Tuesday 12 November 2013
Sarepta Therapeutics announced today that the Food and Drug
Administration (FDA, the American drug regulator) in the USA considered the
company's plans to file an application for eteplirsen to be licensed as
premature.
The FDA is basing their
decision partly on the results of the large phase 3 clinical trial carried out
by GlaxoSmithKline and Prosensa that showed that drisapersen - a drug similar
to eteplirsen - failed to show that boys who received the drug could walk
further than those that received placebo (an inactive form of the potential
drug). They also state that there are new findings regarding the natural
progression of Duchenne muscular dystrophy, which suggests that the
stabilisation observed during Sarepta's phase 2b extension trial might not be
caused by the drug but could be due to the natural course of the condition. The
trial involved only a small number of boys and a larger study will be needed to
demonstrate that eteplirsen is an effective treatment.
The FDA
also expressed doubts that dystrophin can be used as a biomarker in clinical
trials. Biomarkers are biological substances found in blood, urine or other
parts of the body that can be used as an indicator in clinical trials to see
how well the body responds to a potential treatment. In the FDA's opinion,
there is not sufficient knowledge about the levels of dystrophin that are
needed in the muscle to assume that its levels can show whether a treatment
will be effective.
Sarepta
Therapeutics is committed to continuing with a phase 3 trial which they plan to
start early next year. The trial will involve about 120 boys. As soon as we
receive more details we will update this page to keep you informed.
Dr Marita Pohlschmidt, Director of research at Muscular Dystrophy Campaign, said:
“The
refusal of the FDA to grant Sarepta’s request for an opportunity to apply for a
license for eteplirsen will be upsetting news for many families. The decision
reflects concerns that the results of Sarepta’s Phase 2b clinical trial were
based on a very small group of boys and that a Phase 3 trial is necessary to
demonstrate that eteplirsen is an effective treatment for Duchenne muscular
dystrophy. We welcome Sarepta’s commitment to pushing ahead with a Phase 3
trial, due to start early next year.”
Chris Garabedian, president and chief executive officer of Sarepta Therapeutics said:
We are very disappointed with the FDA's decision to
reconsider their openness to a potential NDA filing based on our current data
and the resultant impact this change may have on our efforts to achieve an
earlier approval of eteplirsen. We strongly believe in the potential of
eteplirsen to address a serious unmet medical need in DMD and we are committed
to its development. Our team at Sarepta recognizes the urgency of families who
are seeking new treatments, and we will continue to work with the FDA on an
acceptable confirmatory study design and, in parallel, seek to address their
concerns regarding a potential NDA filing based on our current dataset.
