of and for the year ended December 31, 2025, included in the Company’s Annual Report on Form 10-K filed with the SEC on March 17, 2026.

All historical common share data and per-share amounts prior to the Merger were retrospectively recast to reflect the effect of the exchange ratio of 0.2016 per one share, which was determined in accordance with the Merger Agreement. The number of authorized shares and par value per share were not recast. The conversion ratios for each series of redeemable convertible preferred stock, which were converted into shares of common stock in connection with the closing of the Merger, were proportionally recast.

Unaudited Condensed Financial Statements

The unaudited condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair statement of the Company’s financial position as of March 31, 2026 and its results of operations and its cash flows for the three months ended March 31, 2026 and 2025. The results of operations for the three months ended March 31, 2026 and 2025 are not necessarily indicative of the results to be expected for the year ending December 31, 2026, or for any other future annual or interim period. The consolidated balance sheet as of December 31, 2025 included herein was derived from the audited financial statements as of that date. Certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with GAAP have been condensed or omitted from these unaudited condensed consolidated financial statements.

Marketable Securities

The Company classifies all investments with a remaining maturity of less than one year as short-term marketable securities and investments with a remaining maturity of greater than one year as long-term marketable securities. Marketable securities consist of U.S. treasury securities classified as available-for-sale. The Company's marketable securities are classified as available-for-sale as they are available to fund current operations, even if the Company intends to hold the marketable securities to maturity. Available-for-sale securities are carried at fair value, with the unrealized gains and losses reported in other comprehensive income (loss) until realized. The amortized cost of debt securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization or accretion is included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss. Realized gains and losses are determined using the specific identification method and are included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss. Interest on available-for-sale securities is included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss. The Company reviews its portfolio of marketable securities, using both quantitative and qualitative factors, to determine if declines in fair value below cost have resulted from a credit-related loss. If the decline in fair value is due to credit-related factors, a loss is recognized in other income (expense).

Recently Issued Accounting Pronouncements Not Yet Adopted

ASU 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40)

In November 2024, the FASB issued ASU 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses to improve financial reporting by requiring that public business entities disclose additional information about specific expense categories in the notes to financial statements at interim and annual reporting periods. The amendments in this ASU do not change or remove current expense disclosure requirements; however, the amendments affect where such information appears in the notes to the financial statements because entities are required to include certain current disclosures in the same tabular format as the other disaggregation requirements in the amendments. This ASU is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods

beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact that the updated standard will have on its consolidated financial statement disclosures and financial reporting processes.

ASU 2025-06, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40)