Annual report pursuant to Section 13 and 15(d)

Description of Business

Description of Business
12 Months Ended
Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Description of Business



VistaGen Therapeutics, Inc., a Nevada corporation (which may be referred to as VistaGen, the Company, we, our, or us), is a multi-asset, clinical-stage biopharmaceutical company committed to developing differentiated new generation medications for anxiety, depression and other central nervous system (CNS) diseases and disorders with high unmet need. Our pipeline includes three clinical-stage CNS drug candidates, each with a differentiated mechanism of action, an exceptional safety profile in all clinical studies to date, and therapeutic potential in multiple CNS markets. We aim to become a fully-integrated biopharmaceutical company that develops and commercializes innovative CNS therapies for large and growing mental health and neurology markets where current treatments are inadequate to meet the needs of millions of patients and caregivers worldwide.


PH94B Neuroactive Nasal Spray for Anxiety-related Disorders


PH94B neuroactive nasal spray is an odorless, first-in-class, fast-acting synthetic neurosteroid with therapeutic potential in a wide range of neuropsychiatric indications involving anxiety or phobia. Conveniently self-administered in microgram doses without systemic exposure, we are initially developing PH94B as a potential fast-acting, non-sedating, non-addictive new generation treatment of social anxiety disorder (SAD). SAD affects over 20 million Americans and, according to the National Institutes of Health (NIH), is the third most common psychiatric condition after depression and substance abuse. A person with SAD feels symptoms of anxiety or fear in certain social situations, such as meeting new people, dating, being on a job interview, answering a question in class, or having to talk to a cashier in a store. Doing everyday things in front of people - such as eating or drinking in front of others or using a public restroom - also causes anxiety or fear. A person with SAD is afraid that he or she will be humiliated, judged, and rejected.  The fear that people with SAD have in social situations is so strong that they feel it is beyond their ability to control. As a result, SAD gets in the way of going to work, attending school, or doing everyday things in situations with potential for interpersonal interaction. People with SAD may worry about these and other things for weeks before they happen. Sometimes, they end up staying away from places or events where they think they might have to do something that will embarrass or humiliate them.  Some people with SAD have performance anxiety. They feel physical symptoms of fear and anxiety in performance situations, such as giving a lecture, a speech or a presentation at school or work, as well as playing a sports game, or dancing or playing a musical instrument on stage.  Without treatment, SAD can last for many years or a lifetime and prevent a person from reaching his or her full potential.


Only three drugs, all oral antidepressants (ADs), are approved by the U.S Food and Drug Administration (FDA) specifically for treatment of SAD. These FDA-approved chronic ADs have slow onset of therapeutic effect (often taking many weeks to months) and significant side effects (often beginning soon after administration). Slow onset of effect, chronic administration and significant side effects may make the FDA-approved ADs inadequate or inappropriate treatment alternatives for many individuals affected by SAD episodically. VistaGen’s PH94B is fundamentally differentiated from all current anxiolytics, including all ADs approved by the FDA for treatment of SAD. Intranasal self-administration of only approximately 3.2 micrograms of PH94B binds to nasal chemosensory receptors that, in turn, activate key neural circuits in the brain that lead to rapid suppression of fear and anxiety. In Phase 2 and pilot Phase 3 clinical studies to date, PH94B has not shown psychological side effects (such as dissociation or hallucinations), systemic exposure, sedation or other side effects and safety concerns that may be caused by the current ADs approved by the FDA for treatment of SAD, as well as by benzodiazepines and beta blockers, which are not approved by the FDA to treat SAD but which may be prescribed by psychiatrists and physicians for treatment of SAD on an off-label basis.


