Tag: Weiner

Synthetic DNA’s Role in Advancing Next Generation Checkpoint Inhibitors for Cancer Immunotherapy

Written by The Wistar Institute on January 24, 2019. Posted in Featured News.

An innovative and original synthetic DNA platform created by Dr. David Weiner and team at Wistar’s Vaccine & Immunotherapy Center continues to make great strides in cancer immunotherapy.

Monoclonal antibody (mAb) therapy is one of the most successful approaches for cancer treatment, representing a specific method to zero in on a defined molecular target in the tumor. Antibody technology is central for cancer immunotherapy, which relies on the ability of mAbs to take the breaks off our immune system by inhibiting immune checkpoint molecules. Traditional mAbs are created from cell lines in highly sterile manufacturing plants and are difficult and expensive to make. The Weiner Lab has overcome challenges associated with therapeutic antibody production by developing a novel molecular platform that delivers DNA instructions to a patient that allow the patient’s body to become the production site of its own highly personalized mAbs.

DNA-encoded monoclonal antibodies (DMAbs) are the resulting products of DNA-delivered instructions for the body to make monoclonal antibodies using its own protein manufacturing machinery. The Weiner Lab is advancing this novel technology for cancer and infectious disease immunotherapy.

In a study that was recently published in the journal Oncotarget, they created synthetic DNA-encoded checkpoint inhibitor antibodies targeting the PD-1 checkpoint molecule. Preclinical data presented in this study demonstrated that a single injection of the highly optimized DMAb versions of PD-1 checkpoint inhibitors is sufficient to achieve a robust expression that lasts for several months in mice.

These results reinforce the findings of a previous study, published a few months ago in the journal Cancer Research, in which Weiner and colleagues developed synthetic DNA-encoded checkpoint inhibitor antibodies targeting CTLA-4, another important cancer checkpoint molecule that blocks anti-cancer immunity.

References:

Simplifying checkpoint inhibitor delivery through in vivo generation of synthetic DNA-encoded monoclonal antibodies (DMAbs), Perales-Puchalt A. et al., Oncotarget, 2019

Synthetic DNA-encoded monoclonal antibody delivery of anti-CTLA-4 antibodies induces tumor shrinkage in vivo, Duperret E.K. et al., Cancer Research, 2018

Deja Flu: Revisiting Influenza 100 Years Later

Written by The Wistar Institute on January 3, 2019. Posted in Featured News.

This year marks the 100th anniversary of the 1918 Spanish lnfluenza outbreak, a pandemic that affected millions around the world. Over the decades, advancements in vaccine medicine have saved countless lives, but new tools are still needed to prevent the flu in vulnerable individuals and to make the vaccine more effective. Wistar hopes its new generation synthetic DNA technology will provide a future strategy for the global toolbox against flu.

Now identified as a strain of the H1N1 flu virus, the Spanish flu was an exceptionally lethal strain that took more lives than World War I and World War II combined — killing 20 to 50 million people in mere months — and indiscriminately claimed not only vulnerable individuals but also strong, seemingly healthy young adults. *

The first wave of the outbreak was a mild form that appeared and spread throughout the United States from birds and farm animals to humans. Then as troops deployed during World War I, it traveled to Europe. The second wave of flu became the deadliest—killing people who would otherwise be categorized as healthy—and the effect of military movement helped the virus spread ultimately to Asia. With no treatment or vaccine in place, there was no way to effectively control the spread.

Philadelphia was one of the many urban areas hit hardest by the 1918 pandemic: more than 50,000 people became infected and 12,000 people died.** At a Liberty Loan Parade taking place in the heart of the city along Broad Street, more than 600 people caught the flu while attending the event. Three days after, the city’s 31 hospitals could not keep up fast enough with the demand to take care of the sick.

100 years later, where do we stand with influenza prevention and what strategies are now available to protect us?

The Bill & Melinda Gates Foundation and the Coalition for Epidemic Preparedness Innovations (CEPI) are two global multinational nonprofit organizations advancing science in the form of experimental research that could best respond to a future outbreak before it becomes a pandemic. They, along with health officials and epidemiologists, monitor how emerging viruses can become global health and economic threats. As the world becomes more and more interconnected and borderless, much can be gleaned from past outbreaks like the Spanish flu with the hopes to use that knowledge to prevent future pandemics.

David Weiner, Ph.D., executive vice president of Wistar, director of Wistar’s Vaccine & Immunotherapy Center, and the W.W. Smith Charitable Trust Professor in Cancer Research, and colleagues are funded by the Gates Foundation and CEPI to advance synthetic DNA-based vaccine and antibody technology.

