CytRx Corporation (NASDAQ: CYTR), a biopharmaceutical research and development company specializing in oncology, announced that an in vivo trial investigating aldoxorubicin, its tumor-targeting conjugate of the widely used chemotherapeutic agent doxorubicin, in combination with unconjugated doxorubicin, demonstrated positive results and provided the basis for the Company’s current evaluation of the combination therapy in cancer patients with advanced solid tumors in a Phase 1b clinical trial.
The trial compared the antitumor efficacy and tolerability of weekly intravenous treatments with saline or doxorubicin compared with three dosing regimens of either aldoxorubicin alone or combination aldoxorubicin and doxorubicin in a xenograft model of human pancreatic cancer. As single agents, doxorubicin and aldoxorubicin were administered at their maximum tolerated doses (MTD), while each agent was given at 50% of their MTD when combined. Doxorubicin alone produced only modest tumor inhibition. Aldoxorubicin alone and each combination therapy arm induced both complete and partial remissions, with antitumor efficacy within all arms essentially identical. Importantly, the trial data showed better tolerability for the combination therapy at these low dose levels compared with single agent aldoxorubicin.
The study, “Evaluation of combination therapy schedules of doxorubicin and an acid-sensitive albumin-binding prodrug of doxorubicin in the MIA PaCa-2 pancreatic xenograft model,” Kratz, F., et al., was published in the peer-reviewed International Journal of Pharmaceutics, 441 (2013) pages 499-506.
“The data from this trial are particularly encouraging as pancreatic cancer typically responds poorly to chemotherapy,” said CytRx Executive Vice President and Chief Medical Officer Daniel Levitt, M.D., Ph.D. “The ability of a combined therapy with aldoxorubicin and doxorubicin to demonstrate efficacy in this cancer at doses that were well-tolerated indicates its potential for the treatment of other chemotherapeutic-resistant tumors such as chondrosarcoma and chordomas. The design and rationale behind this trial produced valuable information and we are currently testing this combination in a phase 1b clinical trial in patients with solid tumors. A study abstract has been submitted for presentation at the American Society for Clinical Oncology (ASCO) meeting later this year.”