Then another research associate, Avadhut D. Joshi, began working the phones, frequently overnight when company officials in Belgium, Brazil, China and elsewhere were awake. About 18 months later, friends and contacts he had from pharmacy school in India led him to Aurochem Laboratories, a small company making the drug for the World Health Organization. Officials there agreed to the specs and the paperwork and began shipping the drugs.
Riggins secured some funding from a brain cancer foundation and launched a trial with patients of Hopkins neurosurgeon Dr. Gary Gallia to test the drug's safety. Every few months a few more patients are enrolled and given the standard treatment plus increasingly larger doses of the parasite drug, which was made into chalky, orange-flavored tablets. Eventually, about 20 people are expected to participate.
Researchers are surprised by the drug's lack of toxicity, a problem that dooms many other promising cancer treatments. So far there have been few side effects, but low doses also haven't obstructed the tumors.
If higher doses succeed in prolonging the patients' lives, as they did in the lab mice by 63 percent, they will tweak the drug and even mix it with other drugs to find the most effective treatment. In the meantime, some doctors could seek access to the unproven therapy outside of trials for terminal patients.
Riggins said he can't claim yet that the drug works, but he remains encouraged.
"Being a cancer researcher is a lot like being a professional gambler," he said. "You want to make the next bet even when you know you're going to lose. In this case, I'm glad we made the bet."
This drug is his first brought to trial since he opened his lab in 1997. He has looked in a lot of corners, though, including screening a "drug library" created by a fellow Hopkins researcher, Jun O. Liu. The library contains samples of FDA-approved drugs that scientists can match to different diseases.
Liu, a professor of pharmacology and molecular sciences and oncology, said the library was inspired by such accidental drug discoveries as the one Riggins made.
"In a way," Liu said, "this is like trying to make these accidents more systematic."
There are now at least 3,700 FDA-approved drugs, and the library still contains samples of less than two-thirds of them. He continues to build, but some of the missing drugs are too expensive or are narcotics that have strict storage requirements.
The samples are stored in plastic plates. Researchers can add diseased cells to the plates and see if any drugs have an impact.
The most promising drug found so far is itraconazole, used to treat toenail fungus. It inhibits blood vessel growth and is being investigated as a treatment for macular degeneration, which causes vision loss, as well as breast, skin, lung and prostate cancer.
"This kind of research is getting more popular," Liu said. "I think our studies, as well as others along the way, have convinced more people to do this. ... Cancer is the No. 1 or 2 enemy for the human race, and this is a golden time to discover new drugs."