New Ebola Vaccine Shows Promise in Human Trials

 

It appeared to provoke good immune response in Chinese study, but larger trials are needed

By Robert Preidt 

 

WEDNESDAY, March 25, 2015 (HealthDay News) -- An experimental Ebola vaccine shows promise in an early clinical trial, but requires much more testing, researchers report.

The trial included 120 healthy adults in China who received either a low or high dose of the vaccine, or a placebo. Twenty-eight days later, 38 of 40 people in the low-dose group and all 40 of those in the high-dose group showed an immune response to the vaccine.

No serious side effects occurred among the participants who received the vaccine.

While the results suggest the vaccine is effective and safe, more long-term testing is needed to determine whether it can actually protect people against Ebola, according to the authors of the study published March 25 in The Lancet.

The vaccine is based on the strain of Ebola that has been circulating in the West African outbreak. The researchers note that, until now, all tested Ebola vaccines have been based on the Ebola strain from the 1976 outbreak in Zaire.

The vaccine was developed by the Beijing Institute of Biotechnology and Tianjin CanSino Biotechnology in China. Both helped fund the study, along with China National Science and Technology.

"On the basis of our findings, we believe that the Ebola vaccine we assessed has some potential, and a significant advantage of this type of vaccine is that [it is] stable and much easier to store or transport in tropical areas with inadequate cold-chain capacity, such as Africa," research team leader Fengcai Zhu, from the Jiangsu provincial center for disease prevention and control in China, said in a journal news release.

"However, whether this candidate vaccine could become a final vaccine for widespread use against Ebola outbreaks is still uncertain," Zhu added. "Furthermore, these results only assess immune response up to 28 days, so we plan to assess the persistence of the specific immune response by following up the vaccine recipients of this study."

Still, two experts said the development of the vaccine is a testament to how scientists can effectively respond in a crisis.

This vaccine, "is an example of how quickly existing vaccine platforms can be modified to incorporate a new virus strain, and moved, with minimum testing in animals, into trials in humans during a crisis situation," Andrea Marzi, of the U.S. National Institute of Allergy and Infectious Diseases, and Darryl Falzarano, of the University of Saskatchewan in Canada, wrote in an accompanying commentary.

"However...ultimately, the effectiveness of all these vaccines will only become clear when they proceed to phase 2 efficacy trials in outbreak regions," they added.

The West African Ebola outbreak, while ebbing, is not yet over. According to the U.S. Centers for Disease Control and Prevention, almost 25,000 probable or confirmed cases have been detected in Guinea, Liberia and Sierra Leone, including more than 10,000 deaths.

SOURCE: The Lancet, news release, March 25, 2015

REFERENCE

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Stem Cells in Ophthalmology Update 15 Wills Eye Joins ACT’s Clinical Trials for Dry AMD Using Embryonic Stem Cell derived RPE

Advanced Cell Technology announced yesterday that the Wills Eye Institute in Philadelphia had received institutional review board (IRB) approval to become a site for the Phase I/II clinical trial for dry age-related macular degeneration (Dry AMD) using human embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells. Wills will join UCLA’s Jules Stein Eye Institute and Moorfields Eye Hospital in London as sites participating in the clinical trials for Dry AMD, under ACT’s National Clinical Trials protocols.

"The participation of Wills Eye Institute in this trial will significantly enhance our clinical program," said Robert Lanza, M.D., ACT's chief scientific officer. "Wills Eye Institute is the oldest eye-care facility in the United States and is consistently ranked as one of the best ophthalmology hospitals in the country by the U.S. News & World Report. We are looking forward to working with Dr. Regillo and his team to address the unmet medical needs of degenerative diseases of the retina. With this latest approval, the company continues to assemble a clinical team that includes the best eye hospitals and surgeons in the world in our effort to find an effective therapy for this devastating eye disease."

