Source: DGNews  |  Posted 1 year ago

By Chris Berrie

BARCELONA -- November 3, 2010 -- Combined steroid and bisphosphonate treatment
appear to be associated with significantly improved survival, compared with
steroids alone, for patients with Duchenne muscular dystrophy (DMD), according
to a study presented here at the 4th World Congress on Controversies in
Neurology (CONy).

DMD is characterised by relentlessly progressive weakness, and without
medication with steroids, patients experience progression to loss of ambulation
around 10 years of age, and ultimately death in their mid-20s.

However, the advent of steroid medication and assisted ventilation has
increased life expectancy of these patients, although this remained as their
mid-30s. One further more recent factor was bisphosphonate use in these
patients, for enhanced bone health.

“We realised that our patients, like most people’s patients with Duchenne
dystrophy, were living longer than they used to, and we were not quite clear
why that was,” said Joseph M. Dooley, Division of Paediatric Neurology, IWK
Health Centre, Dalhousie University, Halifax, Nova Scotia, on October 30.

They thus investigated the effects of bisphosphonate therapy on survival of
patients with DMD receiving steroid therapy.

From the records of all patients with muscle-biopsy or genetically confirmed
DMD in 2 Canadian provinces, those born between 1963 and 2006 who had received
at least 1 year of steroid therapy were reviewed from their birth to the study
endpoints of death, loss to follow-up, or last follow-up in 2009.

This provided details regarding their year of diagnosis, and their age at
wheelchair use, mechanical ventilation, steroid use, and bisphosphonate therapy.

Of the 81 boys born with DMD during this period, 44 had been exposed to
continued steroid use for more than 1 year (prednisone only, 5; prednisone
replaced by deflazacort, 13; deflazacort only, 26). Their median age at DMD
diagnosis was 5 years.

Bisphosphonate therapy had been initiated for 36% of these patients, at a
median age of 12.5 years, and a median of 6 years after starting steroid
treatment. By end of follow-up, 70.5% were wheelchair users, and 29.5% had died
at a median age of 16 years.

When these patients were examined specifically for bisphosphonate use and
survival, a significant potential survival benefit was seen, compared with
those who had not used bisphosphonates (P =.005). Dr. Dooley
compared this as 60% survival to 16 years without bisphosphonate use versus 60%
survival to 24 years with bisphosphonate use.

Furthermore, despite the small patient numbers, when the duration of the
bisphosphonate treatment was dichotomised at 6.5 years into 2 equal groups of 8
patients, there was a significant potential therapy effect seen (P
=.007).

Again, while stressing the need for a systematic analysis of a larger group of
DMD patients, “taking bisphosphonates appeared to be associated with a
significant benefit as far as longevity is concerned,” said Dr. Dooley.

“If this is validated, I think it would certainly argue for using
bisphosphonates not only for bone health, but possibly earlier in the condition
in the hope that it will enhance life expectancy,” he concluded.

[Presentation title: The Impact of Bisphosphonates on Survival in Duchenne
Muscular Dystrophy. Abstract B50]