Every year, multiple strains of the flu virus circulate. Six to nine months before the season starts, researchers make an educated guess about which strains will be most prevalent. However, the flu virus can rapidly mutate throughout the season, causing a vaccine directed against a specific circulating strain to become ineffective. If this happens, there is not enough time to make a new vaccine, since the process traditionally takes five to six months.

The Weiner Lab recently published research in the journal Human Gene Therapy on a synthetic DNA vaccine against influenza A, which is responsible for the most severe influenza seasons of the past decade. Using this technology, Weiner created a vaccine cocktail targeting the most probable flu strains circulating during a season, which can offer broad protection against influenza A viruses. The synthetic DNA vaccine being developed by Weiner and his collaborators delivers genetic instructions into the muscle cells to make them produce specific influenza antigens that trigger an anti-flu immune response. Their studies showed that this approach induced increased immunity and protection compared to traditional vaccine technologies.

Though this technology has not been tested in humans for the flu, it is very promising and provides a glimpse of what a new generation of flu vaccine could be: conceptually more safe, potent, faster to make, and easier to distribute and house—a promising strategy against the global threat of influenza.

*Center for Disease Control and Prevention
** “The Flu in Philadelphia,” PBS.org and “Philadelphia was the epicenter of a deadly worldwide flu epidemic 99 years ago,” phillyvoice.com

Microbiology illustration of prescription drug in the human system

Engineered DNA-encoded PCSK9 Inhibitors May Provide an Effective Alternative for Treating High Cholesterol

Written by The Wistar Institute on November 15, 2018. Posted in Press Releases.

PHILADELPHIA — (Nov. 15, 2018) — Researchers at The Wistar Institute have developed novel synthetic DNA-encoded monoclonal antibodies (DMAbs) directed against PCSK9, a protein key to regulating cholesterol levels in the bloodstream. Results of preclinical studies showed a significant cholesterol decrease, opening the door for further development of this approach as a simple, less frequent and cost-effective therapy, as reported in a paper published online in Molecular Therapy.

Elevated, low-density lipoprotein cholesterol (LDL-C) is a major risk factor for cardiovascular disease, the leading cause of death in the U.S. and worldwide. Statins are effective and widely used cholesterol-lowering medications, but have been associated with a number of side effects that have prompted development of alternative treatment strategies, including monoclonal antibodies targeting the PSCK9 protein that result in reduced degradation of LDL-C receptors on liver cells and increased cholesterol clearance from blood circulation.

“Any therapy based on recombinant monoclonal antibodies faces challenges of production among other issues as molecules may be difficult to manufacture and require multiple administrations,” said lead researcher David B. Weiner, Ph.D., executive vice president, director of Wistar’s Vaccine & Immunotherapy Center, and the W.W. Smith Charitable Trust Professor in Cancer Research at The Wistar Institute. “Anti-PCSK9 therapy presents an important opportunity for development of alternative approaches, possibly expanding options for such therapies.”

Weiner and collaborators engineered synthetic DNA constructs that are delivered by intramuscular injection and encode the genetic instructions for the body to make its own functional monoclonal antibodies, entirely bypassing bioprocess and manufacturing factory approaches. This study provides the first proof of principle that such engineered DMAbs may be developed as a new option for coronary artery disease.

The researchers tested expression and activity of the DMAbs targeting PCSK9 in mice. A single intramuscular administration drove robust antibody expression within days and for up to two months, resulting in a substantial increase in the presence of LDL-C receptors on liver cells. This in turn resulted in a significant decrease in total cholesterol and non-high-density lipoprotein cholesterol (non-HDL-C), an important parameter for evaluating cardiovascular risk.

“We are excited about these findings that support the flexibility and versatility of the DMAb platform as a next generation approach that can be optimized for a wide host of applications,” said Makan Khoshnejad, Ph.D., first author on the study and a postdoctoral fellow in the Weiner Lab.

Co-authors of this study from The Wistar Institute include Ami Patel, Krzysztof Wojtak, Sagar B. Kudchodkar, and Kar Muthumani; other co-authors include Laurent Humeau from Inovio Pharmaceuticals, Inc.; and Nicholas N. Lyssenko and Daniel J. Rader from the University of Pennsylvania.

This work was supported by funding from Inovio Pharmaceuticals, Inc.

