January 30, 2012
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Welcome to your Monday Biotech Deal Review for January 30, 2012. Juicy news from last week include the $15M bought-deal that Oncolytics entered into with a syndicate of underwriters, as well as the closing of other private placement financings. Read on to learn more. Read more of this post
January 27, 2012
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An Evolving Concept of Oncolytic Viruses
University of Ottawa ♦ Ottawa Hospital Research Institute ♦ Ontario Cancer Institute ♦ University of Toronto ♦ University of Otago
Published in Molecular Therapy (npg), January 24, 2012
Oncolytic viruses were originally engineered to impose direct damage to tumour cells through infection, replication, and subsequent destruction of cancer cells via cell rupture. Many of today’s oncolytic viruses aim to do this, however it has become apparent that ‘next generation’ oncolytic viruses, those with the greatest efficacy, will be the viruses that not only destroy cancer cells physically but stimulate a strong innate immune response against cancer cells to continue the onslaught following initial infection.
This concept of inducing immune response is not novel. By their nature, oncolytic viruses offer the opportunity to deliver therapeutic genes at the time of infection. Indeed, previous studies have shown that viruses can be engineered to deliver cytokine genes into tumour cells. These cancerous cells then act as factories creating a protein product that leads to their own immune destruction. Suicide.
But researchers have now discovered that it may not be necessary to engineer viruses to do this. Certain viruses are capable of generating such an immune response simply through the presence of the viral particle itself. One example of such a virus is Parapoxvirus ovis, or ORFV. Researchers at the University of Ottawa found that injecting the virus into mice led to a significant upregulation of T cell response, including both CD4+ and CD8+, and an accumulation of B cells, natural killer cells, and various cytokines with anti-tumoural activity.
But there’s more to the story. ORFV infection does not lead to disease in animals, making it an excellent candidate for an oncolytic therapeutic. The real beauty though — the differentiative aspect of this virus — is that ORFV, even in the presence of antibody against the virus, continues to reinfect cancer cells. Animals seem to have a very short-lived immunity against the virus, allowing for an attenuated therapeutic activity unlike any found so far in this field.
January 23, 2012
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Welcome to your Monday Biotech Deal Review for January 23, 2012. Noteworthy news from the previous week include the sweetening of the offer by Valeant for ISTA Pharmaceuticals by an additional dollar per share ($7.50 from $6.50), and the adoption by ISTA of a shareholder rights plan to replace its recently expired plan. Read on to learn more. Read more of this post
January 20, 2012
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Genetic Basis of Jr(a)- Phenotype Discovered
University of Manitoba ♦ Published in Nature Genetics, January 15, 2012
The medical community has been aware of the Jr(a) antigen on red blood cells for quite some time. Roughly 40 years ago it was shown that a small group of individuals created antibodies against this protein motif. In the presence of normal red blood cells the antibodies produced by Jr(a)- individuals react quite vigorously. During transfusion it is important that donor blood does not contain Jr(a) antibodies because they can lead to negative transfusion reactions that are harmful to the recipient. In this recent study, investigators isolated the genetic component responsible for the Jr(a)- phenotype. Carrying out single nucleotide polymorphism analysis, researchers discovered a nearly 400 thousand base pair null region in Jr(a)- individuals that contained the gene ABCG2.
Cutting to the Core of Systemic Immune Response
Ontario Cancer Institute ♦ Published in Science, January 13, 2012
The human body has become adept at regulating pathogens. However, this evolutionary trait also has its down sides. Extreme innate immune response can cause systemic inflammatory reactions that can prove fatal. This recent study out of Tak Mak’s lab identifies a mechanism by which animals induce innate immune response following exposure to foreign pathogens. Tumour necrosis factor alpha (TNF-α) mediates septic shock through its release from cell membranes. This release process is regulated by an enzyme known as TNF-α convertase. Researchers discovered that this enzyme’s maturation and trafficking is controlled by iRhom2. Sure enough, mice deficient in iRhom2 displayed an ability to circumvent lethal doses of bacterial lipopolysaccharide.
Conditions characterized by systemic immune response are some of the hardest to go after in the clinic. As an indication, sepsis has been a graveyard, with only a few of some 40 clinical studies showing any efficacy in the last two decades. Identifying general systemic pathways, like that involving iRhom2, will be critical in creating therapeutics for these complex conditions in the future.
