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Biomarkers Pinpoint the Effects of Thirdhand Smoke on Liver and Lung Found to Worsen Over Time

Researchers at the University of California, Riverside have found that thirdhand-smoke (THS) exposure has a significant effect on health as early as one month after initiation of exposure – an effect that worsens with time.

THS results when exhaled smoke and smoke emanating from the tip of burning cigarettes gets on surfaces such as clothing, hair, homes, and cars. THS has been shown, in mice, to cause type 2 diabetes, hyperactivity, liver and lung damage, and wound-healing complications.

Using a system in which the exposure of mice to THS mimics that of human exposure in the homes of smokers, the researchers investigated the effects of THS exposure on biological molecular markers – or “biomarkers” – found in serum, and in liver and brain tissues. The liver plays a major role in metabolism and detoxification; the brain plays significant roles in behavior.

Thirdhand smoke results when exhaled smoke and smoke emanating from the tip of burning cigarettes gets on surfaces such as clothing, hair, homes, and cars.Photo credit: UCR University Communications.

Our goal was to determine the minimum amount of time required to cause physiological changes in mice when they are exposed to THS, using an exposure system that mimics human exposure,” said Manuela Martins-Green, professor and chair of the Department of Molecular, Cell and Systems Biology, who led the research. “We found that THS exposure as early as one month resulted in liver damage. THS exposure for two months resulted in further molecular damage, and at four to six months caused even more such damage. We also found that the mice showed insulin resistance after long-term THS exposure.”

Damage to the liver can hinder its capability to detoxify the body, leading to more damage by THS toxins. Martins-Green and her team examined the brains of THS-exposed mice and found that stress hormones, such as epinephrine, increased in one month of exposure. Additional stress hormones are seen at two months, four months, and six months, eventually causing immune fatigue in the mice.

Study results appear in Clinical Science, a Portland Press journal.

“THS is a stealth toxin, a silent killer,” Martins-Green said. “Contaminants can be absorbed through the skin and through breathing. Although our research was not done on humans, people should be aware that hotel rooms, cars, and homes that were occupied by smokers are very likely to be contaminated with THS.”

Most people are either unaware they are being exposed to THS, or don’t believe in the damage THS can do, according to Martins-Green. THS toxins, which are invisible but can be smelled, remain on surfaces for many years, and are resistant to even strong cleaning agents. Further, they accumulate and age by reacting with the ambient air, and change into carcinogenic chemicals.

Because THS is absorbed through skin, children are especially vulnerable given their close contact with household surfaces. Children frequently ingest these toxins by putting their hands in their mouths. They also absorb them through the skin. Children living in the homes where smoking has occurred have been known to show tobacco metabolites in their urine as well as tobacco-derived carcinogens called tobacco specific nitrosamines.

“Exposure to tobacco smoke deposited on surfaces in homes and in house dust is an entirely newly recognized form of toxicity: THS,” said Stephen T. Holgate, the Medical Research Council Clinical Professor of Immunopharmacology and Honorary Consultant Physician within Medicine at the University of Southampton, England, who was not involved in the research. “The fact that noxious chemicals in tobacco smoke once deposited change in chemistry to become even more toxic and carcinogenic is of considerable importance to the health of all of us, but our children in particular. The studies of this Californian research team puts further pressure on those who continue to smoke in homes to realize what they are doing to the health of others, as well as mandating a search for methods to remove such products from furnishings and materials used in homes. This study adds to the increasing concerns of chemical exposures in the home and the serious adverse effects this may cause.”

Martins-Green and her team exposed mice to THS for up to six months, collecting brain, liver, and serum samples after one, two, four, and six months of exposure to test for hormonal alterations, insulin resistance, metabolic syndrome, and damage to the liver and brain. To produce THS, the researchers exposed common household fabrics such as curtain material, upholstery, and carpet to secondhand smoke (smoke that is exhaled and that leaves a burning cigarette) that was generated in the lab by a smoking machine devised to mimic the behavior of human smokers. These materials were then placed in cages housing the mice, which were never exposed to secondhand smoke). The researchers then tested 15 biomarkers of damage and disease associated with THS exposure in serum and nine biomarkers in liver and brain tissue of the mice in a time-dependent manner.

“We found a positive time-dependent significant correlation with increased time of THS exposure and the effects it had on all the variables we measured,” Martins-Green said. “These biomarkers, once validated in humans, can be used as critical indicators of exposure to THS, and how long this exposure has occurred.”

In other preliminary experiments, Martins-Green and her team found that mice exposed to THS are less social than unexposed mice. Insulin problems arising because of THS are seen to worsen with the Western diet. Further, the researchers found that over time the mice get addicted to THS.

“Clearly, THS is affecting the behavior of mice,” said Martins-Green, who plans to write a review paper on the health impacts of THS. “It’s not hard to imagine what the impact is on children who, unlike most adults, cannot remove themselves from these harmful environments. Although our work was done on mice, we are confident our results will apply to humans.”

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$1.5 Million NIH SBIR Grant to Support Development of Rheumatoid Arthritis Vaccine

Rheumatoid Arthritis is a chronic inflammatory disease that mainly targets the synovial membrane, cartilage and bone.  It affects about 1% of the global population and is associated with significant morbidity and increased mortality.

Anti-TNF related therapies are the current standard treatment of patients with advanced RA, but over half of the RA patients do not respond to current anti-TNF drugs such as etanercept (Enbrel®) and infliximab (Remicade®).

CEL-SCI Corporation has been awarded a new Phase II Small Business Innovation Research (SBIR) grant by the National Institute of Arthritis and Musculoskeletal and Skin Diseases entitled “Preclinical studies of PG70 LEAPS peptide vaccine for rheumatoid arthritis” in the amount of approximately $1.5 million, that will provide funding to allow CEL-SCI to advance its first LEAPS product candidate, CEL-4000, towards an Investigational New Drug (IND) application, by funding GMP manufacturing, IND enabling studies, and additional mechanism of action studies.  Previous pre-clinical studies show CEL-SCI’s LEAPS technology prevented the development, lessened the severity of arthritis and described in part the mechanism of action and target cells

The work will be conducted at CEL-SCI’s research laboratory and Rush University Medical Center in Chicago, Illinois at the laboratories of Tibor Glant, MD, Ph.D., The Jorge O. Galante Professor of Orthopedic Surgery and Katalin Mikecz, MD, Ph.D. Professor of Orthopedic Surgery & Biochemistry.

The grant was awarded based on published data by Dr. Glant’s team in collaboration with CEL-SCI showing that the administration of a proprietary peptide using their LEAPS technology prevented the development, and lessened the severity, including inflammation, of experimental proteoglycan induced arthritis (PGIA or GIA) when it was administered after the disease was induced in the animals.  This data was recently published in Vaccine in an article titled “An epitope-specific DerG-PG70 LEAPS vaccine modulates T cell responses and suppresses arthritis progression in two related murine models of rheumatoid arthritis” by Mikecz et al.

“These findings, in conjunction with the results from previously conducted studies with LEAPS vaccines in the PGIA and GIA and other autoimmune models suggest that LEAPS vaccines may be used as a therapeutic treatment in a variety of different types of autoimmune conditions.  LEAPS vaccines may be advantageous to other therapies because the LEAPS vaccines act early on the immune system and inhibit the production of disease-promoting inflammatory cytokines, unlike anti-Tumor necrosis factor alpha (TNFa) therapy which generally acts late and neutralizes only one individual inflammatory cytokine out of many involved in the disease process,” said CEL-SCI’s Senior Vice President of Research, Daniel Zimmerman, Ph.D.

Dr. Zimmerman continued, “The successful conclusion of this round of studies in this autoimmune disease takes LEAPS closer to human studies and could open its development to various other autoimmune diseases, such as multiple sclerosis, uveitis, colitis (inflammatory bowel disease) and certain types of diabetes.”

CEL-SCI’s work is focused on finding the best way to activate the immune system to fight cancer and infectious diseases. Its lead investigational immunotherapy, Multikine* (Leukocyte Interleukin, Injection), is currently being studied in a pivotal Phase 3 clinical trial as a potential neoadjuvant treatment for patients with squamous cell carcinoma of the head and neck. The study was designed with the objective that, if the study endpoint, which is an improvement in overall survival of the subjects treated with the Multikine treatment regimen plus the current standard of care (SOC) as compared to subjects treated with the current SOC only, is satisfied, the study results will be used to support applications that the Company plans to submit to regulatory agencies in order to seek commercial marketing approvals for Multikine in major markets around the world.

