Olesoxime (TRO19622) is an experimental neuroprotective compound, initially developed by Trophos, for patients with spinal muscular atrophy (SMA)In early 2015, Roche acquired Trophos, along with the therapy. However, as of June 2018, Roche announced it was halting the development of olesoxime for SMA due to disappointing clinical trial results.  

How olesoxime works

SMA is characterized by the progressive loss of motor neurons, specialized nerve cells that are crucial for controlling movement. Olesoxime was developed with the aim of protecting the health of these neurons.

Scientists believe that the abnormal function of mitochondria, which supply energy to cells, leading to oxidative stress may contribute to motor neuron degeneration seen in SMA.

Olesoxime is a therapy of the cholesterol oxime family intended to preserve mitochondrial function, protecting motor neurons from further degeneration. However, the exact ways in which olesoxime achieves this are not completely understood.

Animal studies on olesoxime demonstrated that the treatment was able to increase survival in SMA mouse models, compared with placebo treatment.

Olesoxime in clinical trials

In June 2018, Roche announced its decision to end the development of olesoxime for SMA.

This decision follows the latest results of the OLEOS study, an open-label Phase 2 clinical trial (NCT02628743) that investigated the long-term safety, tolerability, and efficacy of olesoxime in patients, ages 3 to 25, with type 2 SMA or non-mobile patients with type 3 SMA.

While results at one year indicated that 10 mg per kg of olesoxime twice a day was able to stabilize patients’ ability to move, an analysis at 18 months found that motor function in patients who took the medication had begun to decline. The trial, which began in 2016, was initially scheduled to continue until 2021.

Prior to the OLEOS trial, the same dose of olesoxime taken for two years showed an ability to maintain movement function in SMA patients, compared with those who received placebo in a randomized Phase 2 clinical trial (NCT01302600) that ended in October 2013. However, these results were derived from analysis of secondary targets since the trial did not meet its primary target of improving motor function in SMA patients.

Further information

In light of the decision to pull the plug on olesoxime, Roche says it is working closely with trial sites and investigators to ensure patients who were part of the trial are given alternative treatment options.

Roche is continuing the development of its other SMA therapy candidates, notably RG7916, a compound jointly developed with Genentech and in collaboration with PTC Therapeutics and the SMA Foundation.

Olesoxime was initially granted orphan drug designation by the U.S. Food and Drug Administration and orphan medicinal product designation by the European Medicines Agency for the treatment of SMA.

Besides SMA, olesoxime was previously investigated as a potential treatment for amyotrophic lateral sclerosis (ALS), a liver condition called non-alcoholic steatohepatitis, and peripheral neuropathy. However, research was discontinued for all three diseases when olesoxime failed to achieve the desired therapeutic effects in clinical trials.


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