Since 1999 and directly as a result of the previously discussed multidisciplinary collaborative efforts that were facilitated by the CINRG Coordinating Center, five clinical trials have been developed (4 have been implemented) in the CINRG network.  Each of these clinical trials was developed and implemented using the processes and procedures that are outlined in the “General Methods” section of this application.    An abstract of each is listed in Appendix A.

Principal Investigator:         Diana Escolar, MD (Co-Center Director; PI project 2), Gunnar Buyse, MD, PhD

Co-Investigators:                  Robert Leshner, MD, Erik Henricson, MPH (PI: Core B)

Performance Sites:

Children’s National Medical Center, Children’s Hospital of Virginia, Children’s Hospital of Pittsburgh, University of Mississippi, University of Tennessee, Catholic University of Leuven, Texas Scottish Rite Hospital, University of Puerto Rico, University of Tel Aviv, Washington University at St. Louis

We tested the efficacy and safety of glutamine (0.6 g/kg/d) and creatine (5 g/d) in 50 ambulant boys with Duchenne muscular dystrophy in a double–blind, placebo controlled 6-month clinical trial. Efficacy was determined by the effect of the drugs in maintaining or improving muscle strength measured manually (MMT, 34 muscle groups) and quantitatively (QMT, 10 muscle groups). Timed functional tests, functional parameters and pulmonary function tests were secondary or exploratory outcome measures.  A quality of life (QOL) questionnaire was used to collect pilot data to develop a disease specific QOL instrument. Change of muscle strength was analyzed using repeated measures analysis of variance adjusted for baseline muscle strength. There were no statistically significant differences in the primary outcome measure (MMT score) when the Cr and glutamine groups were compared to the placebo group. Trends in MMT score, QMT score and functional tests are shown in Figure 1.  Interestingly, and in accordance with a recent study of oxandrolone in DMD (Fenichel, Griggs et al. 2001), the placebo group did not show deterioration of muscle strength measured by MMT over a 6 month period.  This unexpected result reduced our statistical power to show groupwise differences. However, we found strong trends that, although did not reach statistical significance, might have clinical significance since they are remarkably consistent, and these are shown in Figure 1.  Subjects on the creatine and glutamine groups have a tendency to perform better over a 6 months period than those in the placebo group in all outcome measures except for MMT. As shown in figure 1, subjects in the Cr group showed less strength deterioration (p=0.07) as measured by QMT than those on placebo.    In the timed climbing test, subjects in the Cr group did significantly better than placebo over time (p=0.015) and there was a trend for the Glutamine group (p>0.05) to deteriorate less than placebo. The same trend was seen with both, glutamine and Cr, in timed running test.

Clinically, a ‘honey moon” period has been long recognized in DMD, where children up to the age of 6 or 7 do well or even increase their muscle strength and function. . As we looked at age as a confounder, we found evidence that age stratum (< 7 and >7 years old) had a highly statistically significant interactive effect on the relationship of treatment to muscle strength and function. This was true for QMT total score (p=0.005), QMT arm score (p=0.0003), time to stand (p<0.0001), time to climb stairs (p=0.0139), and time to run 10 meters (p=0.028).  Because of this, we did a secondary stratified analysis. In the subgroup of younger children  (<7 years old, placebo n= 10, glutamine n=10 and Cr=6) muscle strength measured by QMT mildly increased over the trial period in both the treatment and placebo groups (slope=0.024, 0.020 and 0.026 for QMT by Cr, glutamine and placebo respectively, P >0.05).  In this age strata, change in muscle strength over time was not significantly different across study groups.  However, subjects in the Cr and glutamine groups improved their time-scores (figure 2) on two functional measures, time to stand from a supine position (P=0.003 for Cr and P<0.000 for glutamine) and time to climb 4 standard steps (P< 0.005 for Cr and <0.002 for glutamine) when compared to placebo. Timed running also improved in both Cr and glutamine groups when compared to placebo, but these differences did not reach statistical significance (P  >0.05).

