Category Archives: Gene therapy

A University of Chicago-based research team has overcome challenges that have limited gene therapy and demonstrated how their novel approach with skin transplantation could enable a wide range of gene-based therapies to treat many human diseases.

In a study inthe journal Cell Stem Cell, the researchers provide proof-of-concept. They describe gene-therapy administered through skin transplants to treat two related and extremely common human ailments: Type 2 diabetes and obesity.

We resolved some technical hurdles and designed a mouse-to-mouse skin transplantation model in animals with intact immune systems, said study author Xiaoyang Wu, assistant professor in the Ben May Department for Cancer Research at the University of Chicago. We think this platform has the potential to lead to safe and durable gene therapy in mice and, we hope, in humans, using selected and modified cells from skin.

Beginning in the 1970s, physicians learned how to harvest skin stem cells from a patient with extensive burn wounds, grow them in the laboratory, then apply the lab-grown tissue to close and protect a patients wounds. This approach is now standard. However, the application of skin transplants is better developed in humans than in mice.

The mouse system is less mature, Wu said. It took us a few years to optimize our 3-D skin organoid culture system.

This study is the first to show that an engineered skin graft can survive long term in wild-type mice with intact immune systems. We have a better than 80 percent success rate with skin transplantation, Wu said. This is exciting for us.

The researchers focused on diabetes because it is a common non-skin disease that can be treated by the strategic delivery of specific proteins.

They inserted the gene for glucagon-like peptide 1 (GLP1), a hormone that stimulates the pancreas to secrete insulin. This extra insulin removes excessive glucose from the bloodstream, preventing the complications of diabetes. GLP1 can also delay gastric emptying and reduce appetite.

Using CRISPR, a tool for precise genetic engineering, they modified the GLP1 gene. They inserted one mutation, designed to extend the hormones half-life in the blood stream, and fused the modified gene to an antibody fragment so that it would circulate in the blood stream longer. They also attached an inducible promoter, which enabled them to turn on the gene to make more GLP1, as needed, by exposing it to the antibiotic doxycycline. Then they inserted the gene into skin cells and grew those cells in culture.

When these cultured cells were exposed to an air/liquid interface in the laboratory, they stratified, generating what the authors referred to as a multi-layered, skin-like organoid. Next, they grafted this lab-grown gene-altered skin onto mice with intact immune systems. There was no significant rejection of the transplanted skin grafts.

When the mice ate food containing minute amounts of doxycycline, they released dose-dependent levels of GLP1 into the blood. This promptly increased blood-insulin levels and reduced blood-glucose levels.

When the researchers fed normal or gene-altered mice a high-fat diet, both groups rapidly gained weight. They became obese. When normal and gene-altered mice got the high-fat diet along with varying levels of doxycycline, to induce GLP1 release, the normal mice grew fat and mice expressing GLP1 showed less weight gain.

Expression of GLP1 also lowered glucose levels and reduced insulin resistance.

Together, our data strongly suggest that cutaneous gene therapy with inducible expression of GLP1 can be used for the treatment and prevention of diet-induced obesity and pathologies, the authors wrote.

When they transplanted gene-altered human cells to mice with a limited immune system, they saw the same effect. These results, the authors wrote, suggest that cutaneous gene therapy for GLP1 secretion could be practical and clinically relevant.

This approach, combining precise genome editing in vitro with effective application of engineered cells in vivo, could provide significant benefits for the treatment of many human diseases, the authors note.

We think this can provide a long-term safe option for the treatment of many diseases, Wu said. It could be used to deliver therapeutic proteins, replacing missing proteins for people with a genetic defect, such as hemophilia. Or it could function as a metabolic sink, removing various toxins.

Skin progenitor cells have several unique advantages that are a perfect fit for gene therapy. Human skin is the largest and most accessible organ in the body. It is easy to monitor. Transplanted skin can be quickly removed if necessary. Skins cells rapidly proliferate in culture and can be easily transplanted. The procedure is safe, minimally invasive and inexpensive.

There is also a need. More than 100 million U.S. adults have either diabetes (30.3 million) or prediabetes (84.1 million), according the Centers for Disease Control and Prevention. More than two out of three adults are overweight. More than one out of three are considered obese.

Additional authors of the study were Japing Yue, Queen Gou, and Cynthia Li from the University of Chicago and Barton Wicksteed from the University of Illinois at Chicago. The National Institutes of Health, the American Cancer Society and the V Foundation funded the study.

Article originally appeared on Science Life.

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Gene therapy via skin could treat diseases such as obesity - UChicago News

Pfizer committed to building a $100 million gene therapies plant in North Carolinaand in exchange, North Carolina committed to providing the drugmaker with a quarter-million dollars' worth of help.

Pfizer will expand an 11,000-square-foot plant in Sanford, North Carolina that it acquiredlast year when it bought gene therapies biotech Bamboo Therapeutics in a deal valued at up to $688 million.Bamboo bought the facilitylast year from the University of North Carolina about the time that Pfizer made is initial investment in the company.

The drugmaker considered building a facility in Massachusetts where it has other research and manufacturing operations but decided on North Carolinawhere it will receive a $250,000 performance grant from the state for the project and its 40 jobs.

RELATED:Pfizer looks at building major gene therapy manufacturing facility in North Carolina

Pfizer is proud to further expand our presence in North Carolina, particularly as we build our leadership in gene therapy, Lynn Bottone, site leader at Pfizer Sanford said in a statement. We look forward to the next phase of this expansion as we build a clinical and commercial manufacturing facility.

A Pfizer spokeswoman said in an email Tuesday that it was too early in the process to provide any details about the size of the expansion or when it might be producing materials.

Bamboo has already produced phase I and II materials in the facility using what Pfizer said was superior suspension, cell-based production platform that increases scalability, efficiency and purity.

Bamboo is working on gene therapies for certain rare diseases related to neuromuscular conditions and the central nervous system. With gene therapies, genetic material is introduced into a patients body to replacemutations that cause diseaseand the expectation is that treatments may cure the condition.

