Quality by Design: Development of Safe and Efficacious Full-Thickness Acellular Dermal Matrix Based on EuroGTPII Methodologies

Background

The activities of tissue establishments are constantly and rapidly evolving. The development of a new type of allograft, full-thickness acellular dermal matrix, with high mechanical properties to be used in tendon repair surgeries and abdominal wall reconstruction, has determined the need for quality by design process in order to assess evidence of quality, safety and efficacy. The EuroGTPII methodologies were specifically tailored to perform the risk assessment, identify and suggest tests in order to mitigate the potential risk consequences of a novel tissue preparation implementation.

Methods

The new allograft and associated preparation processes were assessed using the EuroGTP methodologies and characterized to properly evaluate the novelty (Step 1), identify and quantify the potential risks and risk consequences (Step 2), and define the extent of pre-clinical and clinical assessments required to mitigate the risks identified in the assessment (Step 3).

Results

Four risk consequences associated with the preparation process were identified: (i) implant failure related with tissue procurement and the reagents used during the decellularization protocol; (ii) unwanted immunogenicity related with the processing; (iii) disease transmission linked with the processing, reagents used, reduction in the reliability of microbiology testing and the storage conditions; and (iv) toxicity related to the reagents used and handling of the tissue during clinical application. The outcome of the risk assessment was a low level of risk. Nevertheless, it determined the need for a series of risk mitigation strategies proposed to reduce each individual risk and to provide additional evidence of the safety and efficacy of full-thickness acellular dermal matrix grafts.

Conclusion

EuroGTPII methodologies allow us to identify the risks and ensure the correct definition of pre-clinical assessments required to address and mitigate the potential risk consequences, before proceeding with clinical use of the new allografts in patients.

Development of a full-thickness acellular dermal graft from human skin: Case report of first patient rotator cuff patch augmentation repair

The processing and initial testing of a new human tissue preparation is described. Full-thickness Acellular Dermal Matrix (ftADM) is the extracellular matrix (ECM) obtained by decellularization of full-thickness human skin from cadaveric donors. The safety, stability and usability of the graft are discussed with respect to the results of the residual cellular content, maintenance of ECM components, and biomechanical properties. Quantitative and qualitative analysis of the ECM demonstrated the absence of cell debris, while the native structure of human dermis was maintained. Biomechanical testing showed stiffness values comparable to other commercial products used for tendon reinforcement, suggesting that our ftADM could be successfully used not only in soft tissue regeneration surgeries, but also in tendon reinforcement. First case of ftADM in rotator cuff augmentation is described. Technical management of the patch during surgery and clinical outcomes are discussed.

The Quality Management Ecosystem in Cell Therapy in Catalonia (Spain): An Opportunity for Integrating Standards and Streamlining Quality Compliance

Cell therapies are required to meet with compulsory regulations that co-exist with other optional standards and guidelines that together compose a complex quality management system. Indeed, reliable insights on the mechanisms of action and safety of novel cell-based therapies require adherence to solid quality management structures in all steps of the value chain, from early research and tissue procurement to clinical trials and biovigilance, thus guaranteeing reproducibility and solid foundations for better science and improved clinical practice. Herein we present the concept of the quality ecosystem as a tool to understand and assist all stakeholders involved in developing and structuring the integration of standards as novel developments are taking place. We conclude that the various quality management initiatives can all be thought about under the umbrella of an ecosystem.

Evaluating risk, safety and efficacy of novel reproductive techniques and therapies through the EuroGTP II risk assessment tool

STUDY QUESTION

Can risks associated with novelties in assisted reproduction technologies (ARTs) be assessed in a systematic and structured way?

SUMMARY ANSWER

An ART-specific risk assessment tool has been developed to assess the risks associated with the development of novelties in ART (EuroGTP II-ART).

WHAT IS KNOWN ALREADY

How to implement new technologies in ART is well-described in the literature. The successive steps should include testing in animal models, executing pre-clinical studies using supernumerary gametes or embryos, prospective clinical trials and finally, short- and long-term follow-up studies on the health of the offspring. A framework categorizing treatments from experimental through innovative to established according to the extent of the studies conducted has been devised. However, a systematic and standardized methodology to facilitate risk evaluation before innovations are performed in a clinical setting is lacking.

STUDY DESIGN, SIZE, DURATION

The EuroGTP II-ART risk assessment tool was developed on the basis of a generic risk assessment algorithm developed for tissue and cell therapies and products (TCTPs) in the context of the project 'Good Practices for demonstrating safety and quality through recipient follow-up European Good Tissue and cells Practices II (EuroGTP II)'. For this purpose, a series of four meetings was held in which eight ART experts participated. In addition, several tests and simulations were undertaken to fine-tune the final tool.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The three steps comprising the EuroGTP II methodology were evaluated against its usefulness and applicability in ART. Ways to improve and adapt the methodology into ART risk assessment were agreed and implemented.

