Fosbretabulin

Fosbretabulin (CA4P, Combretastatin A4 phosphate) is a chemotherapy agent and a member of the combretastatin family. It is a tubulin polymerization inhibitor derived from the African willow tree Combretum caffrum. Fosbretabulin is primarily researched and developed for its potential use in the treatment of cancer, particularly focusing on its ability to disrupt the blood vessels that supply tumors, a process known as angiogenesis inhibition.

Mechanism of Action[edit | edit source]

Fosbretabulin works by binding to the colchicine site on beta-tubulin, inhibiting the polymerization of tubulin into microtubules. This action leads to the destabilization of the cytoskeleton in endothelial cells, which are cells that line the interior surface of blood vessels. The disruption of endothelial cells results in the blockage of blood flow to the tumor, depriving it of necessary oxygen and nutrients required for growth. This mechanism categorizes fosbretabulin as a vascular disrupting agent (VDA).

Clinical Trials[edit | edit source]

Fosbretabulin has been evaluated in various phases of clinical trials for its efficacy and safety in treating different types of cancers, including ovarian cancer, thyroid cancer, and certain types of solid tumors. Despite showing promise in early-phase trials, the development of fosbretabulin has faced challenges, including mixed results in later-phase trials which have impacted its progression towards regulatory approval.

Adverse Effects[edit | edit source]

The administration of fosbretabulin can lead to several adverse effects, typical of agents that affect the vascular system. These include hypertension, fatigue, nausea, and in some cases, neutropenia. The severity and occurrence of these side effects vary among patients, and managing them is an important aspect of the clinical use of fosbretabulin.

Current Status[edit | edit source]

As of the last update, fosbretabulin remains an investigational drug. Its development for clinical use continues, with researchers focusing on identifying the most effective and safe dosing regimens, as well as potential combinations with other therapies that might enhance its anti-cancer effects. The future of fosbretabulin will depend on the outcomes of ongoing and future clinical trials.