Bioengineered Soft Microfibers Improve T-Cell Production

Columbia engineers bioengineer soft microfibers to improve T-cell production.

T cells play a key role in the body’s immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, chemical-based approaches. These “living drugs” are poised to transform medicine, with a growing number of cellular therapies receiving FDA-approval.

A current bottleneck in these approaches and other Adoptive T-cell Therapies (ACTs) is the production of sufficient numbers of high quality T cells. As a starting material, cells are isolated from the patient and then modified and grown outside the body in a bioreactor. This is still a new manufacturing challenge in medicine, and lack of a therapeutic number of cells is a frequent point of failure in ACT. In addition to technical challenges faced in consistent production of cells, T cells from patients undergoing treatment for cancer often show reduced function due to the disease, and are particularly difficult to grow.

A Columbia Engineering team has developed a new method for improving T-cell manufacture by focusing on the materials involved in this process. The team is a collaboration between Biomedical Engineering faculty Lance C. Kam and Helen H. Lu, whose research programs include immune engineering and smart biomaterial design. Their study, which is published today in Advanced Biosystems, uses a polymer mesh to activate the T cells, a critical step for their production. This approach simplifies processing compared to systems in use today. In addition, making the fibers out of a mechanically soft material improved T-cell growth, outperforming the current gold standard on several fronts.

“Our report shows that this soft mesh material increases the number of functional cells that can be produced in a single step,” Kam says. “In fact, our system provided nearly an order of magnitude more cells in a single process. What’s especially exciting is that we’ve been able to expand cells isolated from patients undergoing treatment for leukemia. These cells are often very difficult to activate and expand, and this has been a barrier to using cellular immunotherapy for the people who need it.”

In testing the effect of a softer material on T-cell production, the team was inspired by the field of mechanobiology. Researchers have known that other cell types can sense the mechanical stiffness of a material. For example, the rigidity of a material used to culture stem cells can direct differentiation, with a softer material promoting production of neuron while a stiffer substrate encourages bone cell differentiation. This effect can be as strong as the chemicals normally used to direct differentiation. However, a similar effect was unexpected in T cells for activation.

“This makes sense for cells normally involved in force-related activities, like muscle cells or fibroblasts that are involved in wound closure and healing. Our group was one of the first to explore this possibility for T cells, which are not associated with such functions,” Kam notes. These early experiments, involving his Microscale Biocomplexity Laboratory group, discovered that T-cells can sense the mechanical rigidity of the materials commonly used in the laboratory. To turn this into a clinically useful system, his group partnered with Lu’s Biomaterials and Interface Tissue Engineering Laboratory to create a microfiber-based platform.

Beyond simplifying the process of cell expansion and improving T-cells expansion, Kam and Lu envision that the mesh platform will have applications beyond immunotherapy. They are refining their platform and exploring how T cells from cancer patients respond to their materials. Says Lu, “It is truly exciting to see how these bioinspired matrices can direct cell function and be successfully used for T-cell therapy.”

Two New Breast Cancer Genes Emerge from Lynch Syndrome Gene Study

The findings suggest that genetic screening for breast cancer should be expanded to include MSH6 and PMS2

Researchers at Columbia University Irving Medical Center and NewYork-Presbyterian have identified two new breast cancer genes. Having one of the genes—MSH6 and PMS2—approximately doubles a woman’s risk of developing breast cancer by age 60.

The study, in collaboration with GeneDx, a genetic testing company, was published online today in Genetics in Medicine.

The two genes were previously known to cause Lynch syndrome, an inherited condition that raises the risk of colorectal, ovarian, stomach, and endometrial cancer. Lynch syndrome is the most common inherited cause of colorectal cancer, accounting for about 3 percent of newly diagnosed cases. One in 440 Americans has a gene variant that causes Lynch syndrome.

Researchers had suspected that Lynch syndrome genes may also cause breast cancer. Some studies had found a link, whereas others had not.

“People with Lynch syndrome aren’t thinking they may also be at risk for breast cancer,” said Wendy Chung, MD, PhD, the Kennedy Family professor of pediatrics (in medicine) at Columbia University Irving Medical Center, clinical geneticist at NewYork-Presbyterian/Columbia, and the study’s senior author. “Given the fact that genomic analysis is becoming more common in patients with a personal or family history of cancer, we have an opportunity to do more targeted breast cancer screening in women who carry any of the genes associated with risk for this disease.”

The researchers analyzed a database of more than 50,000 women who had undergone multi-gene hereditary cancer testing between 2013 and 2015. Of these, 423 women had a mutation in one of the four genes that cause Lynch syndrome: MLH1, MSH2, MSH6, and PMS2.

Additional analyses revealed that women with a mutation in two specific Lynch syndrome genes—MSH6 and PMS2—had a two-fold higher risk of breast cancer compared to women in the general population.

Based on the incidence of cancer in the study population, the researchers calculated that about 31 to 38 percent of women with cancer-causing MSH6 and PMS2 variants will develop breast cancer, compared to around 15 percent of women in the general population.

“The new study suggests MSH6 and PMS2 should be added to the list of genes to screen for when there is a history of breast cancer,” said Dr. Chung, who is also director of the clinical genetics program at NewYork-Presbyterian/Columbia. “Screening for these genes also would give these families potentially life-saving information to prevent colon cancer by encouraging individuals with the genes to increase the frequency of their colonoscopies.”

Currently, testing for Lynch syndrome genes is generally only done when someone has a personal or family history of colon or uterine cancer.

Dr. Chung added, “Given that Lynch syndrome is not rare in the general population, this finding has the potential to impact tens of thousands of people in the U.S. and could change standard practice related to one of the most common cancer predisposition syndromes.”

The study is titled, ‘MSH6 and PMS2 Germline Pathogenic Variants Implicated in Lynch Syndrome are Associated with Breast Cancer.’

UCLA Researchers Create Skeletal Muscle From Stem Cells

Discovery is major step towards a stem cell replacement therapy for Duchenne Muscular Dystrophy

UCLA scientists have developed a new strategy to efficiently isolate, mature and transplant skeletal muscle cells created from human pluripotent stem cells, which can produce all cell types of the body. The findings are a major step towards developing a stem cell replacement therapy for muscle diseases including Duchenne Muscular Dystrophy, which affects approximately 1 in 5,000 boys in the U.S. and is the most common fatal childhood genetic disease.

The study was published in the journal Nature Cell Biology by senior author April Pyle, associate professor of microbiology, immunology and molecular genetics and member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA. Using the natural human development process as a guide, the researchers developed ways to mature muscle cells in the laboratory to create muscle fibers that restore dystrophin, the protein that is missing in the muscles of boys with Duchenne.

Without dystrophin, muscles degenerate and become progressively weaker. Duchenne symptoms usually begin in early childhood; patients gradually lose mobility and typically die from heart or respiratory failure around age 20. There is currently no way to reverse or cure the disease.

For years, scientists have been trying different methods that direct human pluripotent stem cells to generate skeletal muscle stem cells that can function appropriately in living muscle and regenerate dystrophin-producing muscle fibers. However, the study led by Pyle found that the current methods are inefficient; they produce immature cells that are not appropriate for modeling Duchenne in the laboratory or creating a cell replacement therapy for the disease.

“We have found that just because a skeletal muscle cell produced in the lab expresses muscle markers, doesn’t mean it is fully functional,” said Pyle. “For a stem cell therapy for Duchenne to move forward, we must have a better understanding of the cells we are generating from human pluripotent stem cells compared to the muscle stem cells found naturally in the human body and during the development process.”

By analyzing human development, the researchers found a fetal skeletal muscle cell that is extraordinarily regenerative. Upon further analysis of these fetal muscle cells two new cell surface markers called ERBB3 and NGFR were discovered; this enabled the reserchers to precisely isolate muscle cells from human tissue and separate them from various cell types created using human pluripotent stem cells.

Once they were able to isolate  skeletal muscle cells using the newly identified surface markers, the research team matured those cells in the lab to create dystrophin-producing muscle fibers. The muscle fibers they created were uniformily muscle cells, but the fibers were still smaller than those found in real human muscle.

