ARDS Aridis Pharmaceuticals Inc

Item 4.01 Change in Registrant’s Certifying Accountant

As previously disclosed on Form 8-K filed on May 25, 2023, the Audit Committee (the “Audit Committee”) of the Board of Directors of Aridis Pharmaceuticals, Inc. (the “Company”) received a letter from Baker Tilly US, LLP (“BT”), notifying the Audit Committee that BT has decided to resign as the independent registered public accounting firm of the Company effective immediately following the filing of the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2023.

On June 16, 2023, the Company appointed Grassi & Co. CPAs, P.C. (“Grassi”) as the Company’s new independent registered public accounting firm effective as of June 16, 2023.

The Audit Committee of the board of directors of the Company approved the appointment of Grassi.

During the fiscal year ended December 31, 2022 and the interim period from January 1, 2023 through March 31, 2023, neither the Company, nor anyone acting on its behalf, consulted with Grassi regarding (i) the application of accounting principles to a specified transaction, either completed or proposed, or the type of audit opinion that may be rendered on the Company’s financial statements, and Grassi did not provide either a written report or oral advice to the Company that was an important factor considered by the Company in reaching a decision as to the accounting, auditing or financial reporting issue, or (ii) any matter that was either the subject of a disagreement (as defined in Item 304(a)(1)(iv) of Regulation S-K and the related instructions) or a reportable event (as described in Item 304(a)(1)(v) of Regulation S-K).