1 Exhibit 23.1 ARONEX PHARMACEUTICALS, INC. AND SUBSIDIARIES CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report dated February 18, 2000 included in this Form 10-K, into Aronex Pharmaceuticals, Inc. previously filed Registration Statements on Form S-8 dated August 18, 1992, June 7, 1994, December 31, 1997 and August 20, 1999. ARTHUR ANDERSEN LLP March 30, 2000 Houston, Texas