“We were missing another key component,” said Michael Hicks, lead author of the study. The skeletal muscle cells were not maturing properly, he explained. “We needed bigger, stronger muscle that also had the ability to contract.”

Once again, the team looked to the natural stages of human development for answers. Hicks discovered that a specific cell signaling pathway called TGF Beta needs to be turned off to enable generation of skeletal muscle fibers that contain the proteins that help muscles contract. Finally, the team tested their new method in a mouse model of Duchenne.

“Our long term goal is to develop a personalized cell replacement therapy using a patient’s own cells to treat boys with Duchenne,” said Hicks. “So, for this study we followed the same steps, from start to finish, that we’d follow when creating these cells for a human patient.”

First, the Duchenne patient cells were reprogrammed to become pluripotent stem cells. The researchers then removed the genetic mutation that causes Duchenne using the gene editing technology CRISPR-Cas9. Using the ERBB3 and NGFR surface markers, the skeletal muscle cells were isolated and then injected into mice at the same time a TGF Beta inhibitor was administered.

“The results were exactly what we’d hoped for,” said Pyle. “This is the first study to demonstrate that functional muscle cells can be created in a laboratory and restore dystrophin in animal models of Duchenne using the human development process as a guide.”

Further research will focus on generating skeletal muscle stem cells that can respond to continuous injury and regenerate new muscle long-term using the team’s new isolation and maturation strategy.

Researchers repurpose immune-activating cytokine to fight breast cancer

The most lethal form of breast cancer could have a new treatment option, according to new research out of the Case Comprehensive Cancer Center at Case Western Reserve University School of Medicine. In the Proceedings of the National Academy of Sciences, researchers showed triple-negative breast cancer cells are highly vulnerable to interferon-β–a potent antimicrobial that also activates the immune system. The new study shows interferon-β impairs breast cancer cells’ ability to migrate and form tumors. The study also suggests interferon-β treatment could improve outcomes for certain breast cancer patients.

“We demonstrate that interferon-β reverses some of the more aggressive features of triple-negative breast cancer, which are responsible for metastasis and therapy-failure,” said Mary Doherty, first author and pathology graduate student at Case Western Reserve School of Medicine. “Moreover, we found that evidence of interferon-β in triple-negative breast cancer tumors correlates with improved patient survival following chemotherapy.”

Doherty’s advisor, Mark Jackson, PhD, associate professor of pathology and associate director for training and education, Case Comprehensive Cancer Center at Case Western Reserve University School of Medicine, is senior author on the study. The study team also included researchers from Cleveland Clinic Lerner Research Institute, University Hospitals Cleveland Medical Center, Stanford University School of Medicine, and other members of the Case Comprehensive Cancer Center.

Triple-negative breast cancer is one of the deadliest, most aggressive forms of breast cancer. It spreads rapidly and is resistant to many available chemotherapies. Even when therapies appear successful, tumors often recur. Said Doherty, “While chemotherapy kills the majority of tumor cells, it fails to eliminate a sub-set of cancer cells, called cancer stem cells. The survival of these cancer stem cells following therapy is believed to be responsible for therapy failure in patients.”

The new study showed interferon-β directly targets cancer stem cells. In laboratory dishes, regular treatments of interferon-β kept triple-negative breast cancer stem cells from migrating–the first step in metastasis. Even two days after stopping treatment, dishes with interferon-β added had approximately half the number of migrating stem cells as controls. Cells exposed to interferon-β also lacked markers characteristic of early tumors and failed to aggregate into tumor-like spheres.

The researchers validated their laboratory findings using a breast cancer tissue database. They found elevated interferon-β levels in breast tissue correlated with extended patient survival and lower cancer recurrence rates. Patients with higher interferon-β levels in their breast tissue were approximately 25 percent less likely to experience a recurrence than those with low levels. The authors concluded that interferon-β plays a “positive, critical role” in triple-negative breast cancer outcomes.

The researchers are now studying how interferon-β may modulate the immune system to carry out its anti-cancer effects. They also plan to conduct clinical trials evaluating interferon-β as a new therapeutic option for triple-negative breast cancer, either alone or in combination with traditional chemotherapy. Such a study could require novel methods to deliver interferon-β to breast cancer tumors. Said Doherty, “Our future studies will examine improved methods of interferon-β delivery to the tumor site incorporating nanoparticle technology.” Together, the studies could expand treatment options for patients suffering from drug-resistant breast cancers.

Researchers show stress suppresses response to cancer treatments

New research shows that chronic stress suppresses the immune system’s response to cancer, reducing the effectiveness of immunotherapy treatments.

University of Queensland scientists say they are investigating dual therapies for patients to reduce stress signalling and improve their response to treatments.

UQ Diamantina Institute researcher Dr Stephen Mattarollo said lymphoma progressed more rapidly in mouse models when stress pathways were induced to reflect chronic psychological stress.

“When we used immunotherapies on these mice they were not able to respond as effectively as those which had not been stressed,” Dr Mattarollo said.

“This is because the stress led to poor function against the cancer by T-cells, which are very important in the immune system’s control and surveillance of tumours and are a major target in many immunotherapy treatments.”

Dr Mattarollo said increased anxiety was natural with a cancer diagnosis, and it should be managed to ensure the best possible outcome for patients.

“Absolutely there is now pre-clinical evidence to suggest that treatments and lifestyle interventions to manage or reduce stress levels will improve the chances of these patients responding to therapies,” he said.

“This applies particularly to immunotherapies, but many conventional therapies such as chemotherapy also rely on components of the immune system for their effectiveness.

“It is quite possible that by increasing the immune function in patients they will also respond better to some other therapies.”

PhD candidate Michael Nissen said as immunotherapies became more widely available, it was important to build on the knowledge of factors which influence their effectiveness.

“The more we know, the better chance we have of designing them effectively and efficiently to work in cancer patients,” Mr Nissen said.

Dr Mattarollo said the lab was hoping to combine immunotherapy treatments with commonly used blood pressure drugs that block the effects of stress hormones.

“We hope this will reduce the stress-induced neural signalling and improve immune function,” Dr Mattarollo said.

“We are about to test this combination in animal models.”

Dr Mattarollo said psychoneuroimmunology – or the interaction between the mind, the nervous system and the immune system – is a rapidly growing discipline and is becoming an increasing focus of the lab’s cancer research.

The research is published in Cancer Immunology Research.

Dr Mattarollo’s lab is located at the Translational Research Institute.

New strategy for multiple myeloma immunotherapy

In recent decades monoclonal antibody-based treatment of cancer has been established as one of the most successful therapeutic strategies for both solid tumors and blood cancers. Monoclonal antibodies (mAb), as the name implies, are antibodies that are made by clonal cells derived from a single parent cells and therefore share the identical amino acid sequences.

One of the leading technologies to emerge in mAb-based treatment is CAR-T, where CAR stands for “chimeric antigen receptor”, and T represents T cells, a type of white blood cells that have pivotal roles in immune defenses. CARs are produced by combining together the gene for an antibody that recognizes a tumor antigen with the gene for a receptor that resides on the surface of the T cells; insert this new gene into a T cell and it will be precisely targeted at the tumor.

Theoretically, new antigens – molecules capable of inducing an immune response to produce an antibody – that arise from cancer-specific mutations of cell-surface proteins are excellent targets. However, mAb therapy targeting such antigens is impractical because of these proteins’ vast diversity within and between individual tumors, which renders identifying new cancer-specific target antigens difficult.

However, such challenges have driven researchers centered at Japan’s Osaka University to think outside of the box; cancer-specific antigen formed by the modification of proteins during or after synthesis, such as glycosylation (attachment of sugar moieties to protein) or conformational changes, might have been missed in previous analyses. The team believed new antigen epitopes, which is the part of an antigen recognized by the immune cells, could be discovered by thoroughly searching for cancer-specific mAbs and characterizing the antigens they recognize.

