CytRx Corporation just announced that the Food and Drug Administration (FDA)has granted multiple Orphan Drug designation to the cancer drug aldoxorubicin for the treatment of glioblastoma mutliforme (GBM), small cell lung cancer (SCLC), and ovarian cancer.
As many of you know, doxorubicin is highly toxic, which can oftentimes limit the amount of drug a cancer patient can receive. The most common serious side effect that patients may experience is cardiomyopathy when higher doses are administered. This is why it's important for patients to obtain a baseline cardiac study prior to the initiation of treatment. Aldoxorubicin is a modified version of this commonly used chemotherapy drug.
Aldoxorubicin combines doxorubicin with a novel single-agent molecule linker that directly binds with circulating albumin -- a globular protein found in the bloodstream. Circulating albumin may accumulate in tumors, bypassing uptake by other non-specific sites including heart, bone marrow, and the gastrointestinal tract. Once albumin-bound aldoxorubicin reaches the tumor, the acidic environment of the tumor causes cleavage of the acid sensitive linker. Because many healthy tissues are bypassed, greater doses of doxorubicin can be administered while minimizing the risk of side effects -- especially where heart damage is concerned.
So, why would this drug in particular be approved for Orphan Drug designation? The FDA grants this kind of designation for those diseases that are rare (fewer than 200,000) -- along with other requirements -- which include safety and effectiveness.
Considering that GBM, SCLC, and ovarian cancer are associated with high mortality rates, this may help to fulfill an unmet treatment need in these particular cases.
Multiple clinical trials are underway, further evaluating the efficacy and safety of aldoxorubicin.