Development of Novel DNA-encoded PCSK9 Monoclonal Antibodies as Lipid-lowering Therapeutics,
Molecular Therapy (2018). Advance online publication.

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The Wistar Institute is an international leader in biomedical research with special expertise in cancer research and vaccine development. Founded in 1892 as the first independent nonprofit biomedical research institute in the United States, Wistar has held the prestigious Cancer Center designation from the National Cancer Institute since 1972. The Institute works actively to ensure that research advances move from the laboratory to the clinic as quickly as possible. wistar.org.

Synthetic DNA-delivered Antibodies Protect Against Ebola in Preclinical Studies Representing a Novel Platform for Antibody Therapies for Outbreak Infections

Written by The Wistar Institute on November 13, 2018. Posted in Press Releases.

PHILADELPHIA — (Nov. 13, 2018) — Scientists at The Wistar Institute and collaborators have successfully engineered novel DNA-encoded monoclonal antibodies (DMAbs) targeting Zaire Ebolavirus that were effective in preclinical models. Study results, published online in Cell Reports, showed that DMAbs were expressed over a wide window of time and offered complete and long-term protection against lethal virus challenges. DMAbs may also provide a novel powerful platform for rapid screening of monoclonal antibodies enhancing preclinical development.

Ebola virus infection causes a devastating disease, known as Ebola virus disease, for which no licensed vaccine or treatment are available. The 2014-2016 Zaire Ebola virus epidemic in West Africa was the most severe reported to date, with more than 28,600 cases and 11,325 deaths according to the Center for Disease Control. A new outbreak is ongoing in the Democratic Republic of Congo, with a death toll of more than 200 people since August. One of the experimental avenues scientists are pursuing is evaluating the safety and efficacy of monoclonal antibodies isolated from survivors as promising candidates for further development as therapeutics against Ebola virus infection. However, this approach requires high doses and repeated administration of recombinant monoclonal antibodies that are complex and expensive to manufacture, so meeting the global demand while keeping the cost affordable is challenging.

“Our studies show deployment of a novel platform that rapidly combines aspects of monoclonal antibody discovery and development technology with the revolutionary properties of synthetic DNA technology,” said lead researcher David B. Weiner, Ph.D., executive vice president and director of Wistar’s Vaccine & Immunotherapy Center, and W.W. Smith Charitable Trust Professor in Cancer Research.

Weiner’s lab designed and enhanced optimized DMAbs that, when injected locally, provide the genetic blueprint for the body to make functional and protective Ebola virus-specific antibodies, circumventing multiple steps in the antibody development and manufacturing process. Dozens of DMAbs were tested in mice and the best-performing ones were selected for further studies. These proved to be highly effective for providing complete protection from disease in challenge studies.

“Due to intrinsic biochemical properties, some monoclonal antibodies might be difficult and slow to develop or even impossible to manufacture, falling out of the development process and causing loss of potentially effective molecules,” added Weiner. “The DMAb platform allows us to collect protective antibodies from protected persons and engineer and compare them rapidly and then deliver them in vivo to protect against infectious challenge. Such an approach could be important during an outbreak, when we need to design, evaluate and deliver life-saving therapeutics in a time-sensitive manner.”

“We started with antibodies isolated from survivors and compared the activity of anti-Ebola virus DMAbs and recombinant monoclonal antibodies over time,” said Ami Patel, Ph.D., first author on the study and associate staff scientist in the Wistar Vaccine and Immunotherapy Center. “We showed that in vivo expression of DMAbs supports extended protection over traditional antibody approaches.”

The researchers also looked at how DMAbs physically interact with their Ebola virus targets, called epitopes, and confirmed that DMAbs bind to identical epitopes as the corresponding recombinant monoclonal antibodies made in traditional bioprocess facilities.

The Weiner Laboratory is also developing an anti-Ebola virus DNA vaccine. Preclinical results from this efforts were published recently in the Journal of Infectious Diseases.

Co-authors of this study from The Wistar Institute include Daniel H. Park, Marguerite E. Gorman, Sarah T.C. Elliott, Rianne Esquivel, and Kar Muthumani. Other co-authors include Carl W. Davis and Rafi Ahmed from Emory University; Trevor R.F. Smith, Charles Reed, Megan C. Wise, Jian Yan, Jing Chen, Kate E. Broderick, Laurent Humeau, and Niranjan Y. Sardesai from Inovio Pharmaceuticals; Anders Leung, Kevin Tierney, Trina Racine, Shihua He, Xiangguo Qiu, and Darwyn Kobasa from Public Health Agency of Canada; Aubrey Bryan, Edgar Davidson and Benjamin J. Doranz from Integral Molecular; Xiaoying Yu and Erica Ollmann Saphire from The Scripps Research Institute, La Jolla; James E. Crowe from Vanderbilt University; and Gary P. Kobinger from Université Laval, Canada.