“We applied this strategy to identify novel therapeutic targets for multiple myeloma (MM), a cancer that forms in a type of white blood cell called a plasma cell,” explains Naoki Hosen, lead author of the study, which was recently published in Nature Medicine. “Despite advances in MM treatment, relapse remains common. As such, there is an ongoing need for new therapeutic approaches, including mAb-based therapies.”

The team screened more than 10,000 anti-MM mAb clones and identified MMG49 as an MM-specific mAb specifically recognizing a subset of integrin β7, a cell-surface receptors that facilitate cell-extracellular matrix adhesion. MMG49 reacted to MM cells, but not other bone marrow cell types in MM patient samples. This prompted the researchers to design a CAR that incorporates a fragment derived from MMG49. The resulting MMG49 CAR T was found to have anti-MM effects without damaging normal blood cells.

“Our results also demonstrate that the active conformer of integrin β7 can serve as an immunotherapeutic target against MM, even though the expression of the protein itself is not specific to MM,” study coauthor Yukiko Matsunaga says. “Therefore it’s highly plausible that there are other cancer immunotherapeutic targets that have yet to be identified in many cell-surface proteins that undergo conformational changes, even if the expression of the proteins themselves is not cancer-specific.”

Promising new treatment for rare pregnancy cancer leads to remission in patients

Three out of four patients with the cancerous forms of gestational trophoblastic disease (GTD) went into remission after receiving the immunotherapy drug pembrolizumab in a clinical trial carried out by researchers at Imperial College London.

The trial, which took place at Charing Cross Hospital, part of Imperial College Healthcare NHS Trust, is the first to show that pembrolizumab can be used to successfully treat women with GTD.

The team hopes that this small early stage study, published in The Lancet, could provide another treatment option for women who have drug-resistant GTD and lead to a 100 per cent cure rate.

Professor Michael Seckl, lead author of the study, said:

“We have been able to show for the first time that immunotherapy may be used to cure patients of cancerous GTD. The current treatments to tackle GTD cure most cases of the disease. However, there are a small number of women whose cancers are resistant to conventional therapies and as a result have a fatal outcome. Immunotherapy may be a life-saving treatment and can be used as an alternative to the much more toxic high dose chemotherapy that is currently used. These are landmark findings that have implications on how we treat the disease in the UK and around the world.”

GTD is the term used to describe abnormal cells or tumors that start in the womb from cells that normally give rise to the placenta. They are extremely rare but can happen during or after pregnancy.

The most common type of GTD is so-called molar pregnancy where a foetus doesn’t form properly in the womb and a baby doesn’t develop, instead a lot of abnormal placental-like tissue forms. A molar pregnancy can usually be treated with a simple procedure to remove the growth of abnormal placental cells from the womb but some of this material is usually left behind. This can become cancerous and spread to other parts of the body, requiring lifesaving chemotherapy. In around one in 50,000 pregnancies cancerous GTD known as choriocarcinoma develops after other types of pregnancy including normal pregnancies and this also requires life-saving chemotherapy.

Globally, 18,000 women are diagnosed annually with cancerous forms of GTD, most of whom are cured with chemotherapy or surgery. However, up to five per cent of these women’s outcomes are fatal due to factors such as chemotherapy resistance and rare forms of the cancer such as placental site trophoblastic tumours (PSTT) that develop four or more years after the causative pregnancy has ended.

Immunotherapy is a type of treatment that helps a person’s immune system fight diseases such as a cancer. The immune system fights off invading infections but can miss cancer cells. Pembrolizumab works by stimulating the body’s immune system to target and kill cancer cells. The drug is also used to treat some cases of lung cancer and melanoma.

The researchers wanted to test whether pembrolizumab could be used to treat four patients aged between 37-47 years with multi-drug resistant cancerous GTD.

The patients were given pembrolizumab intravenously every three weeks over a period of about six months between 2015-2017.

The trial also took place at the Department of Women’s and Children’s Health in Stockholm.

The researchers then carried out a blood test to measure the amount of the pregnancy hormone hCG in their system, which is an indicator of whether abnormal placental cells are left in the womb or elsewhere in the body.

They found that most patients’ hCG levels started to fall by three doses and once their hCG was normal five consolidation doses of pembrolizumab were given before stopping treatment. This contrasts with melanoma and lung cancer where this drug is given to patients continuously for two or more years. The patients remain without signs of cancer recurrence for between five months to over two years on follow-up.

The researchers also found that pembrolizumab was well tolerated in GTD patients. This is in comparison to chemotherapy which can cause nausea, vomiting and hair loss.

The team suggests that this could have cost saving implications for the NHS as six months of the drug costs about £30,000 per patient compared to two rounds of high dose chemotherapy which costs £70,000.

Melody Ransome took part in the clinical trial after being diagnosed with choriocarcinoma, which had spread from her uterus to her liver, kidney, pancreas, lungs and brain. Melody was given the immunotherapy drug over five months in 2015. After her second infusion, Melody’s hCG levels dropped by 50 per cent and she was in remission two months later. Melody continues to be in remission two and half years after receiving the immunotherapy.

“Before the trial I was being treated by high dosage of chemotherapy which made me feel awful. I experienced hair loss, fatigue and it was difficult to carry out normal tasks like looking after my two children. On top of that, the chemotherapy wasn’t working.

This all changed for me once I was given the immunotherapy drug. Each week I felt better and better. I had no side effects and I started to feel more normal. When I was told that I was in remission I was shocked that the treatment had worked in such a short amount of time. It’s been life changing and I’ve been able to enjoy spending quality time with my family again. I used to be able to swim 40 lengths before my illness and since having the immunotherapy I am close to it. It’s been an incredible journey.”

Following the findings, NHS England has agreed provisional funding to treat some cases of GTD with pembrolizumab for two years at Charing Cross and Sheffield Hospitals where these cases are managed in the UK.

The researchers will carry out a further study to assess the effects of pembrolizumab on fertility to see whether it can be offered to women at an earlier stage of treatment.

Pairing Cancer Genomics with Cognitive Computing Highlights Potential Therapeutic Options

A University of North Carolina Lineberger Comprehensive Cancer Center-led study has demonstrated the ability of cognitive computing to scour large volumes of data from scientific studies and databases to identify potentially relevant clinical trials or therapeutic options for cancer patients based on the genetics of their tumors.

The researchers said their findings, published in the journal The Oncologist, suggest that cognitive computing applications could help physicians to stay abreast of an ever-expanding body of scientific literature as well as highlight potential therapeutic options, specifically as it relates to cancer genetics.

“Our findings, while preliminary, demonstrate that cognitive computing might have a role in identifying more therapeutic options for cancer patients,” said UNC Lineberger’s William Kim, MD, the study’s corresponding author and an associate professor of medicine and genetics in the UNC School of Medicine. “I can tell you that as a practicing oncologist, it’s very reassuring for patients to know that we’re able to explore all possible options for them in a very systematic manner.”

The study’s first authors were Nirali Patel, MD, formerly of UNC Lineberger, and Vanessa Michelini of IBM Watson Health, Boca Raton, Florida. IBM Corp. provided in-kind access to the Watson technology for the study, as well as technical expertise.

The researchers used IBM Watson for Genomics to assess whether cognitive computing was more effective than a panel of cancer experts in identifying therapeutic options for tumors with specific genetic abnormalities. They compared Watson’s ability to identify possible therapeutic options tied to potentially clinically significant genetic mutations with the findings of UNC Lineberger’s molecular tumor board.

In a retrospective analysis of 1,018 cancer cases, the molecular tumor board identified actionable genetic alterations in 703 cases, which Watson also confirmed. In addition, Watson for Genomics identified additional potential therapeutic options in 323 patients, or one third of the cases reviewed that the molecular tumor board hadn’t identified. Of these, 96 were not previously identified as having an actionable mutation.

“To be clear, the additional 323 cases of Watson-identified actionable alterations consisted of only eight genes that had not been considered actionable by the molecular tumor board,” Kim said. In most of those cases, Watson identified a new clinical trial. One of those trials had opened within a week of Watson’s analysis.

