Dec. 3, 2003 — Designing therapeutic drugs to treat degenerative diseases such as Alzheimer’s and Lou Gehrig’s is challenging enough. But getting them past the protective blood-brain barrier and into brain tissue can prove mind-boggling.
Two biotechnology companies that specialize in nanoscale pharmaceuticals signed deals recently that may allow them to accomplish both feats. Advectus Life Sciences Inc. in Vancouver and C Sixty Inc. in Houston announced partnerships that could pave the way for therapies for Alzheimer’s, Lou Gehrig’s disease and other life-threatening conditions.
Advectus and Immune Network Ltd. will have the opportunity to develop a nanoscale formulation of the anti-inflammatory drug, dapsone. C Sixty and Merck & Co. Inc. will collaborate to test the antioxidant properties of buckyballs, also known as fullerenes, a spherical carbon molecule that was discovered in the 1980s.
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In both cases, the scale of the materials that make up the drugs likely plays a role in their ability to penetrate the blood-brain barrier, a defense structure that blocks possibly poisonous molecules in the blood from brain tissue. The blood-brain barrier often impedes drugs as well, making it difficult to treat diseases in the brain.
“Size is one of the determining characteristics,” said Russ Lebovitz, C Sixty’s vice president of business development. C Sixty specializes in modified fullerenes, or fullerenes with molecules attached that make them water soluble, for instance, or more stable in the body. “The overall size of modified fullerenes appears to be small enough” to cross the barrier.
Fullerenes mop up free radicals, which are atoms or molecules with unpaired electrons. Free radicals are a byproduct of oxidation, a chemical reaction in the body and a possible cause of cell damage and even cell death. Autopsies of people who died of Lou Gehrig’s and Alzheimer’s often reveal signs of brain cell stress and damage.
Since the mid-1990s, researchers have been testing fullerenes as antioxidants. For instance, animal studies showed two kinds of fullerenes slowed the emergence of Lou Gehrig’s, a neuron disease that affects motor skills. C Sixty says fullerene-based drugs also may slow the progression of Alzheimer’s, a disease that destroys brain cells.
Philip Epstein, C Sixty’s chief executive officer, said C Sixty will supply Merck with its fullerene compounds, license its research for animal studies and give Merck an exclusive licensing option to market and sell the drugs. But the project is at its earliest stages, with safety, efficacy and a number of other criteria still to be proven to meet federal standards.
The causes of Lou Gehrig’s and Alzheimer’s are still unknown. But dapsone, an anti-inflammatory drug used to treat leprosy, has been shown to reduce the dementia seen in conditions such as Alzheimer’s. Immune Networks already has conducted clinic trials gauging the effectiveness of dapsone for Alzheimer’s. Advectus reported that it has some evidence that nanoscale formulations improve the drug’s performance.