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Biotechnology, Health and Business in Canada, the United States and Worldwide

Monthly Archives: April 2011

Friday Science Review: April 29, 2011

Gene Transfer Restores Regenerative Power to Circulating Angiogenic Cells

St. Michael’s Hospital ♦ University of Toronto

Published in Molecular Therapy, April 26, 2011

An interesting new approach to autologous cell therapy for patients with coronary artery disease uses gene transfer to enhance the regenerative activity of circulating angiogenic cells (CACs). These rare cells circulate freely throughout human vasculature, and are of interest to researchers because of their ability to promote the formation of new blood vessels and contribute to endogenous vascular repair. The regenerative capacity of these cells is impaired in humans that have cardiovascular disease, however, limiting their use as a therapeutic tool for this patient group.

Noting that the regenerative activity of CACs is linked to the availability of nitric oxide  (NO), researchers at St. Michael’s Hospital and the University of Toronto hypothesized that up-regulation of the gene encoding endothelial NO synthase (eNOS) could remedy the problem. This enzyme, typically found in the vasculature, is responsible for endogenous NO production. To test their theory, researchers used a virus to transduce a construct containing the eNOS gene directly into CACs from patients with coronary artery disease; first they looked at the results in vitro. The modified CACs were able to contribute to angiogenic tube formation when grown in the petri dish along with umbilical vein endothelial cells.

A look at the capabilities of transduced CACs in vivo confirmed the in vitro findings. Transduction of the eNOS gene restored the ability of CACs to improve ischemic hind limb perfusion in an animal model. These data support the notion that CACs may prospectively be used to help repair vasculature in patients with coronary artery disease. In this treatment paradigm, CACs would be removed from patients, isolated in the lab, transduced with the eNOS gene, and then injected back into the patient for tissue regeneration.

Ex Vivo Lung Perfusion Determines Viability of High-Risk Donor Lungs

Toronto Lung Transplant Program ♦ Published in NEJM, April 14, 2011

A large majority of donor lung transplants fail to meet the criteria for lung transplantation. A combination of the damage that occurs following brain death, and the injury that occurs to lung tissue in the ICU, renders them unsuitable for medical use. When using sub-optimal donor lungs, graft dysfunction is prevalent, leading to acute lung injury that occurs within the 72 hours following transplantation.

Normothermic ex vivo lung perfusion (EVLP) was developed by a group of researchers in Toronto to increase the percentage of donor lungs that can be used for transplantation. This biotechnology allows for the perfusion of lungs at body temperature in an ex vivo circuit that attempts to mimic normal physiological conditions. EVLP lasts for roughly 4 hours, and provides a means to quantitatively assess the function of donor lungs prior to transplantation. In this clinical study, funded by Vitrolife, researchers assessed the feasability of transplanting high-risk donor lungs into patients following EVLP.

During the clinical study a total of 136 donor lungs were transplanted. Of these, 23 were classified as high-risk and underwent EVLP prior to transplantation, while the remainder made up the control group. The primary endpoint of the study was graft dysfunction after 72 hours; secondary endpoints included 30-day mortality, bronchial complications, duration of mechanical ventilation, and length of stay in the hospital ICU. No significant differences were observed in any of the secondary endpoints between treatments. The incidence of graft dysfunction in patients who received high-risk donor lungs prepared with EVLP was only half of that observed in patients receiving donor lungs considered to be “standard” by clinicians (15% and 30% respectively). These results indicate that EVLP does a better job selecting donor lungs for transplantation.

Q1 2011 Canadian Healthcare Review: some financing carry-over from the strong Q4 2010

The ‘Q1 2011 Canadian Healthcare Review’, which I [Wayne Schnarr] co-author with Ross Marshall, Vice President Healthcare at The Equicom Group, has now been published. Click here to download the full report (pdf).

