• Cryopreservation of mesenchymal stromal cells can attenuate clinical immune effects
    As Jacques Galipeau reported in conferences and in the paper, cryopreservation could negatively affect therapeutic “immunomodulatory value” of mesenchymal stromal cells (MSC). There was no independent confirmation of Galipeau’s findings, and many MSC product developers remained skeptical. This week, Katarina Le Blanc published a report, which supports Galipeau’s conclusions and provides more insight into potential clinical value of this phenomenon. Let me just say – this paper could change the field! Le Blanc concluded that freeze-thawed human MSC compared to […]
  • Cells Weekly – October 19, 2014

    by Alexey Bersenev on October 19, 2014 · 0 comments

    in notes

    Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night!

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    1. First results of embryonic stem cell trial told by Robert Lanza
    Stem cell feed this week was dominated by news about results of ACT’s trial. Here is a video, where Robert Lanza explains published results:

    Also read:
    ACT Interim Clinical Results Are Outstanding by Irv Arons.
    Encouraging New Paper on ACT Stem Cell-Based Trial for Macular Degeneration by Paul Knoepfler

    2. Good news from cellular immunotherapy trials
    Cell therapy feed this week was dominated by news about successful use of T-cells in patients with malignancies. First, NIH/ Kite Pharma published results of Phase 1 trial, assessing gene-modified CAR T-cells in hematological malignancies (ALL and NHL). The authors reported complete remission in 70% “no options” patients. Second, Upenn/ Novartis team reported results of trial, assessing CAR T-cells in pediatric ALL. Complete response was achieved in 90% of “no options” patients. Third, UK-based company AdaptImmune announced interim results of Phase 1 trial, assessing TCR- modified T-cells in patients with synovial sarcoma. 80% of patients responded to experimental therapy in AdaptImmune trial.

    GSK Vice President commented on AdaptImmune and CAR T-cell trials:

    “We believe, if we can push it, that it could be as successful as the CAR approach, just in different patients,” Hoos said. “Really, the two are complementary with each other.”

    3. Hype around Melton’s diabetes study
    As you may heard from last week, Harvard’s Doug Melton’s lab has published a protocol for generation of human beta-like cells from pluripotent cells. Unfortunately, the study was hugely over-hyped not only in mass media, but also by researcher themselves. Paul Knoepfler wrote on hype here and here. Hype was discussed and condemned on twitter here, here and here. Turns out, Harvard is using this hype “as a fundraising tool“. Jonathan Eisen nicely summarized all hype around Harvard-Melton here. My comment:
    Melton’s study is representing methodological advance in the field of “stem cell therapy for diabetes”. One step closer to clinically-relevant protocol in terms of cell number and function of beta-like cells. However, what can we see in coverage of this study – is only hype, Hype, HYPE! No sober analysis of findings and ignorance of achievements of other research groups in the past two decades. Using buzz words like “cure”, “breakthrough”, “giant leap” … can mislead public and undermine the credibility of science. Very unfortunately, researchers themselves over-hyped their work by misleading commentaries. Other groups actually showed glucose sensing by beta-like cells, generated from stem cells (one of such study was covered by the Signals blog) and went as far as first-in-human studies. Researchers, including Melton, and institutions (shameful Harvard’s fundraising campaign) should be responsible for such overhype.

    4. Challenges in whole organ engineering – interview with Tahera Ansari
    Methuselah Foundation interviewed a researcher from UK – Tahera Ansari about the current status and future of liver tissue engineering. Ansari is representing one of six teams, which will compete for New Organ Liver Prize. This interview is so great! I’d highly recommend you to read it all.

    In the end, I wonder whether we may have to figure out how to harvest a smaller portion of organoid units from small biopsies of a patient’s liver, seed them into a scaffold alongside other stem cells, and then somehow get those organoid units to turn the adjacent stem cells into liver cells.