For older children (>7 years old, placebo n=5, glutamine n= 9; Cr n=10), muscle strength measured by QMT decreased over time (slope = -0.11, -0.14, and -0.22 for creatine, glutamine and placebo respectively).  The glutamine and placebo, but not the Cr groups showed significant decreases in QMT scores over time when compared to no-change (slope=0). The Cr group consistently showed a lesser degree of deterioration compared to the other groups in all strength measurements (QMT arm score, QMT leg score, data not shown), but the differences between groups did not achieve statistical significance. In conclusion, a disease-modifying effect of creatine in older DMD and creatine and glutamine in younger DMD could not be excluded. 

In the creatine/glutamine study we were able to demonstrate muscle strength deterioration in the placebo group in children older than 7 years with QMT, as expected by the natural history studies on DMD (Brooke, Fenichel et al. 1983). Using QMT we were also able to measure changes in strength in treatment groups that were undetected by MMT. Strain-gauge QMT was used in the original prednisone trial for DMD (although not as an outcome variable) (Mendell and Florence 1990), the spinal muscular atrophy trials (Cook, Iannaccone et al. 1990; Russman, Iannaccone et al. 1990), amyotrophic lateral sclerosis trials (established outcome measure), verapamil trial for DMD (Munsat 1990) and isaxonide trial in DMD (Heckmatt, Hyde et al. 1988). Despite the extensive use of QMT, at the time of the initial development of the creatine/glutamine protocol it still was not a valid outcome measure in DMD trials, mainly due to the lack of published longitudinal data with QMT showing muscle deterioration in this disease (specificity). Therefore, MMT was chosen as the primary outcome measure for that trial.  To overcome one of the major concerns with QMT, the ability of children to cooperate, we created a modified version of the original Tufts quantitative neuromuscular exam (TQNE (Andres, Hedlund et al. 1986)) designed for ALS clinical trials to make it more applicable to children. We used a more sensitive strain gauge (able to measure as little as 0.25 lbs. of change in strength) added a back support system to avoid the need for manual back stabilization and incorporated an audiovisual feedback system (videogame) to the software (Escolar, Henricson et al. 2001). We then showed that our PQMT system gave sensitive, reliable and quantitative measurement of muscle strength in children (Escolar, Henricson et al. 2001). With the creatine/glutamine trial we have now shown that our PQMT is also specific, able to demonstrate the expected deterioration of muscle strength in the older untreated DMD boys. Thus, we have now demonstrated that PQMT is a valid, more sensitive outcome measure for DMD clinical trials, valuable in determination of a new drug’s effect size and in the evaluation of individual muscle groups.

We recognize that a clinically significant treatment effect would probably be evident with a less sensitive measure (i.e. MMT or functional outcomes). However, because the proposed trial is a non-inferiority trial and we are interested in being able to show that intermittent high dose therapy is at least as effective as the standard therapy, a more sensitive and reliable measure is more appropriate and thus we have elected to use QMT scores as primary outcome measure of effectiveness.

Figure 1: Change in muscle strength from baseline over a 6 months period in the placebo, creatine and glutamine groups. Neither group showed muscle strength deterioration by MMT. There were no significant differences in strength measured by MMT between groups. Muscle strength by QMT score showed lesser deterioration in the creatine group compared to placebo (P =0.07). In the timed climbing test, subjects in the Cr group did significantly better than placebo over time (P=0.015) and there was a trend for the Glutamine group (P>0.05) to deteriorate less than placebo. The same trend was seen with both, glutamine and Cr, in timed running test (P>0.05).

Figure 2 (below): Change in function timed scores over 6 months in subgroup of DMD children younger than 7 years of age. Subjects in the Cr and glutamine groups improved their time-scores on two functional measures, time to stand from a supine position (P=0.003 for Cr and P<0.000 for glutamine) and time to climb 4 standard steps (P< 0.005 for Cr and <0.002 for glutamine) when compared to placebo. Timed running also improved in both Cr and glutamine groups when compared to placebo, but these differences did not reach statistical significance (P  >0.05).

