NEW YORK (TheStreet) -- Shares of ResMed  (RMD - Get Report) fell 15.02% to $55.55 in late morning trading Wednesday after the sleep disorder treatment manufacturer provided an update on its Phase III study of SERVE-HF, an adaptive servo-ventilation (ASV) therapy, in central sleep apnea and chronic heart failure.

The company announced that SERVE-HF did not meet its primary endpoint in the study. ResMed designed the study to assess if treatment of moderate to severe predominant central sleep apnea with ASV therapy could reduce mortality and morbidity in patients with symptomatic chronic heart failure in addition to optimized medical care.

The preliminary data did not indicate a statistically significant difference between patients randomized to ASV therapy and those in the control group in the primary endpoint of time to all-cause mortality or unplanned hospitalization for worsening heart failure.

More than 6 million shares had changed hands as of 11:39 a.m., compared to the daily average volume of 826,749.

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