T cell therapy is in the spotlight once again. This week, Science Translational Medicine dedicated an entire special issue to immunotherapy. Among the articles and perspective, the journal published a review, by Ton Schumacher at Netherlands Cancer Institute and Carl June at the University of Pennsylvania, on the regulatory and manufacturing hurdles currently facing T cell therapy as it fights its way to market. The review, accessible via this link, highlights hurdles such as lack of standardization and scale up when laying down the path for T cell therapy to wider market acceptance. Scale-up manufacturing is a significant concern for therapies that, by the time regulatory filings are underway, have only been manufactured in smaller clinical batches. These manufacturing runs have to be scaled up in ways that will not compromise the efficacy criteria that have been established for the cellular product ahead of the manufacturing campaigns, and thus avoiding to jeopardize any regulatory claims. Moreover, personalization of T cell therapies introduces a new set of criteria which further convolutes simple paradigms for immunotherapy that had been established before.
At the recent 13th International Congress on Targeted Anticancer Therapies, Prof Antoni Ribas at the UCLA Jonsson Comprehensive Cancer Center, Los Angeles discussed the current commercial climate around T cell therapy and claimed that we are now at the cusp of a shift in tide wherein there is enough evidence to know that such therapies work, and, as consequence, we should expect more commercial investment in the further commercialization of such approaches.
You can watch the interview here.
Akron Biotech is part of this shift moving forward: we have been involved in the entire process of cell therapy development – from planning through to raw material qualification and supply and manufacturing and process validation for more rapid regulatory approval – and are innovating in those areas. We are always happy to answer any questions about your process – contact us here.
In related news, Akron Biotech has this week been featured in the Sun Sentinel in an editorial feature. CEO Claudia Zylberberg discussed recent developments at the company, including our recent expansion to a larger facility and much more. Read the feature here.
Cell Therapy Highlights: Stem cell-based HIV Trials, Progenitor Cell Transplantation and Germline editing controversy
This week, we highlight some of the more interesting headline-making news and research findings that have appeared over the past week.
FDA Approves Sangamo’s Stem Cell-based HIV Cure Trials
The Food and Drug Administration (FDA) last week approved clinical trials to test a functional cure to treat HIV based on gene editing of blood stem cells. The technique, developed by Sangamo BioSciences, is based on blood-producing stem cells derived from HIV-infected patients whose genes are edited to to create a mutation in the protein CCR5. This mutation eventually prevents HIV from attaching to the body’s blood cells. While HIV remains in the affected patient’s body, it has no ability of infecting T cells.
The trials will be conducted at the City of Hope Medical Center in California by Sangamo BioSciences and researchers from the Keck School of Medicine at the University of Southern California.
Promising pancreatic progenitor cell transplantation findings for Type 2 diabetes published in Stem Cell Journal
The lab of Timothy Kieffer, of the University of British Columbia in Canada, published promising results of an animal study on the use of stem cell transplantation for the treatment of Type 2 diabetes in the journal Stem Cell Reports last week. The authors treated mice with induced type 2 diabetes with encapsulated pancreatic progenitor cells derived from human embryonic stem cells alongside anti-diabetic drugs. After transplantation and alongside treatment with anti-diabetic drugs, the authors found that the cells developed into fully-functional beta cells, and caused improvement in body weight and hyperglycemia in treated patients.
Germline modification approach draws controversy
A lot was written in the past few weeks by various media outlets about germline cell modification. The gene splicing technology that has enabled such modifications to the germline genome and which has received the most attention – and controversy – recently is called CRISPR-Cas9, which stands for clustered regularly interspaced short palindromic repeats and which we wrote about in a previous blog. Jennifer Doudna, a co-inventor of the technology alongside Craig Mello and David Biltmore and five other scientists, co-wrote an opinion piece in Science magazine this week urging caution in using CRISPR and calling for discussion to support further developments and application of the technology. Others have been less subtle. The ISSCR and ARM both issued statements calling for moratoriums on germline editing calling it potentially unsafe, while proponents say it is a way to “cleanse” the genome from deleterious genes and avoid passing on genetic diseases.
The Whitepaper brings together leading experts in the field of cell therapy. Titled “Critical Elements in the Development of Cell Therapy Potency Assays for Ischemic Conditions,” the Whitepaper discusses key issues of importance in the development of a potency assay for treatment of ischemic disorders treated with cell therapy products. These include issues of function, biological activity and nature of the products, such as cell source and culture method, and in doing so the Whitepaper offers an opinion on the current use of cell therapy products toward more efficient process development.
To read the entire paper, click here.
