A Possible Testing Gold Mine

Ncats has perhaps the world’s largest collection of drugs and compounds, some half a million. During a recent visit, an employee who goes by the name Pepper showed how samples are fetched from glass-walled carousels by giant yellow robotic arms in a meticulously programmed ballet resembling an albatross love dance.

Many of the compounds are untested in people. But one collection contains about 2,800 drugs approved in the United States or other countries. Another library holds about 2,000 compounds that have been through some human safety testing.

Those libraries are potential gold mines. If safety-tested compounds block Zika in laboratory cells, they can be tested in people faster than new drugs or vaccines.

“We want to focus on the drugs that are immediately useful in people with the disease,” said Dr. Christopher Austin, the director of Ncats, noting that similar drug-testing was done with Ebola, yielding some compounds that are in clinical trials now.

The Johns Hopkins researchers needed time to grow more neural progenitor cells, but Dr. Zheng started anyway, first on brain tumor cells he infected with Zika. Three compounds seemed effective - a caspase inhibitor, a Russian antidepressant, and a common vitamin - so he whisked them to other researchers to try.

After receiving progenitor cells, he started again. He found 173 drugs blocked caspase-3 increase, about three dozen did so without harming cells, and one — just one — prevented the Zika virus from killing cells. That drug, which he declined to identify, is not approved but has undergone safety testing and is in a clinical trial with cancer patients, he said.

He sent the drug to Johns Hopkins, where early testing is yielding similar results. But even if results are replicated in mice and humans, hurdles remain, including determining if it is safe for pregnant women and deciding who to treat, since many women infected with Zika have had healthy babies

Also, a drug that can “save the cells after they’re infected” is not the real prize, Dr. Song said. “The best drug would actually prevent the cells from being infected in the first place.”