Autism is far from a drug developer's dream market. There's debate over what exactly causes autism spectrum disorders, although there are studies that indicate that a combination of environmental and genetic factors are at play. One of the known genetic causes is Fragile X syndrome, which is believed to trigger about 5% of autism cases. And given what is known about the syndrome, which is caused by a mutation of the FMR1 gene, companies such as Novartis, Roche and biotech start-up Seaside have advanced experimental compounds.

Novartis has recently seen some promising data in Fragile X with its compound, AFQ056, which was discovered over a decade ago. It fell short in earlier studies in smoking cessation and anxiety, yet Novartis scientists saw the potential benefits of the drug in patients with Fragile X. The drug is supposed to reduce activity related to the mGluR5 protein in the brain, potentially beneficial to patients with the syndrome whose disease causes them to lack a protein that normally lowers mGluR5 levels.

The company is now in recruitment for a Phase II study, which is going to test the safety of the compound and its effects on the abnormal behavior of certain adults with Fragile X, according to ClinicalTrials.gov.  Data from a proof-of-concept study of the drug in Fragile X unveiled in January showed negative results, yet the team behind the trial has found biomarkers that appeared to be predictive of a response to the compound in patients with the syndrome.

Roche is also pursuing the mGluR5 pathway in Fragile X with a compound called RO4917523, which is in a mid-stage clinical trial, according to ClinicalTrials.gov. And the Swiss drugmaker listed autism and Fragile X among the areas of focus in its neuroscience group at the BNP Paribas 13th Healthcare Conference in Paris in May.

Still, Big Pharma has treaded relatively lightly in the autism arena. Pfizer has assigned some scientists to an autism research unit, but the group has been relatively quiet since its public unveiling back in 2009 as the company continues to shake up its R&D organization. And autism drug development poses some of the same hurdles as other brain disorders do in trials. This has prompted several drugmakers such as GlaxoSmithKline, Sanofi and AstraZeneca to scale back or cut R&D in the neuroscience arena. 

Novartis' Johns said: "We're still in a very early stage. I wouldn't even characterize that we have a ‘Therapeutics Program in ASDs' yet. We're very actively engaged in the field and we're following the science carefully."