Shares in NeuroSearch have gone through the roof after the Danish biotechnology firm presented promising late-stage data for its investigational Huntington’s disease drug Huntexil.

The company has reported positive top-line results from the MermaiHD Phase III study of Huntexil (pridopidine) involving 437 Huntington patients. The trial revealed that six months' treatment with the drug results in significant improvements in a broad range of voluntary and involuntary motor symptoms associated with the neurodegenerative disease that is also characterised by cognitive dysfunction and behavioural changes.

Huntexil was generally very well tolerated with an adverse event profile similar to placebo, NeuroSearch says, and the results show no indication that treatment would be associated with worsening of disease signs and symptoms. The company says it is now talking with scientific advisors and regulatory agencies about submissions.

Principal investigator of the trial, Justo García de Yebenes of the Hospital Ramon y Cajal in Madrid, noted that Huntexil is “the first medication to have demonstrated an overall improvement of the motor impairment in Huntington patients with no worsening of other signs or symptoms and without compromising patient safety”. NeuroSearch chief executive Flemming Pedersen added that the drug can provide significant benefits on symptoms not reached by any current treatment, “and this without any ‘trade-offs’ in terms of safety or worsening of any other disease symptoms”.

Investors are impressed with the data and the company’s hopes of filing Huntexil by the end of 2010. NeuroSearch shares almost doubled in value yesterday and have continued to rise this morning, up another 32.4% at 8.30 (UK time) to 222.50 francs.