The study drew on data from UNCseq, a UNC Lineberger clinical trial that used next-generation sequencing to analyze the genomics of a participant’s tumor with the goal of matching tumor abnormalities with a targeted therapeutic. Next-generation sequencing is “fundamental” to the promise of precision medicine, the researchers reported, but sequencing can uncover many different alterations in hundreds of genes, and the “majority of such events have no known relevance to the treatment of patients with cancers.”

“The major finding is that cognitive computing augmented the molecular tumor board process for the interpretation and collection of information regarding a patient’s genomic profile,” Kim said. “The study was not designed to analyze whether or not this helps patients in regard to outcome as defined by prolonged survival or treatment response.”

The program did identify new possible options for some patients. The findings were not relevant to most patients because the majority of the patients did not have active cancer, or had died by the time of the retrospective analysis. But for 47 patients with active disease, and needing additional options, the findings were reported to their treating physicians.

“To my knowledge, this is the first published examination of the utility of cognitive computing in precision cancer care,” Kim said. “I’m optimistic that as we get more sequencing data, well-annotated treatment information, as well as therapy response, tools like Watson for Genomics will begin to show their true promise. But, of course, we still need to formally answer these questions.”

Finding a Key to Unlock Blocked Differentiation in Microrna-Deficient Embryonic Stem Cells

This aids goal to use stem cells in therapy, where an important hurdle is efficient differentiation.

The more than 200 different types of human cells have the same DNA but express different ensembles of genes. Each cell type was derived from embryonic stem cells, which are called pluripotent stem cells because they can differentiate to all those different cell fates.

One very active area of biology is cells that mimic these fountainhead embryonic stem cells, cells that are called induced pluripotent stem cells, or iPSCs. With genetic and biochemical tricks, researchers can reverse a differentiated cell — such as a skin fibroblast — into a pluripotent state.

Such iPSCs have the potential to create tissue for regenerative medicine, such as repair heart attacks, create models of human disease or make cells that enable drug screening. But future progress with iPSCs needs a much greater understanding of the basic biology of pluripotency and differentiation.

“For the goal of using stem cells in therapy, the most important step is differentiation from iPSCs,” said Rui Zhao, Ph.D., an assistant professor of biochemistry and molecular genetics at the University of Alabama at Birmingham. “We need to be able to differentiate the iPSCs into a disease-relevant cell type at high efficiency and high purity.”

In a study published in Stem Cell Reports, Zhao and colleagues have partly solved a long-unanswered basic question about stem cells — why are pluripotent stem cells that have mutations to block the production of microRNAs unable to differentiate?

Zhao and colleagues, including co-corresponding author Kitai Kim, Ph.D., of the Sloan Kettering Institute, have found a key that allows those microRNA-deficient pluripotent stem cells to differentiate into neural cells, including subtypes with markers for dopaminergic, glutamatergic and GABAergic neurons

“For many years, we did not know why these cells did not differentiate,” Zhao said. The answer for neural cell differentiation in the microRNA-deficient cells turned out to be simple — a single microRNA or a single protein.

In the Stem Cell Reports study, Zhao and colleagues show that a microRNA-302 mimic — delivered by a specially constructed lentivirus — was sufficient to enable neural differentiation of mouse embryonic stem cells that lacked Dgcr8, a vital gene for the processing of the more than 2,000 microRNAs in cells.

When they examined gene expression profiles in the differentiated cells, they saw changes in many gene sets regulated by p53, also known as tumor suppressor p53. This tumor suppressor has been called “the guardian of the genome” because of its many roles in preventing DNA damage and cancer.

Zhao, Kim and colleagues showed that microRNA-302 acted to reduce p53 expression in the microRNA-deficient embryonic stem cells by binding to the 3′ untranslated region of p53 mRNA.

They further showed that direct inhibition of p53 with the simian virus large T antigen or short hairpin RNA, or even deleting the p53 gene itself, allowed embryonic stem cells or iPSCs to proceed to neural differentiation without the need for microRNA-302. Thus, the differentiation barrier that prevents the neuronal lineage specification from microRNA-deficient stem cells is expression of p53.

The keys to unlock the paths cells to other cell lineage specifications from microRNA-deficient embryonic stem are still unknown, Zhao says.

Scientists make a major breakthrough to treat fibrotic diseases that cause organ failure

Researchers from Duke-NUS Medical School (Duke-NUS) and the National Heart Centre Singapore (NHCS) have discovered that a critical protein, known as interleukin 11 (IL11) is responsible for fibrosis and causes organ damage. While it is surprising that the importance of IL11 has been overlooked and misunderstood for so long, it has now been very clearly demonstrated by this work.

A protein known as transforming growth factor beta 12 (“TGFB1”) has long been known as the major cause of fibrosis and scarring of body organs, but treatments based on switching off the protein have severe side effects. The scientists discovered that IL11, is even more important than TGFB1 for fibrosis and that IL11 is a much better drug target than TGFB1.

Fibrosis is the formation of excessive connective tissue, causing scarring and failure of bodily organs and the skin. It is a very common cause of cardiovascular and renal disease, where excessive connective tissue destroys the structure and function of the organ with scar tissue. Compared to other Asians, American, and Europeans, Singaporeans have a higher prevalence of coronary artery disease, hypertension, and diabetes, the three most common diseases that lead to heart failure. In addition, kidney failure is an epidemic in Singapore and around the world. Fibrosis of the heart and kidney eventually leads to heart and kidney failure, thus this breakthrough discovery — that inhibiting IL11 can prevent heart and kidney fibrosis — has the potential to transform the treatment of millions of people around the world.

The international team, led by Professor Stuart Cook, Tanoto Foundation Professor of Cardiovascular Medicine, along with Assistant Professor Sebastian Schäfer, both from NHCS and Duke-NUS’ Programme in Cardiovascular and Metabolic Disorders, carried out the translational research to identify the key drivers of chronic fibrotic disease in heart, kidney, and other tissues. The team also includes researchers from Harvard University and University of California, San Diego/UCSD (USA), Max Delbrück Center for Molecular Medicine/MDC-Berlin (Germany), London Institute of Medical Sciences/MRC-LMS and Imperial College London (the UK), and the University of Melbourne (Australia).

“Fibrotic diseases represent a major cause of illness and death around the world. The discovery that IL11 is a critical fibrotic factor represents a breakthrough for the field and for drug development. It is an incredibly exciting discovery,” explained the study’s senior author, Professor Cook, who is also Director, National Heart Research Institute Singapore.

“Currently, more than 225 million people worldwide suffer from heart and kidney failure and there is no treatment to prevent fibrosis. The team is at the stage of developing first-in-class therapies to inhibit IL11 and this offers hope to patients with heart and kidney disease,” shared Professor Terrance Chua, Medical Director, National Heart Centre Singapore.

“This therapeutic target for fibrotic diseases of the heart, kidney and other organs may be exactly what we need to fill the unmet pressing clinical gap for preventing fibrosis in patients. We are proud to announce that the suite of intellectual property arising from this research has been licensed to a newly launched Singapore-funded biotechnology start-up Enleofen Bio Pte Ltd, which is co-founded by Professor Cook and Assistant Professor Schäfer,” said Professor Thomas Coffman, Dean of Duke-NUS Medical School.

No cardiovascular disease reduction with intensive blood pressure lowering treatment

Blood pressure lowering treatment does not reduce death or cardiovascular disease in healthy individuals with a systolic blood pressure below 140. This is shown in a systematic review and meta-analysis from Umeå University. The results, published in JAMA Internal Medicine, support current guidelines and contradict the findings from the Systolic Blood Pressure Intervention Trial (SPRINT).

Blood pressure treatment goals have been intensively debated since the publication of the SPRINT study in 2015. While current guidelines recommend a systolic blood pressure goal < 140 mm Hg, SPRINT found additional mortality and cardiovascular disease reduction with a goal < 120 mm Hg.

A systematic review and meta-analysis from Umeå University, published today in JAMA Internal Medicine, contradicts these findings. The Umeå study shows that treatment does not affect mortality or cardiovascular events if systolic blood pressure is < 140 mm Hg. The beneficial effect of treatment at low blood pressure levels is limited to trials in people with coronary heart disease.