RELATED: Pfizer doubles down on gene therapy pipeline with $70M Sangamo buy-in

Pfizer is among a number of companies exploring the new area and added to its portfolio this spring when it struck a licensing deal with Richmond, California-based Sangamo Therapeutics, which is working on gene therapies for treating hemophilia A. Under the deal, Sangamo got $70 million upfront and could gain $475 million in biobucks and sales royalties on any medications from the collaboration that gain approval.

Others are building manufacturing facilities as well. California-based BioMarin, recently completed the renovation of a 25,000-square-foot building in Novato, Novato, California, for manufacturing the gene therapies for hemophilia A which its has in clinical trials, the Marin Independent Journal reported Monday.

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Pfizer commits $100M for a gene therapies plant in North Carolina ... - FiercePharma

Gene therapy utilizes the delivery of DNA into cells, which can be accomplished by several methods, summarized below. The two major classes of methods are those that use recombinant viruses (sometimes called biological nanoparticles or viral vectors) and those that use naked DNA or DNA complexes (non-viral methods).

All viruses bind to their hosts and introduce their genetic material into the host cell as part of their replication cycle. This genetic material contains basic 'instructions' of how to produce more copies of these viruses, hacking the body's normal production machinery to serve the needs of the virus. The host cell will carry out these instructions and produce additional copies of the virus, leading to more and more cells becoming infected. Some types of viruses insert their genome into the host's cytoplasm, but do not actually enter the cell. Others penetrate the cell membrane disguised as protein molecules and enter the cell.

There are two main types of virus infection: lytic and lysogenic. Shortly after inserting its DNA, viruses of the lytic cycle quickly produce more viruses, burst from the cell and infect more cells. Lysogenic viruses integrate their DNA into the DNA of the host cell and may live in the body for many years before responding to a trigger. The virus reproduces as the cell does and does not inflict bodily harm until it is triggered. The trigger releases the DNA from that of the host and employs it to create new viruses.

The genetic material in retroviruses is in the form of RNA molecules, while the genetic material of their hosts is in the form of DNA. When a retrovirus infects a host cell, it will introduce its RNA together with some enzymes, namely reverse transcriptase and integrase, into the cell. This RNA molecule from the retrovirus must produce a DNA copy from its RNA molecule before it can be integrated into the genetic material of the host cell. The process of producing a DNA copy from an RNA molecule is termed reverse transcription. It is carried out by one of the enzymes carried in the virus, called reverse transcriptase. After this DNA copy is produced and is free in the nucleus of the host cell, it must be incorporated into the genome of the host cell. That is, it must be inserted into the large DNA molecules in the cell (the chromosomes). This process is done by another enzyme carried in the virus called integrase.

Now that the genetic material of the virus has been inserted, it can be said that the host cell has been modified to contain new genes. If this host cell divides later, its descendants will all contain the new genes. Sometimes the genes of the retrovirus do not express their information immediately.

One of the problems of gene therapy using retroviruses is that the integrase enzyme can insert the genetic material of the virus into any arbitrary position in the genome of the host; it randomly inserts the genetic material into a chromosome. If genetic material happens to be inserted in the middle of one of the original genes of the host cell, this gene will be disrupted (insertional mutagenesis). If the gene happens to be one regulating cell division, uncontrolled cell division (i.e., cancer) can occur. This problem has recently begun to be addressed by utilizing zinc finger nucleases[1] or by including certain sequences such as the beta-globin locus control region to direct the site of integration to specific chromosomal sites.

Gene therapy trials using retroviral vectors to treat X-linked severe combined immunodeficiency (X-SCID) represent the most successful application of gene therapy to date. More than twenty patients have been treated in France and Britain, with a high rate of immune system reconstitution observed. Similar trials were restricted or halted in the USA when leukemia was reported in patients treated in the French X-SCID gene therapy trial.[citation needed] To date, four children in the French trial and one in the British trial have developed leukemia as a result of insertional mutagenesis by the retroviral vector. All but one of these children responded well to conventional anti-leukemia treatment. Gene therapy trials to treat SCID due to deficiency of the Adenosine Deaminase (ADA) enzyme (one form of SCID)[2] continue with relative success in the USA, Britain, Ireland, Italy and Japan.

Adenoviruses are viruses that carry their genetic material in the form of double-stranded DNA. They cause respiratory, intestinal, and eye infections in humans (especially the common cold). When these viruses infect a host cell, they introduce their DNA molecule into the host. The genetic material of the adenoviruses is not incorporated (transient) into the host cell's genetic material. The DNA molecule is left free in the nucleus of the host cell, and the instructions in this extra DNA molecule are transcribed just like any other gene. The only difference is that these extra genes are not replicated when the cell is about to undergo cell division so the descendants of that cell will not have the extra gene. As a result, treatment with the adenovirus will require readministration in a growing cell population although the absence of integration into the host cell's genome should prevent the type of cancer seen in the SCID trials. This vector system has been promoted for treating cancer and indeed the first gene therapy product to be licensed to treat cancer, Gendicine, is an adenovirus. Gendicine, an adenoviral p53-based gene therapy was approved by the Chinese food and drug regulators in 2003 for treatment of head and neck cancer. Advexin, a similar gene therapy approach from Introgen, was turned down by the US Food and Drug Administration (FDA) in 2008.

Concerns about the safety of adenovirus vectors were raised after the 1999 death of Jesse Gelsinger while participating in a gene therapy trial. Since then, work using adenovirus vectors has focused on genetically crippled versions of the virus.