This paper is part of Akron’s ongoing engagement with leading industry associations and workgroups, and speaks of our high committment to disseminating knowledge for more effective cell therapies, which we have been striving for since our inception.
Akron has years of experience in designing and developing processes and offering tools that facilitate the discovery and development of new cell therapies, as well as assisting industry and academic institutions in their development efforts. This includes potency assay design, implementation and validation, as well as whole-process optimization and process control.
If you have specific needs, please get in touch with us for a survey and see how we can help at firstname.lastname@example.org.
One of the approaches to further improve the therapeutic potential of induced pluripotent stem cells (iPSCs) has been to develop novel systems for improved proliferation and differentiation. Scaffolds have recently emerged as a potent substrate system for such studies, and a recent slew of papers describes some interesting advances.
A recent study in Biomaterials Science by Stephanie Willert’s lab at the University of Victoria evaluated two different protocols for the differentiation of murine iPSCs into neurons targeting spinal cord injury, after which the neurons were seeded onto fibrin scaffolds to further promote their differentiation. The protocols differend in the length of time the cells were treated prior to seeding onto scaffolds. The scaffold-seeding period lasted 14 days. While this is a short-term study, the authors showed that neurons were successfully formed in fibrin scaffolds during the study period, supporting their argument that the 3D environment provided by the scaffolds promoted more efficient differentiation of iPSCs.
Elsewhere, another study by Jin Nam’s lab at the University of California-Riverside published in Biomaterials investigated a more fundamental set of physicochemical parameters related to the effect of scaffolds on cultured iPSCs: the surface chemistry being the main one. They used electrospun collagen scaffolds as the model system, and found that parameters such as surface chemistry and sphericity significantly affect the proliferation of iPSCs. Moreover, by looking at the genetic profile, they found that colony morphology was significantly affected based on the physical characteristics of the scaffolds. While scaffolds are thought to promote the proliferation of stem cells by providing a 3D environment that is closer to the native environment in vivo, this paper appears to suggest that controlling the physical properties – of three-dimensionality – of the scaffolds, is of critical importance.
Elsewhere, Kevin Healy and colleagues at the University of California San Francisco investigated the theoretical aspects of iPSC contractility and the effect of different surfaces – scaffolds that give rise to different types of three dimensions – on the biological behavior of these cells. Using an isogenic iPSC line harboring the genetically encoded calcium indicator GCaMP6f the authors analyzed the contractility of the cells in different three-dimensional environments and developed software that enables the prediction and modeling of such behavior. For more on their study, see here.
These papers, though only a limited selection of recent literature, reflect the current efforts aimed at better improving the environment for the culture and differentiation of iPSCs toward new therapies.
Developments in the scaffold arena are particularly close to us at Akron – our expertise in development of novel scaffold-based systems based on electrospun nanofibers now encompasses a growing list of materials, including collagen, PCA, PLGA and many others, including composite materials, and allows the addition of compounds such as antibiotics and proteins which further enhance the 3D construct. If you would like to learn more about our expertise or have any questions about any applications, feel free to contact us at email@example.com.
At the tail end of December, the FDA released draft guidelines on Cell and Tissue-Based Products, titled “Minimal Manipulation of Human Cells, Tissues, and Cellular and Tissue-Based Products.” The guidelines came on the heels of another set of guidances, “Same Surgical Procedure Exception under 21 CFR 1271.15(b): Questions and Answers Regarding the Scope of the Exception,” which the FDA had released a month prior.
The December guidelines define a Human Cell or Tissue Therapy Product (HCT/P) under section 361 of the PHS Act and 21 CFR Part 1271 if the following apply (taken from FDA.gov):
- The HCT/P is minimally manipulated;
- The HCT/P is intended for homologous use only, as reflected by the labeling, advertising, or other indications of the manufacturer’s objective intent;
- The manufacture of the HCT/P does not involve the combination of the cells or tissues with another article, except for water, crystalloids, or a sterilizing, preserving, or storage agent, provided that the addition of water, crystalloids, or the sterilizing, preserving, or storage agent does not raise new clinical safety concerns with respect to the HCT/P; and either:
1. The HCT/P does not have a systemic effect and is not dependent upon the metabolic activity of living cells for its primary function; or
2. The HCT/P has a systemic effect or is dependent upon the metabolic activity of living cells for its primary function, and:
a.Is for autologous use;
b.Is for allogeneic use in a first-degree or second-degree blood relative; or
c.Is for reproductive use.
This week, the Alliance for Regenerative Medicine (ARM), a large advocacy organization supporting the cell therapy industry, released a set of comments on the FDA guidelines, asking for the FDA to provide clarification on a number of concepts, one of them being “main function.”
