Featured in this issue: Tadalafil tested in men with BMD * Tests of ACE031 in boys with DMD begin * New tools to measure progression of CMT in children * Idebenone posts disappointing results in FA
For information about active trials in your disease, go to www.clinicaltrials.gov, select Search for Clinical Trials, and enter the disease name in the search box.
The oral drug tadalafil, commonly used to treat erectile dysfunction, is being tested in an MDA-supported trial to see whether it can improve blood flow to forearm muscles in adults with Becker muscular dystrophy (BMD).
In 2008, an MDA-supported study in mice with dystrophin deficiency, the underlying cause of BMD and the related disease Duchenne muscular dystrophy (DMD), found a drug similar to tadalafil improved exercise tolerance, probably by relaxing blood vessels and enhancing blood flow to muscles. A different MDA-supported group that year found another such drug significantly improved heart function in dystrophin-deficient mice.
Tadalafil, marketed by Eli Lilly under the brand name Cialis, belongs to a class of drugs known as phosphodiesterase inhibitors. Viagra also belongs to this group.
Inhibiting phosphodiesterase type 5 (PDE5), the specific action of tadalafil, relaxes the smooth muscles that line blood vessels by enhancing the release of nitric oxide from nerve terminals and blood-vessel cells. This action, which enhances penile erection, may also improve blood flow to skeletal muscles and the heart.
MDA has awarded a grant of approximately $1 million to Ronald Victor, a cardiovascular disease specialist at Cedars-Sinai Medical Center in Los Angeles, where the 48-person, short-term trial will take place.
In the first phase of the study, men ages 18-55 with and without BMD will undergo blood chemistry tests, DNA analysis, MRI scans of the forearm muscles before and after handgrip exercise, and ultrasound studies of blood flow before and after handgrip exercise. This initial phase of the study will establish differences in these results between the BMD and non-BMD participants and determine which BMD-affected participants meet study criteria for the second (medication) phase of the trial.
In the medication phase, 24 men with BMD will repeat the testing after receiving two tadalafil pills on two consecutive days, and on another day after receiving two placebo pills. The baseline evaluation day and the two study periods will each be separated by at least two weeks.
The experimental drug ACE031, which is designed to interfere with the actions of the naturally occurring protein myostatin, is being tested in some 76 boys with Duchenne muscular dystrophy (DMD) who are at least 4 years old.
In April 2010, Acceleron Pharma, of Cambridge, Mass., announced the drug shows promise as a therapy to increase muscle mass, based on results of a trial conducted in healthy volunteers.
The study is being conducted in London, Ontario, Canada. For information, contact Rhiannon Taranik at (519) 685-8441 or Rhiannon.Taranik@lhsc.on.ca; or send e-mail to email@example.com.
New tools for trials in children with CMT
|New scales that measure physical functioning and quality of life in children with CMT are expected to improve the conduct of clinical trials.|
Two new scales that will facilitate the conduct of clinical trials in children and adolescents with Charcot-Marie-Tooth disease (CMT) have been developed, both with MDA support. The scales were presented at the April 2010 meeting of the American Academy of Neurology. Both will expand the ways in which investigators can measure the effects of treatments they will test.
The first, called the CMT Pediatric Scale, measures physical functioning. The second, called the Pediatric CMT Quality of Life Instrument, measures how the disease affects children’s life experience. The two scales eventually will be merged.
The CMT Pediatric Scale includes assessments of foot posture, hand dexterity, sensation, motor function, ankle positioning, hand and foot strength, balance and endurance.
The Quality of Life Instrument includes a 60-item questionnaire that can be administered to children with CMT who are 5-18 years old, and two questionnaires for their parents, one for parents of children up to age 5 and the other for parents of children ages 5-18.
The questionnaires cover six major areas that the investigators concluded were relevant to the child with CMT:
Idebenone, a substance believed to act as an antioxidant and to aid in energy production in cellular structures called mitochondria, has failed to benefit people with Friedreich’s ataxia (FA) in a phase 3 trial conducted at several European centers. The drug is similar to coenzyme Q10, a naturally occurring molecule.
The trial involved 232 people, most of whom were adults, and was conducted by Santhera Pharmaceuticals, a Swiss company that’s developing idebenone for FA and other diseases under the brand names Catena and Sovrima.
Although idebenone (Catena/Sovrima) was safe and well tolerated at doses up to 2,250 milligrams per day, it failed to meet its primary measure of success (end point), which would have been a significant change in the International Cooperative Ataxia Rating Scale (ICARS).
A year ago, Santhera’s phase 3 trial of idebenone in 70 children with FA ages 8 to 17 likewise did not show benefit. That trial was conducted in the United States and lasted six months.
In a May 20, 2010, teleconference, Santhera executives said they will continue to pursue idebenone development for other diseases, including Duchenne muscular dystrophy (DMD) and the mitochondrial myopathy known as MELAS, and that they have not yet made a final decision about pursuing development of idebenone for FA.