NEW YORK & TORONTO — March 5, 2026
Helus Pharma, a clinical-stage pharmaceutical company developing novel serotonergic agonists (NSAs) for mental health conditions, has announced promising topline results from a Phase 2 signal detection study evaluating HLP004 in adults with generalized anxiety disorder (GAD). The investigational therapy demonstrated statistically significant and clinically meaningful improvement in anxiety symptoms when used alongside standard-of-care antidepressant therapy. According to the company, patients receiving the 20 mg dose of HLP004 experienced an average reduction of approximately 10 points on the Hamilton Anxiety Rating Scale (HAM-A) at six weeks compared with baseline, achieving a high level of statistical significance (p<0.0001). These findings suggest that the therapy could represent a potential new adjunctive treatment option for patients who continue to experience anxiety symptoms despite conventional medications.
Phase 2 Trial Demonstrates Meaningful Clinical Improvements
The randomized Phase 2 signal detection study enrolled 36 patients with moderate-to-severe generalized anxiety disorder, a condition affecting millions of adults worldwide. Participants in the study had persistent symptoms despite treatment with standard antidepressant therapies such as selective serotonin reuptake inhibitors (SSRIs) and related medications.
Patients were randomized in a 2-to-1 ratio to receive either HLP004 or placebo, with two intramuscular doses administered three weeks apart. The primary goal of the trial was to evaluate changes in anxiety symptoms using the Hamilton Anxiety Rating Scale, one of the most widely used clinical assessment tools in psychiatric research.
Results from the study revealed clinically meaningful improvements in anxiety scores, with the highest dose group showing a mean reduction of 10.4 points on the HAM-A scale at six weeks. Importantly, this improvement occurred on top of the benefits already observed from standard-of-care therapy, highlighting the potential of HLP004 to enhance existing treatment approaches for anxiety disorders.
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Durable Response and Rapid Treatment Experience
Beyond the initial clinical response, investigators observed sustained therapeutic benefits over time. At the six-month follow-up point, the pooled study population demonstrated a 67% responder rate and 39% remission rate, suggesting that the therapy may produce durable improvements in anxiety symptoms.
Participants in both dosing groups experienced meaningful subjective improvements, with 59% of patients in the 20 mg group achieving response criteria and 32% reaching remission by week six. Even the lower-dose treatment group demonstrated encouraging results, with approximately 30% of patients achieving response and remission.
Another notable advantage of HLP004 is the short in-clinic treatment duration, which aligns with emerging models of interventional psychiatry. In clinical studies, the acute therapeutic effects lasted approximately 90 minutes, and most patients were ready for discharge from the treatment setting within about three hours. This rapid treatment cycle could make the therapy compatible with specialized psychiatric treatment centers, potentially improving accessibility for patients seeking innovative mental health interventions.
Favorable Safety Profile Supports Continued Development
Safety data from the Phase 2 trial indicate that HLP004 was generally well tolerated, with most adverse events reported as mild and transient. Importantly, the study recorded no drug-related serious adverse events and no suicidality-related safety signals, supporting the continued clinical development of the therapy.
HLP004 is designed as a deuterated serotonergic agonist, a class of compounds intended to activate serotonin pathways associated with neuroplasticity and emotional regulation. Researchers believe that enhancing serotonin signaling in specific neural circuits may help restore normal brain function in patients with anxiety disorders.
Generalized anxiety disorder represents a significant unmet medical need in psychiatry. More than 20 million adults in the United States are estimated to suffer from the condition, and many patients experience inadequate responses to currently available medications. Despite decades of research, no adjunctive pharmacologic therapy for GAD has been approved, and no new monotherapy has been introduced in nearly twenty years.
If future studies confirm the current findings, HLP004 could become one of the first novel treatment options developed specifically for patients who remain symptomatic despite existing therapies.
Expanding Pipeline for Mental Health Therapeutics
Helus Pharma is currently advancing a broader pipeline of novel serotonergic agonist therapies designed to address major mental health disorders. In addition to HLP004 for anxiety, the company is also developing HLP003, another investigational compound currently in Phase 3 clinical trials for major depressive disorder.
Through these programs, the company aims to develop next-generation psychiatric medicines capable of delivering durable improvements in mental health outcomes. With growing awareness of the global burden of mental illness, innovative therapies targeting underlying neural mechanisms are becoming a central focus of pharmaceutical research.
The encouraging Phase 2 data for HLP004 represent an important milestone in this effort, highlighting the potential for new pharmacological strategies to transform the treatment landscape for anxiety disorders and other psychiatric conditions.
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Source: Helus Pharma press release
