Actelion will not be taking up its to acquire Trophos after the privately-held French group presented disappointing results from a late-stage trial of olesoxime for the treatment of amyotrophic lateral sclerosis, also known as Lou Gehrig's disease.

Last July, the companies signed an agreement which saw Actelion pay 10 million euros for the option to buy Trophos for 125-195 million euros in cash, depending on regulatory approvals and other clinical progress of the Marseille-based group's pipeline.

However, that deal has now bitten the dust after data from a 512-Phase III study showed that  olesoxime did not demonstrate a significant increase in survival versus placebo in patients receiving Sanofi's off-patent drug Rilutek (riluzole). However, a trend was seen on patients’ function a and olesoxime was very well tolerated.

Trophos said that the inability of the drug to show a greater effect on survival for ALS patients above that of riluzole "is most likely because the disease process is already so severe and rapidly progressing by the time of diagnosis that any further benefit of olesoxime over that of riluzole cannot be detected". The company declared it is known that in the most widely used ALS model, "over 50% of the motor neurons and neuromuscular connections have already been lost by the time the first symptoms appear".

Damian Marron, Trophos' chief executive, said the results are disappointing, "above all for the ALS community, who urgently require new therapies that can prolong survival and improve function". Nevertheless, he added that "we remain convinced of the promise of our cholesterol-oxime, mitochondrial pore modulator compounds".

Mr Marron added that Trophos is financed "until at least the end of 2013, so that we continue to move forward on our other programmes”. These include an ongoing Phase III trial of olesoxime in spinal muscular atrophy and a planned Phase II study of the drug in multiple sclerosis disease progression, subject to securing outside funding.

Actelion noted that the 10 million euro option will be written-off within financial expenses. A research collaboration to screen and characterise Actelion compounds using Trophos’ CNS assay technology will continue.