Neurocrine's Next-Gen TD Drug Enters Phase 2, Aims for New Era

SAN DIEGO, CA – January 26, 2026 – Neurocrine Biosciences has initiated a Phase 2 clinical trial for a new, internally developed compound aimed at treating tardive dyskinesia (TD), signaling the company's intent to deepen its leadership in the movement disorder space. The announcement launches the mid-stage study for NBI-1065890, a next-generation inhibitor of the vesicular monoamine transporter 2 (VMAT2), the same biological target of its blockbuster drug, Ingrezza (valbenazine).

The move is a significant step for the San Diego-based biopharmaceutical company, which pioneered the treatment landscape for TD when it secured the first-ever FDA approval for the condition in 2017. This new trial underscores a strategy focused not just on maintaining market share, but on evolving the standard of care for a debilitating condition that affects an estimated 800,000 adults in the United States.

Building on a VMAT2 Legacy

Neurocrine's foundation in treating tardive dyskinesia is built on nearly two decades of expertise in VMAT2 inhibition. VMAT2 inhibitors work by regulating the storage and release of dopamine, a neurotransmitter, in the brain. In conditions like TD—often a side effect of long-term use of antipsychotic medications—dopamine signaling becomes irregular, leading to the characteristic uncontrolled, repetitive movements of the face, torso, and limbs.

With NBI-1065890, the company aims to leverage this deep scientific knowledge to create a therapy with a potentially superior profile. The press release highlights the possibility of developing "longer-acting options" for TD treatment.

"NBI-'890 is an internally discovered molecule with distinct physical and chemical properties that may allow it to benefit a broader range of patients with tardive dyskinesia," said Dr. Sanjay Keswani, Chief Medical Officer at Neurocrine Biosciences. "Advancing this program to a Phase 2 clinical study is key to our strategy to define the future of VMAT2 biology and deliver lasting impact for patients."

The Phase 2 study is a randomized, double-blind, placebo-controlled trial designed to enroll approximately 100 adult subjects. Its primary goal is to assess the efficacy, safety, and tolerability of the new compound. Efficacy will be measured by the change from baseline in the Abnormal Involuntary Movement Scale (AIMS) total score at Week 8, a standard clinical measure for the severity of TD movements.

A Strategic Play in a Competitive Market

The development of a second-generation VMAT2 inhibitor is a calculated strategic maneuver in a lucrative and increasingly competitive market. The tardive dyskinesia therapeutics market, currently dominated by Neurocrine's Ingrezza and Teva Pharmaceutical's Austedo (deutetrabenazine), generated combined sales of approximately $3.9 billion in 2024. Projections estimate the market could expand to over $5 billion by the early 2030s.

Despite the success of existing treatments, significant unmet needs persist. Industry analysis reveals that TD remains widely underdiagnosed and undertreated, particularly in long-term care facilities where a large portion of affected individuals reside. A therapy with a differentiated profile—such as a longer half-life that allows for less frequent dosing, improved tolerability, or efficacy in a wider patient population—could capture a significant portion of this underserved market.

By investing in NBI-1065890, Neurocrine is not only attempting to improve upon its own success but also future-proofing its franchise against emerging threats. These include potential generic versions of existing VMAT2 inhibitors and new therapeutic classes, such as AbbVie's tavapadon, which operates through a different mechanism of action. This proactive pipeline development reflects a broader corporate strategy to transition from a single-product success story to a diversified biopharmaceutical powerhouse with a goal of launching new medicines every two years. The company's strong financial position, with over $2.1 billion in cash and no debt as of late 2025, provides the necessary capital to fuel this ambitious research and development engine.

The Patient Perspective and Clinical Hurdles

For the hundreds of thousands of people living with tardive dyskinesia, the advancement of a new potential therapy offers a powerful sense of hope. The condition is more than a series of physical movements; it carries a heavy psychosocial burden, impacting a person's ability to eat, speak, work, and engage socially without fear of judgment or stigma. The advent of VMAT2 inhibitors marked a "paradigm shift" in treatment, according to one neurology expert, making sustained symptom reduction and functional remission a realistic goal for the first time.

"Before these drugs, we had very little to offer," a movement disorder specialist commented anonymously. "The ability to treat the TD symptoms without destabilizing the patient's underlying psychiatric condition, which requires the antipsychotic medication in the first place, was a game-changer."

A potential new drug that is longer-acting could significantly improve quality of life by simplifying treatment regimens and improving adherence. However, the path to approval is fraught with challenges. Central Nervous System (CNS) drug development is notoriously difficult, with Phase 2 trials representing a major bottleneck where failure rates can exceed 80%.

Developers of VMAT2 inhibitors must also carefully navigate a complex safety profile. While modern selective inhibitors have demonstrated a much better safety profile than older drugs, potential side effects like parkinsonism, restlessness, and sleepiness remain a key focus for clinicians and regulators. The goal of a 'next-generation' compound like NBI-1065890 is to optimize the balance between efficacy and tolerability, further widening the therapeutic window.

As Neurocrine embarks on this crucial Phase 2 study, patients, clinicians, and investors will be watching closely. The trial represents not just a corporate milestone but the next step in a long journey to provide better, more manageable treatments for those affected by this challenging disorder.