Nanoparticles Could Lead to Stronger Drugs, Fewer Side Effects for Cancer Patients

Cerulean's nanoparticle acts like time-release packaging—instead of dumping all the cancer drug into the tumor at one time, the nanoparticle slowly breaks down and releases the drug bit by bit. A feature of Cerulean's technology is that the nanoparticle and the drug are connected by a chemical bond. While drugs in other nanoparticles used in delivery are held by polymer meshes or inside a fatty capsule, drugs in Cerulean's nanoparticles are tethered by a chemical link. The drug is released as the chemical bond is broken, a process partly controlled by an unknown enzyme in the body. That rate of release can be tuned using different linkers, says Fetzer.

Data from early clinical trials of Cerulean's lead compound—a nanoparticle containing a drug called Camptothecin that is too toxic to be administered on its own—suggests it is well-tolerated. Patients in the trial experienced fewer and milder side effects than do patients given available drugs.

Another player in the nanoparticle-delivery space, BIND Biosciences, adds a layer of specificity to its delivery by affixing targeting molecules to the outside of its nanoparticles (see "Fine-tuning Nanotech to Target Cancer"). The targeting molecules recognize proteins on the outside of cancer cells and so help bring the nanopharmaceutical to its desired location.

Fetzer says that while there may be applications where the targeting is helpful, his company does not think it is necessary. "When we look at the data we've generated with untargeted particles, we haven't seen the need to add another layer of complexity."

The company expects to have results from its human trials of its lead compound in treating lung cancers by the end of the 2012. It recently began testing the effectiveness of the same compound in ovarian cancer patients. To begin to explore the possibility of combining nanoparticle-based cancer drugs with other therapies, Cerulean is also enrolling patients with kidney cancer in a phase I trial that will combine the company's lead compound with bevacizumab, a commercially available cancer drug used in a variety of cancers.

cancer, cancer nanoparticles, Cerulean Therapeutics

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