“Our findings are of great importance to the debate concerning blood pressure treatment goals,” says Dr Mattias Brunström, researcher at the Department of Public Health and Clinical Medicine, Umeå University and lead author.

The study is a meta-analysis, combining data from 74 randomized clinical trials, including more than 300 000 patients. The researchers separated primary preventive studies from studies in people with coronary heart disease or previous stroke. The analysis found that the treatment effect was dependent on how high blood pressure was in previously healthy individuals. If systolic blood pressure was above 140 mm Hg, treatment reduced the risk of death and cardiovascular disease. Below 140 mm Hg, treatment did not affect mortality or the risk of first-ever cardiovascular events.

“Several previous meta-analyses have found that blood pressure lowering treatment is beneficial down to levels below 130 mm Hg. We show that the beneficial effect of treatment at low blood pressure levels is limited to trials in people with coronary heart disease. In primary preventive trials, treatment effect was neutral,” says Mattias Brunström.

Over the Counter Pain Medication as Effective as Opioids in ER Patients-Study

Emergency rooms are where many patients are first introduced to powerful opioid painkillers, but what if doctors offered over-the-counter pills instead? A new study tested that approach on patients with broken bones and sprains and found pain relievers sold as Tylenol and Motrin worked as well as opioids at reducing severe pain.

The results challenge common ER practice for treating short-term, severe pain and could prompt changes that would help prevent new patients from becoming addicted.

The study has limitations: It only looked at short-term pain relief in the emergency room and researchers didn’t evaluate how patients managed their pain after leaving the hospital.

But given the scope of the U.S. opioid epidemic — more than 2 million Americans are addicted to opioid painkillers or heroin — experts say any dent in the problem could be meaningful.

Results were published Tuesday in the Journal of the American Medical Association.

Long-term opioid use often begins with a prescription painkiller for short-term pain, and use of these drugs in the ER has risen in recent years. Previous studies have shown opioids were prescribed in nearly one-third of ER visits and about 1 out of 5 ER patients are sent home with opioid prescriptions.

“Preventing new patients from becoming addicted to opioids may have a greater effect on the opioid epidemic than providing sustained treatment to patients already addicted,” Dr. Demetrios Kyriacou, an emergency medicine specialist at Northwestern University, wrote in an accompanying editorial.

The study involved 411 adults treated in two emergency rooms at Montefiore Medical Center in New York City. Their injuries included leg and arm fractures or sprains. All were given acetaminophen, the main ingredient in Tylenol, plus either ibuprofen, the main ingredient in Motrin, or one of three opioids: oxycodone, hydrocodone or codeine. They were given standard doses and were not told which drug combo they received.

Patients rated their pain levels before taking the medicine and two hours later. On average, pain scores dropped from almost 9 on a 10-point scale to about 5, with negligible differences between the groups.

Ibuprofen and acetaminophen affect different pain receptors in the body so using the two drugs together may be especially potent, said Dr. Andrew Chang, an emergency medicine professor at Albany Medical College in upstate New York, who led the study.

He noted that a pill combining ibuprofen and acetaminophen is available in other countries; his findings echo research from Canada and Australia testing that pill against opioids for pain relief.

For cancer patients with HIV, immunotherapy appears safe

A new category of immunotherapies called checkpoint inhibitors that has been highly effective against many different cancers appears safe to use in patients with both advanced malignancies and HIV, a population excluded from earlier trials of such therapies, according to an early-phase trial.

Study Principal Investigator, Dr. Thomas Uldrick of the HIV & AIDS Malignancy Branch at the National Cancer Institute, will present late breaking results from the first 17 patients on a phase I study of pembrolizumab in patients with HIV and advanced cancers Friday at the Society for Immunotherapy of Cancer’s annual meeting in National Harbor, Maryland. The ongoing, multi-site study is being conducted by the NCI-funded Cancer Immunotherapy Trials Network, which is headquartered at Fred Hutchinson Cancer Research Center.

Cancer has become the leading cause of death for people with HIV. But until now, they and their physicians have had little data to guide them on whether they can safely use powerful new anti-cancer drugs called immune checkpoint inhibitors.

“During the development of these drugs, people with HIV were routinely excluded from studies due to concerns that they would not tolerate these medications or perhaps not benefit from them because of their underlying HIV and associated immune dysfunction,” Uldrick said. “The most important first step was to show that this class of drug would be safe in cancer patients with HIV.”

Study participants — who were on standard antiretroviral therapy to control their HIV infections and had various cancers that had failed to respond to standard therapies — received pembrolizumab (Keytruda), known since 2015 as “the Jimmy Carter drug” after it swiftly beat back melanoma that had spread to the former president’s brain and liver.

Pembrolizumab belongs to a type of immunotherapy that blocks a braking system cancers use to tamp down the immune response. Checkpoint inhibitors have been extremely effective in some patients with advanced cancers otherwise thought untreatable. The treatments have received U.S. Food and Drug Administration approval for melanoma, lung cancer, head and neck cancer, Hodgkin’s lymphoma, and kidney and bladder cancers.

“These drugs are the backbone of cancer immunotherapy at present and have been shown to be effective in subsets of virtually every different kind of cancer,” said Fred Hutch immunotherapy researcher Dr. Martin “Mac” Cheever, who leads the Cancer Immunotherapy Trials Network and is senior author of the new study. “For patients with HIV who are using effective antiretroviral therapy and have cancers for which these drugs are approved, there’s no reason not to consider these drugs as standard therapy.”

HIV and cancer

From the earliest days of the AIDS pandemic, Kaposi sarcoma — a rarely seen cancer until then — was one of a trio of cancers known as AIDS-defining malignancies. It, non-Hodgkin lymphoma and, in women, cervical cancer, often signaled that a person’s HIV infection had progressed to full-blown AIDS. People did not die of AIDS, per se. They died of one of these cancers or of infections like pneumocystis pneumonia and toxoplasmosis that took advantage of a weakened immune system.

Since the advent of antiretroviral therapy for HIV in 1996, full-blown AIDS and AIDS deaths have dropped dramatically. But the association between HIV and cancer remains, and not just with the traditional AIDS-defining malignancies. A large study published in the journal Annals of Internal Medicine in 2015 found higher cancer incidence across the board in HIV patients, including lung cancer and Hodgkin lymphoma.

“Globally, more than 35 million people are infected with HIV, and cancer is the number one reason they are dying,” Uldrick said. “Establishing proven effective regimens to manage cancer in people with HIV is critically important.”

The ongoing study will enroll up to 36 patients, and there are plans to include more patients with Kaposi sarcoma, a cancer for which checkpoint inhibitors have not been studied. It is one of the leading causes of cancer deaths in sub-Saharan Africa — where HIV rates are high — and new treatments are sorely needed.

Further study in Kaposi sarcoma

Kaposi sarcoma is caused by the Kaposi sarcoma herpes virus (also known as human herpesvirus 8, or HHV-8) and most commonly appears as lesions on the skin. KSHV can also cause two other B-cell tumors, primary effusion lymphoma and a form of multicentric Castleman disease. Additionally, it can infect blood cells and spread through the bloodstream to infect other cells in the body, Uldrick said.

Also to be presented Friday is the death of one patient later in the study who had Kaposi sarcoma. The death is still being evaluated but was likely due to dissemination of KSHV. Uldrick and Cheever said review of the case suggests the patient had a history of symptomatic KSHV viremia, and the study has been changed to exclude such patients in the future and provide specific guidelines for management should new symptomatic KSHV viremia be observed.

Six other study participants with Kaposi sarcoma or primary effusion lymphoma have been treated on this study. None has experienced similar problems, and some have benefitted from therapy, Uldrick said.

“We do not believe that this takes away from the safety message in patients with HIV and other, better studied cancers,” Uldrick said. “However, more experience is clearly needed in treating KSHV-associated diseases with checkpoint inhibitors.”