The Company’s LEAPS technology is being developed as a therapeutic vaccine for rheumatoid arthritis and is supported by grants from the National Institutes of Health.

 

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Asthma medication may have psychiatric side effects

In a Pharmacology Research & Perspectives study, the asthma medication montelukast (trade name Singulair) was linked with neuropsychiatric reactions such as depression and aggression, with nightmares being especially frequent in children.

For the study, investigators examined all adverse drug reactions on montelukast in children and adults reported to the Netherlands Pharmacovigilance Center Lareb and the WHO Global database, VigiBase®, until 2016.

“Because of the high incidence of neuropsychiatric symptoms–especially nightmares–after using montelukast in both children and adults, the clinician should discuss the possibility of these adverse events with the patient and parents,” said Meindina Haarman, lead author of the study.

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Re-Interventions Are Common in Long-Term Survivors of Childhood Heart Operations

Among patients who undergo childhood heart surgery for the severe birth defect single-ventricle disease, two-thirds of survivors require a surgical or catheter-based procedure within 20 years. Pediatric cardiology researchers note that doctors should counsel families about the likelihood of re-interventions.

“Unfortunately, for many patients, the Fontan is not the final intervention,” said study leader Andrew Glatz, MD MSCE, referring to the Fontan operation, the third in a series of reconstructive operations performed on children with a severely underdeveloped ventricle, one of the heart’s two pumping chambers. Glatz is a pediatric interventional cardiologist in the Cardiac Center at Children’s Hospital of Philadelphia (CHOP).

Glatz and colleagues published their study on September 1, 2017 in Circulation: Cardiovascular Interventions. Other key members of the study team include Tacy Downing, MD and Kiona Allen, MD (both were pediatric cardiology fellows at CHOP during the work); and David Goldberg, MD and William Gaynor, MD (current faculty members in the Cardiac Center at CHOP).

The study team performed a retrospective review of 773 patients who underwent the Fontan operation at CHOP between 1992 and 2009.

Although the Fontan procedure offers high survival rates for a condition that previously was universally fatal during infancy, it cannot provide normal blood circulation, and carries long-term risks of complications that continue to be analyzed. Clinicians and researchers were aware of the need for re-interventions in long-term Fontan survivors, but there was little detailed knowledge of re-intervention rates until now.

In the current study, the researchers found that 65 percent of Fontan survivors underwent a re-intervention by 20 years after their operation, with a median time to first re-intervention slightly less than 10 years. The re-interventions were either operations or catheterizations, with catheterizations being more common—often to close unwanted openings or to widen narrowed blood vessels. Among operations, the most common were to place or revise a pacemaker.

“The important message from this work is that, for many patients, the Fontan operation is not the ‘final’ procedure, as it is sometimes referred to. Instead, many patients require further interventions after the Fontan to continue to try to optimize the circulation as best as possible. It’s important for families and doctors to understand this, so expectations are clear. This also highlights the need for close and careful ongoing follow-up after the Fontan operation by pediatric cardiologists familiar with potential complications that could befall a Fontan patient,” said Glatz.

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New research on probiotics in the prevention and treatment of colon cancer

In an innovative approach to colorectal cancer (CRC) prevention and treatment, scientists are studying ways to replace missing metabolites in patients prone to gut inflammation and CRC. A new study in The American Journal of Pathology describes how administration of histamine-producing gut microbes to mice lacking the enzyme histidine decarboxylase (HDC) reduced inflammation and tumor formation. These results suggest that alteration of the gut microbiome with probiotics may become a new preventative or therapeutic strategy for patients at risk for inflammatory bowel disease (IBD)-associated CRC.

“We are on the cusp of harnessing advances in microbiome science to facilitate diagnosis and treatment of human disease,” explained James Versalovic, MD, PhD, pathologist-in-chief at Texas Children’s Hospital, and Milton J. Finegold Professor of pathology & immunology at Baylor College of Medicine (Houston). “By simply introducing microbes that provide missing life substances, we can reduce the risk of cancer and supplement diet-based cancer prevention strategies.”

Researchers conducted a series of experiments using mice that were deficient in HDC, the enzyme required to convert histidine to histamine. Experimental mice were orally administered the probiotic Lactobacillus reuteri 6475, which is known to possess the histidine decarboxylase gene (hdc+) and is able to convert histidine to histamine; control animals received a placebo. The probiotic was administered both before and after the mice received a single dose of a colonic carcinogen (azoxymethane) plus an inflammation-inducing chemical (DSS) to induce tumor formation. Fifteen weeks later, the mice were sacrificed and the tissues removed for study.

The probiotic increased expression of bacterial HDC and amounts of histamine in the colons of the mice. Using positron emission tomography (PET) to visualize the tumors, control-treated mice showed evidence of tumors and increased glucose uptake in colon walls. In contrast, mice administered the probiotic had fewer and smaller tumors and significantly diminished areas of glucose uptake.

Inactive L. reuteri strains (those deficient in HDC activity) did not provide protective effects. These mice showed increased numbers of “hot spots” indicative of tumor formation and increased abdominal glucose uptake.

The active probiotic also reduced inflammation induced by the carcinogen plus DSS, as indicated by suppressed pro-inflammatory cytokine gene expression (i.e., those encoding KC, interleukin (IL)-22, IL-6, tumor necrosis factor (TNF), and IL-1α) and reduced cytokine concentrations in plasma (i.e., KC, IL-22, and IL-6). The active probiotic also counteracted an increase in immature myeloid cells induced by the carcinogen. According to Dr. Versalovic, “These observations are consistent with the conclusion that histamine-generating probiotic L. reuteri may attenuate AOM+DSS-induced colon carcinogenesis, at least in part, via enhanced maturation of circulating myeloid cells and concomitant reduction of pro-inflammatory cytokines.”

The role of histamine in human cancer is still unclear. However, when investigators analyzed data obtained from 2,113 CRC patient samples taken from 15 datasets, results showed better survival in patients with elevated patterns of HDC and histamine receptor gene expression. These findings indicate that histamine-generating probiotics, in the presence of sufficient protein (L-histidine) intake, may improve outcomes for patients with sporadic and IBD-associated CRC.

“Our results suggest a significant role for histamine in the suppression of chronic intestinal inflammation and colorectal tumorigenesis. We have also shown that cells, both microbial and mammalian, can share metabolites or chemical compounds that together promote human health and prevent disease,” said Dr. Versalovic.

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Immunotherapy treatment option for selected breast cancer patients, genetic study suggests

Immunotherapy drugs could help some breast cancer patients based on the genetic changes in their tumours, researchers at the Wellcome Trust Sanger Institute and their collaborators find. Published today (13 September) in Cancer Research, scientists identify particular genetic changes in a DNA repair mechanism in breast cancer.

The results open up the possibility to another therapy option for around 1,000 breast cancer patients in the UK, who could benefit from existing drugs.

Breast cancer is the most common cancer in the UK, affecting nearly 55,000 women a year. Globally it accounts for nearly 1.7 million cancer cases.

In the study, scientists found that a particular group of breast cancer patients have genetic changes, or mutations, that occur because of an abnormality of a DNA repair mechanism known as mismatch repair*. These mutations are found in other cancers, such as colorectal cancer, but are rarely looked for in breast cancer.

Colorectal cancers with deficient mismatch repair have recently been treated with immunotherapies called checkpoint inhibitors in the US**, including the drug pembrolizumab. Immunotherapies exploit the fact that, under the influence of check point inhibitors, highly mutated tumour cells can be recognised as ‘foreign’ by the patient’s immune system.

The results of this new study suggest that these immunotherapies could also be effective for some breast cancer patients based on the same mutation patterns seen in their tumours. Therefore clinical trials are required to determine if immunotherapies could help selected breast cancer patients.

In the study, the team analysed the whole genome sequences of 640 breast cancer tumours. They looked for patterns in the mutations, known as mutational signatures, which indicated abnormalities in the mismatch repair mechanism. From the mutational signatures, the team identified 11 tumours that had the mismatch repair defects causing the breast cancer.

Dr Serena Nik-Zainal, lead author from the Wellcome Trust Sanger Institute, said: “We’ve unequivocally found mismatch repair deficient breast cancers. As these tumours have the same mutational signatures as those of other cancers, like colorectal cancer, they should in theory respond to the same immunotherapy drugs. Our results suggest expanding the cohort of cancer patients that could possibly be treated with checkpoint inhibitors to include these mismatch repair deficient breast cancer patients.”