In a peer-reviewed, published double-blind, placebo-controlled Phase 2 clinical trial, PH94B neuroactive nasal spray was significantly more effective than placebo in reducing both public-speaking (performance) anxiety (p=0.002) and social interaction anxiety (p=0.009) in laboratory challenges of individuals with SAD within 15 minutes of self-administration of a non-systemic 1.6 microgram dose of PH94B.  Based on its novel mechanism of pharmacological action, rapid-onset of therapeutic effects and exceptional safety and tolerability profile in Phase 2 and pilot Phase 3 clinical trials to date, we are preparing for Phase 3 clinical development of PH94B for treatment of SAD in adults. Our goal is to develop and commercialize PH94B as the first FDA-approved, fast-acting, on-demand, at-home treatment for SAD. Additional potential anxiety-related neuropsychiatric indications for PH94B include general anxiety disorder, peripartum anxiety (pre- and post-partum anxiety), preoperative or pre-testing (e.g., pre-MRI) anxiety, panic disorder, post-traumatic stress disorder and specific social phobias. The FDA has granted Fast Track designation for development of our PH94B neuroactive nasal spray for on-demand treatment of SAD, the FDA’s first such designation for a drug candidate for SAD.


In addition to development of PH94B as a potential treatment for SAD, in April 2020, we announced plans to expand clinical development of PH94B to include treatment of adjustment disorder, an emotional or behavioral reaction considered excessive or out of proportion to a stressful event or major life change, occurring within three months of the stressor, and/or significantly impairing a person’s social, occupational and/or other important areas of functioning. We plan to submit our proposed protocol for an exploratory Phase 2a study of PH94B for treatment of adjustment disorder with anxiety due to stressors related to the COVID-19 pandemic to the FDA through the Coronavirus Treatment Acceleration Program (CTAP). The proposed Phase 2 study will be conducted in New York City on an open-label basis and involve approximately 30 subjects suffering from adjustment disorder with anxiety from stressors related to the pandemic.


PH10 Neuroactive Nasal Spray for Depression and Suicidal Ideation


PH10 neuroactive nasal spray is an odorless, fast-acting synthetic neurosteroid with therapeutic potential in a wide range of neuropsychiatric indications involving depression and suicidal ideation. Conveniently self-administered in microgram doses without systemic exposure, we are initially developing PH94B as a potential fast-acting, non-sedating, non-addictive new generation treatment of major depressive disorder (MDD).


Depression is a serious medical illness and a global public health concern that can occur at any time over a person's life. While most people will experience depressed mood at some point during their lifetime, MDD is different. MDD is the chronic, pervasive feeling of utter unhappiness and suffering, which impairs daily functioning. Symptoms of MDD include diminished pleasure or loss of interest in activities, changes in appetite that result in weight changes, insomnia or oversleeping, psychomotor agitation, loss of energy or increased fatigue, feelings of worthlessness or inappropriate guilt, difficulty thinking, concentrating or making decisions, and thoughts of death or suicide and attempts at suicide. Current FDA-approved medications available in the multi-billion-dollar global AD market often fall far short of satisfying the unmet medical needs of millions suffering from the debilitating effects of depression.  


While current FDA-approved ADs are widely used, about two-thirds of patients with MDD do not respond to their initial AD treatment. Inadequate response to current ADs is among the key reasons MDD is one of the leading public health concerns in the United States, creating a significant unmet medical need for new agents with fundamentally different mechanisms of action and side effect and safety profiles.


PH10 is a new generation antidepressant with a mechanism of action that is fundamentally different from all current ADs. After self-administration, a non-systemic microgram-level dose of PH10 binds to nasal chemosensory receptors that, in turn, activate key neural circuits in the brain that can lead to rapid-onset antidepressant effects, but without the psychological side effects (such as dissociation and hallucinations) or safety concerns that maybe be caused by ketamine-based therapy (KBT), including intravenous ketamine or esketamine nasal spray, or the significant side effects of current ADs. In an exploratory 30-patient Phase 2a clinical trial, PH10, self-administered at a dose of 6.4 micrograms, was well-tolerated and demonstrated significant (p=0.022) rapid-onset antidepressant effects, which were sustained over an 8-week period, as measured by the Hamilton Depression Rating Scale (HAM-D), without side effects or safety concerns that may be caused by KBT. Based on positive results from this exploratory Phase 2a study, we are preparing for Phase 2b clinical development of PH10 in MDD. With its exceptional safety profile during clinical development to date, we believe PH10, as a convenient at-home therapy, has potential for multiple applications in global depression markets, including as a stand-alone front-line therapy for MDD, as an add-on therapy to augment current FDA-approved ADs for patients with MDD who have an inadequate response to standard ADs, and to prevent relapse following successful treatment with KBT.