    5. Cardiac fibroblasts convert into endothelial cells in injured heart
    New study, published in Nature, demonstrates that cardiac fibroblasts play important role in reparation of damaged myocardium by mesenchymal–endothelial transition and neovascularization. If we figure out the ways to control this process in situ, we may not need to bother with such complex interventions as cell or/and gene therapy.

    6. Advances in generation of gastro-intestinal organoids
    Hans Clever’s group published a protocol for generation of human gastric organoids from biopsies. Remarkably, the model of H. Pylori was re-created in culture:

    We generated organoids from surgical samples of human gastric corpus. Culture conditions were developed based on those for the mouse gastric and human intestinal systems. We used microinjection to infect the organoids with H pylori. Epithelial responses were measured using microarray and quantitative PCR analyses.

    The other group of researchers recently described a system for generation of human intestinal organoids from pluripotent stem cells. Importantly, these organoids were successfully tested in vivo:

    Transplanted intestinal tissues demonstrated digestive functions as shown by permeability and peptide uptake studies. Furthermore, transplanted HIO-derived tissue was responsive to systemic signals from the host mouse following ileocecal resection, suggesting a role for circulating factors in the intestinal adaptive response.

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    This is second post of the series Products in the Pipeline. In this series I’ll provide publicly available information about therapeutic products – candidates for commercialization by cell therapy industry companies. Please leave your feedback and propose cell products to cover!

    Today I’m going to analyze Ixmyelocel-T manufactured by Aastrom

    Product candidate name: Ixmyelocel-T
    Developer: Aastrom Biosciences (Vericel Corporation)
    History of development: Company founded in 1989. Product in development >10 years. Phase 1 studies started ~2005, Phase 2 in 2007
    Type of cells: human autologous, multicellular, expanded ex vivo
    Tissue source: Bone marrow aspirate (~ 50 mL)
    Processing steps: Mononuclear cell (MNC) isolation by gradient centrifugation (using Sepax, Biosafe), ex vivo expansion of MNC in proprietary bioreactor (media includes animal serum) for ~12 days, harvest (including enzymatic digestion and wash), final formulation as fresh concentrated product (final volume = 10 mL)
    Shelf life: 72 hours
    Storage in hypothermic solution (HypoThermosol + Isolyte + HSA)
    Cellular composition: (1) Expanded ~200-fold M2 CD14+ macrophages, (2) expanded ~50-fold mesenchymal stromal cells. The rest – all types of bone marrow cells: (3) hematopoietic CD45+ cells – myeloid (granulocytes, monocytes, myeloid progenitors), lymphoid (T cells, B cells, NK, lymphoid progenitors)
    CD90 + CD14 cells compose >98% of product
    Phenotypic characterization: positive for: CD90, CD105, VEGFR1/2, CD14, CD45, CD163, CD206, CD11b
    Release criteria: number of viable cells: 35-295 millions, viability by trypan blue >70%, positivity for CD90 (~20%) and CD45 (~80%) by flow cytometry
    Proposed mechanisms of action: Immunomodulatory, anti-inflammatory, stimulation of angiogenesis, trophic/ paracrine.
    Administration: Intramuscular, intracardiac – multiple injections
    Key publications:
    Circulation Research doi: 10.1161/CIRCRESAHA.115.304554
    Molecular Therapy doi:10.1038/mt.2012.52
    Stem Cell Res Ther doi:10.1186/scrt345
    Stem Cell Res Ther doi:10.1186/scrt117
    List of publications on CLI and on DCM
    Trials: Ongoing – ixCELL DCM
    List of completed trials
    Analaysis of failure Phase 3 REVIVE trial
    Results of trials: RESTORE-CLI, IMPACT-DCM and Catheter-DCM.
    Key patents:
    Mixed cell populations for tissue repair – WO 2008054825 A2, EP 2314300 B1
    Mesenchymal stromal cell populations – WO 2012159042 A1
    Bioreactor for mammalian cell growth – WO 1996040860 A1

