The U.S. Food and Drug Administration has granted Orphan Drug Designation to aldoxorubicin for three indications, for treatment of patients with glioblastoma multiforme, small cell lung cancer, and ovarian cancer.
Aldoxorubicin combines the chemotherapy agent doxorubicin with a novel single-agent molecular linker that binds directly and specifically to circulating albumin, the protein that concentrates in several tumors, thus increasing the delivery of the linker molecule with the attached doxorubicin to the tumor sites. The doxorubicin is consequently released in the acidic environment of the tumor rather than the neutral environment of healthy tissues, which allows for greater doses of doxorubicin to be administered with reduced toxicity.
The Orphan Drug designation—to encourage development of drugs in the diagnosis, prevention, or treatment of a medical condition affecting fewer than 200,000 people in the U.S.—grants a product market exclusivity for a seven-year period if the sponsor complies with certain FDA specifications, as well as tax credits and prescription drug user fee waivers. The designation does not, though, shorten the duration of the regulatory review and approval process.
Phase III clinical trials evaluating the efficacy and safety of aldoxorubicin as a second-line treatment for patients with soft tissue sarcoma under a Special Protocol Assessment with the FDA are currently ongoing. Also ongoing are two Phase II clinical trials of the drug—one in patients with late-stage glioblastoma multiforme and one in HIV-related Kaposi's Sarcoma. The data from both Phase II trials are expected to be reported in 2015, according to a news release from the manufacturer, CytRx Corporation.
Also planned, the company notes, are a global Phase IIb trial in patients with relapsed small-cell lung cancer and a Phase Ib combination study of aldoxorubicin plus gemcitabine as a potential precursor to a trial in relapsed ovarian cancer.