A passion to ‘change the culture’

Although the NCI has recommended including people with HIV in immunotherapy clinical trials for a decade, virtually every industry-sponsored study over the last five years excluded them, according to a review by Uldrick and others published in the Journal of Clinical Oncology. Uldrick believes that reluctance to include people with HIV in cancer immunotherapy studies dates back to a time when patients were still dying of opportunistic infections and antiretroviral therapies were more toxic than they are today.

As a physician-scientist who focuses on immunology, virology and cancer, Uldrick became frustrated with the lack of data.

“The culture was slow to change,” he said. “It was preventing the advance of appropriate clinical therapies.”

Dr. Holbrook Kohrt, a Stanford oncologist and researcher, shared that frustration. Kohrt instigated the current clinical trial, according to Cheever, driven by his boyhood experience being one of only two hemophiliacs in a special summer camp who did not die of AIDS. (The genetic disorder impairs the blood’s clotting ability and requires infusions of lifesaving clotting factor, which at that time was made from the pooled blood of tens of thousands of donors. Before a test was developed to detect HIV in blood, about half the hemophiliacs in the United States died of AIDS from infected clotting factor.)

“Holbrook had three patients early on with malignancies that he thought would benefit from [checkpoint inhibitors] and could not get access to the drug because they had HIV,” Cheever said. “He was passionate about this study because he was a passionate individual and physician. But he was also influenced by his experience as someone with hemophilia who lost so many peers to HIV.”

Kohrt died in 2016 from complications of hemophilia. He is named as an author of the study.

“He would have predicted these results,” Cheever said.

Getting out the message

The ongoing study is now being conducted at eight sites, each of which includes physician-researchers with expertise in both cancer and HIV. A majority of the early patients were enrolled on the trial through Uldrick’s group at the NCI Intramural Research Program in Bethesda, Maryland.

Uldrick will continue to lead the study after he leaves the NCI to become deputy head of Fred Hutch Global Oncology on Dec. 1.

He and Cheever are hoping that these early results lead to additional studies of checkpoint inhibitors in people with HIV and malignancies, especially those cancers that are more prevalent in people with HIV such as Kaposi sarcoma and cancers caused by another virus, human papillomavirus, such as cervical cancer.

In the meantime, the researchers intend to talk about their findings at multiple scientific communities so that people with HIV and their physicians become aware of the data.

“We’d recommend that patients with HIV and malignancy be considered for this therapy if it’s approved for their particular cancer,” Uldrick said.

Immune Cells Mistake Heart Attacks for Viral Infections

A study led by Kevin King, a bioengineer and physician at the University of California San Diego, has found that the immune system plays a surprising role in the aftermath of heart attacks.  The research could lead to new therapeutic strategies for heart disease.

The team, which also includes researchers from the Center for Systems Biology at Massachusetts General Hospital (MGH), Brigham and Women’s Hospital, Harvard Medical School, and the University of Massachusetts, presents the findings in the Nov. 6 issue of Nature Medicine.

Ischemic heart disease is the most common cause of death in the world and it begins with a heart attack. During this process, heart cells die, prompting immune cells to enter the dead tissue, clear debris and orchestrate stabilization of the heart wall.

But what is it about dying cells in the heart that stimulates the immune system? To answer this, researchers looked deep inside thousands of individual cardiac immune cells and mapped their individual transcriptomes using a method called single cell RNA-Seq. This led to the discovery that after a heart attack, DNA from dying cells masquerades as a virus and activates an ancient antiviral program called the type I interferon response in specialized immune cells. The researchers named these “interferon inducible cells (IFNICs).”

When investigators blocked the interferon response, either genetically or with a neutralizing antibody given after the heart attack, there was less inflammation, less heart dysfunction, and improved survival. Specifically, blocking antiviral responses in mice improved survival from 60 percent to over 95 percent. These findings reveal a new potential therapeutic opportunity to prevent heart attacks from progressing to heart failure in patients.

“We are interested to learn whether interferons contribute to adverse cardiovascular outcomes after heart attacks in humans,” said King, who did most of the work on the study while he was a cardiology fellow at Brigham and Women’s Hospital and at the Center for Systems Biology at MGH in Boston.

The immune system has evolved innate antiviral programs to defend against a diverse range of invading pathogens. Immune cells do this by detecting molecular fingerprints of pathogens, activating a protein called IRF3, and secreting interferons, which orchestrate a defense program mediated by hundreds of interferon-stimulated genes. Investigators found that surprisingly, the antiviral interferon response is also turned on after a heart attack despite the absence of any infection. Their results point to dying cell DNA as the cause of this confusion because the immune system interprets it as the molecular signature of a virus.

Surprisingly, the immune cells participating in the interferon response were a previously unrecognized subset of cardiac macrophages. These cells could not be identified by conventional flow sorting because unique markers on the cell surface were not known. By using single cell RNA Seq, an emerging technique that combines microfluidic nanoliter droplet reactors with single cell barcoding and next generation sequencing, the researchers were able to examine expression of every gene in over 4,000 cardiac immune cells and found the specialized IFNIC population of responsible cells.

Future studies will aim to better understand the interferon response and the IFNIC cell type and explore their roles in the infarcted and remodeling heart. The team is also working to understand the interferon response in other tissues and diseases where cell death occurs.

Trained T-Cells to Target Toxic Viruses in Pediatric Patients New Cellular Therapy Approach for Children with Compromised Immune Systems

Michael Pulsipher, MD, of the Children’s Center for Cancer and Blood Diseases at Children’s Hospital Los Angeles, along with Michael Keller, MD from Children’s National Health System in Washington, DC, have been awarded $4.8 million by the California Institute for Regenerative Medicine (CIRM) to study the use of a new T-cell therapy to help fight active viral infections in children with severe immune deficiencies. In what will be the largest multi-center pediatric clinical trial of this kind to date, investigators will test the feasibility of using “viral specific” T-cells that are engineered to target three common and potentially toxic viruses: Epstein-Bar virus (EBV), cytomegalovirus (CMV) and adenovirus.

In healthy individuals infections with EBV, CMV and adenovirus cause fatigue, sore muscles, sore throat and swollen glands, but after a short period they recover. For children with weakened immune systems, however, infection with these viruses can lead to severe organ damage or death.

“When patients have severe inherited immune deficiencies or are intensely immune suppressed after a bone marrow transplant, standard antiviral medications are sometimes not enough and patients can die from common viral infections,” explained Pulsipher. “Patients often need at least some function of their own immune systems in addition to antiviral medications in order to clear these infections, but sometimes the patient’s own T-cells are not up to the task.”

Previous studies have demonstrated success in restoring immunity against a particular virus by using donor T-cells that are engineered to target a specific virus for therapy following BMT.

For the new clinical trial, Pulsipher, Keller and their collaborators will use T-cells from healthy donors that have been trained and expanded to target the viruses, then preserved in a donor “bank” for use in the trial. The cells are then individually matched to specific patients based upon their genetic make-up and the viral infection they are experiencing, and shipped to individual centers for infusion. After infusion, the virus-specific targeted T-cells can not only control the active infection, but can help prevent other infections.

“It is our hope that with these trained T-cells, we can help the most vulnerable patients fight off life-threatening viral infections,” said Keller. “By offering a ‘donor’ bank, we are significantly expanding the reach of this therapy and increasing access to even more children, which is extremely exciting.”

“Our study design is to use a multi-virus T-cell therapy to reconstitute immunity against all three of these viruses,” said Pulsipher. “Restoring immunity against multiple viruses simultaneously provides patients with protection from severe viral infections and reduces the need for continued prophylaxis with pharmacotherapy drugs after transplant which can have adverse effects.”

The study, which is expected to include up to 30 centers, will be run through the Pediatric Blood and Marrow Transplant Consortium (PBMTC) Operations Center at CHLA and was developed and is being performed in collaboration with the Primary Immune Deficiency Treatment Consortium (PIDTC). Cell manufacturing for use in the clinical trial will be conducted by the Program for Cell Enhancement and Technologies for Immunotherapy (CETI) of the Children’s National Health System.