The public Canadian healthcare sector started 2011 with a steady but relatively quiet flow of events until Valeant Pharmaceuticals announced that it had made a proposal to acquire Cephalon for US$73 per share in cash. This is just one example of trends which the larger, profitable pharmaceutical and biotechnology companies appear to have carried over from 2010 – growing the top line and product portfolios using acquisitions and growing the bottom line from rationalizing operations, including their R&D infrastructure.

The financing climate for Canadian public healthcare companies was unexpectedly strong in Q4 2010. Some of this strength appears to have carried over into Q1 2011, with gross proceeds of equity and convertible debt financings completed in Q1 totalling $208.2 million. The companies with financings over $10 million which were completed in Q1 2011 are:

  • $58.2 million – GLG LifeTech
  • $40.3 million – Paladin Labs
  • $21.5 million – Centric Health
  • $15.0 million – Novadaq Technologies
  • $14.5 million – Oncolytics Biotech (two warrant exercises)
  • $12.7 million – Bioniche Life Sciences (Canada/Australia offering)
  • $12.1 million – EnWave
  • $12.0 million – IntelliPharmaceutics

Two additional financings (MethylGene for $34.5 million and Medicago for $17.4 million) were announced in Q1 but did not close until April. The first three companies mentioned above are not development stage biotech, being either profitable (Paladin Labs, Centric Health) or focused on manufacturing and marketing (GLG LifeTech) and they account for 58% of the healthcare sector total. Outside of the deals mentioned above, there were 24 financings under $10 million with total proceeds of only $36.4 million, an average of about $1.5 million per financing. Fourteen of the financings were for $1 million or less.

Friday Science Review: April 22, 2011

Fibroblast Growth Factor 9 Helps Form Vasoreactive Vessels

University of Western Ontario ♦ Published in Nature Biotechnology, April 17, 2011

Some interesting findings from the University of Western Ontario could have implications for future angiogenesis therapies and tissue engineering approaches to the treatment of vascular disease. Researchers discovered that fibroblast growth factor 9 (FGF9), an angiogenic growth factor, contributes to the development of vasoreactive blood vessels. Two primary processes must occur within implants to produce functional grafts. Firstly, endothelial cells must be stimulated to produce angiogenic sprouts, and secondly, these sprouts must be muscularized by being wrapped in smooth muscle cells. The latter of these two processes is crucial for vasoreactivity — the ability of vessels to alter the luminal diameter to control the flow of blood into capillary beds. Fibroblast growth factor 2 (FGF2)  has been shown to stimulate endothelial cells to form angiogenic sprouts, but its utility in producing functioning grafts has been limited because it does not stimulate the formation of cords of smooth muscle cells that allow for vasoreactivity. FGF9, on the other hand, fails to produce angiogenic sprouts but seems to direct mesenchymal cells to produce the muscle necessary for control over luminal diameter. Researchers show that delivering FGF9 to implants produces stable, durable, and vasoresponsive blood vessels that can remain physiologically competent for at least a year. This research challenges the notion that endothelial cells must be targeted for vascular repair, and suggests that targeting mesenchymal cells may be the more crucial consideration in developing angiogenesis therapies. It will likely be a combination of targeting both cell types and using a variety of angiogenic growth factors, including FGF2 and FGF9.

B Cells Drive Insulin Resistance in Animal Model

Stanford University ♦ University of Toronto ♦ Duke University Medical Center

Published in Nature Medicine, April 17, 2011

One of the key drivers of insulin resistance and glucose intolerance is chronic inflammation of the visceral adipose tissue (VAT). Inflammation of VAT is caused by the infiltration of macrophages that produce proinflammatory cytokines, and infiltration by T cells that also trigger inflammatory mechanisms. It now looks like B cells are in the mix as well, exhibiting a pathogenic role in the development of metabolic abnormalities. Using a knockout mouse model that fails to produce mature B cells, researchers showed that mice without B cells had lower fasting glucose and greater glucose tolerance than wild type mice. Knockout mice also had reduced fasting insulin and improved insulin sensitivity, and fewer proinflammatory macrophages in VAT compared to normal animals. Investigation into the mechanisms in which B cells promote metabolic abnormality led to the finding that B cells activate T cells through the presentation of an MHC complex, and that this was linked to glucose tolerance. In addition to modulating T cells, B cells also release IgG antibodies that regulate immune function. It was found that IgG in VAT induced a considerable decline in glucose tolerance, the effects of which were associated with decreased fasting insulin, one of the hallmarks of insulin resistance. Treating mice with CD20, a B cell-depleting antibody, attenuated disease, while transfer of IgG antibodies from mice with diet-induced obesity to normal mice rapidly induced glucose intolerance.

