City of Buenos Aires, April 6th , 2026 Messrs. Comisión Nacional de Valores (CNV) Messrs. Bolsas y Mercados Argentinos S.A. (BYMA) Messrs. A3 Mercados S.A. Ref.: LOMA NEGRA C.I.A.S.A. – Relevant Event Dear Sirs, We are writing in order to comply with article 8, Section II, Chapter III, Title II, and Article 3, item 3), Section II, Chapter I, Title XII of the CNV Rules (2013 revised version). In this regard, we inform that on the date hereof LOMA NEGRA C.I.A.S.A. (the “Company”) received notice of the resignations submitted by Mr. Paulo Sergio de Oliveira Diniz from his position as Director and Chairman of the Board, and by Ms. Laura Gé and Messrs. Humberto Junqueira de Farías, Javier Enrique Patrón, Sergio Daniel Alonso and César Javier Graña from their positions as Directors of the Company. As a result of the aforementioned resignations, vacancies were created on the Board of Directors that prevent its normal operation in accordance with the Company’s bylaws. In light thereof, given the absence of alternate directors and considering the need to ensure the continuity and regularity of the Company’s management until the next Ordinary General Shareholders’ Meeting, as well as the immediacy of certain non-deferrable decisions to be adopted by the Board of Directors, the Supervisory Committee, in exercise of the powers set forth in the final paragraph of Section 258 of the Argentine General Corporation Law No. 19,550 and Article Ten of the Company’s bylaws, acknowledged the resignations submitted and appointed Messrs. Marcos Marcelo Mindlin, Darío Gustavo Epstein, Juan Pablo Trujillo, Diego Dayenoff, Fernado Tisné and Gregorio Charnas to hold the positions of full Directors of the Company, and Messrs. Andres Mindlin, Sean Mulroy and Christopher Theuerkauf to hold the position of alternate Directors of the Company, to fill the existing vacancies for the remainder of the current term. Furthermore, it is hereby informed that Messrs. Marcos Marcelo Mindlin, Fernando Tisné, Andres Mindlin, Sean Mulroy and Christopher Theuerkauf qualify as “non-independent”, while Messrs. Dario Gustavo Epstein, Juan Pablo Trujillo, Diego Dayenoff and Gregorio Charnas qualify as “independent”, all in accordance with the provisions of Section 109 of the Argentine Capital Markets Law No. 26,831, the CNV Rules (2013 revised version), the Securities and Exchange Commission (SEC) and the New York Stock Exchange (NYSE). Additionally, it is hereby informed that at its meeting held on April 6th, 2026, the Board of Directors resolved to approve the distribution of Board position, which has been constituted as follows:

Position Name Status President Marcos Marcelo Mindlin Non Independent Vice-president Sergio Damian Faifman Non Independent Full Member Dario Gustavo Epstein Independent Full Member Juan Pablo Trujillo Independent Full Member Diego Dayenoff Independent Full Member Fernando Tisné Non Independent Full Member Gregorio Charnas Independent Alternate Member Andres Mindlin Non Independent Alternate Member Sean Mulroy Non Independent Alternate Member Christopher Theuerkauf Non Independent Moreover, we inform that at its meeting held on April 6th , 2026, the Board of Directors resolved to approve the new composition of the Audit Committee, which is as follows: Position Name Status Chairperson Dario Gustavo Epstein Independent Vice-Chairperson Juan Pablo Trujillo Independent Member Gregorio Charnas Independent Finally, in accordance with the applicable SEC regulations, it is hereby informed that Mr. Dario Gustavo Epstein qualifies as an Audit Committee Financial Expert. Sincerely, ___________________ Marcos Isabelino Gradin Investor Relations Officer

Loma Negra Compania Industrial Argentina Sociedad Anonima 6-K