FDA Announces First Approval of Targeted Therapy Based on Basket Study

Precision medicine clinical trial leads to approval of first treatment for Erdheim-Chester disease

The US Food and Drug Administration (FDA) has announced that it has approved the drug vemurafenib for the treatment of patients with BRAF V600-mutant Erdheim-Chester disease (ECD). This is the first approval of a targeted therapy based on a basket study and the first-ever drug approved for ECD, a rare blood disorder.

This landmark approval came as a direct result of research at Memorial Sloan Kettering Cancer Center (MSK). MSK researchers, led by Physician-in-Chief José Baselga, MD, PhD, pioneered the concept of a basket study, which harnesses the power of precision medicine by assigning treatments to patients based on the genetic alterations driving their cancers rather than where their tumors originated in the body. This approval is based off of the data of 22 ECD patients enrolled in the phase II VE-BASKET study. 

ECD is one of an extremely rare form of blood cancers known collectively as histiocytoses that can lead to life-threatening complications, including damage to the heart, lungs, and kidneys. It’s estimated that there are fewer than 300 cases of ECD in the United States. More than 50 percent of people with ECD have BRAF V600-mutant disease, indicating that they would benefit from this drug. Previous treatments for ECD have included off-label use of chemotherapy, radiation, steroids, and the immunotherapy drug interferon, but all of these have limited efficacy based on anecdotal reports and potentially severe side effects.

Based on the work of MSK medical oncologist Paul Chapman, MD, vemurafenib was previously approved for the treatment of advanced melanoma that carries the BRAF V600E mutation. Dr. Chapman led the phase III trial for vemurafenib that led to the drug’s approval for that disease in 2011. In August 2017, vemurafenib was granted FDA Priority Review and Breakthrough Therapy Designation for the treatment of BRAF V600-mutant ECD.

About the Study

This approval is based on data from the phase II VE-BASKET study, a nonrandomized, histology-independent evaluation of the efficacy of vemurafenib, an inhibitor of BRAF V600 kinase, in non-melanoma cancers, including ECD. This first-in-kind study enrolled participants across multiple diseases, based predominantly on genetic profile rather than where the cancer originated. Initial study results were published in the New England Journal of Medicine in August 2015.

Final results for the 22 people with ECD showed a best overall response rate of 54.4 percent by RECIST v1.1. Importantly, responses and disease control were extremely durable. The median duration of response was not estimable at a median follow-up time of 26.6 months. At two years, 83 percent of patients remained progression free. The safety of vemurafenib in ECD patients was similar to that previously reported in patients with melanoma. The most common adverse events were joint pain, rash, hair loss, fatigue, change in heart rhythm and skin tags. 

Precision Medicine at MSK

Experts at MSK have taken the lead in developing clinical trials for a number of promising treatments that are based on tumors’ mutational profiles. Since August 2015, when MSK experts published initial results of the first basket study, histology-agnostic clinical trials have emerged as one important means of systematically testing a targeted therapy across a variety of tumor types. This innovative clinical trial design helps collect data faster and may accelerate the development of medicines for diseases with high unmet need. Basket studies can include many more people than disease-specific trials, allowing researchers to evaluate multiple diseases simultaneously. This is particularly important for diseases such as ECD that are extremely rare, making it difficult to fully enroll a disease or tumor-specific trial.

MSK leadership saw the promise of precision oncology early on and committed to realizing its ability to create better treatment options for all people with cancer. In 2014, the Marie-Josée and Henry R. Kravis Center for Molecular Oncology (CMO) was established to improve cancer care and research through genomic analysis and MSK-IMPACT™ (Integrated Mutation Profiling of Actionable Cancer Targets) was launched. This powerful diagnostic test provides detailed genetic information about a patient’s cancer that can guide treatment and identify clinical trial opportunities. To date, more than 20,000 MSK patients with advanced cancer have had their tumors sequenced through MSK-IMPACT. Most recently, Dr. Baselga and colleagues published a roadmap to precision oncology in the form of a seminal review paper in Cell.  

Breast cancer researchers track changes in normal mammary duct cells leading to disease

Breast cancer researchers have mapped early genetic alterations in normal-looking cells at various distances from primary tumours to show how changes along the lining of mammary ducts can lead to disease.

The findings of the multidisciplinary team of surgeons, pathologists and scientists led by principal investigator Dr. Susan Done are published online today in Nature Communications. Dr. Done, a pathologist affiliated with The Campbell Family Institute for Breast Cancer Research at Princess Margaret Cancer Centre, University Health Network, is also an associate professor in the Department of Laboratory Medicine and Pathobiology, University of Toronto.

“We have found another piece in the cancer puzzle – knowledge that could one day be used for more precision in screening and breast cancer prevention, and also help with therapeutic approaches to block some of the earliest alterations before cancer develops and starts to spread.”

Lead author Moustafa Abdalla writes: “Almost all genomic studies of breast cancer have focused on well-established tumours because it is technically challenging to study the earliest mutational events occurring in human breast epithelial cells.” Instead, this study found a way to identify early changes that preceded the tumour, enabling better understanding of cancer biology and disease development.

“Normal breast epithelium from the duct giving rise to a breast cancer has not been previously studied in this way.”

Dr. Done explains: “Most breast cancer starts in the epithelial cells lining the mammary ducts. But the breast ducts are complex structures, like the branches of a tree. Guesstimating which duct is close to the tumour is not very accurate. Thanks to our surgeons, we were able to obtain samples along normal-looking ducts close to the nipple and close to the tumour, as well as samples on the opposite side of the same breast to study and compare.”

In the operating room, surgeons inserted a fibre-optic scope through the nipple into the ducts below, and then injected dye into cancerous breasts being removed. This ductoscopy technique enabled the pathologists to identify the exact duct leading to the tumour and subsequently classify genetic alterations either increasing or decreasing as they moved nearer to the cancer.

“Cancer is not a switch that happens overnight. Once a patient notices a lump the tumour has been present for some time accumulating genetic changes. It is difficult at that point to identify the first changes that may have had a role in initiating or starting the cancer,” says Dr. Done.

The research further identified genes that seem to be acting together in groups or pathways. “Some of these genes were either increased or decreased in the area of the tumour, no matter the type of breast cancer, and this is important because within the patterns we identified were predictable alterations. This meant we could determine from the sample where it came from in the breast,” says Dr. Done.

“Our research demonstrated and supports earlier research from elsewhere that changes in cells occur before you can see them. The fact that changes are already present in different regions of the breast could be important in the delivery of radiation therapy or surgical margin assessment. We’re a long way from bringing this into clinic, but it is something we will think about as we continue our research.”

New molecule shows promise in HIV vaccine design

Researchers at the University of Maryland and Duke University have designed a novel protein-sugar vaccine candidate that, in an animal model, stimulated an immune response against sugars that form a protective shield around HIV. The molecule could one day become part of a successful HIV vaccine.

“An obstacle to creating an effective HIV vaccine is the difficulty of getting the immune system to generate antibodies against the sugar shield of multiple HIV strains,” said Lai-Xi Wang, a professor of chemistry and biochemistry at UMD. “Our method addresses this problem by designing a vaccine component that mimics a protein-sugar part of this shield.”

Wang and collaborators designed a vaccine candidate using an HIV protein fragment linked to a sugar group. When injected into rabbits, the vaccine candidate stimulated antibody responses against the sugar shield in four different HIV strains. The results were published in the journal Cell Chemical Biology on October 26, 2017.

The protein fragment of the vaccine candidate comes from gp120, a protein that covers HIV like a protective envelope. A sugar shield covers the gp120 envelope, bolstering HIV’s defenses. The rare HIV-infected individuals who can keep the virus at bay without medication typically have antibodies that attack gp120.

Researchers have tried to create an HIV vaccine targeting gp120, but had little success for two reasons. First, the sugar shield on HIV resembles sugars found in the human body and therefore does not stimulate a strong immune response. Second, more than 60 strains of HIV exist and the virus mutates frequently. As a result, antibodies against gp120 from one HIV strain will not protect against other strains or a mutant strain.

To overcome these challenges, Wang and his collaborators focused on a small fragment of gp120 protein that is common among HIV strains. The researchers used a synthetic chemistry method they previously developed to combine the gp120 fragment with a sugar molecule, also shared among HIV strains, to mimic the sugar shield on the HIV envelope.

