FDA Approves Once-Monthly Subcutaneous Olanzapine for Schizophrenia

The FDA has approved olanzapine extended-release injectable suspension (Weltruza; Teva Pharmaceuticals), a once-monthly subcutaneous long-acting injectable (LAI) for the treatment of schizophrenia in adults, Teva announced October 9, 2026.¹

The company describes the treatment as the first and only once-monthly subcutaneous injectable formulation of olanzapine. According to Teva, treatment requires no loading doses, no oral supplementation, and no postinjection monitoring.

Olanzapine will be available in 318 mg, 425 mg, and 531 mg once-monthly doses, which correspond to the approved daily oral olanzapine doses of 10 mg, 15 mg, and 20 mg, respectively. The formulation uses SteadyTeq, a Medincell-proprietary copolymer technology that provides controlled, sustained release of olanzapine. Teva expects the product to be available in the US in the coming weeks.

What did the SOLARIS trial show?

The approval is based on the phase 3 SOLARIS trial (NCT05693935), a multinational, randomized, double-blind, placebo-controlled study of adults aged 18 to 64 years with schizophrenia. In the first 8 weeks, 675 patients with acute exacerbation of schizophrenia were randomized 1:1:1:1 to low-, medium-, or high-dose olanzapine or placebo. During the next 48 weeks, patients who had received placebo were rerandomized equally to 1 of the 3 Weltruza doses, and those who had received olanzapine stayed on their established dose.

The primary objective was efficacy as measured by the Positive and Negative Syndrome Scale (PANSS), with Clinical Global Impressions-Severity (CGI-S) and Personal and Social Performance (PSP) scales as key secondary measures. In results presented at Psych Congress Elevate 2025, all 3 doses (318 mg, 425 mg, and 531 mg) produced significantly greater improvement in PANSS total score than placebo from baseline to week 8, with differences vs placebo of -9.75 (95% CI, –13.60 to –5.89), –11.27 (95% CI, –15.01 to –7.53), and –9.76 (95% CI, –13.50 to –6.02), respectively.² All 3 doses also showed significantly greater improvement than placebo on CGI-S and PSP.

Olanzapine Safety Considerations

In SOLARIS, all 3 doses were similarly tolerated. The most common adverse events were increased weight, somnolence, headache, constipation, and injection site reactions. Weight gain and metabolic changes were consistent with the safety profile of oral olanzapine, including clinically significant weight gain. Discontinuations due to common adverse events occurred in 5% of patients receiving the treatment and 4% of those receiving placebo.

Olanzapine carries a boxed warning for increased risk of death in older adults with dementia-related psychosis, and it is not approved for that population. Postinjection delirium/sedation syndrome has occurred with another extended-release olanzapine product given intramuscularly, and it is not known whether it can occur with this form of subcutaneous olanzapine, according to the safety information. As of March 2025, no suspected or confirmed cases had been reported across about 3487 active injections in the SOLARIS program, according to the poster abstract.²

Why a Monthly Olanzapine Option Matters

Olanzapine is the most widely prescribed atypical antipsychotic for schizophrenia as a daily oral treatment, but Teva notes that daily dosing can make adherence difficult, raising the risk of instability and relapse.¹ An estimated 2.1 million people in the US are diagnosed with schizophrenia.

Eric Hughes, MD, PhD, Teva’s chief medical officer, said the formulation aims to “eliminate the need for monitoring after each injection.” Christoph Correll, MD, of the Zucker School of Medicine at Hofstra/Northwell, said it achieves therapeutic blood levels without oral cotreatment, loading doses, or booster injections.

The European Medicines Agency accepted Teva’s marketing authorization application in May 2026, and the product is not yet approved in Europe.

References

1. Teva announces U.S. Food and Drug Administration (FDA) approval of WELTRUZA (olanzapine) for extended-release injectable suspension, as the first and only once-monthly subcutaneous injectable olanzapine for adults with schizophrenia. News release. Teva Pharmaceuticals. October 9, 2026. Accessed October 9, 2026. https://ir.tevapharm.com/news-and-events/press-releases/press-release-details/2026/Teva-Announces-U-S--Food-and-Drug-Administration-FDA-Approval-of-WELTRUZA-Olanzapine-For-Extended-Release-Injectable-Suspension-as-the-First-and-Only-Once-Monthly-Subcutaneous-Injectable-Olanzapine-for-Adults-with-Schizophrenia/default.aspx
2. Correll C, Shulman K, Bar-Nur T, et al. Efficacy of olanzapine extended-release injectable suspension (TV-44749) for subcutaneous use demonstrated in patients with schizophrenia: results from a phase 3 randomized, double-blind, placebo-controlled trial (SOLARIS). Presented at: Psych Congress Elevate; 2025. Accessed October 9, 2026. Poster 34. https://www.hmpgloballearningnetwork.com/node/341431