The viral vectors described above have natural host cell populations that they infect most efficiently. Retroviruses have limited natural host cell ranges, and although adenovirus and adeno-associated virus are able to infect a relatively broader range of cells efficiently, some cell types are refractory to infection by these viruses as well. Attachment to and entry into a susceptible cell is mediated by the protein envelope on the surface of a virus. Retroviruses and adeno-associated viruses have a single protein coating their membrane, while adenoviruses are coated with both an envelope protein and fibers that extend away from the surface of the virus. The envelope proteins on each of these viruses bind to cell-surface molecules such as heparin sulfate, which localizes them upon the surface of the potential host, as well as with the specific protein receptor that either induces entry-promoting structural changes in the viral protein, or localizes the virus in endosomes wherein acidification of the lumen induces this refolding of the viral coat. In either case, entry into potential host cells requires a favorable interaction between a protein on the surface of the virus and a protein on the surface of the cell. For the purposes of gene therapy, one might either want to limit or expand the range of cells susceptible to transduction by a gene therapy vector. To this end, many vectors have been developed in which the endogenous viral envelope proteins have been replaced by either envelope proteins from other viruses, or by chimeric proteins. Such chimera would consist of those parts of the viral protein necessary for incorporation into the virion as well as sequences meant to interact with specific host cell proteins. Viruses in which the envelope proteins have been replaced as described are referred to as pseudotyped viruses. For example, the most popular retroviral vector for use in gene therapy trials has been the lentivirus Simian immunodeficiency virus coated with the envelope proteins, G-protein, from Vesicular stomatitis virus. This vector is referred to as VSV G-pseudotyped lentivirus, and infects an almost universal set of cells. This tropism is characteristic of the VSV G-protein with which this vector is coated. Many attempts have been made to limit the tropism of viral vectors to one or a few host cell populations. This advance would allow for the systemic administration of a relatively small amount of vector. The potential for off-target cell modification would be limited, and many concerns from the medical community would be alleviated. Most attempts to limit tropism have used chimeric envelope proteins bearing antibody fragments. These vectors show great promise for the development of "magic bullet" gene therapies.

A replication-competent vector called ONYX-015 is used in replicating tumor cells. It was found that in the absence of the E1B-55Kd viral protein, adenovirus caused very rapid apoptosis of infected, p53(+) cells, and this results in dramatically reduced virus progeny and no subsequent spread. Apoptosis was mainly the result of the ability of EIA to inactivate p300. In p53(-) cells, deletion of E1B 55kd has no consequence in terms of apoptosis, and viral replication is similar to that of wild-type virus, resulting in massive killing of cells.

A replication-defective vector deletes some essential genes. These deleted genes are still necessary in the body so they are replaced with either a helper virus or a DNA molecule.

[3]

Replication-defective vectors always contain a transfer construct. The transfer construct carries the gene to be transduced or transgene. The transfer construct also carries the sequences which are necessary for the general functioning of the viral genome: packaging sequence, repeats for replication and, when needed, priming of reverse transcription. These are denominated cis-acting elements, because they need to be on the same piece of DNA as the viral genome and the gene of interest. Trans-acting elements are viral elements, which can be encoded on a different DNA molecule. For example, the viral structural proteins can be expressed from a different genetic element than the viral genome.

[3]

The Herpes simplex virus is a human neurotropic virus. This is mostly examined for gene transfer in the nervous system. The wild type HSV-1 virus is able to infect neurons and evade the host immune response, but may still become reactivated and produce a lytic cycle of viral replication. Therefore, it is typical to use mutant strains of HSV-1 that are deficient in their ability to replicate. Though the latent virus is not transcriptionally apparent, it does possess neuron specific promoters that can continue to function normally[further explanation needed]. Antibodies to HSV-1 are common in humans, however complications due to herpes infection are somewhat rare.[4] Caution for rare cases of encephalitis must be taken and this provides some rationale to using HSV-2 as a viral vector as it generally has tropism for neuronal cells innervating the urogenital area of the body and could then spare the host of severe pathology in the brain.

Non-viral methods present certain advantages over viral methods, with simple large scale production and low host immunogenicity being just two. Previously, low levels of transfection and expression of the gene held non-viral methods at a disadvantage; however, recent advances in vector technology have yielded molecules and techniques with transfection efficiencies similar to those of viruses.[5]

This is the simplest method of non-viral transfection. Clinical trials carried out of intramuscular injection of a naked DNA plasmid have occurred with some success; however, the expression has been very low in comparison to other methods of transfection. In addition to trials with plasmids, there have been trials with naked PCR product, which have had similar or greater success. Cellular uptake of naked DNA is generally inefficient. Research efforts focusing on improving the efficiency of naked DNA uptake have yielded several novel methods, such as electroporation, sonoporation, and the use of a "gene gun", which shoots DNA coated gold particles into the cell using high pressure gas.[6]

Electroporation is a method that uses short pulses of high voltage to carry DNA across the cell membrane. This shock is thought to cause temporary formation of pores in the cell membrane, allowing DNA molecules to pass through. Electroporation is generally efficient and works across a broad range of cell types. However, a high rate of cell death following electroporation has limited its use, including clinical applications.

More recently a newer method of electroporation, termed electron-avalanche transfection, has been used in gene therapy experiments. By using a high-voltage plasma discharge, DNA was efficiently delivered following very short (microsecond) pulses. Compared to electroporation, the technique resulted in greatly increased efficiency and less cellular damage.

The use of particle bombardment, or the gene gun, is another physical method of DNA transfection. In this technique, DNA is coated onto gold particles and loaded into a device which generates a force to achieve penetration of the DNA into the cells, leaving the gold behind on a "stopping" disk.

Sonoporation uses ultrasonic frequencies to deliver DNA into cells. The process of acoustic cavitation is thought to disrupt the cell membrane and allow DNA to move into cells.

In a method termed magnetofection, DNA is complexed to magnetic particles, and a magnet is placed underneath the tissue culture dish to bring DNA complexes into contact with a cell monolayer.

Hydrodynamic delivery involves rapid injection of a high volume of a solution into vasculature (such as into the inferior vena cava, bile duct, or tail vein). The solution contains molecules that are to be inserted into cells, such as DNA plasmids or siRNA, and transfer of these molecules into cells is assisted by the elevated hydrostatic pressure caused by the high volume of injected solution.[7][8][9]

The use of synthetic oligonucleotides in gene therapy is to deactivate the genes involved in the disease process. There are several methods by which this is achieved. One strategy uses antisense specific to the target gene to disrupt the transcription of the faulty gene. Another uses small molecules of RNA called siRNA to signal the cell to cleave specific unique sequences in the mRNA transcript of the faulty gene, disrupting translation of the faulty mRNA, and therefore expression of the gene. A further strategy uses double stranded oligodeoxynucleotides as a decoy for the transcription factors that are required to activate the transcription of the target gene. The transcription factors bind to the decoys instead of the promoter of the faulty gene, which reduces the transcription of the target gene, lowering expression. Additionally, single stranded DNA oligonucleotides have been used to direct a single base change within a mutant gene. The oligonucleotide is designed to anneal with complementarity to the target gene with the exception of a central base, the target base, which serves as the template base for repair. This technique is referred to as oligonucleotide mediated gene repair, targeted gene repair, or targeted nucleotide alteration.

