AP Health Writer

WASHINGTON (AP) _ A Canadian drugmaker working on an experimental drug for Ebola said Wednesday that it is not ready to make the treatment available in Africa, despite assurances by international health officials that it is ethical to use untested treatments to fight the deadly outbreak.

Tekmira Pharmaceuticals Corp. said that the “regulatory framework” for giving its drug to patients in Africa is not clear, given that the drug’s safety and effectiveness has not been established.

“There can be no assurance that an appropriate framework for the use of this product will be found,” said CEO Mark Murray on a call with investors and analysts. “Given the severity of the situation, we are carefully evaluating options for use of our investigational drug within accepted clinical and regulatory protocols.”

Murray said the company is continuing discussions with governments and international agencies trying to contain the outbreak, including the World Health Organization.

The company’s announcement comes one day after the WHO ruled that it is OK to use unproven Ebola treatments if patients give their informed consent and are guaranteed confidentiality and freedom of choice.

There was no specific advice on who should get them; the panel only said more analysis and discussion was needed.

Tekmira is one of a handful of companies worldwide that are developing drugs and vaccines to treat Ebola. The Vancouver, British Columbia-based company has a $140 million contract with the U.S. government to develop its drug, TKM-Ebola, which targets the genetic material of Ebola.

It made international headlines last week when it announced that the U.S. Food and Drug Administration had eased a hold placed on the injectable drug due to safety problems that emerged in early testing. The company suggested the FDA’s move to a “partial clinical hold” might clear the way for emergency use of TKM-Ebola in infected patients.

Murray said Wednesday he is confident the company can address the FDA’s safety questions, but stressed “we’re not there yet.”

Another experimental drug from a U.S. company has been given to two American aid workers and a Spanish missionary priest infected with the virus. The Spanish priest died Tuesday and the U.S. aid workers who received it earlier are said to be improving. But health experts say there is no way to tell if their recovery is related to the drug, called ZMapp.

There is no proven treatment or vaccine for Ebola. ZMapp, made by Mapp Pharmaceuticals, is so new that it has never been tested in humans, although an early version worked in some monkeys infected with Ebola. It’s aimed at boosting the immune system’s efforts to fight off Ebola.

The outbreak in West Africa, the biggest in history, has killed more than 1,000 people in Guinea, Sierra Leone, Liberia and Nigeria.

U.S.-traded shares of Tekmira fell $2.21, or 12 percent, to $16.39 in after-hours trading.