An open-label pilot study of the safety and efficacy of Oxatomide in steroid-naive Duchenne muscular dystrophy (MDA)

Principal Investigator:         Diana Escolar, MD, Gunnar Buyse, MD, PhD

Co-Investigators:                  Erik Henricson, MPH

Performance Sites:              Children’s National Medical Center, Catholic University of Leuven, University of Mississippi

Oxatomide is another drug that was targeted by the group for transition into DMD trials.  Due to the small number of subjects who are to be enrolled in the trial, three sites were picked to participate in order to ensure that each site would enroll at least four to five subjects, thus enhancing reliability of the patient assessments.  The study was initiated in the summer of 2000, and is projected to be completed in the fall of this year. 

An open-label pilot study of the safety and efficacy of Coenzyme Q-10 in steroid-treated Duchenne muscular dystrophy (MDA)

Principal Investigator:         Diana Escolar, MD

Co-Investigators:                  Erik Henricson, MPH

Performance Sites:              Children’s National Medical Center, Washington University at St. Louis

The CoQ10 study at first presented significant challenges.  Similar to reports in the adult cardiology literature, efforts at maintaining stable serum levels of the drug proved difficult in boys with DMD.  Consultation with Mendel Tuchman, MD, Director of the CNMC Pediatric Clinical Research Center led to alterations in both dosing and administration schedule of the drug.  Subsequent to those changes, serum levels have been much more readily maintained and enrollment is progressing steadily.  The study has been fully enrolled, and completion is expected in the fall of this year.

An open-label pilot study of the safety and efficacy of Pentoxifylline in steroid-naive Duchenne muscular dystrophy (MDA)

Principal Investigator:         Diana Escolar, MD

Co-Investigators:                  Carolina Tesi-Rocha, MD, Erik Henricson, MPH

Performance Sites:              Children’s National Medical Center, Children’s Hospital of Pittsburgh, Texas Scottish Rite Hospital, Mayo Clinic

Pentoxifylline is another drug that was identified in the original high-throughput screening program.  A potent antifibrotic as well as an anti-inflammatory agent, pentoxifylline is expected to reduce both muscle inflammation and to retard the development of muscle fibrosis and fatty replacement.  This pilot study is slated to begin in the spring of 2003 at four institutions, and will also provide a testbed for the further investigation of MRI procedures for detecting muscle fibrosis that were discussed by CINRG investigators and invited experts at the Fall 2002 CINRG investigator’s meeting.

In addition to clinical trials, the investigators of CINRG has been involved in non-pharmacological projects, each one developed to investigate other DMD and neuromuscular disease-related topics.  These topics range from evaluation of potential clinical trial outcome measures such as quantitative muscle testing and MRI, to evaluation of learning, psychosocial adaptation and family needs, to quality of life and enhancement of community function in individuals with neuromuscular disease.

Clinical evaluator reliability for quantitative and manual muscle testing measures of strength in children (Escolar, Henricson et al. 2001) (CNMC/PCRC Funding Support)

Principal Investigators:       Diana Escolar, MD, Erik Henricson, MPH, Paula Clemens, MD

Co-Investigators:                  Julaine Florence, PhD, Jill Mayhew, BS, Robert Leshner, MD

Performance Sites:              Children’s National Medical Center

Initially, this study was conducted as the result of comments from project reviewers of the creatine/glutamine clinical trial (both MDA and FDA), who were concerned about maintenance of reliability in such a large group of clinical evaluators.  Following this initial study, CINRG developed policies that require each site to participate in both initial reliability testing and then annually thereafter, and initiated an intensive program where the group’s clinical evaluator trainers travel to each new site to conduct training and testing.  Measurements of muscle strength in clinical trials of Duchenne muscular dystrophy have relied heavily on manual muscle testing (MMT). The high level of intra-rater and inter-rater variability of MMT compromises clinical study results (top right).  Therefore, since clinical evaluators require extensive training to lower the variability level, implementation of MMT as an outcome measure in large multi-institutional clinical trials is cumbersome. This outcome measure requires extensive evaluator training due to its subjective nature, and is difficult to implement in large multi-institutional clinical trials. We reported significantly higher inter-rater reliabilities of quantitative muscle testing (QMT) (bottom right) as compared to the reliability that can be achieved for MMT measures for pediatric neuromuscular evaluation designed for use in clinical trials.