To improve the delivery of the new DNA into the cell, the DNA must be protected from damage and positively charged. Initially, anionic and neutral lipids were used for the construction of lipoplexes for synthetic vectors. However, in spite of the facts that there is little toxicity associated with them, that they are compatible with body fluids and that there was a possibility of adapting them to be tissue specific; they are complicated and time consuming to produce so attention was turned to the cationic versions.

Cationic lipids, due to their positive charge, were first used to condense negatively charged DNA molecules so as to facilitate the encapsulation of DNA into liposomes. Later it was found that the use of cationic lipids significantly enhanced the stability of lipoplexes. Also as a result of their charge, cationic liposomes interact with the cell membrane, endocytosis was widely believed as the major route by which cells uptake lipoplexes. Endosomes are formed as the results of endocytosis, however, if genes can not be released into cytoplasm by breaking the membrane of endosome, they will be sent to lysosomes where all DNA will be destroyed before they could achieve their functions. It was also found that although cationic lipids themselves could condense and encapsulate DNA into liposomes, the transfection efficiency is very low due to the lack of ability in terms of endosomal escaping. However, when helper lipids (usually electroneutral lipids, such as DOPE) were added to form lipoplexes, much higher transfection efficiency was observed. Later on, it was figured out that certain lipids have the ability to destabilize endosomal membranes so as to facilitate the escape of DNA from endosome, therefore those lipids are called fusogenic lipids. Although cationic liposomes have been widely used as an alternative for gene delivery vectors, a dose dependent toxicity of cationic lipids were also observed which could limit their therapeutic usages.

The most common use of lipoplexes has been in gene transfer into cancer cells, where the supplied genes have activated tumor suppressor control genes in the cell and decrease the activity of oncogenes. Recent studies have shown lipoplexes to be useful in transfecting respiratory epithelial cells.

Polymersomes are synthetic versions of liposomes (vesicles with a lipid bilayer), made of amphiphilic block copolymers. They can encapsulate either hydrophilic or hydrophobic contents and can be used to deliver cargo such as DNA, proteins, or drugs to cells. Advantages of polymersomes over liposomes include greater stability, mechanical strength, blood circulation time, and storage capacity.[10][11][12]

Complexes of polymers with DNA are called polyplexes. Most polyplexes consist of cationic polymers and their fabrication is based on self-assembly by ionic interactions. One important difference between the methods of action of polyplexes and lipoplexes is that polyplexes cannot directly release their DNA load into the cytoplasm. As a result, co-transfection with endosome-lytic agents such as inactivated adenovirus was required to facilitate nanoparticle escape from the endocytic vesicle made during particle uptake. However, a better understanding of the mechanisms by which DNA can escape from endolysosomal pathway, i.e. proton sponge effect,[13] has triggered new polymer synthesis strategies such as incorporation of protonable residues in polymer backbone and has revitalized research on polycation-based systems.[14]

Due to their low toxicity, high loading capacity, and ease of fabrication, polycationic nanocarriers demonstrate great promise compared to their rivals such as viral vectors which show high immunogenicity and potential carcinogenicity, and lipid-based vectors which cause dose dependence toxicity. Polyethyleneimine[15] and chitosan are among the polymeric carriers that have been extensively studies for development of gene delivery therapeutics. Other polycationic carriers such as poly(beta-amino esters)[16] and polyphosphoramidate[17] are being added to the library of potential gene carriers. In addition to the variety of polymers and copolymers, the ease of controlling the size, shape, surface chemistry of these polymeric nano-carriers gives them an edge in targeting capability and taking advantage of enhanced permeability and retention effect.[18]

A dendrimer is a highly branched macromolecule with a spherical shape. The surface of the particle may be functionalized in many ways and many of the properties of the resulting construct are determined by its surface.

In particular it is possible to construct a cationic dendrimer, i.e. one with a positive surface charge. When in the presence of genetic material such as DNA or RNA, charge complimentarity leads to a temporary association of the nucleic acid with the cationic dendrimer. On reaching its destination the dendrimer-nucleic acid complex is then taken into the cell via endocytosis.

In recent years the benchmark for transfection agents has been cationic lipids. Limitations of these competing reagents have been reported to include: the lack of ability to transfect some cell types, the lack of robust active targeting capabilities, incompatibility with animal models, and toxicity. Dendrimers offer robust covalent construction and extreme control over molecule structure, and therefore size. Together these give compelling advantages compared to existing approaches.

Producing dendrimers has historically been a slow and expensive process consisting of numerous slow reactions, an obstacle that severely curtailed their commercial development. The Michigan-based company Dendritic Nanotechnologies discovered a method to produce dendrimers using kinetically driven chemistry, a process that not only reduced cost by a magnitude of three, but also cut reaction time from over a month to several days. These new "Priostar" dendrimers can be specifically constructed to carry a DNA or RNA payload that transfects cells at a high efficiency with little or no toxicity.[citation needed]

Inorganic nanoparticles, such as gold, silica, iron oxide (ex. magnetofection) and calcium phosphates have been shown to be capable of gene delivery.[19] Some of the benefits of inorganic vectors is in their storage stability, low manufacturing cost and often time, low immunogenicity, and resistance to microbial attack. Nanosized materials less than 100nm have been shown to efficiently trap the DNA or RNA and allows its escape from the endosome without degradation. Inorganics have also been shown to exhibit improved in vitro transfection for attached cell lines due to their increased density and preferential location on the base of the culture dish. Quantum dots have also been used successfully and permits the coupling of gene therapy with a stable fluorescence marker.