Monday Biotech Deal Review: April 18, 2011

Welcome to your Monday Biotech Deal Review for April 18, 2011.  Just by way of FYI, readers may be interested to know that The Canadian Institute will be hosting its 5th annual conference on Drug Pricing and Reimbursement in Canada in Toronto from June 14 – 15 at the Sutton Place Hotel.  The conference aims to bring key stakeholders together to share perspectives and strategies on maintaining competitiveness and compliance in these difficult markets.  Stay tuned on crossborderbiotech for coverage from the conference.  Back to the deal review, there was a fair bit of commercial activity last week, with some interesting licensing and commercial transactions announced or closed.  Read on to learn more.     Read more of this post

Friday Science Review: April 15, 2011

New Prognostic Signature for NSCLC

The Campbell Family Cancer Research Institute ♦ University of Toronto

Published in PNAS, April 7, 2011

It has long been known that the tumour microenvironment, or niche, plays a major role in the development of cancer, the progression of disease, and eventually metastasis. Non-small cell lung carcinoma (NSCLC), which accounts for 85% of lung-cancer related deaths, is highly prone to influence from fibroblasts in the stroma surrounding cancer cells.  Researchers at The Campbell Family Cancer Research Institute have been investigating one of the leading causes of cancer cell invasion, a process known as desmoplasia. During desmoplasia several things occur that exacerbate disease conditions, one of which is the evolution of normal fibroblasts to what are known as carcinoma-associated fibroblasts (CAFs). It seems that CAFs are able to enhance the tumorigenicity of lung cancer cell lines, and have a degree of prognostic power in assessing outcome. Using 15 resected NSCLCs, Dr. Tsao and his team established 15 matched normal fibroblast and CAF cell lines and carried out microarray gene-expression analysis to identify differentially expressed genes. In doing so the lab group identified 46 genes that were either upregulated or downregulated between the two sets of cells. A subset of 11 genes from this group was able to form a prognostic gene expression signature that was subsequently validated in several NSCLC microarray datasets. It was found that these genes encode extracellular matrix proteins that are regulated by the TGF-β signaling pathway. Protein-protein interaction analyses suggested that the focal adhesion and MAPK signaling pathways are involved in the transition from the normal to carcinoma-associated fibroblast states.

Bioinformatics Approach Reveals Resistance-based Genes

Mount Sinai Hospital ♦ Translational Genomics Research Institute (TGen), Arizona

Published in PLoS ONE, April 4, 2011

Statins have traditionally been used to lower cholesterol but recent evidence suggests they may have a future in treating cancer. Cholesterol accumulates in cell membranes in structures known as lipid rafts, which can influence processes such as cell growth and survival. By augmenting the composition of these lipid rafts, statins may exert cytotoxic effects on cancer cells. Many cancer cell lines exhibit resistance to statins though, limiting their utility as cancer therapeutics. In this eloquent study researchers used a panel of cancer cell lines (NCI60) and publicly available genomic and pharmacological data, to identify genes that conferred resistance to two statins, simvastatin and lovastatin. Pharmacological data identified simvastatin and lovastatin resistant cell lines which were then analyzed by whole-genome single marker association tests to uncover genes that regulate resistance. Three genes (NRP1, COL13A1, and MRPS31) were linked to resistance to simvastatin while another six (EAF2, ANK2, AKAP7, STEAP2, LPIN2, PARVB) were linked to resistance in the case of lovastatin. To confirm their findings researchers carried out a functional validation with the gene EAF2. Silencing this gene with RNAi changed the response of the colon cancer cell line HCT-116 to both statins. This work really illustrates the power of today’s genomic and pharmacological databases, and how they can be leveraged to provide insight into treating cancer.