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    First results of embryonic stem cell trials

    by Alexey Bersenev on October 14, 2014 · 0 comments

    in cell product

    Today – October 14 of 2014 is a very important day in “stem cell history”. US-based company Advanced Cell Technology (ACT) released results of the clinical trials, where embryonic stem cell-derived product was tested in patients with macular degeneration. The first ever peer-reviewed results of FDA-approved clinical trials, involved use of embryonic stem cells (ESC), published online in Lancet (keep renewing your browser window until Lancet will put abstract in). You can download article here. This is a big milestone in stem cell research and cell therapy industry! I think, it’s probably the most important event of the year so far! Here is why:

    1. Out of few, approved by federal regulatory agencies, ESC-based trials, none results were published in peer-reviewed literature until now (I don’t count Asterias PR and ACT two cases report).
    2. Everybody were eagerly awaiting for results of safety profile of ESC-based therapeutic. ACT’s study concluded that ESC-derived product is safe during observation time of 2 years. Study is feasible.
    3. Even though, trials were not design to assess efficacy, more than half of patients demonstrate different degree of improvement of sight.
    4. There were some signs of engraftment of ESC-derived cells in more than half patients. That’s what we are missing in “adult stem cell studies”.
    5. Despite criticism and some critical financial periods, ACT was able to conduct/ complete the trials and report results. ACT shows – it’s possible! What a courage and inspiration for others! No matter how the next phase will progress, ACT is blazed the trail for other developers.
    6. With positive data, this study is triggering a new wave of interest to embryonic stem cell-based therapies.

    Now, some considerations against premature hype:

    1. The report is not final, but interim. Patients from 2 separate trials (NCT01345006 and NCT01344993) were combined for analysis. Each trial has an enrollment goal of 16 patients by the end of this year. So data could change when all patients will be analyzed.
    2. Two years is mid-term observation, but long-term follow-up (10-15 years) is required to conclude safety of ESC-derived products. And… yes – we still don’t know the efficacy until Phase 2 will be concluded.
    3. Some complications were reported in the study (but not in official company’s PR and mass media coverage): 4 eyes had significant progression of cataract, requiring surgery 6-12 months after cell therapy, 1 patient developed bacterial eye infection 4 days after cell therapy, 1 eye – “sterile inflammation”, 1 eye – subretinal bleb. All complications were resolved and did not lead to enucleation. There was no evidence for direct relation to a product, but seem like complications were procedure-related (surgery).
    4. Instead of paying much attention to PR and mass media coverage, I’d encourage you to read an article and do your own assessment.

    *******************
    PS: I do not have any conflicts, related to ACT.

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    Cells Weekly – October 12, 2014

    by Alexey Bersenev on October 12, 2014 · 0 comments

    in notes

    Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night!

    CD34+Banner_490x90

    1. Stem Cell Person of the Year 2014
    Paul Knoepfler runs annual contest Stem Cell Person of the Year. Please cast your vote!
    I noticed that most nominee are keep doing a lot of good things for stem cell field persistently from year to year. So, in order to pick the best one, I propose to nominate candidates who blew your mind this particular year (2014)! This year I nominated JuuichiJigen – Japanese blogger who investigated and brought to the public problems with STAP papers. Importantly, his investigations demonstrated the role of social media and post-publication peer review in rapid self-correction of science. It was the most significant event for stem cell research and open science online this year so far. Yet another person, who “rock the boat” this year – Masayo Takahashi.

    2. Long-term outcome of cell gene therapy of “bubble boy” disease
    Gene therapy of inherited immunodeficiencies, such as X-linked severe combined immunodeficiency (SCID-X1) is effective method, which can provide recovery of normal immune system. However, previous trials unveiled serious adverse events – viral vector-induced leukemias in 25% of patients. The study, published this week, reports results of using new generation vector – self-inactivating γ-retrovirus:

    After 12.1 to 38.7 months of follow-up, eight of the nine children were still alive. One patient died from an overwhelming adenoviral infection before reconstitution with genetically modified T cells. Of the remaining eight patients, seven had recovery of peripheral-blood T cells that were functional and led to resolution of infections.