AV-101, an Oral NMDA Receptor Antagonist


AV-101 (4-Cl-KYN) targets the NMDAR (N-methyl-D-aspartate receptor), an ionotropic glutamate receptor in the brain. Abnormal NMDAR function is associated with numerous CNS diseases and disorders. AV-101 is an oral prodrug of 7-chloro-kynurenic acid (7-Cl-KYNA), which is a potent and selective full antagonist of the glycine co-agonist site of the NMDAR that inhibits the function of the NMDAR. Unlike ketamine and many other NMDAR antagonists, 7-Cl-KYNA is not an ion channel blocker. In all studies to date, AV-101 has exhibited no dissociative or hallucinogenic psychological side effects or safety concerns similar to those that may be caused by amantadine and KBT. With its exceptionally few side effects and excellent safety profile, AV-101 has potential to be a differentiated oral, new generation treatment for multiple large-market CNS indications where current treatments are inadequate to meet high unmet patient needs. The FDA has granted Fast Track designation for development of AV-101 as both a potential adjunctive treatment for MDD and as a non-opioid treatment for neuropathic pain.


We recently completed a double-blind, placebo-controlled, multi-center Phase 2 clinical trial of AV-101 as a potential adjunctive treatment, together with a standard FDA-approved oral AD (either a selective serotonin reuptake inhibitor (SSRI) or a serotonin norepinephrine reuptake inhibitor (SNRI)), in MDD patients who had an inadequate response to a stable dose of a standard AD (the Elevate Study). Topline results of the Elevate Study (n=199) indicated that the AV-101 treatment arm (1440 mg) did not differentiate from placebo on the primary endpoint (change in the Montgomery-Åsberg Depression Rating Scale (MADRS-10) total score compared to baseline), potentially due to sub-therapeutic levels of 7-Cl-KYNA in the brain. As in prior clinical studies, AV-101 was well tolerated, with no psychotomimetic side effects or drug-related serious adverse events.


Recent discoveries from successful AV-101 preclinical studies suggest that there is a substantially increased brain concentration of AV-101 and its active metabolite, 7-Cl-KYNA, when AV-101 is given together with probenecid, a safe and well-known oral anion transport inhibitor used to treat gout. These surprising effects were first revealed in our recent preclinical studies, although they are consistent with well-documented clinical studies of probenecid increasing the therapeutic benefits of several unrelated classes of approved drugs, including certain antibacterial, anticancer and antiviral drugs. When probenecid was administered adjunctively with AV-101 in an animal model, substantially increased brain concentrations of both AV-101 (7-fold) and of 7-Cl-KYNA (35-fold) were discovered. We also recently identified that some of the same kidney transporters that reduce drug concentrations in the blood, by excretion in the urine, are also found in the blood brain barrier and function to reduce 7-Cl-KYNA levels in the brain by pumping it out of the brain and back into the blood. In the recent preclinical studies with AV-101 and probenecid, we discovered that blocking those transporters in the blood brain barrier with probenecid resulted, as noted above, in a substantially increased brain concentration of 7-Cl-KYNA. This 7-Cl-KYNA efflux-blocking effect of probenecid, with the resulting increased brain levels and duration of 7-Cl-KYNA, suggests the potential impact of AV-101 with probenecid could result in far more profound therapeutic benefits for patients with MDD and other NMDAR-focused CNS diseases and disorders than demonstrated in the Elevate Study. Some of the new discoveries from our recent AV-101 preclinical studies with adjunctive probenecid were presented by a collaborator of VistaGen at the British Pharmacological Society’s Pharmacology 2019 annual conference in Edinburgh, UK in December 2019.


