capitalist at Domain Associates in San Diego. Weber, a former professor of pharmacy at UC Irvine and a prolific inventor, takes a broad view.
“There are different manifestations of innovation. A new use of a drug used for something else is one form, and developing new molecules for an old disease is another form,” he said. “It all has a place in the advancement of treating disease and furthering medicine. I don’t know that one is more innovative than the other.”
The process of repositioning an existing drug is not as easy as it sounds, according to Weber. He found the lead candidate for one of his companies by doing a literature search, but it took several years for San Diego-based Novalar to reformulate the blood-pressure drug phentolamine into a form dentists could use. The drug, called OraVerse, is approved to reverse the effects of local anesthesia after dental treatment. Dental anesthetics contain a drug that constricts blood vessels to prolong the numbing sensation. Phentolamine reverses that effect by dilating the vessels.
Developing a drug is never risk-free. Avanir, for example, has spent years reformulating and testing different versions of its tablet to satisfy FDA safety concerns. And companies working with existing drugs face the possibility of generic competition. BiDil, a much-anticipated heart drug approved for treatment in African Americans, was a combination of two cheap generics, isosorbide and hydralazine. The tablet flopped, and its developer, Lexington, Mass.-based NitroMed, stopped promoting it in 2008. NitroMed agreed to sell itself to a health care investment firm earlier this year.
Katkin believes Avanir can avoid a similar fate because its tablet contains a very low dose of quinidine that is not available in generic form. Novalar is selling ready-to-use phentolamine; generic phentolamine is freeze-dried and must be mixed with water before it can be used. “You want to be very careful that your formulation is not easily recreated,” Katkin said.
No company can guard against the unexpected. Just ask San Diego’s Victory Pharmaceuticals. The venture-backed company focused on reviving old drugs saw a merger deal blow up after an FDA advisory panel recommended an outright ban on prescription drugs that combine acetaminophen and a narcotic. The panel was concerned about overdoses, and possible liver damage. Unfortunately for Victory, its best-selling drug combines acetaminophen and hydrocodone. Concerns raised by the FDA advisory panel about excessive use of acetaminophen also triggered questions—at least in some quarters—about the prospects of the intravenous acetaminophen under development at Cadence Pharmaceuticals, although the company says it’s not worried.
If there’s a lesson to be learned, it may be that repurposing old drugs may not be such a low-risk path for drug development after all.