"Vanda Pharmaceuticals Inc said its experimental drug for a rare sleep disorder proved effective in a second latestage trial and the company now plans to apply for a U.S. approval for the drug in mid.  The study named Reset was a patient trial designed to test the maintenance effect of a  mg dose of the drug tasimelteon.  Vanda on December  said the drug performed better than a placebo in the first of the four planned latestage trials on the drug. The companys shares rose as much as  percent on that day.  While the first two are efficacy studies the remaining two are intended to establish the safety profile of the drug.  The second trial showed that patients treated by the drug maintained their clinical benefits while placebotreated patients showed significant deterioration in measures of nighttime sleep daytime naps and timing of sleep.   The drug is being tested for nonhour disorder that has no approved treatment. The condition in which a persons body clock does not automatically set to the hour day affects a majority of blind people.  These results also highlight the importance of chronic therapy in treating Non CEO Mihael Polymeropoulos said in a statement on Wednesday.  Tasimelteon received orphan drug status  which offers several years of marketing exclusivity for drugs developed for rare conditions  from the FDA in  and from the European Commission in .  An orphan drug if approved can usually fetch a premium pricing in the market.  Shares of Vanda which has a market of about  million closed at . on Tuesday on the Nasdaq. They have gained nearly  percent since December .  Reporting by Esha Dey in Bangalore Editing by Maju Samuel Our StandardsThe Thomson Reuters Trust Principles. httpthomsonreuters.comenaboutustrustprinciples.html"