A highly anticipated trials of Ebola drug that has shown promise in monkeys was arrested soon after he apparently failed to show a benefit for patients.
the company that developed the drug, Tekmira Pharmaceuticals in Burnaby, Canada, and the Wellcome Trust, which sponsored the trial, announced today that they would not register because all other patients that the trial had reached "a predefined statistical parameter." initial results suggest that the addition of more patients in the study "was unlikely to demonstrate an overall therapeutic benefit to patients," said the Wellcome Trust in its declaration.
scientists have yet to analyze the data collected to learn more about how the drug, called TKM-Ebola Guinea, was tolerated and the specific effects it had on the disease outcomes said Peter Horby of the University of Oxford in the UK, who led the study. The trial, which began in March in Port Loko, Sierra Leone, which aims to enroll 100 patients. The company did not say how many patients have been enrolled to date.
The drug faces several obstacles in the trial, said Thomas Geisbert of the University of Texas Medical Branch in Galveston, who tested TKM-Ebola in monkeys and 'found the three protected animals that received from a normally lethal dose of Ebola virus. TKM-Ebola Guinea is a set of small RNA molecules packed into lipid nanoparticles. RNA interferes with three Ebola proteins and prevents the virus from replicating. Geisbert said that lipid nanoparticles used in the human trial are an older formulation than in recent monkey experiments. The previous version protected only about half of the monkeys in the previous tests, he said. "You compare apples to kumquats," he said. But the new formulation was not due to security phase I trials in humans and therefore could not be used in patients Ebola.
The trial design was also a challenge, said Geisbert. Many say that the allocation of patients to a placebo arm is unethical, so the TKM-Ebola trial was a single arm study supposedly in which everyone in a treatment center receives the drug and their survival compared with patients in centers not involved in the trial. But it makes the data very difficult to interpret, said Geisbert. "You can not draw reasonable conclusions. I doubt that something out that will tell one way or another" if the drug benefits patients. The end of the trial should not be the end of the drug, he said. "If you can not get an answer, and then you want to kill the drug? It's crazy."
The other drug considered the best shot in the fight against Ebola, cocktail 'zmapp antibody, is still being evaluated in a test. The National Institute of Allergy and Infectious Diseases (NIAID) launched the lawsuit in February in Liberia and the United States. It then spread to Sierra Leone and is about to enroll patients in Guinea as well, said Anthony Fauci, head of NIAID, located in Bethesda, Maryland.
The trial zmapp is a different trial design TKM-Ebola. He attributes randomly patients receive either three infusions zmapp and supportive care only or supportive care, including fluids and treatment of secondary infections intravenously. Fauci is optimistic that the trial zmapp give a clear answer. More than 30 patients have been enrolled, he said. "We are likely to need many more patients than to get a result, but less than 100." With Guinea added to the test, this should be accessible, he said.
* The Ebola virus files: science and science Translational Medicine made a collection of research and articles on Ebola virus and the current epidemic available for researchers and the general public.
0 Komentar