Cell-penetrating peptides (CPPs), also known as peptide transduction domains (PTDs), are short peptides (< 40 amino acids) that efficiently pass through cell membranes while being covalently or non-covalently bound to various molecules, thus facilitating these molecules entry into cells. Cell entry occurs primarily by endocytosis but other entry mechanisms also exist. Examples of cargo molecules of CPPs include nucleic acids, liposomes, and drugs of low molecular weight.[20][21]

CPP cargo can be directed into specific cell organelles by incorporating localization sequences into CPP sequences. For example, nuclear localization sequences are commonly used to guide CPP cargo into the nucleus.[22] For guidance into mitochondria, a mitochondrial targeting sequence can be used; this method is used in protofection (a technique that allows for foreign mitochondrial DNA to be inserted into cells' mitochondria).[23][24]

Due to every method of gene transfer having shortcomings, there have been some hybrid methods developed that combine two or more techniques. Virosomes are one example; they combine liposomes with an inactivated HIV or influenza virus. This has been shown to have more efficient gene transfer in respiratory epithelial cells than either viral or liposomal methods alone. Other methods involve mixing other viral vectors with cationic lipids or hybridising viruses.

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Vectors in gene therapy - Wikipedia

Alliance for Gene Cancer Therapy Executive Director Margaret C. Cianci and President and CEO John E. Walter outside the nonprofits headquarters in Stamford. Photo by Phil Hall.

The development of an experimental gene-targeting therapy in cancer treatment that could be approved for the U.S. market this year was sparked in large part by the research funding support of a Stamford nonprofit.

The chimeric antigen receptor T-cell (CAR-T) drug, labeled tisagenlecleucel by its manufacturer, Novartis, in July was unanimously recommended for approval by the oncologic drugs advisory committee of the U.S. Food and Drug Administration. If the FDA grants final approval as expected this fall, it will be the first drug treatment targeting human genes approved for the U.S. market.

In Stamford, the Alliance for Cancer Gene Therapy since 2004 has provided a total of $1.8 million to Dr. Carl June at the University of Pennsylvania, the lead researcher in developing the CAR-T therapy. John E. Walter, president and CEO of the Stamford organization, said Junes work has helped to redefine perceptions of what gene therapy can accomplish.

Oftentimes, gene therapy is perceived as taking the bad genes out and putting some good genes in, Walter said. In this case, a patients T-cells are being removed and re-engineered with a virus and reintroduced in the body. With this genetic re-engineering, they become killer T-cells they go in and go after and kill the cancer cells.

Cancer cells in your body multiply and dont know how to die, said Alliance for Gene Cancer Therapy Executive Director Margaret C. Cianci. We have cells in our system all of the time that are growing and dying, but cancer cells dont do that. This therapy is for supercharging your own immune system to recognize these cancer cells and kill them.

If approved, the Novartis drug would mark a milestone achievement for the Alliance, whose creation in 2001 was driven by a tragic loss caused by cancer in its co-founders family. Edward Netter, chairman and CEO of Geneve Corp., a financial services holding company in Stamford, and his wife Barbara, a staff therapist at Pelham Family Services in Westchester County, lost their daughter-in-law, Kimberly Lawrence-Netter, to breast cancer. Edward Netter died from cancer in 2011. His wife serves as the nonprofits honorary board chairwoman.

Walter, who served as CEO of the Leukemia & Lymphoma Society before joining the Alliance in May 2016, noted that this organization differed from most because all of its raised funds are used solely to finance research. Our administrative expenses are paid for by our board and by the Netters, he said, and the nonprofits four-person staff works out of Geneve Corp. headquarters. One hundred percent of your contributions go to research.

Since its founding, the Alliance has allocated approximately $29 million in grants to U.S. and Canadian projects. These are grants to two different types of scientists, said Cianci. We started funding young investigators at assistant professor level who have just become independent. It is difficult for them to get funding, especially in an area as innovative as gene therapy, and the government doesnt like to fund what they see as high-risk projects. We also fund clinical investigators, which included Dr. June.

The Alliance puts out two requests for funding applications each year, which are judged through a peer-review process coordinated by a scientific advisory committee.

There is always more research than there are dollars, said Walter. Invariably, we are leaving research on the table because we dont have the dollars to fund those.

The nonprofit itself receives funding through contributions from longtime donors and an annual fundraising event coordinated by Swim Across America that is held in the Long Island Sound directly across from its offices. That raises about $400,000 a year, Walter said.

Dr. Junes Alliance-funded research was published in a medical journal in 2011 in a study of three patients with advanced chronic lymphocytic leukemia. Novartis, the Swiss pharmaceutical company, expressed interest in the results and paid the University of Pennsylvania $20 million to license the technology.

Once we have survival data for these patients in Novartis-sponsored clinical trials, over time the FDA could consider using this as frontline treatment instead of highly toxic chemotherapy, said Walter.

For Cianci, the Alliances mission is crucial in encouraging new generations of researchers to focus on cancer and gene therapy solutions, especially when federal funding is being threatened by budget cuts.

If we dont fund the young scientists, they are going to leave the field, she warned. We dont want to lose some of these incredible minds. The average age for getting your first grant from the National Institute of Health is 42. What do you tell someone who just became a postdoctoral researcher and wants to have their own lab? How are they going to get funding?

One in four people could potentially get cancer in their lifetimes, Cianci said. And who hasnt been touched by cancer in one way or another?

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Alliance for Gene Cancer Therapy funded pioneering cancer treatment research - Westfair Online

Agilis Biotherapeutics has formed a joint venture with Japans Gene Therapy Research Institution (GTRI). The alliance gives Agilis a base in Japan and a partnership with a fellow CNS specialist to support its development of adeno-associated virus (AAV) vectors and gene therapies.

Cambridge, Massachusetts-based Agilis set up the joint venture using a grant from the Japanese government. The agreement will establish an AAV manufacturing facility in Japan, from where Agilis and GTRI will work on vectors using Sf9 baculovirus and HEK293 mammalian cell systems. Agilis and GTRI plan to develop and manufacture AAV gene therapy vectors through the joint venture.

