Eteplirsen keeps up its steady walk toward approval. Sarepta Therapeutics (NASDAQ:SRPT) reported the latest clinical study results today for its Duchenne muscular dystrophy, or DMD, drug. Shares in the biotech are up nearly 5% as the trading day winds down.

Latest results
Sarepta's news related to results from 74 weeks into a phase 2b study of eteplirsen. Patients taking the drug demonstrated continued stabilization of walking ability on the six-minute walk test, a standard assessment of walking capability and clinical function for neuromuscular diseases. 

As with earlier points in this study, DMD patients taking eteplirsen showed significant improvement in walking ability compared to patients on placebo. This was true for groups taking the 30 mg/kg and 50 mg/kg dosages of the drug. 

Eteplirsen also continued to be well-tolerated. Sarepta reported that no patients experienced significant treatment-related adverse events or any serious adverse events. At week 62, one patient had a temporary elevation of urine protein, but that was resolved and the patient stayed in the study with no further problems.

Chris Garabedian, Sarepta's president and CEO, said that the company was "encouraged to see a continued stabilization of walking ability in patients treated with eteplirsen for nearly one and a half years." Garabedian added that "these results continue to support the potential of eteplirsen to be a major advance in the treatment of DMD in altering the course of this progressive and irreversible disease."

Looking ahead
This latest good news from Sarepta was no surprise. Expectations have been quite high ever since the company reported results for eteplirsen back in October.

The next big step for the biotech related to possible accelerated approval from the Food and Drug Administration. Sarepta is in discussions with the FDA about this option, which allows a much quicker path to market. 

Accelerated approval hinges on how much credibility the FDA places on increased dystrophin levels found in  the phase 2 study of eteplirsen. If these increases are viewed as an acceptable surrogate endpoint for actual clinical efficacy, Sarepta should receive good news. If not, it seems quite likely that eteplirsen will still ultimately be approved but on a slower timetable.

Although its shares have soared more than 450% over the last year, I continue to view Sarepta as one of the better biotech plays on the market. The stock -- and hopefully DMD patients -- should keep on walking.

Fool contributor Keith Speights has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.