Biomarkers in clinic – are we there yet?

This was the question posed at ECNP 2015 in a session on biomarkers in the clinic. A gathering of leading experts spoke about their insights into the use of biomarkers within psychiatry; the conclusion was that whilst we’re not there yet, we’re not far off.

Biomarkers for bipolar

There is a wide range of potential biomarkers to gain information about the brain. Some involve measurements directly on biological media (e.g., blood or cerebrospinal fluid) or measurements such as brain imaging, which measure changes in the composition or function of the nervous system.

So why are biomarkers of importance in bipolar? It’s often the case that individuals with bipolar disorder frequently present to clinical services when depressed but are often misdiagnosed with unipolar depression, leading to inadequate treatment and poor outcome. Increased accuracy in diagnosing bipolar disorder is therefore a key long-term goal: this can be facilitated by identifying biomarkers that reflect pathophysiologic processes in bipolar disorder, such as impaired emotion regulation, impaired attention, and distractibility, which persist during depression and remission and are not common to unipolar depression.

Companies offering pharmacogenetic tests

While not approved by the FDA/EMA in the same way as drugs are, companies are beginning to offer pharmacogenetic tests that predict response to psychiatric medications.

Dr Anthony Altar, Senior Vice President of Neurosciences at Assurex Health, spoke about the company’s GeneSight test. GeneSight analyses a patient’s genes and gives healthcare providers information to help them select the medicine(s) that are more likely to work for that patient. By doing so, GeneSight provides answers that can lead to a personalized treatment plan and faster response and remission for patients.

GeneSight Psychotropic analyses how your genes affect the way your body may respond to FDA-approved medicines commonly prescribed to treat depression, anxiety, bipolar disease, schizophrenia or other behavioural health conditions.

The test is a combinatorial pharmacogenomic test that creates a composite phenotype based on allelic variations in eight genes encoding CYP2D6, CYP2C19, CYP2C9, CYP1A2, CYP2B6, CYP3A4, the serotonin transporter (SLC6A4), and the serotonin 5-HT2A receptor (HTR2A).

The test recommends medication selections and dose adjustments to clinicians. It stratifies 38 psychotropic medications into one of three cautionary categories, based on the metabolic pathways and mechanisms of action for each medication.

Going digital

In the final talk in this session Dr Paul Wicks, Vice President of Innovation at PatientsLikeMe, an online community for people living with medical conditions, turned the focus to digital biomarkers bringing the likes of social media and mobile phone applications into the spotlight.

While traditional clinical biomarkers such as blood, neuroimaging and cerebrospinal fluid are likely to have precedence in determining a biological marker of illness, digital channels are far more accessible. They can be useful for continually assessing phenotypic markers of illness, such as physical activity, sleep and voice.

But Wicks warned that much of the digital space is developed by technology enthusiasts rather than clinically trained scientists, so while there is great potential a cautious and transparent scientific approach should be advocated, with patients (and clinicians) continually engaged in the design and evaluation process.