Agilis and GTRI also plan is to collaborate on the development and commercialization of certain CNS gene therapies.

GTRIs background suggests it is well-equipped to contribute to the project. The Japanese company grew out of the work of Shin-ichi Muramatsu, M.D., a scientist who sequenced AAV3 in the 1990s before going on to create AAVs designed to cross the blood-brain barrier. GTRI is working on gene therapies against diseases including Alzheimers, amyotrophic lateral sclerosis and Parkinsons that build on this research into AAVs.

Both biotechs are developing gene therapies to treat aromatic l-amino acid decarboxylase (AADC) deficiency. GTRI aims to get its candidate into the clinic in 2019. Agilispicked up its candidate from a university in Taiwan, which enrolled 18 patients in two clinical trials of the gene therapy. Those trials have taken the candidate toward a pivotal trial.

These programs may benefit from the joint venture. Working out of the Life Science Innovation Center of Kawasaki City, the joint venture intends to develop and produce AAVs for use in gene therapies against AADC deficiency and Parkinson's.

The joint venture marks the second time Agilis has looked outside of its walls for help with AAV vectors. Late in 2013, Agilis struck a deal with Intrexon that gave it access to the latters vector platform. Agilis is using the vectors to develop a treatment for Friedreichs ataxia.

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Agilis forms joint venture to advance gene therapy vectors - FierceBiotech

Man's best mend Gene therapy reverses muscular dystrophy symptoms in dogs Digital Trends Their solution involves using gene therapy to restore muscle strength and stabilize clinical symptoms. This is achieved by way of a shortened version of the dystrophin gene, containing just 4,000 base pairs, which is combined with a viral vector and ... and more »

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Man's best mend Gene therapy reverses muscular dystrophy symptoms in dogs - Digital Trends

Weve always said in the past gene editing shouldnt be done, mostly because it couldnt be done safely, said Richard Hynes, a cancer researcher at the Massachusetts Institute of Technology who co-led the committee. Thats still true, but now it looks like its going to be done safely soon, he said, adding that the research is a big breakthrough.

What our report said was, once the technical hurdles are cleared, then there will be societal issues that have to be considered and discussions that are going to have to happen. Nows the time.

Scientists at Oregon Health and Science University, with colleagues in California, China and South Korea, reported that they repaired dozens of embryos, fixing a mutation that causes a common heart condition that can lead to sudden death later in life.

If embryos with the repaired mutation were allowed to develop into babies, they would not only be disease-free but also would not transmit the disease to descendants.

The researchers averted two important safety problems: They produced embryos in which all cells not just some were mutation-free, and they avoided creating unwanted extra mutations.

It feels a bit like a one small step for (hu)mans, one giant leap for (hu)mankind moment, Jennifer Doudna, a biochemist who helped discover the gene-editing method used, called CRISPR-Cas9, said in an email.

Scientists tried two techniques to remove a dangerous mutation. In the first, genetic scissors were inserted into fertilized eggs. The mutation was repaired in some of the resulting embryos but not always in every cell. The second method worked better: By injecting the scissors along with the sperm into the egg, more embryos emerged with repaired genes in every cell.

When gene-editing components were introduced into a fertilized egg, some embryos contained a patchwork of repaired and unrepaired cells.

Gene-editing

components inserted

after fertilization

Cell with

unrepaired

gene

Mosaicism in

later-stage embryo

When gene-editing components were introduced with sperm to the egg before fertilization, more embryos had repaired mutations in every cell.

Gene-editing components

inserted together with sperm,

before fertilization

In 42 of 58

embryos

tested, all

cells were

repaired

Uniform

later-stage embryo

When gene-editing components were introduced into a fertilized egg, some embryos contained a patchwork of repaired and unrepaired cells.

Gene-editing

components inserted

after fertilization

Cell with

unrepaired

gene

Mosaicism in

later-stage embryo

When gene-editing components were introduced with sperm to the egg before fertilization, more embryos had repaired mutations in every cell.

Gene-editing

components inserted

together with sperm,

before fertilization

In 42 of 58

embryos

tested, all

cells were

repaired

Uniform

later-stage embryo

I expect these results will be encouraging to those who hope to use human embryo editing for either research or eventual clinical purposes, said Dr. Doudna, who was not involved in the study.

Much more research is needed before the method could be tested in clinical trials, currently impermissible under federal law. But if the technique is found to work safely with this and other mutations, it might help some couples who could not otherwise have healthy children.

Potentially, it could apply to any of more than 10,000 conditions caused by specific inherited mutations. Researchers and experts said those might include breast and ovarian cancer linked to BRCA mutations, as well as diseases like Huntingtons, Tay-Sachs, beta thalassemia, and even sickle cell anemia, cystic fibrosis or some cases of early-onset Alzheimers.

You could certainly help families who have been blighted by a horrible genetic disease, said Robin Lovell-Badge, a professor of genetics and embryology at the Francis Crick Institute in London, who was not involved in the study.

You could quite imagine that in the future the demand would increase. Maybe it will still be small, but for those individuals it will be very important.

The researchers also discovered something unexpected: a previously unknown way that embryos repair themselves.

In other cells in the body, the editing process is carried out by genes that copy a DNA template introduced by scientists. In these embryos, the sperm cells mutant gene ignored that template and instead copied the healthy DNA sequence from the egg cell.

We were so surprised that we just couldnt get this template that we made to be used, said Shoukhrat Mitalipov, director of the Center for Embryonic Cell and Gene Therapy at Oregon Health and Science University and senior author of the study. It was very new and unusual.

The research significantly improves upon previous efforts. In three sets of experiments in China since 2015, researchers seldom managed to get the intended change into embryonic genes.

And some embryos had cells that did not get repaired a phenomenon called mosaicism that could result in the mutation being passed on as well as unplanned mutations that could cause other health problems.

In February, a National Academy of Sciences, Engineering and Medicine committee endorsed modifying embryos, but only to correct mutations that cause a serious disease or condition and when no reasonable alternatives exist.

