Elinafide (LU 79553) is a bisintercalating naphthalamide and a topoisomerase II inhibitor has demonstrated a higher binding affinity for DNA and significant antitumour efficacy against a panel of established tumour cell lines, including several multidrug resistant-positive sublines. Elinafide had been in phase II clinical trial for the treatment of ovarian cancer and phase I trials for the treatment of various solid tumours. The major haematological toxicities observed were anaemia and neutropenia. The major non-haematological toxicities observed in the 3-weekly schedule were neuro-muscular presenting clinically as a mixed syndrome of severe weakness (sometimes with pain in both legs), myalgia and arthralgia, asthenia/fatigue/malaise. One fatality was considered related to LU 79553, as the patient had fever and neutropenia. Clinical study of this drug candidate was discontinued due to its neuromuscular dose-limiting toxicity.