FDA Fast Tracks PH10 for Treatment of Major Depressive Disorder

According to a press release, the US Food and drug administration has granted fast track designation to a nasal spray PH10 for the treatment of major depressive disorder.

"Vistagen is laser focused on bringing an innovative treatment option to individuals suffering with debilitating depression. The FDA's grant of the Fast Track designation for the development of PH10 in major depressive disorder is a significant regulatory milestone, aligned with our belief in PH10's potential to improve the standard of care in a significant market where new and differentiated treatments are urgently needed," stated Shawn Singh, Chief Executive Officer of Vistagen.

"Nearly two-thirds of diagnosed and treated depression patients do not achieve remission with a first line therapy. With 21 million adults in the U.S. suffering at least one major depressive episode in the past year, potentially millions of individuals are not getting the help they need. We look forward to working with the FDA's Fast Track program as we advance development of PH10 in the United States."

The FDA's decision is informed by the results of Vistagen's nonclinical studies and three prior clinical studies of PH10, including a Phase 2A clinical study in MDD. At a 6.4 μg dose administered intranasally twice daily for 8 weeks in the published randomized, double-blind, placebo-controlled parallel design Phase 2A study of PH10 in MDD, PH10 significantly reduced depressive symptoms as early as one week based on the 17-item Hamilton Depression Scale (HAM-D-17) scores compared to placebo (p = 0.022). PH10 was well-tolerated and did not cause psychological side effects (such as dissociation or hallucinations) or other safety concerns that may be associated with other approved pharmacological therapies for MDD.

More information about the PH10 Phase 2A study in MDD can be found in the peer-reviewed article, A Placebo Controlled Trial of PH10: Test of a New Rapidly Acting Intranasally Administered Antidepressant, published in the November-December 2019 edition of the British Journal of Pharmaceutical and Medical Research. 

About PH10

PH10 is an investigational pherine nasal spray designed with a potential rapid-onset mechanism of action (MOA) that is fundamentally differentiated from the MOA of all currently approved treatments for depression disorders. PH10, which is administered at microgram-level doses, engages and activates chemosensory neurons in the nasal passages, connected to neural circuits in the brain that produce antidepressant effects.

Specifically, PH10's proposed MOA involves binding to receptors for chemosensory neurons in the nasal passages to regulate the olfactory amygdala "fear on" neural circuits believed to increase activity of the limbic-hypothalamic sympathetic nervous system and increase the release of catecholamines. Importantly, unlike all currently approved oral antidepressants and rapid-onset ketamine-based therapy (KBT), including both intravenous ketamine and intranasal ketamine, we believe PH10 does not require systemic uptake to produce rapid-onset of antidepressant effects and does not cause the side effects and safety concerns potentially associated with rapid-onset KBT.