MAIN RESULTS AND THE ROLE OF CHANCE

Assessment of the novelty (Step 1), consisting of seven questions, is the same as for other TCTPs. Practical examples were included for better understanding. Identification of potential risks and consequences (Step 2), consisting of a series of risks and risk consequences to consider during risk assessment, was adapted from the generic methodology, adding more potential risks for processes involving gonadic tissues. The algorithm to score risks was also adapted, giving a specific range of highest possible risk scores. A list of strategies for risk reduction and definition of extended studies required to ensure effectiveness and safety (Step 3) was also produced by the ART experts, based on generic EuroGTP II methodology. Several explanations and examples were provided for each of the steps for better understanding within this field.

LIMITATIONS, REASONS FOR CAUTION

A multidisciplinary team is needed to perform risk assessment, to interpret results and to determine risk mitigation strategies and/or next steps required to ensure the safety in the clinical use of novelties.

WIDER IMPLICATIONS OF THE FINDINGS

This is a dynamic tool whose value goes beyond assessment of risk before implementing a novel ART in clinical practice, to re-evaluate risks based on information collected during the process.

STUDY FUNDING / COMPETING INTEREST(S)

This study was called EUROGTP II and was funded by the European Commission (Grant agreement number 709567). The authors declare no competing interests concerning the results of this study.

Passive slow freezing is an efficacious and cost-effective alternative to controlled slow freezing for ovarian tissue cryopreservation

We aimed to assess the feasibility of passive slow freezing (PSF using Mr. Frosty container, Nalgene) as an alternative to controlled slow rate freezing (CSF using (Freezal™, Air liquide)) for human ovarian tissue (OT) cryopreservation. Validation studies needed were determined after assessing the risk associated (EuroGTP-II ART tool) and were conducted in 66 OT samples from 10 transgender men aged 23.4 ± 5.1 y. Folliculogenesis was assessed in vitro (after 2 h and 2 days of culture) and in vivo (2, 4 and 6 weeks xenotransplantation in Balbc/nude mice) by haematoxilin-eosin staining. Fibrosis was assessed by Masson's trichrome staining. Immunohistochemistry was used to study cell proliferation (PCNA and Ki-67) and apoptosis (caspase-3 and TUNEL). Differences in percentages were estimated using a generalized estimated equations method. After 2 days of in vitro culture, higher odds of primordial follicles (PF) (OR 1.626; 95%CI (1.162-2.266); P = 0.004) and lower odds of growing follicles (GF) (OR 0.616; 95%CI (0.441-0.861); P = 0.004) were associated with the established CSF technique. No statistical differences were found in the mean estimated proportion of proliferating (Ki-67+ or PCNA+) or apoptotic (caspase-3+ or Tunel+) follicles. Two and 6 weeks after xenotransplantation, respectively lower odds of GF (OR 0.419; 95%CI (0.217-0.809); P = 0.010) and secondary follicles (OR 0.135; 95%CI (0.071-0.255); P < 0.001) were associated with CSF. Proportion of fibrosis was similar. This validation study shows a higher follicle activation after 2 days in vitro and after 2 weeks following xenotransplantation in mice using PSF. PSF may be an easy, cost-effective low-risk alternative to CSF for cryopreservation of human OT.

Banking of corneal stromal lenticules: a risk-analysis assessment with the EuroGTP II interactive tool

We evaluated the feasibility and performed a risk-benefit analysis of the storage and widespread distribution of stromal lenticules for clinical application using a new systematic tool (European Good Tissue and cells Practices II-EuroGTP II tool), specifically designed for assessing the risk, safety and efficacy of substances of human origin. Three types of potential tissue preparations for human stromal lenticules were evaluated: cryopreserved, dehydrated and decellularized. The tool helps to identify an overall risk score (0-2: negligible; 2-6: low; 6-22: moderate; > 22: high) and suggests risk reduction strategies. For all the three types of products, we found the level of risk to be as "moderate". A process validation, pre-clinical in vitro and in vivo evaluations and a clinical study limited to a restricted number of patients should therefore be performed in order to mitigate the risks. Our study allowed to establish critical points and steps necessary to implement a new process for safe stromal lenticule preparation by the eye banks to be used in additive keratoplasty. Moreover, it shows that the EuroGTP II tool is useful to assess and identify risk reduction strategies for introduction of new Tissue and Cellular Therapies and Products into the clinical practice.