The FDA has approved olanzapine extended-release injectable suspension (Weltruza™; Teva Pharmaceuticals) for adults with schizophrenia. The once-monthly subcutaneous treatment requires no loading dose, oral supplementation, or postinjection monitoring, according to an announcement from Teva. The company expects it to become available in the US in the coming weeks.¹

Olanzapine will be available in doses of 318 mg, 425 mg and 531 mg that correspond to the approved daily dose range of oral olanzapine of 10 mg, 15 mg and 20 mg, respectively, according to Teva.¹

“Olanzapine has been a trusted and foundational treatment option for people living with schizophrenia for more than 30 years, but adherence continues to be a major barrier to stability, particularly for those who rely on daily oral medications,” Christoph Correll, MD, Clinical Professor of Psychiatry at the Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, said in the release. “By offering a subcutaneous long-acting injectable formulation with achievement of therapeutic blood levels without oral cotreatment, loading doses or booster injections, this new treatment option can help empower patients, support their care partners and provide clinicians with an important new tool to assist in managing this complex condition more effectively.”¹

Approval was supported by the phase 3 SOLARIS trial, which enrolled 675 adults aged 18 to 64 years with schizophrenia. During an 8-week randomized, double-blind period, participants received monthly subcutaneous olanzapine at one of three doses or placebo. All 3 doses met the primary endpoint of change in Positive and Negative Syndrome Scale (PANSS) total score from baseline to week 8. The placebo-adjusted differences were −9.71 points for the high dose, −11.27 points for the medium dose, and −9.71 points for the low dose (adjusted P < .001 for each comparison). Clinical Global Impressions–Severity and Personal and Social Performance scores also improved significantly versus placebo, Teva reported.¹˒²

Participants could then enter an open-label safety period lasting up to 48 weeks. In a company-reported analysis through week 56, no suspected or confirmed PDSS events occurred across 3470 injections. That finding does not establish that the risk is absent: Teva’s safety information states that it is unknown whether PDSS can occur with olanzapine.¹˒³

The formulation retains the metabolic concerns associated with olanzapine. In the long-term SOLARIS analysis, increased weight was reported in 36% of participants receiving injectable olanzapine. Injection-site induration and pain each occurred in 12%, erythema in 10%, pruritus in 7%, and somnolence in 7%. Among 137 participants treated for at least 48 weeks, mean weight gain from baseline was 5.6 kg, according to Teva.³ The company’s approval announcement also listed headache and constipation among commonly reported adverse events.¹

Olanzapine carries the antipsychotic boxed warning for increased mortality in older adults with dementia-related psychosis and is not approved for that use. For clinicians considering a switch from oral therapy, the simpler monthly administration must be weighed alongside olanzapine’s potential for clinically significant weight gain, hyperglycemia, and dyslipidemia. The placebo-controlled phase of SOLARIS lasted 8 weeks; the longer safety findings came from an open-label period.¹˒³

References

1. Teva Pharmaceuticals. 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. Published October 9, 2026. Accessed October 9, 2026. https://www.tevapharm.com/news-and-media/latest-news/teva-announces-u.s.-food-and-drug-administration-fda-approval-of-weltruza-olanzapine-for-extended-re
2. Teva Pharmaceuticals. Teva and Medincell Announce Positive Phase 3 Efficacy Results from SOLARIS Trial Evaluating TEV-‘749 (olanzapine) as a Once-Monthly Subcutaneous Long-Acting Injectable in Adults with Schizophrenia. Published May 8, 2024. Accessed October 9, 2026. https://www.tevausa.com/news-and-media/press-releases/teva-and-medincell-announce-positive-phase-3-efficacy-results-from-solaris-trial-evaluating-tev-749-ola/?utm_source=chatgpt.com
3. Teva Pharmaceuticals. New Long-term Safety Data from the Completed Phase 3 SOLARIS Trial Support the Potential of Olanzapine LAI (TEV-'749) as the First Long-Acting Olanzapine Treatment Option for Schizophrenia with No PDSS Observed. Published September 21, 2025. Accessed October 9, 2026. https://www.tevapharm.com/news-and-media/latest-news/new-long-term-safety-data-from-the-completed-phase-3-solaris-trial-support-the-potential-of-olanzapine-la/?utm_source=chatgpt.com