The Phase I/II trial for dry AMD is a prospective, open-label study designed to determine the safety and tolerability of the hESC-derived RPE cells following sub-retinal transplantation into patients with dry AMD. The trial will ultimately enroll 12 patients, with cohorts of three patients each in an ascending dosage format. Which patients will be enrolled at the Wills Eye Institute will be determined in the near future.

"Degenerative diseases of the retina often lead to a significant visual impairment," said Carl Regillo, M.D., director of clinical retina research at Wills Eye Institute and professor of ophthalmology at Thomas Jefferson University. "Replacing lost or damaged cells with functional and healthy cells may provide a treatment option that could slow vision loss, and perhaps even reverse the effects of disease. We are looking forward to collaborating with ACT to evaluate the potential of the stem cell-derived RPE cells for debilitating diseases such as Stargardt's macular dystrophy and dry AMD."

Dry AMD, or "central geographic atrophy," is the "dry" form of advanced age-related macular degeneration. Dry AMD occurs when the light-sensitive cells (photoreceptors) in the macula slowly break down, gradually blurring central vision in the affected eye. Over time, as less of the macula functions, central vision is gradually lost in the affected eye, often progressing to blindness. The loss of photoreceptors is a direct result of a preceding degeneration of the retinal pigment epithelial (RPE) layer of cells just below the retina. As many as 30 million people in the United States and Europe suffer from macular degeneration, which represents a $25-30 billion worldwide market that has yet to be effectively addressed. Approximately 10% of people ages 66 to 74 will have symptoms of macular degeneration, the vast majority suffering from the "dry" form of AMD -- which is currently untreatable. The prevalence increases to 30% in patients 75 to 85 years of age.

"We are honored to have the opportunity to work with one of the foremost eye care centers in the world", said Gary Rabin, chairman and chief executive officer of ACT. "This clinical trial represents the culmination of years of innovation and hard work by ACT's scientific team. The whole world is focused on our trials, most especially patients suffering from dry AMD and other forms of macular degeneration. Wills Eye Institute has a strong tradition of innovation and discovery, and we are excited at their participation in bringing this cutting-edge technology through the clinic."

Additional details about these studies, for which the Jules Stein Institute at the University of California, Los Angeles and Moorfields Eye Hospital in London have also received IRB approval, can be found at ClinicalTrials.gov Identifier: NCT01344993.

Editors Note: As noted in the above quote from Dr. Regillo, it can be speculated that Wills Eye will soon join both Jules Stein and Moorfields in also treating Stargardt’s disease, under ACT’s National Clinical Trials NCT01345006 and NCT01469832.

It should also be noted that Wills Eye is also one of the clinical sites participating in the Centecor (J&J) clinical study of Dry AMD using adult stem cells from umbilical cord blood, NTC01226628.

Breaking News – as of January 19th, Wills Eye had been added to ACT’s clinical protocol for treating Dry AMD with embryonic stem cell-derived RPE cells, and was actively recruiting patients.

About Wills Eye Institute

Wills Eye Institute is a global leader in ophthalmology, established in 1832 as the nation's first hospital specializing in eye care. U.S. News & World Report has consistently ranked Wills Eye as one of America's top three ophthalmology centers since the survey began in 1990. Wills Eye is a premier training site for all levels of medical education. Its resident and post-graduate training programs are among the most competitive in the country. One of the core strengths of Wills is the close connection between innovative research and advanced patient care. Wills provides the full range of primary and subspecialty eye care for improving and preserving sight, including cataract, cornea, retina, emergency care, glaucoma, neuro-ophthalmology, ocular oncology, oculoplastics, pathology, pediatric ophthalmology and ocular genetics, refractive surgery and retina. Ocular Services include the Wills Laser Correction Center, Low Vision Service, and Diagnostic Center. Its 24/7 Emergency Service is the only one of its kind in the region. Wills Eye also has a network of nine multi-specialty, ambulatory surgery centers throughout the tri-state area. To learn more, please visit www.willseye.org .