We compared the reliability of 12 clinical evaluators in performing MMT and quantitative muscle testing (QMT) on 12  children with muscular dystrophy.  QMT was reliable, with an interclass correlation coefficient (ICC) of > 0.9 for biceps and grip strength, and > 0.8 for quadriceps strength. Training of both subjects and evaluators was easily accomplished easily in a minimum amount of time. MMT was not as reliable, and required repeated training of evaluators to bring all groups to an ICC >0.75 for shoulder abduction, elbow flexion,and hip flexion, knee extension and ankle dorsiflexion. QMT of ankle dorsiflexion showed a lower level of reliability than other muscle groups (ICC=0.7).

Principal Investigator:         Bruce Markle, MD

Co-Investigators:                  Erik Henricson, MPH, James Fleckenstein, MD, Diana Escolar, MD, Franklin Marden, MD, Carolina Tesi-Rocha, MD

Performance Sites:              Children’s National Medical Center

Following the Fall 2002 CINRG meeting, where Drs. Marden and Fleckenstein presented preliminary data on MRI studies in DMD (unpublished data), this project was developed to formally evaluate MRI as a potential surrogate outcome measure in clinical trials.  This project has been further developed and integrated into the group’s pentoxifylline clinical trial, which will examine proposed MRI sequences across multiple institutions.

Principal Investigator:         Veronica Hinton, PhD

Performance Sites:              All CINRG Sites

This project aims to establish a standardized means of investigating the cognitive phenotype associated with Duchenne muscular dystrophy, and will use a develop computerized set of cognitive skills tests that is easy administer at multiple locations.  Subjects at CINRG sites will participate to help develop tests of verbal span, visual span and categorization, to establish that the tests are sensitive to the verbal working memory deficits observed in DMD, and to examine whether the measures are capable of identifying individuals with DMD who are at an increased risk of learning disabilities.  Dr. Hinton is pursuing a DMD Centers of Excellence Development Grant for her clinic at Columbia University in conjunction with her research in cognitive function in DMD.

Principal Investigator:                     Erik Henricson, MPH

Co-Principal Investigator:               Veronica Hinton, PhD

Co-Investigator:                                Diana Escolar, MD

Performance Sites:                          All CINRG Sites

Expanding on the collaborative processes of the CINRG program, this project has spawned a new research partnership between CINRG, the MDA, Parent Project Muscular Dystrophy and the US Centers for Disease Control.  The study represents the nation’s first large-scale look at the needs of the DMD community, how families adapt to and cope with a diagnosis of DMD in a child, and how availability of neonatal screening programs could affect parents and physicians attitudes and beliefs about utility of treatments (and clinical research) for DMD.  Assembly of the CINRG investigators over the past 4 years placed the group in a position of being a top contender for, and ultimately the awardee of, this project by the CDC.

Principal Investigator:                     Craig M. McDonald, MD

Performance Sites:                          University of California, Davis; All USA CINRG Sites

In October of 2002, Dr. McDonald joined the CINRG group.  Dr. McDonald is the principal investigator of an existing NIH award that are focused on the neuromuscular disease population.  The project focuses on rehabilitative techniques, enhancement of community integration, risk of genetic testing, information seeking and training of NMD rehabilitation researchers.  In addition to UC Davis’ participation in clinical trials, Dr. McDonald has plans to expand the reach of his current studies to the CINRG clinic network.