    Good results so far! patients will be monitored for 15 years. From press release:

    “Our goal was to take the molecular data from the prior trial and use it to produce a vector that would remain effective and at the same time reduce the risk of leukemia,” said David A. Williams,

    “The efficacy data from our study is clear: The vector does work to correct the disease. And by a surrogate endpoint, we have improved the treatment’s safety, although it’s too early to say that we’ve completely eliminated the long-term risk of leukemia.”

    Also read: SCID-X1 Gene Therapy, Take 2 – DNA Science Blog by Ricki Lewis

    3. Australian “stem cell therapeutic” company under fire
    Sydney-based Regeneus recently made headlines with news about “approval by AFL” of use their commercial product HiQCell in athletes. Australian media outlet ABC reported this week that “company is under fire” for giving misleading information about their products and trials:

    7.30 has also learned the AFL was displeased when Regeneus put out the press release because it felt was dressed up to look like an official AFL endorsement.
    In fact, it was based on one discussion with the AFL chief medical officer about one player from one club.

    However, the complaint letter obtained by 7.30 points out the statement left out some key information.
    “It is misleading because the control (placebo) group in that trial also achieved the same reduction in pain and slowing of cartilage degeneration,” the letter said.

    You can read company’s reply here.

    4. Isolation of mesenchymal stromal cells by biophysical characteristics
    A group of researchers identified biophysical characteristics of MSC, which could be used to isolate these cells via microfluidic device. From press release:

    After measuring several other physical traits, the researchers found two that could be combined with size to completely distinguish MSCs from other stem cells: stiffness of the cell, and the degree of fluctuation in the cell’s nuclear membrane.
    “You don’t need more than these three, but you also can’t use fewer than these three,” Van Vliet says. “We now have a triplet of characteristics that identifies populations of cells that are going to be multipotent versus populations of cells that are only going to be able to become bone or cartilage cells.”

    Looks like great investment opportunity!

    5. Risk of feeder-derived tumorigenesis in human iPS cell culture
    Japanese researchers investigated potential risk of tumorigenesis, related to xenogenic feeder cells, routinely used for culture of human iPS cells:

    We examined the genetic origin and characteristics of tumors, that were formed when 13 hiPSC lines, established by ourselves, and 201B7 hiPSC from Kyoto University were transplanted into severe combined immune-deficient (SCID) mice. Though teratomas formed in 58% of mice, five angiosarcomas, one malignant solitary fibrous tumor and one undifferentiated pleomorphic sarcoma formed in the remaining mice.
    … hiPSCs grown on MMC-SNL feeder cells have a high risk of generating feeder-derived malignant tumors. The possible mechanism(s) of growth restoration and the formation of multiple tumor types are discussed with respect of the interactions between MMC-SNL and hiPSC.

    What else should be said against using xeno-feeder for human pluripotent stem cell culture?

    6. Exchange of membrane components between MSC and cardiac cells
    Interesting phenomenon, related to MSC biology was recently described. In experimental model in vitro, MSC and cardiac cells actively exchanged membrane components:

    This study clearly demonstrates for the first time that MSC and HL-1 cells exchange membrane components in a time-dependent manner when cocultured. We found that 100% of the MSC gained membrane from the HL-1 cells after 20 hours while 48% of the HL-1 cells gained membrane from the MSC.

    This phenomenon can explain potential mechanism of action of MSC in cardiac diseases and “transdifferentiation magic”.