Dr Helen Davies, first author from the Wellcome Trust Sanger Institute, said: “Using whole genome sequencing we can start to stratify breast cancer patients into different categories based on their mutational signatures. Current clinical criteria means these tumours would not have been detected as being deficient in the mismatch repair pathway. We have shown that there is in fact another category of breast cancers – those with defective mismatch repair.”

Professor Karen Vousden, Cancer Research UK’s chief scientist, said: “Immunotherapies have shown promise for some cancer patients, but the challenge for doctors has been predicting which patients they are likely to help. This study, using a technique called whole genome sequencing, reveals more about the genetic patterns that could show which women with breast cancer are more likely to respond to immunotherapy treatments. The next step will be to test this approach in clinical trials to find out if identifying these patterns and using them to tailor breast cancer treatments helps to improve survival.”

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Modulating T-Cell Metabolism Uncovers New Technology for Enhancing Immunotherapy

T lymphocytes found in tumors and implicated in killing tumor cells cope with the shortage of oxygen and nutrients in the tumor microenvironment by using fat as the main source of energy. Promoting a switch from glucose to fatty acid to generate energy enhances T cell antitumor activity. These findings from a study conducted at The Wistar Institute were published in the journal Cancer Cell.

The presence of tumor infiltrating T lymphocytes (TILs) in solid tumors is often associated with better clinical outcomes and better patient responses to some immunotherapeutic treatments. These cells can be isolated from a cancer patient, manipulated ex vivo, and infused into the same patient to treat her/his own cancer. However, the effectiveness of TILs antitumor responses is limited by their progressive loss of functions. Metabolic stress plays a central role in the exhaustion of T cells as they compete with tumor cells for oxygen and nutrients in the tumor microenvironment. In these unfavorable conditions, the function of TILs is impaired, reducing their potency against the tumor and the efficacy of T cell-based immunotherapy.

“The mechanisms behind TILs exhaustion are poorly understood,” said lead author of the study Hildegund C.J. Ertl, M.D., Caspar Wistar Professor in Vaccine Research and member of Wistar’s Vaccine & Immunotherapy Center. “Considering the central importance of TILs for cancer immunotherapy, we believe that our findings may have critical implications to boost the efficacy of T cell-based therapies.”

This study by Ertl and colleagues shows that low oxygen levels combined with low glucose availability cause TILs to adapt their metabolism and change their source for energy production from glucose to fatty acids, the building blocks of fat. Further inducing this metabolic shift instructs the T cells to increase their use of fatty acids for energy production, thus improving TILs’ effector functions and their ability to delay tumor progression.

The Ertl lab studied the effectiveness of metabolic manipulations to improve TIL functions in two melanoma mouse models and in the context of two different immunotherapy approaches. Ertl and colleagues confirmed the clinical relevance of these observations by showing that T cells isolated from metastases of melanoma patients have increased fatty acid metabolism compared with circulating lymphocytes from healthy donors. Furthermore, using fibrates, a class of FDA approved drugs used to lower cholesterol levels, they promoted the breakdown of fatty acids and observed that this enforced metabolic switch is associated with improved T cell functions within tumors. Importantly, these drugs can also synergize with immune checkpoint blockade therapy, improving the efficacy of this melanoma immunotherapy.

“Pharmacological interventions aimed at promoting the metabolic adaptation of TILs towards fatty acid metabolism may have a broad implication for T cell-based immunotherapy for different cancer types,” added Ertl.

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Cell Surface Protein May Offer Big Target in Treating High-Risk Childhood Cancers

Oncology researchers studying high-risk children’s cancers have identified a protein that offers a likely target for immunotherapy–harnessing the immune system in medical treatments. In cell cultures and animal models, a potent drug attached to an antibody selectively zeroes in on cancer cells without harming healthy cells.

“We have built a strong foundation for developing a completely new and hopefully much less toxic treatment for neuroblastoma, the most common cancer in infants,” said study supervisor John M. Maris, MD, a pediatric oncologist at Children’s Hospital of Philadelphia (CHOP). “Furthermore, our findings may also lend support to the development of other immune-based therapies, such as CAR T-cells, in children with multiple aggressive cancers in addition to neuroblastoma.”

Maris, along with study leader and first author Kristopher R. Bosse, MD, and colleagues published their study today in Cancer Cell, which featured their findings as the cover story.

Neuroblastoma is a cancer of the developing peripheral nervous system that usually occurs as a solid tumor in a child’s chest or abdomen, and is the most common cancer in infants. It accounts for a disproportionate share of cancer deaths in children. Over decades, CHOP clinicians and researchers have built one of the world’s leading programs in neuroblastoma.

The study team used sophisticated sequencing tools to first discover molecules that are much more commonly found on the surface of neuroblastoma cells than on normal cells. “Our rationale was to identify a cell-surface molecule that an immune-based therapy could target without damaging healthy tissues,” said Bosse. “Using this approach, we identified a protein called glypican-2, or GPC2.” GPC2 is one of a family of glypicans—cell-surface proteins that interact with growth factors and cell surface receptors, influencing many intracellular signaling pathways important in development and cancer.

In addition to GPC2’s presence on neuroblastoma cells, the study team also found that GPC2 is necessary for a neuroblastoma tumor to proliferate. Both of those facts implied that a compound that acted against GPC2 might kill cancer cells, spare healthy cells, and limit the possibility of these tumors developing “immune escape” mechanisms, in which cancer cells resist an immunotherapy by shedding the target. “Given GPC2’s critical role in the growth of neuroblastomas, we hope that tumors will not be able to simply downregulate this protein in order to escape recognition by our immunotherapies that target GPC2,” said Bosse.

After pinpointing GPC2 as a very promising target for therapy, the researchers next worked with their colleagues at the National Cancer Institute to search for a weapon. They developed an antibody-drug conjugate (ADC) called D3-GPC2-PBD, which combined a very specific antibody that recognizes GPC2 with a potent chemotherapy drug that is internalized specifically by cancer cells. The drug payload damages DNA in tumors, while sparing healthy tissues from its toxic effects.

In cell cultures and mouse models of neuroblastoma, the ADC robustly killed neuroblastoma cells with no discernible toxicity to normal cells. “These findings establish that this type of immunotherapy could be potentially safe and effective against neuroblastoma,” said Maris. “Our next steps will be to further evaluate this ADC and also develop other immune-based therapies directed against GPC2. Because other glypicans in addition to GPC2 are overexpressed in other childhood cancers, it may also be possible to apply this approach across various types of high-risk pediatric cancers.”

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Accelerating the Development of Next-Generation Cancer Therapies

To accelerate the development of next-generation cancer therapies, the Gene Editing Institute of the Helen F. Graham Cancer Center & Research Institute at Christiana Care Health System has agreed to provide genetically modified cell lines to Analytical Biological Services, Inc. (ABS) of Wilmington, Delaware.

Under a three-year agreement, the Gene Editing Institute will act as sole provider of gene editing services and genetically modified cell lines to ABS for replication, marketing and distribution to leading pharmaceutical and biomedical research companies worldwide.

“This agreement with ABS will speed the progress in the discovery of effective cancer therapies and accelerate the path to prevention, diagnosis and treatment of many forms of cancer,” said Nicholas J. Petrelli, M.D., the Bank of America endowed medical director of the Helen F. Graham Cancer Center & Research Institute at Christiana Care Health System.

“This partnership greatly enhances our capability to provide the highest quality genetically engineered cells for drug discovery,” said ABS President and CEO Charles Saller, Ph.D. “Our partners at the Gene Editing Institute are advancing molecular medicine, and their expertise adds a new dimension to our efforts to speed up drug discovery.”

“One goal of The Gene Editing Institute is to develop community partnerships that can advance translational cancer research,” said Eric Kmiec, Ph.D., founder and director of the Gene Editing Institute. “The Gene Editing Institute is driving innovation in gene engineering, and ABS has the know-how to grow and expand the cells in sufficient quantities, as well as to market them to pharmaceutical and biotechnology clients for drug screening and research.”