Sheldon Krimsky, a bioethicist at Tufts University, said the main uncertainty about the new technique was whether reasonable alternatives to gene editing already exist.

As the authors themselves noted, many couples use pre-implantation genetic diagnosis to screen embryos at fertility clinics, allowing only healthy ones to be implanted. For these parents, gene editing could help by repairing mutant embryos so that more disease-free embryos would be available for implantation.

Hank Greely, director of the Center for Law and the Biosciences at Stanford, said creating fewer defective embryos also would reduce the number discarded by fertility clinics, which some people oppose.

The larger issue is so-called germline engineering, which refers to changes made to embryo that are inheritable.

If youre in one camp, its a horror to be avoided, and if youre in the other camp, its desirable, Dr. Greely said. Thats going to continue to be the fight, whether its a feature or a bug.

For now, the fight is theoretical. Congress has barred the Food and Drug Administration from considering clinical trials involving germline engineering. And the National Institutes of Health is prohibited from funding gene-editing research in human embryos. (The new study was funded by Oregon Health and Science University, the Institute for Basic Science in South Korea, and several foundations.)

The authors say they hope that once the method is optimized and studied with other mutations, officials in the United States or another country will allow regulated clinical trials.

I think it could be widely used, if its proven safe, said Dr. Paula Amato, a co-author of the study and reproductive endocrinologist at O.H.S.U. Besides creating more healthy embryos for in vitro fertilization, she said, it could be used when screening embryos is not an option or to reduce arduous IVF cycles for women.

Dr. Mitalipov has pushed the scientific envelope before, generating ethical controversy with a so-called three-parent baby procedure that would place the nucleus of the egg of a woman with defective cellular mitochondria into the egg from a healthy woman. The F.D.A. has not approved trials of the method, but Britain may begin one soon.

The new study involves hypertrophic cardiomyopathy, a disease affecting about one in 500 people, which can cause sudden heart failure, often in young athletes.

It is caused by a mutation in a gene called MYBPC3. If one parent has a mutated copy, there is a 50 percent chance of passing the disease to children.

Using sperm from a man with hypertrophic cardiomyopathy and eggs from 12 healthy women, the researchers created fertilized eggs. Injecting CRISPR-Cas9, which works as a genetic scissors, they snipped out the mutated DNA sequence on the male MYBPC3 gene.

They injected a synthetic healthy DNA sequence into the fertilized egg, expecting that the male genome would copy that sequence into the cut portion. That is how this gene-editing process works in other cells in the body, and in mouse embryos, Dr. Mitalipov said.

Instead, the male gene copied the healthy sequence from the female gene. The authors dont know why it happened.

Maybe human sex cells or gametes evolved to repair themselves because they are the only cells that transmit genes to offspring and need special protection, said Juan Carlos Izpisua Belmonte, a co-author and geneticist at the Salk Institute.

Out of 54 embryos, 36 emerged mutation-free, a significant improvement over natural circumstances in which about half would not have the mutation. Another 13 embryos also emerged without the mutation, but not in every cell.

The researchers tried to eliminate the problem by acting at an earlier stage, injecting the egg with the sperm and CRISPR-Cas9 simultaneously, instead of waiting to inject CRISPR-Cas9 into the already fertilized egg.

That resulted in 42 of 58 embryos, 72 percent, with two mutation-free copies of the gene in every cell. They also found no unwanted mutations in the embryos, which were destroyed after about three days.

The method was not perfect. The remaining 16 embryos had unwanted additions or deletions of DNA. Dr. Mitalipov said he believed fine-tuning the process would make at least 90 percent of embryos mutation-free.

And for disease-causing mutations on maternal genes, the same process should occur, with the fathers healthy genetic sequence being copied, he said.

But the technique will not work if both parents have two defective copies. Then, scientists would have to determine how to coax one gene to copy a synthetic DNA sequence, Dr. Mitalipov said.

Otherwise, he said, it should work with many diseases, a variety of different heritable mutations.

R. Alta Charo, a bioethicist at University of Wisconsin at Madison, who led the committee with Dr. Hynes, said the new discovery could also yield more information about causes of infertility and miscarriages.

She doubts a flood of couples will have edited children.

Nobodys going to do this for trivial reasons, Dr. Charo said. Sex is cheaper and its more fun than IVF, so unless youve got a real need, youre not going to use it.

Read the original here:
In Breakthrough, Scientists Edit a Dangerous Mutation From Genes in Human Embryos - New York Times

Shares of Spark Therapeuticssurged nearly 20 percentWednesday after the Philadelphia gene therapy company revealed promisingresults from a study of its potential one-time therapy for hemophilia A.

Preliminary data from a Phase 1/2 dose-escalation clinical trial of SPK-8011showed human proof-of-concept in three participants, the drug maker said.

The encouraging start for hemophilia A reinforces the strength of our gene-therapy platform and positions us well to potentially transform the current treatment approach for this life-altering disease with a onetime intervention, said Katherine A. High, Sparks president and chief scientific officer.

Hemophilia is a genetic disorder caused by missing or defective factor VIII, a clotting protein. About 20,000 Americans live with hemophilia. The way the medical community has addressed the disorder is to ensure that patients have continuous injections of blood-clotting factors. Patients infuse themselves two to three times a week for the rest of their lives.

In the study, three patientsreceived infusions of vector genomes and no serious adverse events were reported, Spark said. One person has been followed for 23 weeks and another for 12 weeks. The initial dose created stable factor VIII levels with no spontaneous bleeds, the company said.

For a third patient, the genome dose was doubled and that persons factor VIII activity level is tracking proportionally higher, consistent with the dose escalation. So far, the drug has been safe and well tolerated, with no reports of serious adverse events, no thrombotic events, no immune responses, and no elevations of liver enzymes, the company said.

The data must be considered preliminary and one must be careful not to overinterpret them, said Cowen & Co. analyst Phil Nadeau in a client update. That being said, we find the results quite encouraging.