January 16, 2012
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Welcome to your Monday Biotech Deal Review for January 16, 2012. News from last week includes a $5M raise by MedGenesis Therapeutics to support its therapeutic research for the treatment of Parkinson’s Disease, as well as a $70k private placement by PharmaGap. Read on to learn more. Read more of this post
January 13, 2012
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Disruption of Gatekeeper Genes Causes Two-fold Mutation
University of Toronto ♦ Published in EMBO, January 10, 2012
Certain genes have a critical role in maintaining the stability of the genome by exerting a certain control over DNA metabolism. Researchers at the Donnelly Centre in Toronto have discovered that disruption of these so called ‘gatekeeper’ genes has consequences beyond disregulating the direct influence they have on genomic stability. As expected, perturbing gatekeeper genes led to spontaneous DNA damage, however, this damage became amplified downstream. Measurements of ribonucleotide reductase (RNR) in budding yeast showed that expression of this enzyme increased as DNA damage occurred, and that RNR activity was associated with an increase in dNTP pools. A second wave of mutation occurred as yeast cells were then capable of synthesizing DNA in the presence of hydroxyurea in the next S phase.
Movement and Breathing, Where’s the Link?
University of Montreal ♦ Published in PNAS, January 10, 2012
As we exercise the rate at which we respire increases, and can do so dramatically. However, there is much to be elucidated in terms of the neural connections that elicit the body’s breathing response to movement. To interrogate this matter, researchers used the lamprey as a model. They first identified the region of the brain that was associated with an increase in respiration. In lampreys, stimulation of the mesencephalic locomotor region (LMR) increased the rate of respiration. Researchers then used a technique called ‘patch-clamp’, that is capable of taking electrophysiological recordings from single neurons, and used it to show that neurons in the dorsal region of the MLR are directly connected to a respiratory generator. To cross-check their findings, an inhibitor of the innervated region of the respiratory generator was used to show that inhibition at this site did indeed reduce respiration.
January 9, 2012
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Happy New Year and welcome back to your Monday Biotech Deal Review for January 9, 2012, following a holiday hiatus. Link below to our review of transactions that have occurred over the previous three weeks. Noteworthy transactions include various acquisitions by Valeant as well as a refinancing of its existing debt facilities. Read on to learn more. Read more of this post
January 9, 2012
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The numbers have been crunched in preparation for the 2011 Canadian Healthcare Annual Review, which I co-author with Ross Marshall, Senior Vice President at The Equicom Group. Prior to its publication later this month, we are going to give you a look at some of the top-line numbers.
The biggest concern in the sector is financing, both in Canada and globally. Two groups of numbers are shown below for our universe of public Canadian healthcare companies (132 companies to start 2011) – total equity and convertible debt financings by the group, and financings by development stage companies only (shown in millions of dollars). The 2011 total for the development stage companies is about the same at it was for the prior two years but is less than half of the average raised in 2005-2007.
Another major concern for both companies and shareholders is share price performance. We monitor share prices of a group of companies which started 2011 with a share price of $0.10 or higher and also look at two sub-groups. There were 104 companies in this group to start 2011 but only 97 companies actively trading as healthcare companies at the end.
The Equicom 2011 Canadian Healthcare Annual Review will look more closely at these numbers and the events from 2011, and discuss the results of its recent investor survey.
January 6, 2012
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MSC Anti-Immune Power
McGill University ♦ Published in Molecular Therapy (npg), January 2012
Mesenchymal stem cells have great potential as a source of therapeutic cell types for transplantation because they are capable of differentiating into bone, fat, cartilage, and muscle. Some reports show they even have the ability to differentiate into neural cells. The research community is beginning to learn, however, that perhaps the most interesting application of MSCs will be as a suppressant for the immune system. MSCs exhibit the unique ability to moderate T cell response. As a result, they are being investigated in clinical studies for treatment of disorders characterized by inflammation and autoimmunity. Rheumatoid arthritis is a model indication for MSC therapy down the line.
Results from clinical trials thus far have been varied. In order to gain a mechanistic understanding of the variability clinicians are observing, researchers at McGill University cross-examined MSCs from normal adult volunteers. Using an in vitro model, 7 different MSC lines were tested for their ability to suppress T cell proliferation. Results of this study indicate that MSCs possessing the most potent anti-immune power upregulate expression of an enzyme known as indoleamine 2,3-dioxygenase (IDO) in response to interferon-α. IDO is the first enzyme in the kynurenine pathway that catalyzes the degradation of trytophan. Several of the metabolites of this pathway are known to activate the stress response kinase CGN2, which causes apoptosis of T cells. Researchers also found that IDO activity is implicated in the differentiation of monocytes into immunosuppressive macrophages that regulate T cell proliferation in an IL-10 dependent fashion.
Elucidating the molecular mechanisms that contribute to the ability of MSCs to temper the immune system will allow us to generate MSC lines that have the most potent anti-immune power for the treatment of inflammatory and autoimmune disease.