The Gene Editing Institute is a worldwide leader in the design of the tools that scientists need to manipulate and alter human genetic material easier and more efficiently than ever before. Scientists at the Gene Editing Institute have designed and customized an expanding tool-kit for gene editing, including the renowned CRISPR-Cas9 system, to permanently disrupt or knock out genes, add or knock in DNA fragments and create point mutations in genomic DNA. Last year, scientists at the Gene Editing Institute described in the journal Scientific Reports how they combined CRISPR and short strands of synthetic DNA to greatly enhance the precision and reliability of the CRISPR gene editing technique. Called Excision and Corrective Therapy, or EXACT, this new tool acts as both a Band-Aid and a template during gene mutation repairs.

Genetically modified cells can help advance cancer research. By inactivating a single gene, scientists can test if it affects tumor formation or somehow alters the response to cancer therapies. Similarly, inserting a gene into a cell can produce a gene product that is a target for potential new drugs.

“Gene editing and the CRISPR technology is having a major impact on anticancer drug development because it allows us to validate the target of the candidate drug,” said Dr. Kmiec. “Pharmaceutical companies want to use gene editing tools to identify new targets for anti-cancer drugs and to validate the targets they already have identified.”

The Delaware BioScience Association helped connect the Gene Editing Institute with ABS. “The collaborative agreement between the Gene Editing Institute and ABS exemplifies the power of building a strong biotech community, flourishing further innovation, and keeping businesses engaged and thriving in the state of Delaware,” said Helen Stimson, president and CEO of The Delaware BioScience Association. “The Delaware BioScience Association is committed to fostering meaningful relationships, such as this one, among its members, and establishing strategic partnerships that bolster the state’s innovation economy,” she said.

“This is one of those times when the forces of nature align to bring two perfectly matched skill sets together,” said Dr. Kmiec. “There is no question that our collaboration with ABS will accelerate the pace of drug discovery around the world.”

About The Gene Editing Institute

The Gene Editing Institute of Christiana Care Health System’s Helen F. Graham Cancer Center & Research Institute is unlocking the genetic mechanisms that drive cancer that can lead to new therapies and pharmaceuticals to revolutionize cancer treatment. Gene editing in lung cancer research has already begun setting the stage for clinical trials.

The Gene Editing Institute is integrated into the Molecular Screening Facility at The Wistar Institute in Philadelphia, PA, where its innovative gene-editing technologies are available to research projects at Wistar and to external users. Working with Wistar scientists, the Gene Editing Institute has begun research to conduct a clinical trial in melanoma. With funding from the National Institutes of Health, the Gene Editing Institute is partnering with A.I. duPont/Nemours to develop a gene editing strategy for the treatment of sickle cell anemia and leukemia. Under a grant from the U.S.–Israel Binational Industrial Research & Development Foundation, the Gene Editing Institute is working with Jerusalem-based NovellusDx to improve the efficiency and speed of cancer diagnostic screening tools. This work could lead to earlier identification of genetic mechanisms responsible for both the onset and progression of many types of cancers and the development of individualized therapeutics.

Gene Editing Institute scientists also provide instruction in the design and implementation of genetic tools. Partnerships with Bio-Rad Inc. and the Delaware Technical and Community College are producing gene editing curricula and teacher training workshops for both community colleges and secondary schools.

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KEYNOTE-040 evaluates pembrolizumab in head and neck cancer

Immunotherapy with the checkpoint inhibitor pembrolizumab may be a better option than standard treatments for patients whose head and neck cancer has spread, or recurred after an initial round of chemotherapy, according to results of the Keynote-040 trial presented at the ESMO 2017 Congress in Madrid. (1)

Although the 19% improvement in overall survival among patients treated with pembrolizumab did not meet the prespecified difference for statistical significance, it was nevertheless a clinically meaningful difference for this population who only lived seven to eight months, on average, after initiating treatment, said lead investigator Dr. Ezra Cohen, from the University of California, San Diego Moores Cancer Center, in La Jolla, California.

“Even though the study did not meet its primary endpoint, I still think it is a positive trial,” he said. “It reinforces that pembrolizumab should continue to be offered as an important option for all patients with this devastating disease.”

The KEYNOTE-040 trial was a global, open-label, phase 3 study which included patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) after a platinum-based chemotherapy.

Patients were randomised to receive either pembrolizumab (n=247) or standard of care (SOC) treatment (n=248), which was the investigator’s choice of either methotrexate, docetaxel, or cetuximab.

Median overall survival (OS) was only marginally higher in the pembrolizumab compared to standard treatment arm (8.4 versus 7.1 months, hazard ratio [HR] 0.81 95% CI 0.66-0.99, P= .0204), however for a subset of patients who had PD-L1-expressing tumours, pembrolizumab was associated with dramatic and significantly improved outcomes.

Specifically, among patients with combined tumour and immune cell PD-L1-expression (CPS) of at least 1%, median OS was 8.7 months with pembrolizumab versus 7.1 months with standard treatments (HR 0.75; 95% CI 0.59-0.95, P=.0078), and among patients with PD-L1-expression in more than 50% of their cancer cells, median OS was 11.6 versus 7.9 months respectively (HR 0.54; 95% CI 0.35-0.82, P=.0017).

Compared to the other treatments, pembrolizumab measured up well in terms of side-effects.

“In almost every category it had a better side-effect profile, meaning a lower incidence of toxicity, versus standard treatments,” said Cohen. “The exception is hypothrodism, which occurred in 13% of those treated with pembro versus only 1% of those given other treatments.”

Overall, Cohen said the KEYNOTE-040 trial reinforces what is already known about anti-PD therapy in head and neck cancer. “From a clinician’s perspective I would feel the same in any country. This is a meaningful therapy that improves survival.”

Asked to comment for ESMO, Dr. Amanda Psyrri, from the University of Athens Medical School, and Attikon University Hospital in Athens said: “Keynote-040 did not reach its primary endpoint of overall survival; however, pembrolizumab was superior to investigator’s choice in terms of toxicity, an important consideration in treatment decisions for these poor-prognosis patients with recurrent/metastatic platinum-refractory HNSCC. As the authors point out, subsequent immunotherapy in the SOC arm may have confounded OS analysis. The magnitude of treatment effect was greater in patients with PD-L1 combined positive score (CPS) ? 1%, especially those with CPS ?50%,suggesting that pembrolizumab may represent the preferable treatment option for this subset of patients.”

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Cancer Immunotherapy May Get a Boost by Disabling Specific T Cells

Cancer immunotherapy drugs only work for a minority of patients, but a generic drug now used to increase blood flow may be able to improve those odds, a study by Columbia University Medical Center (CUMC) researchers suggests.

In mice with melanoma, the researchers found that the drug – called pentoxifylline – boosts the effectiveness of immune-checkpoint inhibitors, a type of immunotherapy now commonly used in the treatment of melanoma and other cancers.

The study was published today in the online edition of Cell.

Checkpoint-blockade immunotherapy drugs – the first drugs were approved in 2011 – target proteins on tumor cells or cells of the immune system that prevent “killer” T cells from attacking cancer. These drugs have revolutionized cancer care, but do not work for all patients. “In advanced melanoma, for example, the cure rate is only about 20 percent. That’s a remarkable improvement over previous therapies,” says study leader Sankar Ghosh, PhD, Chair and Silverstein and Hutt Family Professor of Microbiology & Immunology. “But why doesn’t it work for the other 80 percent? There must be another mechanism that contributes to the suppression of the immune response.”

Dr. Ghosh and other cancer biologists suspected that a different type of T cell, known as regulatory T cells, or Tregs, may also suppress the immune system’s attack on cancer. Large numbers of these cells are found within several types of tumors. “One possible therapy would be to get rid of Tregs,” he said. “But Tregs are also needed to keep the immune system in check, and shutting down Tregs completely would unleash an attack against the body’s healthy cells and organs.”

This point is underscored by a related study, published today in Immunity, in which Dr. Ghosh and colleagues found that removing NF-kB from Tregs caused widespread and lethal autoimmunity in mice. However, a partial inhibition of NF-kB, achieved by removing only one, specific, NF-kB protein, called c-Rel, changed Treg function without causing widespread autoimmunity.  In the Cell study Ghosh and colleagues showed that these c-Rel deficient Tregs were specifically crippled in their ability to protect cancer cells. As a result, when c-Rel is blocked, killer T cells mounted a more robust attack on cancer cells without causing autoimmunity.

Pentoxifylline is a drug that is used in patients to increase blood flow in the hands and feet of people with poor circulation, but it’s also known to inhibit the c-Rel protein. In the Cell study, the researchers demonstrated that pentoxifylline blocked Treg function and boosted the effectiveness of standard checkpoint-blockade immunotherapies.  As a result, mice treated with both drugs showed significantly reduced melanoma tumor burden, compared to animals that received the standard therapy alone.