In addition, a Phase 1b target engagement study completed after the Elevate Study by the Baylor College of Medicine (Baylor) with financial support from the U.S. Department of Veterans Affairs (VA), involved 10 healthy volunteer U.S. military Veterans who received single doses of AV-101 (720 mg or 1440 mg) or placebo, in a double-blind, randomized, cross-over controlled trial. The primary goal of the study was to identify and define a dose-response relationship between AV-101 and multiple electrophysiological (EEG) biomarkers related to NMDAR function, as well as blood biomarkers associated with suicidality (the Baylor Study). The findings from the Baylor Study suggest that, in healthy Veterans, the higher dose of AV-101 (1440 mg) was associated with dose-related increase in the 40 Hz Auditory Steady State Response (ASSR), a robust measure of the integrity of inhibitory interneuron synchronization that is associated with NMDAR inhibition. Findings from the successful Baylor Study were presented at the 58th Annual Meeting of the American College of Neuropsychopharmacology (ACNP) in Orlando, Florida in December 2019.


The successful Baylor Study and the recent discoveries in our preclinical studies involving AV-101 and adjunctive probenecid suggest that it may be possible to increase therapeutic concentrations and duration of 7-Cl-KYNA in the brain, and thus increase NMDAR antagonism in MDD patients with an inadequate response to standard ADs when AV-101 and probenecid are combined. During 2020, we plan to conduct additional AV-101 preclinical studies with adjunctive probenecid to evaluate its potential applicability to MDD, suicidal ideation and other NMDAR-focused CNS indications for which we have existing preclinical data with AV-101 as a monotherapy, including epilepsy, levodopa-induced dyskinesia, and neuropathic pain, to determine the most appropriate path forward for potential future clinical development and commercialization of AV-101.


VistaStem Therapeutics – Stem Cell Technology for Drug Rescue and Regenerative Medicine


In addition to our current CNS drug candidates, we have stem cell technology-based, pipeline-enabling programs through our wholly-owned subsidiary, VistaStem Therapeutics (VistaStem). VistaStem is focused on applying human pluripotent stem cell (hPSC) technologies, including our customized cardiac bioassay system, CardioSafe 3D, to discover and develop small molecule New Chemical Entities (NCEs) for our CNS pipeline or out-licensing. In addition, VistaStem’s stem cell technologies involving hPSC-derived blood, cartilage, heart and liver cells have multiple potential applications in the cell therapy (CT) and regenerative medicine (RM) fields.


To advance potential CT and RM applications of VistaStem’s hPSC technologies related to heart cells, we licensed to BlueRock Therapeutics LP, a next generation CT/RM company formed jointly by Bayer AG and Versant Ventures, rights to develop and commercialize certain proprietary technologies relating to the production of cardiac stem cells for the treatment of heart disease. As a result of its acquisition of BlueRock Therapeutics in 2019, Bayer AG now holds rights to develop and commercialize VistaStem’s hPSC technologies relating to the production of heart cells for the treatment of heart disease (the Bayer Agreement).  In a manner similar to the Bayer Agreement, we may pursue additional collaborations involving rights to develop and commercialize VistaStem’s hPSC technologies for production of blood, cartilage, and/or liver cells for CT and RM applications, including, among other indications, treatment of arthritis, cancer and liver disease.




As noted above, VistaStem is our wholly-owned subsidiary. Our Consolidated Financial Statements in this Annual Report on Form 10-K (Annual Report) also include the accounts of VistaStem’s two wholly-owned inactive subsidiaries, Artemis Neuroscience, Inc., a Maryland corporation, and VistaStem Canada, Inc., a corporation organized under the laws of Ontario, Canada.