This work was supported by a grant from the Defense Advanced Research Projects Agency (DARPA) awarded to Inovio Pharmaceuticals and by National Institutes of Health contract HHSN272201400058C.

In Vivo-delivered Synthetic Human DMAbs Protect Against Ebolavirus Infection in a Mouse Model,
Cell Reports (2018). Advanced online publication.

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Synthetic DNA Vaccine Against Ebola Virus Shows Potent and Long-term Efficacy in Preclinical Studies

Written by The Wistar Institute on October 10, 2018. Posted in Press Releases.

PHILADELPHIA — (October 10, 2018) — A novel synthetic DNA vaccine developed based on technology pioneered by scientists at The Wistar Institute Vaccine & Immunotherapy Center offers complete protection from Zaire Ebolavirus (EBOV) infection in promising preclinical research. Study results were published online in the Journal of Infectious Diseases.

Ebola virus infection causes a severe hemorrhagic fever that has a 50% fatality rate, according to the World Health Organization. Recent advances have led to the development of promising experimental vaccine candidates that may be associated with side effects and/or may not be applicable in specific vulnerable populations, such as children, pregnant women and immunocompromised individuals. In addition, there is a need to boost these vaccines to provide long-term protection.

Using a unique approach, Wistar scientists designed optimized synthetic DNA vaccine candidates targeting a virus surface protein called glycoprotein. They demonstrated efficacy of the novel vaccine candidates and durability of the immune responses in animal models. Importantly, results showed strong immune responses one year after the last dose, supporting the long-term immunogenicity of the vaccine – a particularly challenging area for Ebola vaccines.

“Synthetic non-viral based DNA technology allows for rapid vaccine development by delivery directly into the skin, resulting in consistent, potent and rapid immunity compared to traditional vaccine approaches,” said lead researcher David B. Weiner, Ph.D., executive vice president and director of Wistar’s Vaccine & Immunotherapy Center, and W.W. Smith Charitable Trust Professor in Cancer Research. “An anti-Ebola virus DNA vaccine like this may provide an important new tool for protection, and we are excited to see what future studies will unveil.”

The researchers optimized a shorter, dose-sparing, immunization regimen and simplified vaccine administration directly into the skin. This new approach induced rapid and protective immunity from virus challenges. The detected antibody levels were equal or higher to those reported for other vaccines currently being evaluated in the clinic, according to the study.

“The success of intradermal delivery of a low-dose regimen is very encouraging,” said Ami Patel, Ph.D., associate staff scientist in the Weiner Lab. “The ultimate goal of our work is to create effective and safe vaccines that are optimized for field use in at-risk areas.”

This work was supported in part by a grant from the Defense Advanced Research Projects Agency (DARPA) to Inovio Pharmaceuticals and a subcontract to The Wistar Institute/University of Pennsylvania. Additional funding was provided by Inovio Pharmaceuticals.

Co-authors of this study from The Wistar Institute include Emma L. Reuschel, Daniel H. Park, Amelia A. Keaton, and Kar Muthumani. Other co-authors include Kimberly A. Kraynyak, Dinah Amante, Megan C. Wise, Jewell Walters, Jean Boyer, Kate E. Broderick, Jian Yan, Amir S. Khan, and Niranjan Y. Sardesai from Inovio Pharmaceuticals, Inc.; Trina Racine, Jonathan Audet, Gary Wong, Marc-Antoine de La Vega, Shane Jones, Alexander Bello, Geoff Soule, Kaylie N. Tran, Shihua He, Kevin Tierney, and Xiangguo Qiu from National Microbiology Laboratory, Public Health Agency of Canada; Veronica L. Scott from William Carey University; Daniel O. Villarreal, Devon J. Shedlock, and Ross Plyler from University of Pennsylvania; Gary P. Kobinger from Université Laval, Canada.

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The Wistar Institute is an international leader in biomedical research with special expertise in cancer and infectious disease research and vaccine development. Founded in 1892 as the first independent nonprofit biomedical research institute in the United States, Wistar has held the prestigious Cancer Center designation from the National Cancer Institute since 1972. The Institute works actively to ensure that research advances move from the laboratory to the clinic as quickly as possible. wistar.org.