This article is more than 5 years old. Information may no longer be current.

GeneSight improves outcomes in patients with treatment-resistant MDD

Bryan Dechairo

Myriad Genetics has announced study findings that showed patients with major depression who received treatment guided by GeneSight, a pharmacogenomic test, experienced a higher rate of remission and response, as well as greater improvement in symptoms than those who received treatment-as-usual, according to a press release.

“This is a land-breaking study showing how we can finally, after 30 or 40 years, improve patient outcomes in depression by marrying-up the right medication to the right patient using their genetics,” Bryan Dechairo, PhD, executive vice president of clinical development at Myriad Genetics, told Healio Psychiatry. “I know patients with depression are in need of these data, and [the results] really are game-changing.”

The double-blind, randomized, controlled Genomics Used to Improve DEpresssion Decisions (GUIDED) trial enrolled 1,167 outpatients with treatment-resistant MDD from 60 sites across the U.S. Patients were assigned 1:1 to treatment as usual or a pharmacogenomics-guided intervention using GeneSight.

With GeneSight, researchers can stratify more than 55 different psychiatric medications by whether the drug is genetically appropriate for a patient — or in a “green” category, according to Dechairo. Those drugs with potential gene-drug interactions usually corrected through dose modification are put into a ‘yellow’ or cautionary category for the physicians, while drugs with significant gene-drug interaction — ie, that are not compatible with a patient’s genetics — are placed into the ‘red’ category so physicians know to avoid those medications, he explained.

“This allows the doctor to find the right medication for the patient faster, leading to dramatic improvements in remission, which is the goal of treatment for patients today,” Dechairo said.

The researchers measured symptom improvement via change in Hamilton Depression Rating Scale (HAM-D) as well as response and remission at week 8. They found that patients with treatment-resistant MDD in the GeneSight cohort experienced a 50% higher rate of remission (15.3% vs. 10.1%, P = .007) and a 30% higher rate of response (26% vs. 19.9%; P = .013) than those in the treatment-as-usual group at week 8, according to the release. These patients also saw an 11% greater improvement in symptoms (P = .11).

Furthermore, these results were durable and continued to improve through 24-week follow-up, with remission rates increasing to 31%, while response rates rose to 44% and symptom improvement to 43%, the release said.

“While remission is the goal, what people really want to know is will this be durable because patients can relapse and their depression can come back,” Dechairo said in the interview. “What we were able to show over a 6-month period was that not only were the results durable, but they also doubled again over that period, and all of the endpoints were statistically significant.”

Moving forward, Dechairo said he and colleagues will research ways to help treatment-naïve patients, and those on their first antidepressant.

“Our studies have been focused on patients who have failed one or more medications, but why should you wait until they fail? Because genetics is something you’re born with, the fact that we’ve proven this works for patients who have failed one or more medications, there’s absolutely no reason why this can’t help the patients on their first medication,” he told Healio Psychiatry. “There’s been a lot of talk about precision medicine and making sure the right patients get the right treatment at the right time and that’s really what we’re talking about here. We’re optimistic and hopeful that these study results will lead to an end of the ‘trial and error’ approach to treatments.” – by Savannah Demko

Disclosure: Dechairo is executive vice president of clinical development at Myriad Genetics.