“The next step is to test this drug combination in human clinical trials,” Dr. Ghosh says. “If trials are successful, the use of c-Rel inhibitors could become a standard addition to immune checkpoint therapy for many types of cancer.”

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Study Unlocks How Changes in Gene Activity Early During Therapy Can Establish the Roots of Drug-Resistant Melanoma

FINDINGS
A UCLA-led study of changes in gene activity in BRAF-mutated melanoma suggests these epigenomic alterations are not random but can explain how tumors are already developing resistance as they shrink in response to treatment with a powerful class of drugs called MAP kinase (MAPK)-targeted inhibitors. The discovery marks a potential milestone in the understanding of treatment-resistant melanoma and provides scientists with powerful targets for drug development and new clinical studies.

BACKGROUND
Approximately 50 percent of advanced melanoma tumors are driven to grow by the presence of BRAF mutations. The use of BRAF inhibitors, both alone and in combination with another MAPK pathway inhibitor called MEK, have shown unprecedented responses as a treatment for these types of tumors, rapidly shrinking them. However, BRAF-mutated tumors frequently show early resistance to treatment and respond only partially to BRAF inhibitors, leaving behind cancer cells that may evolve to cause eventual tumor regrowth.

The findings build upon research by Dr. Roger Lo, professor of medicine (dermatology) and molecular and medical pharmacology at the David Geffen School of Medicine, and lead author of the new study. Previously, he discovered that epigenomic alterations (via a regulatory mechanism called CpG methylation) accounted for a wide range of altered gene activities and behaviors in BRAF-mutant therapy-resistant melanoma tumor cells. The loss of tumor-fighting immune or T-cells in drug-resistant tumors may lead to resistance to subsequent salvage immunotherapy, Lo said, and drug resistance can grow at the same time that anti-tumor immune cells diminish and weaken.

This means that in some patients the melanoma might develop resistance to both MAP kinase-targeted therapy and anti-PD-L1 antibodies, which capitalize on the abundance of immune cells inside the tumor to unleash their anti-cancer activities. Lo concluded that non-genomic, epigenomic, and immunologic evolution of melanoma explain why patients relapse on MAPK-targeted therapies.

Along with co-first authors, Drs. Chunying Song, Marco Piva and Lu Sun, Lo hypothesized that epigenomic and immunologic resistance evident during clinical relapse may be developing already during the first few weeks of therapy as the tumors shrink and clinical responses are viewed as successes. If this proves to be true, then scientists could potentially identify combination treatments that suppress the earliest resistance-promoting activities.

METHOD
Lo’s team utilized state-of-the-art technologies to comprehensively profile recurrent patterns of gene activity changes. They analyzed 46 samples of patients’ melanoma tumors, both before and early during MAPK therapy. They also replicated the process outside of the human body, modeling both non-genomic drug resistance by growing melanoma cell lines from patients’ tumors and immunologic resistance in mouse melanoma. Patient-derived cell lines and mouse melanoma tumors were treated with drugs that block the MAP kinase pathway and sampled at various times over the course of the study to track gene activity changes.

The researchers found that MAPK therapies fostered CpG methylation and gene activity reprogramming of tumors. This reduced the tumor cells’ dependence on the mutated BRAF protein, and switched their growth and survival strategies to rely on proteins called receptor-tyrosine kinases and PD-L2. In addition, PD-L2 gene activity was found to be turned on in immune cells surrounding the tumor cells. They also demonstrated that blocking PD-L2 with an antibody could prevent the loss of T-cells in the tumor’s immune microenvironment and suppressing therapy resistance.

Lo’s team continues to identify other adaptations during this early phase of therapy that could be targets of future combination treatment regiments.

IMPACT
More than 87,000 new cases of melanoma will be diagnosed this year in the United States alone, and more than 9,500 people are expected to die of the disease.

The findings can prompt drug development and new clinical studies based on epigenetic or gene expression and immune targets in combination with mutation-targeted therapies. As scientists learn what these mechanisms of tumor resistance are, they can combine inhibitor drugs that block multiple resistance routes and eventually make the tumors shrink for much longer or go away completely, Lo said.

JOURNAL
The research is published online in Cancer Discovery, the peer-reviewed journal of the American Association of Cancer Research.

AUTHORS
UCLA’s Dr. Roger Lo is senior author. The co-first authors are Drs. Chunying Song, Marco Piva and Lu Sun at the David Geffen School of Medicine at UCLA. Other authors are Drs. Aayoung Hong, Gatien Moriceau, Xiangju Kong, Hong Zhang, Shirley Lomeli, Jin Qian, Clarissa Yu, Robert Damoiseaux, Philip Scumpia, Antoni Ribas and Willy Hugo at UCLA; and Mark Kelley, Kimberly Dahlman, Jeffrey Sosman, Douglas Johnson at Vanderbilt University. Lo, Damoiseaux, Scumpia and Ribas are members of UCLA’s Jonsson Comprehensive Cancer Center.

FUNDING
The research was supported by the National Institutes of Health, the American Cancer Society, the Melanoma Research Alliance, the American Skin Association, the American Association for Cancer Research, the National Cancer Center, the Burroughs Wellcome Fund, the Ressler Family Foundation, the Ian Copeland Melanoma Fund, the SWOG/Hope Foundation, the Steven C. Gordon Family Foundation, the Department of Defense Horizon Award, the Dermatology Foundation, and the ASCO Conquer Cancer Career Development Award.

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Neuroscientists Focus on Cell Mechanism That Promotes Chronic Pain

Researchers have discovered a new pain-signaling pathway in nerve cells that eventually could make a good target for new drugs to fight chronic pain.

The findings, published in the journal PLoS Biology by a UT Dallas neuroscientist and his colleagues, suggest that inhibiting a process called phosphorylation occurring outside of nerve cells might disrupt pain signals, and provide an alternative to opioid drugs for alleviating chronic pain.

Dr. Ted Price, the study’s co-author and associate professor of neuroscience in the School of Behavioral and Brain Sciences at UT Dallas, said the finding is significant.

“We found a key new signaling pathway that can be managed,” Price said. “Now we hope we can use the findings to discover a new drug.”

Phosphorylation is a biological process that occurs when a kinase — a type of enzyme — attaches a chemical called phosphate to a protein. This common process modifies proteins and their functions.

Phosphorylation was known to occur inside cells, but Dr. Matthew Dalva at Thomas Jefferson University, a co-author of the study, found that the process also occurs outside of cells, specifically nerve cells called neurons within the brain and spinal cord.

The new work shows that molecules called ephrins, which are bound in neuron membranes and include a portion that sticks out of the outer surface of the cell, are phosphorylated at those outward-facing sites. This extracellular phosphorylation event causes another type of protein, called NMDA receptors, to accumulate on the neuron’s surface.

Where those NMDA receptors gather is important: It’s at the synapse, the narrow space between two neurons where neurochemical signals are transmitted between cells.

NMDA receptors are critical to normal learning and memory development in the brain, but they also play a key role in controlling signals related to pathological pain. This type of pain is felt when there is no underlying cause, or when the pain continues long after the event.

“We know that the NMDA receptor plays a key role in neural plasticity for learning and memory. But it also plays a key role in learning or neural plasticity for pain,” Price said.

He said phosphorylating kinases appear to be the key factor for regulating the cell-signaling that occurs through NMDA receptors. Now that scientists understand that the phosphorylation process can occur both inside and outside the cell, they can research strategies to specifically block the process from happening outside the cell.

“We found this completely new type of signaling is what regulates the NMDA receptors. That was completely unexpected. The data are just extremely convincing,” Price said.

Price and his colleagues used isolated cells and animal models to specifically look at how this new signaling information applies to pain.

“We know that the extracellular phosphorylation event can drive pain, and we know if we reduce that process, it decreases pain,” he said. “Even after pain amplification has been established for a very, very long time, we can reverse extracellular phosphorylation very rapidly, and this reduces pain.”

Researchers were limited when they believed phosphorylation occurred only inside cells, Price said. Many drugs can’t move on in development because they are not able to cross cell membranes and, thus, are not able to get inside the cell. But he said discovering that extracellular phosphorylation also plays a key role in the processes associated with injury and pain makes it easier to develop drugs that can specifically target that process.

“If you don’t have to worry about all the kinases that are inside the cell, that limits the number of kinases that have to be targeted. Those extracellular kinases, which are a very distinct subset of that family of proteins, become a nice target to pursue,” he said.

