Successful development and clinical translation of a novel anterior lamellar artificial cornea

Abstract

Blindness due to corneal diseases is a common pathology affecting up to 23 million individuals worldwide. The tissue-engineered anterior human cornea, which is currently being tested in a Phase I/II clinical trial to treat severe corneal trophic ulcers with preliminary good feasibility and safety results. This bioartificial cornea is based on a nanostructured fibrin-agarose biomaterial containing human allogeneic stromal keratocytes and cornea epithelial cells, mimicking the human native anterior cornea in terms of optical, mechanical, and biological behavior. This product is manufactured as a clinical-grade tissue engineering product, fulfilling European requirements and regulations. The clinical translation process included several phases: an initial in vitro and in vivo preclinical research plan, including preclinical advice from the Spanish Medicines Agency followed by additional preclinical development, the adaptation of the biofabrication protocols to a good manufacturing practice manufacturing process, including all quality controls required, and the design of an advanced therapy clinical trial. The experimental development and successful translation of advanced therapy medicinal products for clinical application has to overcome many obstacles, especially when undertaken by academia or SMEs. We expect that our experience and research strategy may help future researchers to efficiently transfer their preclinical results into the clinical settings.

Keywords: advanced therapy medicinal products (ATMPs); clinical translation; cornea; preclinical research; regulatory issues; tissue engineering; tissue-engineered anterior human cornea (TEAHC).

Figure 1

Primary cell cultures and tissue‐engineered anterior human cornea (TEAHC) generated by tissue engineering. (a) Schematic structure of the TEAHC. (b) Phase‐contrast microscopic images of cultured stromal keratocytes. (c) Phase‐contrast microscopic images of cultured corneal epithelial cells. (d) Macroscopic image of the artificial cornea after being subjected to nanostructuration. (e) Histological analysis of the artificial cornea stained with hematoxylin and eosin. (f) TEAHC implanted in the corneal lesion using interrupted 10–0 nylon sutures. Scale bar: 100 μm [Colour figure can be viewed at http://wileyonlinelibrary.com] [Colour figure can be viewed at http://wileyonlinelibrary.com]

Figure 2

Microarray profiling of mRNA expression in primary cell cultures and tissue‐engineered anterior human cornea (TEAHC). (a) Hierarchical clustering of the 3,205 differentially expressed genes (condition FDR F‐test <0.05 and fold change ±2) in TEAHC compared with epithelial cells and keratocytes. (b) Selected genes related to corneal epithelium development and morphogenesis. (c) Selected genes related to corneal transparency (LDHA), proliferation (PCNA), apoptosis (CASP9), and malignant transformation (TERT, C‐MYC, and MRAS) [Colour figure can be viewed at http://wileyonlinelibrary.com]

Figure 3

In vivo and histological evaluation of tissue‐engineered anterior human cornea (TEAHC) grafted on the eye surface of laboratory rabbits. (a) Control nonoperated cornea, (b) grafted TEAHC after 3 weeks, (c) grafted TEAHC at 3 months, (d) grafted TEAHC after 6 months, (e) optical coherence tomography (OCT) analysis of the control nonoperated cornea, and (f) OCT analysis of the grafted TEAHC after 6 months. The white arrow shows a heterogeneity area at the central stroma. (g) Histological study of native control and (h) TEAHC grafted in vivo in laboratory rabbits for 6 months using hematoxylin and eosin staining [Colour figure can be viewed at http://wileyonlinelibrary.com]

Figure 4

Clinical‐grade Production and quality controls in the production of the tissue‐engineered anterior human cornea (TEAHC) in compliance with good manufacturing practice. (a) Quality controls and acceptance criteria defined to release each product of the manufacturing process. H, high; HAC, human allogeneic cornea (TEAHC); K, keratocytes; LSC, limbal stem cells; M, medium. (b) Limbal cell karyotype included in the quality controls of the TEAHC; (c) Example of the absence of microorganism in mycoplasma assay quality control [Colour figure can be viewed at http://wileyonlinelibrary.com]

Figure 5

Product development and clinical translation process of the tissue‐engineered anterior human cornea (TEAHC). The translation of an advanced therapy medicinal product from basic research into a clinical‐grade product applicable in a human clinical trial is a complex, integrated activity that requires multidisciplinary expertise involving basic researchers, clinicians, manufacturing facilities, technology transfer offices, regulatory agencies, and patient organizations. The whole clinical translational process is facilitated by entities like the Andalusian Initiative for Advanced Therapies that promotes communication among strategic stakeholders and coordinates the activities of the research teams involved in the development of the TEAHC [Colour figure can be viewed at http://wileyonlinelibrary.com]