From the release:
“ARM requests more information on the concept, origin and application of the draft guidance’s inclusion of the new and yet-undefined term “main function” of the human cells, tissues, cellular and tissue-based products (HCT/Ps) when assessing minimal manipulation, as these products may have more than one function and it is not clear which of these functions would be considered primary.”
ARM calls on the FDA to “hold a public hearing to engage with stakeholders in a full airing of the topic.”
Similar comments and requests for clarification followed the release of the FDA’s previous guideline. Nonetheless, the industry appears to agree on the consensus that the FDA’ efforts in standardizing the development of cell therapy products are commendable
Because of a shortage of autologous vascular tissue for transplant procedures, in recent years, researchers and surgeons have turned to to synthetic options to achieve biocompatible vascular graft suitable for therapy. Achieving optimal physicochemical behavior of tissue engineered-scaffolds has been a significant challenge, however, as new technologies have had to adapt to the sophisticated needs of three-dimensional tissue.
Now, an interesting new development in scaffold-based tissue engineering appeared: Authors led by Quingxi Hu at Shanghai University described the creation of composite multi-layer vascular channels formed by both micro-imprinting and electrospinning.
The term “multi-layer” here refers to the generation of two electrospun layers of chitosan and polyvinyl alcohol which surround a middle later of micro-imprinted poly-p-dioxanone.
The “sheet” was rolled into a tube to create a vessel-like 3D structure.
Image of the finished 3D stucture.
The use of both electrospinning and micro-imprinting generated a rigid structure with a higher tensile and radial strength.
The authors demonstrated that the new scafffold promoted cell proliferation of rat fibrloblasts seeded on the scaffold over 21 days of culture, and the hydrophilic surface yielded good biocompatibility.
As more complex applications call for more sophisticated tissue engineering products, composite approaches like the one described in this paper appear as innovative solutions to these problems. There is still a ways to go before this scaffold reaches the clinic, but we are excited to see new applications of novel electrospinning-based fabrication approaches.
Akron has been a pioneer of electrospinning – our capabilities of creating custom shapes of electrospun tissue in a variety of polymers are the result of extensive research and development efforts that are now being expanded into more process-intensive and sophisticated applications. If you have any questions about any of these processes, contact us.
Despite a growing number of publications discussing various aspects of stem cell cryopreservation, a clear understanding of an optimal set of guidelines, including protocols and, most importantly, cryopreservation solutions that are clinically-suitable is still lacking. The unpredictable behavior and differing biophysical characteristics of different cell types has made making such generalizations less straightforward, as an understanding of individualized cell behavior is becoming of increasing importance.
A recent study by the University of Leuven in Belgium sought to bring some more clarity to these issues. The authors compared seven different freezing and thawing protocols using human amniotic fluid-derived stem cells.
- (1) 10% dimethyl sulfoxide (DMSO)
- (2) 2.5% DMSO, caspase inhibitor, and catalase
- (3) 5% glycerol, caspase inhibitor, and catalase
- (4) sperm freezing medium
- (5) slow-freezing solution
- (6) ethylene glycol, sucrose, and Ficoll 70
- (7) vitrification solution
Medium 4, sperm freezing medium, was Irvine Scientific’s TYB Freezing Medium, solution 6 was Vitrolife’s FreezeKit medium, while the vitrification solution (7) was Vitrolife’s RapidVit vitrification kit.
While protocols 1, 2, 5 and 6 resulted in successful recovery of hAFSCs based on live/dead assay, a lower CD marker expression profile was much weaker for protocol 2.
Expression levels of GAPDH, Oct-4, SOX17, vimentin, KSP and NCAM showed increased SOX17 gene expression for protocols 1, 2 and 6 compared to the unfrozen control samples.
Taking all of the results into account, the authors identified approaches 1, 5 and 6 as being superior in terms of recovery of cells by yielding a significant amount of cells with strong surface marker expression.
Out of these, the slow-freezing solution (5) was identified by the authors as being the most robust in terms of cell recovery and desirable properties after thawing, and recommendations were made as to its clinical use.
While these are preliminary results that apply to stem cells derived from amniotic fluids, the paper raises important points about the development of freezing solutions by highlighting the important fact that cell-specific behavior does not necessarily show consistency across a range of assays when analyzing treatment response and that multiple analyses need to be considered as a whole.
At Akron, we have been investigating a range of new solutions for cell cryopreservation that are both DMSO-based as well as DMSO-free and have developed a strong know-how of products and solutions for various cell types, particularly those that are free from DMSO. If you have any questions or need help understanding your options for cell cryopreservation (without or with DMSO), feel free to get in touch with us via email at firstname.lastname@example.org.