The Price and Dalva labs are pursuing additional research grants to learn more about how this extracellular phosphorylation event works, identify the particular kinase involved and test it in pain models. With additional insight, they are hopeful that they can develop drugs capable of reversing chronic pain states in humans.

In addition to UT Dallas and Thomas Jefferson University scientists, researchers from the University of Arizona and New York University School of Medicine worked on the project.

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Liver Cancer Patients Can Start with Lower Dose of Chemotherapy and Live Just as Long

Penn study shows patients can benefit from fewer side effects and lower treatment costs

Patients with the most common type of liver cancer who are taking the chemotherapy drug sorafenib can begin their treatment with a lower dose than is currently considered standard, and it will not affect how long they live when compared to patients who start on the full dose. That finding comes from a new study from the Abramson Cancer Center of the University of Pennsylvania, published this week in the Journal of Clinical Oncology, and it opens the door for patients with hepatocellular carcinoma to begin with a reduced dose of sorafenib, which helps to minimize the drug’s side effects while also saving money for patients, providers, and insurers.

Hepatocellular carcinoma (HCC) is the most common form of liver cancer among adults and is the second leading cause of cancer-related deaths worldwide. Currently, sorafenib is the only first-line treatment approved for HCC by the U.S. Food and Drug Administration, but its side effects can be particularly difficult on patients. A recent study found 85 percent of HCC patients taking the drug experienced adverse events. In 31 percent of patients on that study, the effects were severe enough to stop treatment. The standard dose sorafenib is 400mg, twice per day.

“Previous studies have started patients with half that dose, escalating only after the patients show they can handle it, but those studies have all been on a smaller scale,” said the study’s lead author Kim A. Reiss, MD, an assistant professor of Hematology Oncology in the Perelman School of Medicine at the University of Pennsylvania. “We wanted to see if we could reproduce those results using a much larger cohort of patients.”

Reiss and her team used a Veterans Health Administration database and identified almost 5,000 HCC patients who were treated with sorafenib between 2006 and 2015, but they couldn’t do a side-by-side analysis of those who received a reduced dose versus those who received the full amount.

“One of the challenges that we faced was that the sickest patients tended to get the reduced dose because of concerns over how much they could tolerate, so any attempt to evaluate these groups based on how long they lived was skewed,” Reiss said.

To solve that problem, researchers looked at patient information to match people from each group based on disease stage, overall health, and other factors. That left them with two groups, each with 1,675 patients.

“Essentially, we used a computer model to simulate putting these patients into a randomized, controlled clinical trial,” said senior author David E. Kaplan, MD, MSc, an assistant professor of Gastroenterology and an associate professor of Medicine at the Corporal Michael J. Crescenz VA Medical Center in Philadelphia.

The controlled data showed the reduced dose had no effect on overall survival. Patients starting at a lower dose had a median survival of 198 days, compared to 195 days for patients starting at the full dose.

In addition, about 40 percent of patients receiving the reduced dose escalated the drug amount within the first two months, while almost 12 percent of standard dose patients had to reduce their level within the same time period.

“It’s important to remember that the reduced dose patients will ramp up as they show they can handle it, while the full dose patients may have to ramp down because of these toxicities, so the dosage levels will converge in the middle,” Reiss said. “All of the patients get the treatment they need, but the reduced dose approach helps keep cost and toxicities down.”

The cost saving was significant. The study found the reduced dose patients took an average of about 100 fewer pills over the course of their treatment. That translated to an average savings of about $3,000 per patient. Reiss noted those numbers are based on VA prices, which tend to be lower than other centers, meaning the real savings for many patients could be even larger.

The researchers note that some doctors are already making use of this practice, which is why they were able to identify so many reduced dose patients for this study, but the majority of physicians are still starting with the full dose.

“Our data suggest starting at a reduced dose is a safe strategy that can be used more commonly,” Reiss said.

This study was supported by research funds from Bayer Healthcare Pharmaceuticals and the VA HIV, Hepatitis, and Related Conditions Programs in the Office of Specialty Care Services.

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Vaccine to Prevent Most Cervical Cancers Shows Long-Term Effectiveness

More than 14,000 women around the world were followed up to six years.

A vaccine that can literally eradicate the majority of cervical cancer cases shows long-term effectiveness in a study published today in The Lancet. This study of 14,215 women in 18 countries extends and solidifies the initial phase 3 efficacy and safety trial of the nine-valent human papilloma virus vaccine, Gardasil 9, that was published in February 2015 in The New England Journal of Medicine.

These new results strengthen the promise that vaccination with Gardasil 9 can reduce 90 percent of cervical cancers.

“There is no question that the vaccine works,” said primary author Warner Huh, M.D., professor and director of the University of Alabama at Birmingham Division of Gynecologic Oncology and a senior scientist at the UAB Comprehensive Cancer Center. “We’re on the verge of a dramatic change that will positively affect all individuals, particularly women, in the United States. The challenge is to get the new vaccine into widespread use among young women.”

The UAB Comprehensive Cancer Center and a coalition of Alabama health groups last year launched a formal call for action, urging Alabama parents and health care providers to get children — girls and boys — vaccinated against the sexually transmitted human papillomavirus, or HPV. The vaccine is unique in its ability to prevent certain cancers.

HPV infections cause global disease, including an estimated 266,000 deaths from cervical cancer worldwide in 2012, according to the World Health Organization. Routine screening by Pap smears or tests for HPV infection has reduced death rates in developed countries compared to less developed regions of the globe. Still, an estimated 12,200 U.S. women a year are diagnosed with cervical cancer.

Gardasil 9, marketed by Merck & Co., was approved by the U.S. Food and Drug Administration in December 2014. The vaccine immunizes against nine genotypes of HPV known to cause cervical cancer, as well as vulvar, vaginal and anal cancers and genital warts caused by HPV. It is an advance over the four-valent HPV vaccine, Gardasil, which was approved by the FDA in 2006.

Huh helped develop and test Gardasil, which targets the two HPV genotypes known to cause about 70 percent of cervical cancer and two other genotypes that cause genital warts. Gardasil 9 targets those four genotypes and five additional ones as well. Both vaccines are prophylactic, meant to be given before females or males become exposed to possible HPV infection through intimate contact.

“Nationwide, 40 percent of girls and boys do not receive the HPV vaccine, and in the state of Alabama, almost half of girls and boys do not receive the HPV vaccine,” Huh said. “With this new vaccine, there is a very legitimate opportunity to wipe out cancers that are caused by HPV, particularly cervical cancer in women.

“Seventy-five years ago, cervical cancer was a very common cause of mortality in the United States. Looking forward, with widespread vaccination, it is highly likely that cervical cancer will evolve into historical interest only, and screening, like Pap smears, might go away altogether. HPV vaccines are one of the most scrutinized vaccines ever, but multiple studies have demonstrated the vaccine to be safe and well-tolerated.”

In the Lancet study, women were followed for efficacy at preventing disease for up to six years after the first vaccine shots, and they were followed for production of infection-halting antibodies against the nine genotypes of HPV for more than five years. The randomized double-blind efficacy, immunogenicity and safety study involved 105 sites in Austria, Denmark, Germany, Norway and Sweden; Brazil, Chile, Colombia and Peru; Canada, Mexico and the United States; and Hong Kong, Japan, New Zealand, South Korea, Taiwan and Thailand.

Half the women were vaccinated with the four-valent Gardasil and half with the nine-valent Gardasil 9. They were followed via gynecological exams for evidence of infections or disease, and their blood sera were tested for antibody levels against HPV.

Gardasil 9 showed 97.4 percent efficacy to prevent infections and disease caused by the five additional HPV genotypes not included in the four-valent Gardasil vaccine. Gardasil 9 vaccination produced similar antibody protection against the four HPV genotypes in Gardasil. The two vaccines also had similar safety profiles.

The nine-valent HPV vaccine has now been licensed in more than 60 countries for prevention of HPV-related anogenital cancers and precancers, and genital warts. Results of the Lancet study support the public health value of — and the need for — comprehensive vaccination programs.

The study was sponsored and funded by Merck & Co. Huh and 27 co-authors represent 21 universities in Europe, Canada, South America, Australia and the United States, as well as Merck & Co.

At UAB, Huh holds the Margaret Cameron Spain Chair in Obstetrics and Gynecology.

