Vanda Pharmaceuticals Receives FDA Approval for BYSANTI and BLA Acceptance for Imsidolimab

Vanda Pharmaceuticals Inc. (Nasdaq: VNDA) announced on February 20, 2026 that the U.S. Food and Drug Administration has approved BYSANTI™ (milsaperidone) tablets, a first line therapy for the acute treatment of manic or mixed episodes associated with bipolar I disorder and for the treatment of schizophrenia in adults. Shares of the company jumped about 45% in extended trading following the approval announcement.

BYSANTI is a new chemical entity that belongs in the class of atypical antipsychotics. In clinical studies BYSANTI demonstrated bioequivalence to iloperidone across the therapeutic dosing spectrum enabling it to leverage well-established knowledge of efficacy and safety derived from a rich clinical development program and more than 100,000 patient-years of real-world experience with Fanapt (iloperidone).

BYSANTI (milsaperidone), a new chemical entity, rapidly interconverts to iloperidone, providing dual active molecules that work in tandem by antagonizing dopamine D2, serotonin 5-HT2A, and alpha1-adrenergic receptors to modulate key pathways in these disorders. Its safety profile aligns closely with that established for iloperidone. BYSANTI's unique in-class receptor binding profile, featuring strong alpha-adrenergic binding in excess of dopamine and serotonin receptor binding, makes it suitable for further investigation in conditions that include symptoms of hostility, agitation, and hyperarousal.

Vanda anticipates commercial availability of BYSANTI in Q3 of 2026. BYSANTI marketing exclusivity is expected to be protected by regulatory data exclusivity and issued US patents, with the latest expiring in 2044. BYSANTI is currently being tested as a once-daily adjunctive treatment in treatment-resistant major depressive disorder in an ongoing clinical study expected to complete by the end of this year.

Bipolar I disorder impacts a significant portion of the roughly 10 million Americans with bipolar disorder, characterized by manic or mixed episodes that require effective symptom management to enhance outcomes. Schizophrenia affects approximately 1% of the U.S. adult population (about 2.8 million people), often causing substantial functional impairment, frequent hospitalizations, and diminished quality of life.

In a separate announcement on February 25, 2026, Vanda disclosed that the FDA has accepted the filing of its Biologics License Application (BLA) for imsidolimab for the treatment of Generalized Pustular Psoriasis (GPP), with a target action date of December 12, 2026.

GPP is a rare, chronic, life-threatening autoinflammatory skin disorder characterized by sudden flares of widespread pustules, erythema, and systemic symptoms such as fever and fatigue. The pathogenesis of GPP is increasingly understood through its genetic characterization (OMIM #614204), and its molecular etiology is mainly attributed to excessive activity of the interleukin-36 (IL-36) pathway. The majority of GPP cases for which a causal single gene defect has been identified are caused by various consequential genetic variants in the IL36RN gene, encoding the IL-36 receptor antagonist (IL-36Ra).

Imsidolimab is a fully humanized IgG4 monoclonal antibody that inhibits IL-36 receptor signaling and is believed to achieve its therapeutic effects in GPP where IL-36 signaling is unbalanced. Imsidolimab was studied in global clinical studies conducted in the United States, France, Spain, Poland, Turkey, Malaysia, Thailand, Georgia, Tunisia, Taiwan, and Morocco.

In the pivotal efficacy studies GEMINI-1 and GEMINI-2, a single intravenous dose of imsidolimab led to rapid disease clearance, with 53% of patients achieving clear or almost clear skin (GPPPGA 0/1) at Week 4 compared to 13% on placebo. Efficacy was maintained throughout an approximately 2-year maintenance period with monthly doses, and no flares occurred in the active treatment arm. Imsidolimab exhibited a favorable safety profile and demonstrated a low incidence of anti-drug antibodies, which can be a significant advantage over existing treatments.

GPP is a rare disorder with prevalence estimates varying widely by region, ranging from approximately 2 to 124 cases per million worldwide (lower in Europe and higher in parts of Asia). Regulatory and patent exclusivity for imsidolimab is expected to extend into the late 2030s. Vanda holds an exclusive global license for the development and commercialization of imsidolimab from AnaptysBio (Nasdaq: ANAB).

If imsidolimab is approved, it will be the third new drug product approved for Vanda in the past 12 months, following NEREUS (tradipitant) and BYSANTI (milsaperidone). BYSANTI is the second new drug approval for Vanda in less than 2 months following the approval of NEREUS in December of 2025.