    7. Using organotypic units for tissue engineering
    A group of researchers used freshly isolated or cultured “esophageal organoid units” to engineer esophagus in vivo on simple degradable scaffold:

    None have generated human TEE with mesenchymal components. We hypothesized that sufficient progenitor cells might only require basic support for successful generation of murine and human TEE.
    Tissue-engineered esophagus forms after transplantation of mouse and human organ-specific stem/progenitor cells in vivo on a relatively simple biodegradable scaffold.

    8. All about cell fate
    EuroStemCell posted a great summary on cell fate decision and reprogramming. Also watch produced by EuroStemCell and freshly released documentary Cell Fate: Journeys to specialisation.

    9. Stem cell culture advances
    The Cell Culture Dish blog posted an overview of new stem cell culture tools, presented on ISSCR 2014 conference.

    *************************************
    bonus:

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    Using molecular beacons for isolation of human osteogenic progenitors from adipose SVF

    by Alexey Bersenev October 9, 2014 adipose

    Molecular beacons (MB) is a new technique for cell isolation, based on capture of genetic (intracellular or intranuclear) markers. MB have been used in research for isolation of embryonic stem cells and cardiomyocytes since 2011. I’m dreaming about using MB for clinical cell isolation. Recently, a group of researchers from Brown University published a study, which makes one step closer to clinical application of MB. The authors used MB, which captures mRNA of alkaline phosphatase (ALPL) in osteogenic progenitors, derived […]

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    Barcoding in situ to study steady state hematopoiesis

    by Alexey Bersenev October 7, 2014 hematopoietic

    Few days ago, Harvard’s investigator Fernando Camargo published results of long-term study, which challenges our current understanding of steady state hematopoiesis. Remarkably, the authors showed that long-lasting polyclonal progenitors contribute to normal blood turnover the most rather than hematopoeitic stem cells. It’s actually not a big news if you follow discussions from recent studies of steady state hematopoiesis. However, what makes Camargo’s study special is a methodology. The authors used very sophisticated and quite complicated approach to label blood cells […]

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    Cells Weekly – October 5, 2014

    by Alexey Bersenev October 5, 2014 notes

    Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night! 1. Placental stromal cells in multiple sclerosis – results of clinical trial Celgene Cellular Therapeutics published results of Phase 1b clinical trial, assessing allogeneic placenta-derived mesenchymal-like cells in patients with multiple sclerosis: PDA-001 infusions were safe and well tolerated in relapsing-remitting multiple sclerosis and secondary progressive multiple sclerosis patients. No paradoxical worsening […]

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    Breaking down fat: Use of freshly isolated SVF versus cultured ASC

    by Alexey Bersenev October 3, 2014 adipose

    We defined Stromal Vascular Fraction (SVF) – as cell fraction, freshly isolated from native adipose tissue or liposuction aspirates and Adipose-derived Stromal (stem) Cells (ASCs) as plastic adherent cell population, derived from SVF and propagated in culture. The big question in cell therapy is how to decide what to use SVF or ASC. There are many considerations for decision making, but most important the following: Experimental data, which support the preferential use of one cell product type versus another in […]

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    Products in the pipeline – Celgene’s Cenplacel-L

    by Alexey Bersenev September 30, 2014 cell product

    I’m starting new series of posts – Products in the pipeline. In this series I’ll provide publicly available information about therapeutic products – candidates for commercialization by cell therapy industry companies. “Publicly available” means (1) published in literature, (2) reported on conferences, (3) freely available from patents, (4) available from clinical trials registries, (5) posted in companies press releases. I’d also like to include information, provided by company’s representative with legal permission (please contact me!). The purpose of this series […]

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    Cells Weekly – September 28, 2014

    by Alexey Bersenev September 28, 2014 notes

    Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night! 1. More insight into STAP puzzle Researcher from RIKEN, Takaho Endo published results of genetic analysis of STAP cells, using RNA sequencing: The analysis indicated that different types of cells and chromosomal abnormalities might have been erroneously included in the dataset. Particularly, he identified trisomy chromosome 8 – a mutation, which resembles […]

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