Despite a low starting dose, the gene therapy produced stable and clinically meaningful factor levels sufficient to prevent spontaneous bleeds in patients, Nadeau said. Moreover, the safety profile is clean thus far. The results suggest the company may be able to achieve greater factor levels at higher doses. We find SPK-8011s early data encouraging, and think they suggest that Spark has a viable and competitive hemophilia A program.

Spark will present full data at a medical conference in December.

The hemophilia A results, though early, along with previously reported data for the companys hemophilia B candidate, confirm Sparks thought leadership in hemophilia gene therapy, and the likelihood of achieving a leading position in the overall hemophilia market (currently $7 billion, growing to $14 billion in 2030), Chardan Capital Markets analyst Gbola Amusa said in a client note. Chardan raised its peak earnings forecast for Sparks hemophilia A therapy to $1.3 billion, up from $397 million.

Sparks lead drug, a treatment for rare inherited blindness, is under priority review with the U.S. Food and Drug Administration, with a possible approval date of Jan. 12, 2018. If approved, it would be the first gene therapy for a genetic disease in the United States.

Spark, which was spun out of Childrens Hospital of Philadelphia, reported a second-quarter financial loss of $74.4 million in the quarter ended June 30, or $2.40 per share, on revenue of $1.5 million from itscollaboration with Pfizer Inc. for hemophilia B.

Sparks shares have risen 58 percent since Jan. 1 and 37 percent in the last 12 months. The stock closed up 19.72 percent, or $13.13, to $79.72.

Published: August 2, 2017 1:12 PM EDT

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Excerpt from:
Philly gene therapy company reports early promising hemophilia A results - Philly.com

Chiesi has cut its ties to uniQures hemophilia B gene therapy. The split gives uniQure full rights to AMT-060 but leaves it without a partner to cofund R&D as it closes in on the start of a pivotal trial.

Italian drugmaker Chiesi picked up the rights to commercialize AMT-060 in certain markets in 2013 as part of a deal that also gave it a piece of Glybera, the gene therapy that made history by coming to market in Europe only to flop commercially. Chiesi backed out of the Glybera agreement earlier this year and has now completed its split from uniQure by terminating the hemophilia B pact.

Amsterdam, the Netherlands-based uniQure framed the termination as it reacquiring the rights to AMT-060, rather than Chiesi dumping the program. But as the deal will see money transfer from Chiesi to uniQure and the former stated a shift in priorities prompted it to sever ties to AMT-060, it seems clear the Italian drugmaker wanted to exit the agreement.

That leaves uniQure facing the prospect of taking AMT-060 into a pivotal trial without the financial support of a partner. Chiesi and uniQure have evenly shared R&D costs since 2013. The loss of the support of Chiesi will add $3 million to uniQures outlay this year, although the Dutch biotech still thinks it has enough cash to take it into 2019.

After a trying time on public markets dotted with stock drops following unfavorable comparisons to Spark Therapeutics rival hemophilia B program, uniQure is less well equipped to raise more money than in the past. But uniQure CEO Matthew Kapusta spun the regaining of full rights to the gene therapy as a boost for the company.

We believe uniQure is better positioned to accelerate the global clinical development plan, maximize shareholder return on our pipeline and take advantage of new potential opportunities related to the program, Kapusta said in a statement.

If the potential opportunities are to include a deal covering AMT-060, uniQure must persuade a potential partner of the merits of its asset. UniQure has sought to focus attention on the durable clinical benefits associated with AMT-060 but investors have fixated on Sparks clear advantage in terms of Factor IX activity.

More:
Chiesi dumps uniQure's hemophilia B gene therapy - FierceBiotech

Xconomy Boston

Gene therapy offers the potential for a long-lasting, if not permanent, treatment for an inherited disease, but cells that divide rapidly, such as those in the liver, present a thorny problem. Because of how they insert themselves in the cells, some forms of gene therapy get diluted as the cells divide.

Its a particular problem in growing children. Cambridge, MA-based LogicBio says it has developed a workaround by combining gene editing with gene therapy. The firm has raised $45 million in additional capital to help bring this technology into human testing, and it is moving from California to the LabCentral shared incubator space in Cambridges Kendall Square.

LogicBio calls its technology GeneRide. The company says its approach can transfer genetic material to specific sites to repair a faulty genetic sequence. The companys focus is metabolic disorders that affect the liver in children. Published research shows that metabolic disorders of the liver can progress to injury affecting other organs. In rare cases, the severity of the disease requires a pediatric liver transplant.

If GeneRide works as the company envisions, the gene therapy would offer a one-time treatment that avoids side effects.

London-based Arix Bioscience (LSE: ARIX) led the Series B round of investment, which was joined by new investors OrbiMed, Edmond De Rothschild Investment Partners, Pontifax, and SBI Japan-Israel Innovation Fund. Earlier investor OrbiMed Israel Partners also joined in the latest investment. In total, LogicBio says it has raised approximately $50 million in financing to date.

Gene therapy remains largely experimental. UniQure (NASDAQ: QURE) received the Western worlds first gene therapy approval in 2012 for alipogene tiparovec (Glybera), a treatment for a rare metabolic disorder. But earlier this year, the company, split between the Netherlands and Lexington, MA, announced it would not seek renewal of its conditional approval, set to expire in October. Patient demand for the drug was limited and the company did not expect that to change.

The first U.S. approval could come soon. Philadelphia-based Spark Therapeutics (NASDAQ: ONCE) is awaiting an FDA decision on a gene therapy for an inherited form of blindness. Cambridge-based Bluebird Bio (NASDAQ: BLUE) last week released early data from a Phase 3 study in patients with beta-thalassemia, a rare blood disorder.

The technologies underlying LogicBios approach were developed at Stanford University by company co-founders Mark Kay, Adi Barzel, and Leszek Lisowski. In addition to its Cambridge site, the company also has scientists in Tel Aviv, Israel.

Frank Vinluan is editor of Xconomy Raleigh-Durham, based in Research Triangle Park. You can reach him at fvinluan [at] xconomy.com

Read the original here:
LogicBio Lands $45M for Gene Therapies in Rare Pediatric Diseases - Xconomy