Human tests of Tekmira Pharmaceuticals Corp.’s treatment for Ebola, one of the world’s most lethal diseases, have been put on hold by U.S. regulators due to safety concerns.
The Food and Drug Administration has requested additional information to ensure the drug is safe at higher doses, the company said today in a statement. The therapy is in the first of three stages of clinical trials usually required by regulators for approval.
Tekmira will “continue our dialogue with the FDA, provided for under our fast-track status, in order to advance the development of this important therapeutic agent,” Tekmira’s Chief Executive Officer Mark Murray said in the statement. The company didn’t say how long the hold was expected to last, and spokeswoman Julie Rezler didn’t immediately respond to a phone call requesting comment.
Shares of the Vancouver-based drugmaker fell 16 percent to $11.63 at the close in New York, the biggest single-day decline since April 14.
The Ebola virus kills as many as 90 percent of those it strikes, and the latest outbreak in Guinea, Liberia and Sierra Leone is the worst on record, resulting in more than 450 deaths. The World Health Organization has said the outbreak may last another three to four months.
Despite the deadly nature of the disease, the relative rarity of outbreaks and their confinement to primarily rural areas of poor African nations make Ebola an unattractive target for big drugmakers.
Instead, much of the research in Ebola treatments has been funded by the U.S. government. Tekmira said its drug, an RNA-based therapy, is being developed under a $140 million contract with the U.S. Department of Defense.
Among the most promising experimental drugs are antibody cocktails. One is being developed at Canada’s National Microbiology Laboratory, though it needs more work before it can be tested in humans, according to Public Health Canada.
Mapp Biopharmaceutical Inc., a closely held company in San Diego, is developing another, along with the U.S. Defense Advanced Research Projects Agency, the National Institutes of Health and the U.S. Defense Threat Reduction Agency.