Dear Valued Visitor,

We have noticed that you are using an ad blocker software.

Although advertisements on the web pages may degrade your experience, our business certainly depends on them and we can only keep providing you high-quality research based articles as long as we can display ads on our pages.

To view this article, you can disable your ad blocker and refresh this page or simply login.

We only allow registered users to use ad blockers. You can sign up for free by clicking here or you can login if you are already a member.

GlaxoSmithKline plc (ADR) (GSK), Sarepta Therapeutics Inc (SRPT): The Good and Bad of a Competitor’s Failure

Page 1 of 2

GlaxoSmithKline plc (ADR) (NYSE:GSK)On the surface, GlaxoSmithKline plc (ADR) (NYSE:GSK)‘s release of phase 2 data on drisapersen looks like good news for Sarepta Therapeutics Inc (NASDAQ:SRPT)‘s competing Duchenne Muscular Dystrophy drug, eteplirsen.

Investors seem to think so; shares of Sarepta Therapeutics Inc (NASDAQ:SRPT) were up almost 3.3% Friday, while Prosensa, which developed drisapersen and licensed it to GlaxoSmithKline plc (ADR) (NYSE:GSK), was down 8%.

But be careful though. Sometimes, one man’s trash is just another man’s trash.

First, the blah data
Keep in mind this is phase 2 data. GlaxoSmithKline plc (ADR) (NYSE:GSK) is already running a phase 3 trial that should read out later this year. The phase 2 data will have little influence on the approvability of drisapersen, but it could give hints as to whether the phase 3 trial will be successful and how it might compete with Sarepta Therapeutics Inc (NASDAQ:SRPT)’s eteplirsen.

The study looked at both continuous dosing of drisapersen, defined as once weekly, and intermittent dosing, which consisted of alternating between once and twice a week for six weeks and then taking the seventh to 10th weeks off before restarting the cycle.

The continuous dosing clearly worked better after 25 weeks on the drug, with 72% of patients showing an increase in dystrophin, the protein missing in Duchenne muscular dystrophy patients that leads to muscle wasting. The intermittent dosing produced increases in dystrophin levels in 59% of patients. Only one out of 18 of the patients treated with placebo registered positive, so drisapersen is clearly doing something.

The problem for Galxo and Prosensa is Sarepta Therapeutics Inc (NASDAQ:SRPT)’s data indicate that all of patients taking eteplirsen had an increase in dystrophin levels. One hundred percent trumps 72%, although the two companies measured dystrophin levels in different ways, and it isn’t clear which one is more stringent.

Be careful
In addition to the apples-to-oranges comparison across clinical trials, there’s the issue of using dystrophin as an endpoint for approval. Sarepta Therapeutics Inc (NASDAQ:SRPT) has two options for approval using its phase 2 data. It could gain accelerated approval based on the surrogate endpoint of increasing dystrophin or the Food and Drug Administration could award full approval based on the boys taking eteplirsen walking further, a clinically meaningful endpoint.

Page 1 of 2

Biotech Stock Alert - 20% Guaranteed Return in One Year

Hedge Funds and Insiders Are Piling Into

One of 2015's best hedge funds and two insiders snapped up shares of this medical device stock recently. We believe its transformative and disruptive device will storm the $3+ billion market and help it achieve 500%-1000% gains in 3 years.

Get your FREE REPORT and the details of our 20% return guarantee today.

Subscribe me to Insider Monkey's Free Daily Newsletter
This is a FREE report from Insider Monkey. Credit Card is NOT required.
Loading Comments...

Thanks! An email with instructions is sent to !

Your email already exists in our database. Click here to go to your subscriptions

Insider Monkey returned 102% in 3 years!! Wondering How?

Download a complete edition of our newsletter for free!