Turning Regenerative Medicine Breakthrough Ideas and Innovations into Commercial Products.

The TERMIS-Europe (EU) Industry committee intended to address the two main critical issues in the clinical/commercial translation of Advanced Therapeutic Medicine Products (ATMP): (1) entrepreneurial exploitation of breakthrough ideas and innovations, and (2) regulatory market approval. Since January 2012, more than 12,000 publications related to regenerative medicine and tissue engineering have been accepted for publications, reflecting the intense academic research activity in this field. The TERMIS-EU 2014 Industry Symposium provided a reflection on the management of innovation and technological breakthroughs in biotechnology first proposed to contextualize the key development milestones and constraints of allocation of financial resources, in the development life-cycle of radical innovation projects. This was illustrated with the biofuels story, sharing similarities with regenerative medicine. The transition was then ensured by an overview of the key identified challenges facing the commercialization of cell therapy products as ATMP examples. Real cases and testimonies were then provided by a palette of medical technologies and regenerative medicine companies from their commercial development of cell and gene therapy products. Although the commercial development of ATMP is still at the proof-of-concept stage due to technology risks, changing policies, changing markets, and management changes, the sector is highly dynamic with a number of explored therapeutic approaches, developed by using a large diversity of business models, both proposed by the experience, pitfalls, and successes of regenerative medicine pioneers, and adapted to the constraint resource allocation and environment in radical innovation projects.

Changes in ventricular remodelling and clinical status during the year following a single administration of stromal cell-derived factor-1 non-viral gene therapy in chronic ischaemic heart failure patients: the STOP-HF randomized Phase II trial.

BACKGROUND: Stromal cell-derived factor-1 (SDF-1) promotes tissue repair through mechanisms of cell survival, endogenous stem cell recruitment, and vasculogenesis. Stromal Cell-Derived Factor-1 Plasmid Treatment for Patients with Heart Failure (STOP-HF) is a Phase II, double-blind, randomized, placebo-controlled trial to evaluate safety and efficacy of a single treatment of plasmid stromal cell-derived factor-1 (pSDF-1) delivered via endomyocardial injection to patients with ischaemic heart failure (IHF). METHODS: Ninety-three subjects with IHF on stable guideline-based medical therapy and left ventricular ejection fraction (LVEF) ≤40%, completed Minnesota Living with Heart Failure Questionnaire (MLWHFQ) and 6-min walk distance (6 MWD), were randomized 1 : 1 : 1 to receive a single treatment of either a 15 or 30 mg dose of pSDF-1 or placebo via endomyocardial injections. Safety and efficacy parameters were assessed at 4 and 12 months after injection. Left ventricular functional and structural measures were assessed by contrast echocardiography and quantified by a blinded independent core laboratory. Stromal Cell-Derived Factor-1 Plasmid Treatment for Patients with Heart Failure was powered based on change in 6 MWD and MLWHFQ at 4 months. RESULTS: Subject profiles at baseline were (mean ± SD): age 65 ± 9 years, LVEF 28 ± 7%, left ventricular end-systolic volume (LVESV) 167 ± 66 mL, N-terminal pro brain natriuretic peptide (BNP) (NTproBNP) 1120 ± 1084 pg/mL, MLWHFQ 50 ± 20 points, and 6 MWD 289 ± 99 m. Patients were 11 ± 9 years post most recent myocardial infarction. Study injections were delivered without serious adverse events in all subjects. Sixty-two patients received drug with no unanticipated serious product-related adverse events. The primary endpoint was a composite of change in 6 MWD and MLWHFQ from baseline to 4 months follow-up. The primary endpoint was not met (P = 0.89). For the patients treated with pSDF-1, there was a trend toward an improvement in LVEF at 12 months (placebo vs. 15 mg vs. 30 mg ΔLVEF: -2 vs. -0.5 vs. 1.5%, P = 0.20). A pre-specified analysis of the effects of pSDF-1 based on tertiles of LVEF at entry revealed improvements in EF and LVESV from lowest-to-highest LVEF. Patients in the first tertile of EF (<26%) that received 30 mg of pSDF-1 demonstrated a 7% increase in EF compared with a 4% decrease in placebo (ΔLVEF = 11%, P = 0.01) at 12 months. There was also a trend towards improvement in LVESV, with treated patients demonstrating an 18.5 mL decrease compared with a 15 mL increase for placebo at 12 months (ΔLVESV = 33.5 mL, P = 0.12). The change in end-diastolic and end-systolic volume equated to a 14 mL increase in stroke volume in the patients treated with 30 mg of pSDF-1 compared with a decrease of -11 mL in the placebo group (ΔSV = 25 mL, P = 0.09). In addition, the 30 mg-treated cohort exhibited a trend towards improvement in NTproBNP compared with placebo at 12 months (-784 pg/mL, P = 0.23). CONCLUSIONS: The blinded placebo-controlled STOP-HF trial demonstrated the safety of a single endocardial administration of pSDF-1 but failed to demonstrate its primary endpoint of improved composite score at 4 months after treatment. Through a pre-specified analysis the STOP-HF trial demonstrates the potential for attenuating LV remodelling and improving EF in high-risk ischaemic cardiomyopathy. The safety profile supports repeat dosing with pSDF-1 and the degree of left ventricular remodelling suggests the potential for improved outcomes in larger future trials.

