Scientists halted a clinical trial early when two antibody drugs were found to be more effective, allowing up to 94 percent of those treated to recover.

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Two people with Ebola who were treated with new drugs in the city of Goma in the Democratic Republic of the Congo (DRC) have been declared “cured,” said a local health official.

The drugs were being tested as part of a randomized clinical trial in four towns in the DRC. This week, researchers halted the trial early when preliminary results showed that two of the four drugs being tested — known as REGN-EB3 and mAb114 — were found to be more effective.

Until now, the medical community had no reliable way to treat people infected with Ebola.

In the current DRC Ebola outbreak, 67 percent of those infected with the virus have died. But with one of the new drugs, up to 94 percent of people recovered.

These early results bring scientists closer to curing the disease, which has resulted in at least 1,900 deaths in the DRC since the outbreak began last summer.

The randomized clinical trial began in November and had enrolled 681 people at four Ebola treatment centers in the DRC.

Those who were given one of the two more effective drugs had a greater chance of survival — the mortality rate for patients given REGN-EB3 was 29 percent and for patients given mAb114 it was 34 percent.

The mortality rate for the other two drugs was higher — 49 percent for ZMapp and 53 percent for Remdesivir.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), said the mortality rate was even lower for people treated early — 6 percent for REGN-EB3 and 11 percent for mAb114.

Stewart Schneller, PhD, a professor of chemistry and biochemistry at Auburn University in Alabama, whose research group seeks drug candidates for Ebola and other viruses, said this is a “significant” development.

“The announcement of success with REGN-EB3 and mAb114 offers a promising breakthrough for managing [Ebola virus] outbreaks, in this case in the DRC and perhaps the neighboring countries,” said Schneller.

These results are preliminary, with additional research needed. People currently in the study will be randomly assigned to one of the two better performing treatments. This will allow scientists to see which drug works the best.

In addition, people in the DRC infected with Ebola who aren’t part of the trial will continue to be able to access REGN-EB3 or mAb114. The other two drugs will no longer be distributed.

REGN-EB3 is a mixture of three synthesized monoclonal antibodies (made by Regeneron Pharmaceuticals, Inc.), while mAb114 is a monoclonal antibody from someone who survived infection with the Ebola virus in the 1990s (licensed to Ridgeback Biotherapeutics LP).

The study is cosponsored and funded by the Institut National de Recherche Biomédicale (INRB) and the NIAID. The World Health Organization (WHO) coordinated the research teams carrying out the clinical trial.

The success of these two new drugs will make it easier to treat people infected with the virus, but the Ebola problem isn’t solved.

This week the first two cases in the DRC’s South Kivu region were confirmed, showing how difficult it is to contain the outbreak in spite of the use of an effective vaccine in the country.

Schneller said health officials still face several challenges in the DRC, including community mistrust of the federal government and medical organizations, limited healthcare resources, and armed attacks on healthcare workers and treatment centers.

Last month, the WHO formally declared the year-old epidemic in the DRC a global health emergency. This may help mobilize resources needed to contain the outbreak, including healthcare workers, security personnel, infrastructure — and money.

Between February and July of this year, the WHO received only $49 million from international donors — half of the amount it needs, reported the New York Times.

However, Dr. Craig Spencer, the director of global health in emergency medicine at New York-Presbyterian/Columbia Medical Center, said in a post on the university’s website in July that battling Ebola isn’t just a question of financial support.

“More than a massive infusion of cash, what’s needed in this outbreak is more community engagement and trust-building,” said Spencer. “It’s safe to say that although the [WHO emergency] declaration may help, it will be no magic bullet.”

Efforts to vaccinate people against Ebola will also help slow the spread of the disease.

A vaccine made by Merck & Co., Inc. is already being distributed in the DRC.

This vaccine is estimated to be 97.5 percent effective. But shortages of the vaccine have prompted health officials to consider using a second vaccine made by Johnson & Johnson.

Even with the two new antibody drugs and an effective vaccine, development and testing of drugs to treat and prevent Ebola will still need to continue.

One reason, said Schneller, is that with any antibody therapy, the virus can mutate and become resistant to the therapy. So it’s good to have another option to choose from.

However, many places in the DRC are remote and may not have adequate healthcare facilities — both REGN-EB3 and mAb114 need to be refrigerated — which can hamper getting drugs to those who need it.

“Further study of small molecule antivirals, which are more easily administered in urban and remote areas and do not require refrigeration, should be encouraged to complement antibody-based therapies,” said Schneller.