Monday Biotech Deal Review: April 11, 2011

Welcome to your Monday Biotech Deal Review for April 11, 2011.  Notable events in the Canadian biotech space over the past week included: (i) the filing by Valeant with the SEC of a consent solicitation statement in furtherance of its efforts to replace the board of its hostile target Cephalon; (ii) the approval by creditors of the plan put forward by Angiotech in respect of its restructuring and the sanctioning of the plan by courts in Canada and the U.S.; (iii) the closing of a $34.5M private placement by MethylGene; and (iv) the resignation of the board of directors of Ambrilia and the seeking by Ambrilia to pursue insolvency proceedings under the Bankruptcy statute as opposed to creditor protection under the CCAA.  Read on to learn more.  Read more of this post

Friday Science Review: April 8, 2011

Cancer Immunotherapy in the Clinic: Dendritic Cells Present the Possibility

McMaster University ♦ Medical School of the Vrije Universiteit Brussel

Review Published in Molecular Therapy (npg), April 5, 2011

Dendritic cells play a vital role in the generation of T-cell responses to invading pathogens in the body. They fall into a class of cells known as antigen presenting cells (APCs), that display small protein segments, otherwise known as antigens, to T-cells such that an immune response may be mounted against foreign pathogens. There are three mechanisms of activation that lead to a rapid and efficient immune response. The first is the recognition of an antigen on the surface of APCs by T-cells. After a T-cell and APC meet one another, the second signal occurs by way of reinforcement through the interaction of costimulatory ligands on the extremity of both cells that work to enhance the first signal and ensure the T-cell acts upon its recognition of the foreign antigen. The third signal comes in the form of cytokines, small soluble chemical messengers released by APCs that promote T-cell polarization — immune activity geared towards foreign invaders. Dendritic cells are unique in their ability to trigger all three of these signaling mechanisms, and thus the proposition of using this cell type in immunotherapy vaccines is an interesting one.

Without knowing it, scientists have been moving towards utilizing immunotherapy in the clinic for more than 100 years. In the early 20th century researchers were already clueing in to the fact that there may exist some form of immune surveillance system allowing specific cell types to recognize and eradicate transformed cells from the body. In this recent review, written in part by researchers at McMaster University, the topic of immunotherapy is discussed in the context of manipulating dendritic cells to be amenable for use in immunotherapy vaccines.  The general concept is to engineer dendritic cells such that they express small peptides known as tumour-associated antigens (TAAs). After being injected into the body TAAs elicit an immune response polarized towards tumour cells in the body. This is achieved with genetic manipulation in the petri dish prior to preparing the vaccination. During this process a single gene or multiple genes can be introduced to dendritic cells, resulting in the continuous production of native TAA peptides that are packaged and delivered to the cell surface on MHC class II molecules.

Each of the three signaling mechanisms that promote T-cell response may be exploited for immunotherapy in vivo. The foundation of this therapeutic approach to cancer is T-cell recognition of the tumour-specific antigen on the surface of engineered dendritic cells. This recognition is translated to action by receptor/ligand costimulation, which can be magnified by one of two means: enhancing the expression of costimulatory molecules, or downregulating molecules that inhibit or suppress T-cell response to dendritic cells. This is achieved by gene transfer or silencing mechanisms in vitro. Enhancing the CD40-CD40L receptor/ligand pair and downregulating the inhibitory zinc-finger protein A20 have proven effective in increasing overall costimulation at the T-cell/APC interface. Modifying the cytokine and chemokine milieu, the environment in which the immune cells reside, helps to direct the polarization of the ensuing immune response. Anticancer T-cell responses are best suited to occur in polarized niches established by type I IFN, IFN-γ, and IL-12p70. These niches are characterized by the presence of CD8+ T-cells (cytotoxic T-cells), CD4+ T-cells (helper T-cells), and natural killer cells. To achieve modification of the immune microenvironment dendritic cells are engineered to continuously express various cytokines and chemokines.