An open-label dose escalation study to evaluate the safety of administration of nonviral stromal cell-derived factor-1 plasmid to treat symptomatic ischemic heart failure.

RATIONALE: Preclinical studies indicate that adult stem cells induce tissue repair by activating endogenous stem cells through the stromal cell-derived factor-1:chemokine receptor type 4 axis. JVS-100 is a DNA plasmid encoding human stromal cell-derived factor-1. OBJECTIVE: We tested in a phase 1, open-label, dose-escalation study with 12 months of follow-up in subjects with ischemic cardiomyopathy to see if JVS-100 improves clinical parameters. METHODS AND RESULTS: Seventeen subjects with ischemic cardiomyopathy, New York Heart Association class III heart failure, with an ejection fraction ≤40% on stable medical therapy, were enrolled to receive 5, 15, or 30 mg of JVS-100 via endomyocardial injection. The primary end points for safety and efficacy were at 1 and 4 months, respectively. The primary safety end point was a major adverse cardiac event. Efficacy end points were change in quality of life, New York Heart Association class, 6-minute walk distance, single photon emission computed tomography, N-terminal pro-brain natruretic peptide, and echocardiography at 4 and 12 months. The primary safety end point was met. At 4 months, all of the cohorts demonstrated improvements in 6-minute walk distance, quality of life, and New York Heart Association class. Subjects in the 15- and 30-mg dose groups exhibited improvements in 6-minute walk distance (15 mg: median [range]: 41 minutes [3-61 minutes]; 30 mg: 31 minutes [22-74 minutes]) and quality of life (15 mg: -16 points [+1 to -32 points]; 30 mg: -24 points [+17 to -38 points]) over baseline. At 12 months, improvements in symptoms were maintained. CONCLUSIONS: These data highlight the importance of defining the molecular mechanisms of stem cell-based tissue repair and suggest that overexpression of stromal cell-derived factor-1 via gene therapy is a strategy for improving heart failure symptoms in patients with ischemic cardiomyopathy.

Continuous delivery of stromal cell-derived factor-1 from alginate scaffolds accelerates wound healing.

Proper wound diagnosis and management is an increasingly important clinical challenge and is a large and growing unmet need. Pressure ulcers, hard-to-heal wounds, and problematic surgical incisions are emerging at increasing frequencies. At present, the wound-healing industry is experiencing a paradigm shift towards innovative treatments that exploit nanotechnology, biomaterials, and biologics. Our study utilized an alginate hydrogel patch to deliver stromal cell-derived factor-1 (SDF-1), a naturally occurring chemokine that is rapidly overexpressed in response to tissue injury, to assess the potential effects SDF-1 therapy on wound closure rates and scar formation. Alginate patches were loaded with either purified recombinant human SDF-1 protein or plasmid expressing SDF-1 and the kinetics of SDF-1 release were measured both in vitro and in vivo in mice. Our studies demonstrate that although SDF-1 plasmid- and protein-loaded patches were able to release therapeutic product over hours to days, SDF-1 protein was released faster (in vivo K(d) 0.55 days) than SDF-1 plasmid (in vivo K(d) 3.67 days). We hypothesized that chronic SDF-1 delivery would be more effective in accelerating the rate of dermal wound closure in Yorkshire pigs with acute surgical wounds, a model that closely mimics human wound healing. Wounds treated with SDF-1 protein (n = 10) and plasmid (n = 6) loaded patches healed faster than sham (n = 4) or control (n = 4). At day 9, SDF-1-treated wounds significantly accelerated wound closure (55.0 +/- 14.3% healed) compared to nontreated controls (8.2 +/- 6.0%, p < 0.05). Furthermore, 38% of SDF-1-treated wounds were fully healed at day 9 (vs. none in controls) with very little evidence of scarring. These data suggest that patch-mediated SDF-1 delivery may ultimately provide a novel therapy for accelerating healing and reducing scarring in clinical wounds.

