Improving translatability of preclinical studies for neuromuscular disorders: lessons from the TREAT-NMD Advisory Committee for Therapeutics (TACT).

Clinical trials for rare neuromuscular diseases imply, among other investments, a high emotional burden for the whole disease community. Translation of data from preclinical studies to justify any clinical trial must be carefully pondered in order to minimize the risk of clinical trial withdrawal or failure. A rigorous distinction between proof-of-concept and preclinical efficacy studies using animal models is key to support the rationale of a clinical trial involving patients. This Review evaluates the experience accumulated by the TREAT-NMD Advisory Committee for Therapeutics, which provides detailed constructive feedback on clinical proposals for neuromuscular diseases submitted by researchers in both academia and industry, and emphasizes that a timely critical review of preclinical efficacy data from animal models, including biomarkers for specific diseases, combined with adherence to existing guidelines and standard protocols, can significantly help to de-risk clinical programs and prevent disappointments and costly engagement.

A phase I/IItrial of MYO-029 in adult subjects with muscular dystrophy.

OBJECTIVE: Myostatin is an endogenous negative regulator of muscle growth and a novel target for muscle diseases. We conducted a safety trial of a neutralizing antibody to myostatin, MYO-029, in adult muscular dystrophies (Becker muscular dystrophy, facioscapulohumeral dystrophy, and limb-girdle muscular dystrophy). METHODS: This double-blind, placebo-controlled, multinational, randomized study included 116 subjects divided into sequential dose-escalation cohorts, each receiving MYO-029 or placebo (Cohort 1 at 1 mg/kg; Cohort 2 at 3 mg/kg; Cohort 3 at 10 mg/kg; Cohort 4 at 30 mg/kg). Safety and adverse events were assessed by reported signs and symptoms, as well as by physical examinations, laboratory results, echocardiograms, electrocardiograms, and in subjects with facioscapulohumeral dystrophy, funduscopic and audiometry examinations. Biological activity of MYO-029 was assessed through manual muscle testing, quantitative muscle testing, timed function tests, subject-reported outcomes, magnetic resonance imaging studies, dual-energy radiographic absorptiometry studies, and muscle biopsy. RESULTS: MYO-029 had good safety and tolerability with the exception of cutaneous hypersensitivity at the 10 and 30 mg/kg doses. There were no improvements noted in exploratory end points of muscle strength or function, but the study was not powered to look for efficacy. Importantly, bioactivity of MYO-029 was supported by a trend in a limited number of subjects toward increased muscle size using dual-energy radiographic absorptiometry and muscle histology. INTERPRETATION: This trial supports the hypothesis that systemic administration of myostatin inhibitors provides an adequate safety margin for clinical studies. Further evaluation of more potent myostatin inhibitors for stimulating muscle growth in muscular dystrophy should be considered.

The TREAT-NMD advisory committee for therapeutics (TACT): an innovative de-risking model to foster orphan drug development.

Despite multiple publications on potential therapies for neuromuscular diseases (NMD) in cell and animal models only a handful reach clinical trials. The ability to prioritise drug development according to objective criteria is particularly critical in rare diseases with large unmet needs and a limited numbers of patients who can be enrolled into clinical trials. TREAT-NMD Advisory Committee for Therapeutics (TACT) was established to provide independent and objective guidance on the preclinical and development pathway of potential therapies (whether novel or repurposed) for NMD.We present our experience in the establishment and operation of the TACT. TACT provides a unique resource of recognized experts from multiple disciplines. The goal of each TACT review is to help the sponsor to position the candidate compound along a realistic and well-informed plan to clinical trials, and eventual registration. The reviews and subsequent recommendations are focused on generating meaningful and rigorous data that can enable clear go/no-go decisions and facilitate longer term funding or partnering opportunities. The review process thereby acts to comment on viability, de-risking the process of proceeding on a development programme.To date TACT has held 10 review meeting and reviewed 29 program applications in several rare neuromuscular diseases: Of the 29 programs reviewed, 19 were from industry and 10 were from academia; 15 were for novel compounds and 14 were for repurposed drugs; 16 were small molecules and 13 were biologics; 14 were preclinical stage applications and 15 were clinical stage applications. 3 had received Orphan drug designation from European Medicines Agency and 3 from Food and Drug Administration. A number of recurrent themes emerged over the course of the reviews and we found that applicants frequently require advice and education on issues concerned with preclinical standard operating procedures, interactions with regulatory agencies, formulation, repurposing, clinical trial design, manufacturing and ethics.Over the 5 years since its establishment TACT has amassed a body of experience that can be extrapolated to other groups of rare diseases to improve the community's chances of successfully bringing new rare disease drugs to registration and ultimately to market.

Recombinant human bone morphogenetic protein-2 for treatment of open tibial fractures: a prospective, controlled, randomized study of four hundred and fifty patients.