So where do we stand in the clinic? Protocols for the generation of dendritic cells from monocytes have been established and implemented to create immunotherapies for the clinic. Phase 1 studies illustrate that immunotherapy is well-tolerated. The preparation of dendritic cells for immunotherapy applications is somewhat of a recipe. Dendritic cells are first mixed with tumour-associated antigens, and then matured with the addition of a cocktail of cytokines including PDE-2, IL-β, IL-6, and TNF-α. Improvements upon this protocol using IFN I produce “DC1″ dendritic cells that create a more highly polarized immune response following administration. One dendritic-cell based cellular vaccine has been approved by the FDA for the treatment of prostate cancer. This immunotherapy, Sipuleucel-T, was used to treat patients with castration-resistant prostate cancer and was reported to extend patient survival by 4.1 months. The authors of this review completed a clinical study involving 35 patients with metastatic melanoma. Roughly 60% of patients under therapy mounted an immune response against one or more of the vaccine antigens. Disease control of greater than 6 months with regression of metastases was noted in 35% of patients, while recurrence free survival was 23 months.

Things are looking promising in this emerging field with demonstrable safety and several clinical studies underway. While T-cell activation appears to be consistent, current engineered dendritic cells fail to provide strong enough costimulation to maintain a proinflammatory immune environment and recruit all of the necessary components necessary to eradicate transformed cells. As tumours maintain immunosuppressive environments successful immunotherapies will have to elicit persistent and aggressive responses to tumours in vivo. This will likely be achieved through the transfer of several genetic components that simultaneously enhance all three mechanisms of immune response activation.

Myriad Genetics v ACLU in the Federal Circuit

The ACLU had its day in court at the Federal Circuit yesterday, with oral arguments occupying 70 minutes of the court’s time in front of an audience of “hundreds” according to coverage from The Salt Lake Tribune (Myriad’s hometown paper). This case, you will recall, is a challenge to the patentability of isolated DNA. When the District Court ruled in favour of the ACLU, I argued that the decision was not a big deal. One of the reasons — that the Federal Circuit would overturn the decision — is one step closer to being tested. In the meantime, I stand by the other four.

The arguments are online, if you want to listen to the whole thing (thanks to @genomicslawyer for the link), and FierceBiotech and The Atlantic also have coverage.

Flow-Through Shares for Healthcare Part 3 of 3: What If It Actually Happens

Part 1 of this series described the basics of flow-throughs and Part 2 examined both the structure and the level of financing that flow-through shares have provided to the mining and oil & gas industries. This part analyzes the factors contributing to a decision by the government to expand flow-throughs to healthcare and biotech companies, and the impact that decision might have on the industry.

Read more of this post

Monday Biotech Deal Review: April 4, 2011

Welcome to your Monday Biotech Deal Review for April 4, 2011.  Valeant was a major headline last week with its hostile $5.7 billion leveraged-buyout offer for Cephalon, Inc., which some are suggesting may herald a new era of M&A activity in the biotech sector (you’ll recall that Valeant itself is the product of the recent merger with biotech heavyweight Biovail Corporation).   In addition, CCAA-protected Angiotech has filed a second amended and restated plan of compromise or arrangement and has made amendments to its support agreements, which plan is scheduled to be voted by creditors this week.  Last week continued the previous weeks’ pick-up in financing, with some newly announced and closed private placements.  And to top it off there were also a number of interesting commercial and licensing transactions.  Read on to learn more.   Read more of this post

Friday Science Review: April 1st, 2011

Temperature Sensitive Yeast Library Poised to Uncover Gene Function

University of Toronto ♦ Published in Nature Biotechnology, Mar. 27, 2011

In efforts to document the roles of essential eukaryotic genes, a group of researchers at The Terrence Donnelly Centre for Cellular and Biomolecular Research have constructed an expansive library of yeast mutants that can be manipulated with temperature to provide insight into gene function. A set of 787 temperature-sensitive strains was produced by amplifying temperature-sensitive alleles from yeast mutants and then integrating these back into a common genetic background at their native loci. To allow for the use of high-throughput screening methods a selectable marker (kanMX) was linked to each allele.