Effect of host species on recG phenotypes in Helicobacter pylori and Escherichia coli.

Recombination is a fundamental mechanism for the generation of genetic variation. Helicobacter pylori strains have different frequencies of intragenomic recombination, arising from deletions and duplications between DNA repeat sequences, as well as intergenomic recombination, facilitated by their natural competence. We identified a gene, hp1523, that influences recombination frequencies in this highly diverse bacterium and demonstrate its importance in maintaining genomic integrity by limiting recombination events. HP1523 shows homology to RecG, an ATP-dependent helicase that in Escherichia coli allows repair of damaged replication forks to proceed without recourse to potentially mutagenic recombination. Cross-species studies done show that hp1523 can complement E. coli recG mutants in trans to the same extent as E. coli recG can, indicating that hp1523 has recG function. The E. coli recG gene only partially complements the hp1523 mutation in H. pylori. Unlike other recG homologs, hp1523 is not involved in DNA repair in H. pylori, although it has the ability to repair DNA when expressed in E. coli. Therefore, host context appears critical in defining the function of recG. The fact that in E. coli recG phenotypes are not constant in other species indicates the diverse roles for conserved recombination genes in prokaryotic evolution.

Extensive repetitive DNA facilitates prokaryotic genome plasticity.

Prokaryotic genomes are substantially diverse, even when from closely related species, with the resulting phenotypic diversity representing a repertoire of adaptations to specific constraints. Within the microbial population, genome content may not be fixed, as changing selective forces favor particular phenotypes; however, organisms well adapted to particular niches may have evolved mechanisms to facilitate such plasticity. The highly diverse Helicobacter pylori is a model for studying genome plasticity in the colonization of individual hosts. For H. pylori, neither point mutation, nor intergenic recombination requiring the presence of multiple colonizing strains, is sufficient to fully explain the observed diversity. Here we demonstrate that H. pylori has extensive, nonrandomly distributed repetitive chromosomal sequences, and that recombination between identical repeats contributes to the variation within individual hosts. That H. pylori is representative of prokaryotes, especially those with smaller (<2 megabases) genomes, that have similarly extensive direct repeats, suggests that recombination between such direct DNA repeats is a widely conserved mechanism to promote genome diversification.

Plasticity of repetitive DNA sequences within a bacterial (Type IV) secretion system component.

DNA rearrangement permits bacteria to regulate gene content and expression. In Helicobacter pylori, cagY, which contains an extraordinary number of direct DNA repeats, encodes a surface-exposed subunit of a (type IV) bacterial secretory system. Examining potential DNA rearrangements involving the cagY repeats indicated that recombination events invariably yield in-frame open reading frames, producing alternatively expressed genes. In individual hosts, H. pylori cell populations include strains that produce CagY proteins that differ in size, due to the predicted in-frame deletions or duplications, and elicit minimal or no host antibody recognition. Using repetitive DNA, H. pylori rearrangements in a host-exposed subunit of a conserved bacterial secretion system may permit a novel form of antigenic evasion.

Natural variation in populations of persistently colonizing bacteria affect human host cell phenotype.

The highly diverse bacterium Helicobacter pylori, which persistently colonizes the human stomach, provides models to study the role of genome plasticity in host adaptation. Within H. pylori populations from 2 colonized individuals, intragenomic recombination between cagA DNA repeat sequences leads to deletion or duplication of tyrosine phosphorylation sites in the CagA protein, which is injected by a type IV secretion system into host cells. Experimental coculture of gastric epithelial cells with the strains containing these naturally occurring CagA phosphorylation site variants induced markedly divergent host cell morphologic responses. Mutants were constructed in which a phosphorylation site was either added or deleted in the expressed CagA protein; coculture studies confirmed that the naturally occurring differences in CagA phosphorylation are responsible for the observed phenotypic variation. These findings indicate that within an individual host, intragenomic recombination between H. pylori repetitive DNA produces strain variants differing in their signals to host cells.