Next, the researchers injected the protein-sugar vaccine candidate into rabbits and found that the rabbits’ immune systems produced antibodies that physically bound to gp120 found in four dominant strains of HIV in circulation today. Injecting rabbits with a vaccine candidate that contained the protein fragment without the sugar group resulted in antibodies that primarily bound to gp120 from only one HIV strain.

“This result was significant because producing antibodies that directly target the defensive sugar shield is an important step in developing immunity against the target and therefore the first step in developing a truly effective vaccine,” Wang said.

Although the rabbits’ antibodies bound to gp120, they did not prevent live HIV from infecting cells. This result did not surprise Wang, who noted that it usually takes humans up to two years to build immunity against HIV and the animal study only lasted two months.

“We have not hit a home run yet,” Wang noted. “But the ability of the vaccine candidate to raise substantial antibodies against the sugar shield in only two months is encouraging; other studies took up to four years to achieve similar results. This means that our molecule is a relatively strong inducer of the immune response.”

The researchers’ next steps will be to conduct longer-term studies in combination with other vaccine candidates, hone in on what areas of gp120 the antibodies are binding to and determine how they can increase the antibodies’ effectiveness at neutralizing HIV.

Cancer trial led by University of Minnesota Medical School’s Dr. Clark Chen shows promise

New data from a Phase I clinical trial led by Clark Chen, M.D., Ph.D., Lyle French Chair in Neurosurgery and Head of the University of Minnesota Medical School Department of Neurosurgery shows more than a quarter of patients with recurrent high-grade glioma, a form of brain cancer, were alive more than three years after treatment.

“Given the deadly nature of this disease, three-year survival is rarely reported in the recurrent setting. It is notable that the survival benefit was seen across a range of patients and not just limited to patients with specific genetic mutations,” said Chen. “This finding indicates that many patients could benefit from this treatment.”

As Chen explained at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics two steps were involved in the treatment of the 56 patients who participated in this clinical trial. First, patients were injected with Toca 511, which is a replicating virus that only infects actively dividing tumor cells. Once inside the cancer cell, the virus delivered a gene for an enzyme, cytosine deaminase (CD). As the virus began to replicate and spread to other cancer cells, it programmed them to make CD. Next, patients received a pill, Toca FC, which is an inert compound. Once inside the cancer cell, CD converted Toca FC into the anticancer drug 5-fluorouracil, which killed the cancer cell. In addition to destroying the cancer cells, 5-fluorouracil killed certain immune suppressive myeloid cells, thus boosting the patient’s immune system to recognize and attack the cancer cells.

“The treatment we tested in this trial delivers local chemotherapy specifically to the brain tumor. Toca 511 and Toca FC work together to turn the brain tumor into a factory that produces an anticancer drug while also activating the immune system through a combination of mechanisms, which together work to attack the cancer,” Chen said.

Dr. Chen also noted that five patients are experiencing a durable complete response with a median of at least 35.7 months. Within a subgroup of 23 patients, there were an additional five patients who achieved stable disease, bringing the number of patients who derived benefit from Toca 511 to 10 (or 43.4 percent of the patients who underwent Toca 511 therapy).

According to Chen, the median survival in this trial is nearly double that of historical data. In the subgroup, median survival was 14.4 months, compared to approximately eight months for historical controls.

“Brain cancer is one of the deadliest cancers, giving urgency to finding an effective treatment,” Chen said. “The 160,000 people diagnosed with high-grade gliomas worldwide each year–and high-profile cases including U.S. Senator John McCain, Senator Edward Kennedy, and Beau Biden–demonstrate the high unmet need of this disease. The data generated in the Toca 511 research provides hope for patients with brain cancer and their families.”

This study was a single arm trial without a control group which acted as a limitation. “The ongoing randomized phase II/III trial will be important to confirm the promising safety and efficacy results reported in this Phase I study,” Chen noted.

Public-Private Consortium Aims to Cut Preclinical Cancer Drug Discovery from Six Years to Just One

Scientists from two U.S. national laboratories, industry and academia today launched an unprecedented effort to transform the way cancer drugs are discovered by creating an open and sharable platform that integrates high-performance computing, shared biological data from public and industry sources and emerging biotechnologies to dramatically accelerate the discovery of effective cancer therapies.

The goal of the consortium – Accelerating Therapeutics for Opportunities in Medicine (ATOM) – is to create a new paradigm of drug discovery that would reduce the time from an identified drug target to clinical candidate from the current approximately six years to just 12 months. ATOM aims to transform cancer drug discovery from a time-consuming, sequential and high-risk process into an approach that is rapid, integrated and with better patient outcomes — using supercomputers to pretest many molecules simultaneously for safety and efficacy.

The consortium comprises the Department of Energy’s Lawrence Livermore National Laboratory (LLNL), GSK, the National Cancer Institute’s Frederick National Laboratory for Cancer Research (FNLCR), and the University of California, San Francisco (UCSF). ATOM welcomes additional public and private partners who share the vision.

“The goals of ATOM are tightly aligned with those of the 21st Century Cures Act, which aims in part to enable a greater number of therapies to reach more patients more quickly,” said FNLCR Laboratory Director David Heimbrook. “Although initially focused on precision oncology – treatments targeted specifically to the characteristics of the individual patient’s cancer – the consortium’s discoveries could accelerate drug discovery against many diseases.”

ATOM will develop, test and validate a multidisciplinary approach to drug discovery in which modern science, technology and engineering, supercomputing simulations, data science and artificial intelligence are highly integrated into a single drug-discovery platform that can untimately be shared with the drug development community at large.

“As we have learned more about what modern supercomputers can do, we’ve gained confidence that this approach can make a big difference in creating medicines,” said John Baldoni, senior vice president, R&D at GSK. “We must do all that we can to reduce the time it takes to get medicines to patients. GSK is working to set a precedent with pharmaceutical companies by sharing data on failed compounds.”

GSK will initially contribute chemical and in vitro biological data for more than 2 million compounds from its historic and current screening collection, as well as preclinical and clinical information on 500 molecules that have failed in development but could help accelerate development of new compounds by providing knowledge about the underlying biology of candidate compounds and that of the human body. Combined with data on successful drugs, GSK’s offering represents a broad base of information for ATOM researchers. In addition, GSK will provide expertise in drug discovery and development, computational chemistry and biology.

The ATOM team will combine data provided by GSK with publicly available data, and that of future consortium members, to generate new dynamic models that can better predict how molecules will behave in the body compared to the current iterative and time-consuming practices. In this effort, LLNL will contribute its best-in-class supercomputers, including its next-generation system Sierra, as well as its expertise and innovative approaches to modeling and simulation, cognitive computing, machine learning and algorithm development. More broadly, by tackling the ambitious challenge of cancer therapies, ATOM will drive technologies vital to the core missions of the Department of Energy and National Nuclear Security Administration (NNSA).

“ATOM is a novel public-private partnership that draws on the lab’s unique capabilities to create a paradigm change in drug development,” said LLNL Director Bill Goldstein. “It will help to strengthen U.S. leadership in high-performance computing and, by speeding the discovery of therapeutics, contribute to biosecurity.”

For its part, FNLCR will contribute from its wealth of scientific expertise in precision oncology, computational chemistry and cancer biology, as well as support for open sharing of data sets and predictive modeling and simulation tools. UCSF will provide expertise from a long history of innovation in drug discovery and medicine to improve the lives of patients.

“We at UCSF are eager to lend our expertise to this effort,” said UCSF Chancellor Sam Hawgood, MBBS. “UCSF scientists and clinicians have long been leaders in drug discovery, therapeutics, and cancer biology with the UCSF Helen Diller Family Comprehensive Care Center among the top-ranked cancer institutes in the country. Our role with ATOM is therefore in lock step with UCSF’s mission of advancing health worldwide.”

ATOM welcomes additional public and private partners who share the vision of the consortium, which will have physical headquarters in the Mission Bay neighborhood of San Francisco, adjacent to UCSF’s newest campus.