Strong Ph I data for ArQule's ARQ501

Massachussetts, USA-based drugmaker ArQule has said that results from a Phase I monotherapy trial with its lead product, ARQ 501, provide evidence of clinical tolerability and promising antitumor activity in cancer patients with advanced solid tumors who had failed prior chemotherapy.

Data from this trial, which were presented as a late-breaking poster session at the 97th annual meeting of the American Association for Cancer Research in Washington DC, showed antitumor activity in 18 out of 38 patients evaluable for efficacy. Of these 18, evidence of regression was observed in five patients, two of whom had partial responses and three of whom had minor responses (tumor regression by more than 15% but less than 30%). In addition, 13 of these patients achieved disease stabilization.

The data also demonstrated the clinical tolerability and favorable pharmacokinetics of ARQ 501. Drug-related serious adverse events included hemolytic anemia and hyperbilirubinemia, although these were transient and clinically manageable. Hemolytic anemia was identified as the dose-limiting toxicity associated with administration of ARQ 501.