Helicobacter pylori interstrain restriction-modification diversity prevents genome subversion by chromosomal DNA from competing strains.

Helicobacter pylori, bacteria that colonize the human gastric mucosa, possess a large number of genes for restriction-modification (R-M) systems, and essentially, every strain possesses a unique complement of functional and partial R-M systems. Nearly half of the H.pylori strains studied possess an active type IIs R-M system, HpyII, with the recognition sequence GAAGA. Recombination between direct repeats that flank the R-M cassette allows for its deletion whereas strains lacking hpyIIRM can acquire this cassette through natural transformation. We asked whether strains lacking HpyII R-M activity can acquire an active hpyIIRM cassette [containing a 1.4 kb kanamycin resistance (aphA) marker], whether such acquisition is DNase sensitive or resistant and whether restriction barriers limit acquisition of chromosomal DNA. Our results indicate that natural transformation and conjugation-like mechanisms may contribute to the transfer of large (4.8 kb) insertions of chromosomal DNA between H.pylori strains, that inactive or partial R-M systems can be reactivated upon recombination with a functional allele, consistent with their being contingency genes, and that H.pylori R-M diversity limits acquisition of chromosomal DNA fragments of >/=1 kb.

Phenotypic and genotypic variation in methylases involved in type II restriction-modification systems in Helicobacter pylori.

To determine relationships between Helicobacter pylori geographical origin and type II methylase activity, we examined 122 strains from various locations around the world for methylase expression. Most geographic regions possessed at least one strain resistant to digestion by each of 14 restriction endonucleases studied. Across all of the strains studied, the average number of active methylases was 8.2 +/- 1.9 with no significant variation between the major geographic regions. Although seven pairs of isolates showed the same susceptibility patterns, their cagA/vacA status differed, and the remaining 108 strains each possessed unique patterns of susceptibility. From a single clonal group, 15 of 18 strains showed identical patterns of resistance, but diverged with respect to M.MboII activity. All of the methylases studied were present in all major human population groupings, suggesting that their horizontal acquisition pre-dated the separation of these populations. For the hpyV and hpyAIV restriction-modification systems, an in-depth analysis of genotype, indicating extensive diversity of cassette size and chromosomal locations regardless of the susceptibility phenotype, points toward substantial strain-specific selection involving these loci.

A Helicobacter pylori restriction endonuclease-replacing gene, hrgA, is associated with gastric cancer in Asian strains.

The sensitivity of Helicobacter pylori chromosomal DNA to MboI digestion was investigated in 208 strains from several continents. Only 11 (5%) of strains were sensitive to MboI, and it was hypothesized that HpyIII, a type II restriction/modification enzyme with sequence homology to MboI, mediated the protection. This was confirmed by PCR analysis of the gene locus of hpyIII, normally composed of hpyIIIR and hpyIIIM. In all but one strain sensitive to MboI, no PCR product of hpyIIIR was obtained. In contrast, all strains yielded a product for hpyIIIM, independent of MboI phenotype. Further examination of the hpyIII locus in strains lacking a hpyIIIR PCR product identified a novel gene, hrgA, upstream of hpyIIIM. All 208 strains examined had either hpyIIIR or hrgA, but not both, upstream of hpyIIIM. Although hrgA has homology with a Campylobacter jejuni gene (Cj1602), its function is not known. In Western countries, hrgA was more prevalent (53%) than in Asia (25%; P < 0.0001, chi(2)). In Asia, hrgA was more prevalent among gastric cancer patients (18 of 43; 42%) than among noncancer patients (16 of 95; 17%; P = 0.001, chi(2)). All 143 Asian strains tested were cagA(+), but among Western strains, hrgA was more prevalent in cagA(+) strains (26 of 42; 62%) than in cagA(-) strains (9 of 23; 39%; P = 0.04, chi(2)). In coculture with epithelial cells, hpyIIIR and hrgA strains did not show any significant differences in interleukin-8 induction and apoptosis. Although a direct function for hrgA in virulence could not be demonstrated, our data indicate that hrgA is a strain-specific gene that might be associated with gastric cancer among H. pylori isolates from Asian patients.