FDA Approves Once-Monthly Subcutaneous Olanzapine for Schizophrenia

The US Food and Drug Administration (FDA) has approved olanzapine extended-release injectable suspension (Weltruza) as the first once-monthly subcutaneous long-acting injectable (LAI) olanzapine for adults with schizophrenia, based on results from the phase 3 SOLARIS trial, Teva Pharmaceuticals announced on October 9, 2026.¹

Olanzapine is the most widely prescribed atypical antipsychotic for schizophrenia as a daily oral therapy, according to Teva, but adherence challenges with daily dosing can raise the risk of instability and relapse.¹ Teva submitted the new drug application (NDA) for the formulation, previously known as TEV-‘749, in December 2025.²

“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,” said Christoph Correll, MD, clinical professor of psychiatry at the Zucker School of Medicine at Hofstra/Northwell. “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

Olanzapine LAI Efficacy in the Phase 3 SOLARIS Trial

The Subcutaneous Olanzapine Extended-Release Injection Study (SOLARIS) was a multinational, multicenter, randomized, double-blind, parallel-group, placebo-controlled phase 3 trial in patients with schizophrenia aged 18 to 64 years.¹ During the 8-week first period, 675 participants were randomized 1:1:1:1 to a low, medium, or high once-monthly dose of subcutaneous olanzapine or placebo.¹

In the 48-week second period, participants completing period 1 on placebo were re-randomized equally to 1 of the 3 active doses, and those on active treatment continued at their established dose strength.¹ The primary efficacy measure was the Positive and Negative Syndrome Scale (PANSS), with the Clinical Global Impression-Severity (CGI-S) scale and the Personal and Social Performance (PSP) scale as key secondary measures.¹ End-of-treatment and follow-up visits occurred 4 and 8 weeks after the final dose.¹

According to Teva, olanzapine LAI improved overall symptoms on the PANSS, significantly reduced illness severity on the CGI-S, and improved personal and social functioning on the PSP.¹ The company did not report effect sizes, CIs, or P values for these endpoints in its announcement.¹

Weltruza Dosing, Monitoring, and Safety Profile

Weltruza will be available in once-monthly doses of 318 mg, 425 mg, and 531 mg, corresponding to daily oral olanzapine doses of 10 mg, 15 mg, and 20 mg, respectively.¹ The formulation uses SteadyTeq, a copolymer technology proprietary to Medincell, to provide steady, sustained release of olanzapine.¹ Treatment requires no loading doses, oral supplementation, or post-injection monitoring.¹

All 3 doses were similarly tolerated in SOLARIS, with the most common adverse events including weight gain, somnolence, headache, constipation, and injection site reactions.¹ Teva reported weight gain and metabolic changes consistent with the systemic safety profile of oral olanzapine, including clinically significant weight gain.¹ Discontinuations due to common adverse events occurred in 5% of participants receiving olanzapine LAI and 4% of those receiving placebo.¹

“Weltruza combines proven science and novel formulation innovation to eliminate the need for monitoring after each injection, addressing a significant barrier to treatment and advancing care for people living with schizophrenia,” said Eric Hughes, MD, PhD, executive vice president, global R&D and chief medical officer at Teva.¹

Teva expects Weltruza to be available in the US in the coming weeks.¹ The European Medicines Agency accepted the marketing authorization application for the olanzapine LAI in May 2026, and the agent is not yet approved in Europe.¹

In a previously reported SOLARIS attitudes survey, more than 92% of patients, 87% of nurses, and 73% of physicians said they were satisfied or very satisfied with the initiation regimen, monthly dosing schedule, and dosing options.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.tevausa.com/en/us/news-and-media/press-releases

2. Teva Pharmaceuticals submits NDA on TEV-‘749 for schizophrenia to the FDA. HCPLive. https://www.hcplive.com/view/teva-pharmaceuticals-submits-nda-tev--749-for-schizophrenia-fda. Published December 9, 2025. Accessed October 9, 2026.

3. HCPLive. TEV-‘749 once-monthly LAI yields high satisfaction in phase 3 trial, with Andrew J. Cutler, MD. https://www.hcplive.com/view/tev--749-once-monthly-lai-yields-high-satisfaction-in-phase-3-trial-with-andrew-j-cutler-md. Published April 21, 2025. Accessed October 9, 2026.