[Arthur Andersen Letterhead] June 19, 1998 Office of the Chief Accountant Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Dear Sir/Madam: We have read Item 4 included in the Form 8-K dated June 19, 1998 of Biomune Systems, Inc. and subsidiaries to be filed with the Securities and Exchange Commission and are in agreement withthe statements contained therein. Very truly yours, ARTHUR ANDERSEN LLP By /s/ Kent M. Bowman