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Penn’s Glowing Cancer Tool Illuminates Benign, but Dangerous, Brain Tumors during Pituitary Surgery

Fluorescent, targeted dye illuminates molecular signature of tumor tissue in personalized surgery.

An experimental imaging tool that uses a targeted fluorescent dye successfully lit up the benign brain tumors of patients during removal surgery, allowing surgeons to identify tumor tissue, a new study from researchers at the Perelman School of Medicine at the University of Pennsylvania shows. The tumors, known as pituitary adenomas, are the third most common brain tumor, and very rarely turn cancerous, but can cause blindness, hormonal disorders, and in some cases, gigantism.

Findings from the pilot study of 15 patients, published this week in the Journal of Neurosurgery, build upon previous clinical studies showing intraoperative molecular imaging developed by researchers at Penn’s Center for Precision Surgery can improve tumor surgeries. According to first author John Y.K. Lee, MD, MSCE, an associate professor of Neurosurgery in the Perelman School of Medicine at the University of Pennsylvania and co-director of the Center for Precision Surgery, this study describes the first targeted, near infrared dye to be employed in brain tumor surgery. Other dyes are limited either by their fluorescent range being in the busy visible spectrum or by lack of specificity.

“This study heralds a new era in personalized tumor surgery. Surgeons are now able to see molecular characteristics of patient’s tumors; not just light absorption or reflectance,” Lee said. “In real time in the operating room, we are seeing the unique cell surface properties of the tumor and not just color. This is the start of a revolution.”

Non-specific dyes have been used to visualize and precisely cut out brain tumors during resection surgery, but this dye is believed to be the first targeted, near infrared dye to be used in neurosurgery. The fluorescent dye, known as OTL38, consists of two parts: vitamin B9 (a necessary ingredient for cell growth), and a near infrared glowing dye. As tumors try to grow and proliferate, they overexpress folate receptors. Pituitary tumors can overexpress folate receptors more than 20 times above the level of the normal pituitary gland in some cases. This dye binds to these receptors and thus allows us to identify tumors.

“Pituitary adenomas are rarely cancerous, but they can cause other serious problems for patients by pushing up against parts of their brain, which can lead to Cushing’s disease, gigantism, blindness and death,” Lee explained. “The study shows that this novel, targeted, near infrared fluorescent dye technique is a safe, and we believe this technique will improve surgery.”

Lee says larger studies are warranted to further demonstrate its clinical effectiveness, especially in nonfunctioning pituitary adenomas.

A big challenge with this type of brain surgery is ensuring the entire tumor is removed. Parts of the tumor issue are often missed by conventional endoscopy approaches during removal, leading to a recurrence in 20 percent of patients. The researchers showed that the technique was safe and effective at illuminating the molecular features of the tumors in the subset of patients with nonfunctioning pituitary adenomas.

The technique uses near-infrared, or NIR, imaging and OTL38 fluoresces brightly when excited by NIR light. The VisionSense IridiumTM 4mm endoscope is a unique camera system which can be employed in the narrow confines of the nasal cavity to illuminate the pituitary adenoma. Both the dye and the camera system are needed in order to perform the surgery successfully.

The rate of gross-total resection (GTR) for the 15 patients, based on postoperative MRI, was 73 percent. The GTR with conventional approaches ranges from 50 to 70 percent. Residual tumor was identified on MRI only in patients with more severe tumors, including cavernous sinus invasion or a significant extrasellar tumor.

In addition, for the three patients with the highest overexpression of folate, the technique predicted post-operative MRI results with perfect concordance.

Some centers have resorted to implementing MRI in the operating room to maximize the extent of resection. However, bringing a massive MRI into the operating room theater remains expensive and has been shown to produce a high number of false-positives in pituitary adenoma surgery. The fluorescent dye imaging tool, Lee said, may serve as a replacement for MRIs in the operating room.

Co-authors on the study include M. Sean Grady, MD, chair of Neurosurgery at Penn, and Sunil Singhal, MD, an associate professor of Surgery, and co-director the Center for Precision Surgery.

Over the past four years, Singhal, Lee, and their colleagues have performed more than 400 surgeries using both nonspecific and targeted near infrared dyes. The breadth of tumor types include lung, brain, bladder and breast.

Most recently, in July, Penn researchers reported results from a lung cancer trial using the OTL38 dye. Surgeons were able to identify and remove a greater number of cancerous nodules from lung cancer patients with the dye using preoperative positron emission tomography, or PET, scans. Penn’s imaging tool identified 60 of the 66 previously known lung nodules, or 91 percent. In addition, doctors used the tool to identify nine additional nodules that were undetected by the PET scan or by traditional intraoperative monitoring.

Researchers at Penn are also exploring the effectiveness of additional contrast agents, some of which they expect to be available in the clinic within a few months.

“This is the beginning of a whole wave of new dyes coming out that may improve surgeries using the fluorescent dye technique,” Lee said. “And we’re leading the charge here at Penn.”

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Exploring Immunotherapy for Carcinoid and Pancreatic Neuroendocrine Tumors

A clinical trial testing the immunotherapy drug pembrolizumab shows the drug to be well tolerated among patients who have carcinoid or pancreatic neuroendocrine tumors.  Janice M. Mehnert, MD, director of the Phase 1 and Developmental Therapeutics Program at Rutgers Cancer Institute of New Jersey, is the lead author of research that is part of an oral presentation at the European Society for Medical Oncology 2017 Congress taking place this week in Madrid, Spain. Dr. Mehnert, who is also a medical oncologist in the Melanoma and Soft Tissue Oncology Program at Rutgers Cancer Institute, shares more about the work, conducted by a collective of international investigators.

Q: Why explore immunotherapy in these particular patient populations?

A: Immunotherapy drugs put the body’s natural defenses back to work by targeting the PD-L1 protein and PD-1 receptor and blocking their ability to prevent T cells from destroying cancer cells. Pembrolizumab has shown anti-tumor activity in advanced malignancies including melanoma and non-small cell lung cancer. With treatment options being limited for patients with carcinoid and pancreatic neuroendocrine tumors, it is imperative to explore new therapy options for these populations.

Q:  How was the study structured?

A: At the time our abstract was submitted, 25 participants who presented with advanced carcinoid tumors and 16 patients with pancreatic neuroendocrine tumors were accrued from multiple international sites.  Participants received 10 mg of pembrolizumab for up to 24 months or until confirmed progression or intolerable toxicity.  Safety, tolerability and response were assessed every eight weeks for the first six months and every 12 weeks thereafter.

Q:  What did you find?

A: At the time our results were reported we discovered findings similar to other trials of immunotherapy agents, with the majority of patients actually not responding to therapy. 12 percent of patients with carcinoid tumors and six percent of patients with pancreatic neuroendocrine tumors experienced a response to therapy. However, patients who achieved response were likely to have durable control of their disease, with all responses greater than or equal to six months in duration. Therapy was overall well tolerated and safe, with some side effects related to autoimmune processes caused by the medication.

Q: What is the implication of these findings?

A: These findings are interesting but need further validation in larger studies of patients with carcinoid and pancreatic neuroendocrine tumors. As well, investigative work focusing on identifying valuable biomarkers that could help predict which patients would respond to treatment with these agents is critical. Discoveries in this realm would improve the selection of patients for this particular therapeutic approach.

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$8.7 Million Awarded to Support Phase III Femoral Neck Fracture Trial by EU Horizon 2020 Program

Pluristem Therapeutics Inc., a leading developer of placenta-based cell therapy products, announced today that its Phase III study of PLX-PAD cells to support recovery following surgery for femoral neck fracture has been awarded an $8.7 million (7.4 million Euro) non-dilutive grant from the Horizon 2020 program, the European Union’s largest research and innovation program. Final approval of the grant is subject to the finalization of the consortium and Horizon 2020 grant agreements.

The Phase III trial of PLX-PAD cells in the treatment of femoral neck fracture will be a collaborative effort between Pluristem and an international consortium led by the Charité – Universitätsmedizin Berlin, under the leadership of Dr. Tobias Winkler, Principal Investigator at the Berlin-Brandenburg Center for Regenerative Therapies, Julius Wolff Institute and Center for Musculoskeletal Surgery. Dr. Winkler also served as Senior Scientist for Pluristem’s completed Phase I/II study of PLX-PAD for hip surgery. That trial demonstrated that patients treated with Pluristem’s PLX-PAD cells during total hip arthroplasty experienced significant muscle regeneration compared to the control group with an improvement in muscle force and in muscle volume six months after surgery.