Temperature sensitive alleles allow for fine tuning of gene function with three conditions or states: permissive, semi-permissive, and restrictive. In this study, led by Dr. Charles Boone, chemical-genetic suppression analyses were carried out on the temperature-sensitive mutant collection using small molecule compounds at both permissive and non-permissive states. If a yeast mutant grows under non-permissive conditions, it can be concluded that it contains a mutation that is suppressed by a given small molecule. By creating a library populated with mutant strains with a common genetic background, researchers were able to use high-throughput strain manipulation and then carry out high-content screens at the single cell level. Gene function was determined by visualization and quantitative measurement of specific morphological features. In order to score the entire library Dr. Boone’s group created customized software that carried out automated image analysis using features such as cell shape, budding index, organelle density and a panel of 85 more reporter-specific parameters. Impressively, all computationally derived phenotypes were confirmed manually with no discrepancy in findings. Researchers took the library for a test run and performed quantitative analysis of a GFP-tubulin marker revealing that condensin and cohesin have roles in spindle disassembly.

Researchers believe the mutant library will be amenable to exploration with high-throughput methods such as high-resolution growth profiling, chemical-genetic suppression, and high content screening to elucidate the role of highly conserved signaling pathways in the model organism. Yeast has 1,101 essential genes; the mutant collection created here represents 45% of these (497 alleles). A non-overlapping set of mutants created recently covers another 250 alleles. Taken together these collections cover roughly 65% of the essential genes in yeast and are a powerful means to begin annotating the functions of all of yeast’s essential genes.

Normalizing Src-Kinase Enhancement of NMDAR, A New Paradigm for Treating Schizophrenia

The Hospital for Sick Children ♦ University of Toronto ♦ Tufts University School of Medicine

Published in Nature Medicine, Mar. 27, 2011

Excessive NRG1β-ErbB4 signaling in the brain is a hallmark of individuals suffering from schizophrenia. This aberrant signaling is believed to contribute to the hypofunction of a specific glutamate receptor, NMDAR, that is crucial for synaptic plasticity and long-term potentiation at Schaffer collateral-CA1 synapses in the hippocampus and prefrontal cortex. A popular hypothesis for the cognitive deficits and hallucinations associated with schizophrenia has been that they are the result of the general hypofunction of NMDAR.

Dr. Michael Salter and his team at The Hospital for Sick Children proposed something a little different. They hypothesized that the underlying cause of schizophrenic symptoms was actually the result of interference in a cellular mechanism that enhances NMDAR function. The tyrosine kinase Src is the primary agent mediating NMDAR phosphorylation and enhancement, and is also involved in promoting NMDAR-dependent long-term potentiation. For these reasons Dr. Salter and his team sought to investigate whether NRG1β-ErbB4 signaling has an effect on Src-mediated phosphorylation of NMDAR. It turns out it does.

Analysis of whole-cell recordings of neurons in the CA1 layer of acute slices of hippocampus removed from adult animals revealed that NRG1β-ErbB4 signaling does indeed affect Src-mediated enhancement of NMDAR function. The same was found in slices of prefrontal cortex. Researchers believe that NRB1β signaling, via its cognate receptor ErbB4, compromises the catalytic activity of Src kinase which in turn interferes with downstream events that require Src-mediated enhancement, including long-term potentiation at Schaffer collateral synapses. NRB1β-ErbB4 signaling could exert its effects by suppressing activators or facilitating inhibitors of kinase function. The work by Dr. Salter and his team provides a vital piece to the mysterious puzzle that is schizophrenia, and identifies a novel therapeutic regime to tackle cognitive dysfunction associated with the disorder.

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