BACKGROUND: The treatment of open fractures of the tibial shaft is often complicated by delayed union and nonunion. The objective of this study was to evaluate the safety and efficacy of the use of recombinant human bone morphogenetic protein-2 (rhBMP-2; dibotermin alfa) to accelerate healing of open tibial shaft fractures and to reduce the need for secondary intervention. METHODS: In a prospective, randomized, controlled, single-blind study, 450 patients with an open tibial fracture were randomized to receive either the standard of care (intramedullary nail fixation and routine soft-tissue management [the control group]), the standard of care and an implant containing 0.75 mg/mL of rhBMP-2 (total dose of 6 mg), or the standard of care and an implant containing 1.50 mg/mL of rhBMP-2 (total dose of 12 mg). The rhBMP-2 implant (rhBMP-2 applied to an absorbable collagen sponge) was placed over the fracture at the time of definitive wound closure. Randomization was stratified by the severity of the open wound. The primary outcome measure was the proportion of patients requiring secondary intervention because of delayed union or nonunion within twelve months postoperatively. RESULTS: Four hundred and twenty-one (94%) of the patients were available for the twelve-month follow-up. The 1.50-mg/mL rhBMP-2 group had a 44% reduction in the risk of failure (i.e., secondary intervention because of delayed union; relative risk = 0.56; 95% confidence interval = 0.40 to 0.78; pairwise p = 0.0005), significantly fewer invasive interventions (e.g., bone-grafting and nail exchange; p = 0.0264), and significantly faster fracture-healing (p = 0.0022) than did the control patients. Significantly more patients treated with 1.50 mg/mL of rhBMP-2 had healing of the fracture at the postoperative visits from ten weeks through twelve months (p = 0.0008). Compared with the control patients, those treated with 1.50 mg/mL of rhBMP-2 also had significantly fewer hardware failures (p = 0.0174), fewer infections (in association with Gustilo-Anderson type-III injuries; p = 0.0219), and faster wound-healing (83% compared with 65% had wound-healing at six weeks; p =0.0010). CONCLUSIONS: The rhBMP-2 implant was safe and, when 1.50 mg/mL was used, significantly superior to the standard of care in reducing the frequency of secondary interventions and the overall invasiveness of the procedures, accelerating fracture and wound-healing, and reducing the infection rate in patients with an open fracture of the tibia.

Pathways activated during human asthma exacerbation as revealed by gene expression patterns in blood.

BACKGROUND: Asthma exacerbations remain a major unmet clinical need. The difficulty in obtaining airway tissue and bronchoalveolar lavage samples during exacerbations has greatly hampered study of naturally occurring exacerbations. This study was conducted to determine if mRNA profiling of peripheral blood mononuclear cells (PBMCs) could provide information on the systemic molecular pathways involved during asthma exacerbations. METHODOLOGY/PRINCIPAL FINDINGS: Over the course of one year, gene expression levels during stable asthma, exacerbation, and two weeks after an exacerbation were compared using oligonucleotide arrays. For each of 118 subjects who experienced at least one asthma exacerbation, the gene expression patterns in a sample of peripheral blood mononuclear cells collected during an exacerbation episode were compared to patterns observed in multiple samples from the same subject collected during quiescent asthma. Analysis of covariance identified genes whose levels of expression changed during exacerbations and returned to quiescent levels by two weeks. Heterogeneity among visits in expression profiles was examined using K-means clustering. Three distinct exacerbation-associated gene expression signatures were identified. One signature indicated that, even among patients without symptoms of respiratory infection, genes of innate immunity were activated. Antigen-independent T cell activation mediated by IL15 was also indicated by this signature. A second signature revealed strong evidence of lymphocyte activation through antigen receptors and subsequent downstream events of adaptive immunity. The number of genes identified in the third signature was too few to draw conclusions on the mechanisms driving those exacerbations. CONCLUSIONS/SIGNIFICANCE: This study has shown that analysis of PBMCs reveals systemic changes accompanying asthma exacerbation and has laid the foundation for future comparative studies using PBMCs.

Challenges in drug development for muscle disease: a stakeholders' meeting.

Current treatment benefits for patients with muscle disease are limited, but progress in legislative and scientific initiatives have set the stage for the development of new therapies. The MD-CARE Act (Public Law 107-84), which allocates federal resources to muscular dystrophy, was approved by Congress and signed into law by the President of the United States in 2001. This has shifted the emphasis toward translational research. To facilitate a push toward therapy for muscle disorders, the Muscular Dystrophy Association (MDA) sponsored a meeting with representatives from industry, the Food and Drug Administration (FDA), the National Institutes of Health (NIH), and other government agencies and academia. Each contributed in different ways. The FDA helped define the necessary data to support investigational new drug (IND) applications including the design of proof-of-principle studies, outcome measures for clinical trials, and the pathway for developing surrogate measures for fast-tracking promising new drugs. The NIH, other government agencies, and the MDA described potential funding sources for translational research. Industry delineated a complementary role with academia, and academic investigators elucidated the current strengths and weaknesses of available clinical endpoints. The meeting provided a format for communication for diverse disciplines that usually have no common meeting ground, helping to lay the foundation for bringing products to market in a timely fashion.

Clinical evaluation of recombinant human bone morphogenetic protein-2.

Recombinant human bone morphogenetic protein-2 is an osteoinductive protein that plays a pivotal role in bone growth and regeneration. Several hundred studies were conducted in the past 7 years in numerous animal models to establish unequivocally the efficacy, safety, mechanism of action, pharmacokinetics, and surgical handling properties of recombinant human bone morphogenetic protein-2, building a solid foundation for clinical development programs. Pilot clinical trials have shown the feasibility and safety of recombinant human bone morphogenetic protein-2 treatment, and defined the effective dose for its use in open long bone fractures and for augmentation or preservation of the alveolar bone in the dental ridge. Prospective observational clinical studies helped define clinical efficacy end points, identify significant variables, and estimate appropriate population sample size for pivotal clinical trials. Pivotal clinical trials of recombinant human bone morphogenetic protein-2 are underway in patients with open tibial shaft fractures and in patients with a deficiency of the alveolar ridge.