This marks the second grant awarded to a Pluristem Phase III trial by Horizon 2020, following an $8 million (7.6 million Euro) award for its ongoing Phase III study of PLX-PAD cells in the treatment of Critical Limb Ischemia (CLI), which was awarded in August 2016.

Dr. Winkler commented, “Following the impressive results from the Phase I/II study of PLX-PAD cells in a similar orthopedic indication, we are excited to advance PLX-PAD cell therapy into a Phase III study to aid in muscle regeneration in patients recovering from femoral neck fracture. If similar results are achieved in this Phase III trial, it could show that PLX-PAD cells can improve outcomes in these procedures and change the way recovery is managed worldwide.”

Femoral neck fracture is the most common form of hip fracture, with mortality rates of up to 36%, and annual treatment costs estimated to be between $10-$15 billion in the U.S. alone. The number of surgeries performed annually to treat femoral neck fractures is increasing as populations age. Following surgery, many patients do not regain their baseline capabilities due to poor muscle healing and regeneration, which leads to significantly increased morbidity and a lower quality of life.

“We are honored to receive this second grant from the Horizon 2020 program,” stated Pluristem Chairman and Co-CEO Zami Aberman. “We believe this grant reflects a vote of confidence by the European Union and signals the need for cell therapy solutions to enable patients to lead healthier lives and to relieve health systems’ financial burdens. We are confident that this grant will help us move towards rapid entry into the European and U.S. markets.”

Pluristem’s PLX-PAD program is one of only a handful to be accepted into Europe’s Adaptive Pathway program, the purpose of which is to shorten the time it takes for innovative medicines to reach patients with serious conditions that lack adequate treatment options. Pluristem plans to enroll patients at clinical sites throughout Europe and the U.S. The study is expected to serve as a pivotal trial for regulatory approval in both regions.

The Berlin-Brandenburg Center for Regenerative Therapies (BCRT) was founded as a cooperative research institution of the Charité University Hospital in Berlin, which is one of the largest university hospitals in Europe, and Germany’s largest research association, the Helmholtz Association. The goal of the BCRT is to enhance endogenous regeneration by cells, biomaterials, and factors which can be used to develop and implement innovative therapies and products. The primary focus of the BCRT is on diseases of the immune system, the musculoskeletal system and the cardiovascular system for which currently only unsatisfactory treatment options are available.

Pluristem Therapeutics Inc. is a leading developer of placenta-based cell therapy products. The Company has reported robust clinical trial data in multiple indications for its patented PLX (PLacental eXpanded) cells, and is entering late-stage trials in several indications. PLX cell products release a range of therapeutic proteins in response to inflammation, ischemia, muscle trauma, hematological disorders, and radiation damage. The cells are grown using the Company’s proprietary three-dimensional expansion technology and can be administered to patients off-the-shelf, without tissue matching.

 

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Drug May Curb Female Infertility From Cancer Treatments

An existing drug may one day protect premenopausal women from life-altering infertility that commonly follows cancer treatments, according to a new study.

Women who are treated for cancer with radiation or certain chemotherapy drugs are commonly rendered sterile. According to a 2006 study from Weill Cornell Medicine, nearly 40 percent of all female breast cancer survivors experience premature ovarian failure, in which they lose normal function of their ovaries and often become infertile.

Women are born with a lifetime reserve of oocytes, or immature eggs, but those oocytes are among the most sensitive cells in the body and may be wiped out by such cancer treatments.

The current study, published in the journal Genetics, was led by John Schimenti, Cornell University professor in the Departments of Biomedical Sciences and Molecular Biology and Genetics. The study builds on his 2014 research that identified a so-called checkpoint protein (CHK2) that becomes activated when oocytes are damaged by radiation.

CHK2 functions in a pathway that eliminates oocytes with DNA damage, a natural function to protect against giving birth to offspring bearing new mutations. When the researchers irradiated mice lacking the CHK2 gene, the oocytes survived, eventually repaired the DNA damage, and the mice gave birth to healthy pups.

The new study explored whether the checkpoint 2 pathway could be chemically inhibited.

“It turns out there were pre-existing CHK2 inhibitor drugs that were developed, ironically enough, for cancer treatment, but they turned out not to be very useful for treating cancer,” said Schimenti, the paper’s senior author. Vera Rinaldi, a graduate student in Schimenti’s lab, is the paper’s first author. “By giving mice the inhibitor drug, a small molecule, it essentially mimicked the knockout of the checkpoint gene,” Rinaldi said.

By inhibiting the checkpoint pathway, the oocytes were not killed by radiation and remained fertile, enabling birth of normal pups.

“The one major concern,” Schimenti said, “is that even though these irradiated oocytes led to the birth of healthy mouse pups, it’s conceivable that they harbor mutations that will become manifested in a generation or two, because we are circumventing an evolutionarily important mechanism of genetic quality control. This needs to be investigated by genome sequencing.”

When doctors recognize the need for oocyte-damaging cancer treatments, women may have their oocytes or even ovarian tissue removed and frozen, but this practice delays treatment. Also, when women run out of oocytes, women’s bodies naturally undergo menopause, as their hormonal systems shift.

“That is a serious dilemma and emotional issue,” Schimenti said, “when you layer a cancer diagnosis on top of the prospect of having permanent life-altering effects as a result of chemotherapy, and must face the urgent decision of delaying treatment to freeze oocytes at the risk of one’s own life.”

The study sets a precedent for co-administering this or related drugs and starting cancer therapy simultaneously, though such interventions would first require lengthy human trials.

“While humans and mice have different physiologies, and there is much work to be done to determine safe and effective dosages for people, it is clear that we have the proof of principle for this approach,” Schimenti said.

The study was funded by the National Institutes of Health.

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Study Suggests that Zika Virus Could Be Used to Treat Brain Cancer Patients

Recent outbreaks of Zika virus have revealed that the virus causes brain defects in unborn children. But in a study to be published September 5 in The Journal of Experimental Medicine, researchers from Washington University School of Medicine in St. Louis and the University of California, San Diego report that the virus could eventually be used to target and kill cancer cells in the brain.

Glioblastoma is the most common form of brain cancer and is frequently lethal; most patients die within two years of diagnosis. Just like normal, healthy tissues, the growth and development of glioblastomas is driven by stem cells that proliferate and give rise to other tumor cells. Glioblastoma stem cells are hard to kill because they can avoid the body’s immune system and are resistant to chemotherapy and radiation. But killing these cells is vital to prevent new tumors from recurring after the original tumor has been surgically removed.

“It is so frustrating to treat a patient as aggressively as we know how, only to see his or her tumor recur a few months later. We wondered whether nature could provide a weapon to target the cells most likely responsible for this return,” says Milan Chheda from Washington University School of Medicine in St. Louis.

One approach to killing cancer stem cells involves using viruses that specifically target tumor cells. Zika virus appears to disrupt fetal brain development by preferentially targeting neural stem and progenitor cells. The virus’ effects on adult brains—which contain fewer active stem cells that developing fetal brains—are generally much less severe.

“We hypothesized that the preference of Zika virus for neural precursor cells could be leveraged against glioblastoma stem cells,” says Michael Diamond, also from Washington University School of Medicine in St. Louis, who co-directed the study with Milan Chheda and with Jeremy Rich, from the University of California, San Diego and the Cleveland Clinic Lerner Research Institute.

The researchers found that Zika virus preferentially infected and killed patient-derived glioblastoma stem cells compared with other glioblastoma cell types or normal neural cells. When mice with aggressive glioma were injected with a mouse-adapted strain of Zika virus, the virus slowed tumor growth and significantly extended the animals’ lifespan.

The researchers then tested a mutant strain of Zika that is less virulent than naturally occurring strains of the virus. This “attenuated” strain, which is more sensitive to the body’s immune response, was still able to specifically target and kill glioblastoma stem cells and was even more effective when combined with a chemotherapy drug, temozolomide, that usually has little effect on these cells. “This effort represents the creative synthesis of three research groups with complementary expertise to attack a deadly cancer by harnessing the cause of another disease,” says Jeremy Rich. “Adults with Zika may suffer less damage from their infection, suggesting that this approach could be used with acceptable toxicity.”

“Our study is a first step towards the development of safe and effective strains of Zika virus that could become important tools in neuro-oncology and the treatment of glioblastoma,” says Diamond. “However, public health concerns will need to be addressed through pre-clinical testing and evaluations of the strains’ ability to disseminate or revert to more virulent forms.”