Head-to-head evidence
Olanzapine (Zyprexa) vs Quetiapine (Seroquel XR)
Same mechanism, same race: design-graded trial evidence for both assets, with the grading rationale shown. Grades describe the quality of the evidence, never the merits of either security.
Schizophrenia
Shared mechanism: Dopamine D2 and serotonin 5-HT2A receptors (antagonist) · full Schizophrenia pipeline
Olanzapine (Zyprexa)
Marketed by Cheplapharm Arzneimittel GmbH and partners
NCT00712686 · Phase 3 · completed
The study was a large randomized, double-blind, active-controlled comparison of aripiprazole and olanzapine, with clinical outcomes including PANSS symptom scores. Because the registry does not report whether either primary endpoint was met, the treatment comparison cannot be judged as positive, negative, or mixed.
Next expected readout: February 2027 · NCT03781115 (registry estimate)
Quetiapine (Seroquel XR)
Marketed by Cheplapharm Arzneimittel GmbH and partners
NCT00640601 · Phase 3 · completed
This was a nonrandomized, single-group, open-label study of 295 treated participants, without a placebo or active comparator. Although 56.88% were reported to have improved clinical benefit on the primary CGI-CB measure, the uncontrolled design cannot determine how much of the improvement was due to quetiapine rather than other factors.
Next expected readout: February 2032 · NCT07152184 (registry estimate)
The full competitive landscape for each asset (every same-race competitor with aligned evidence, sortable) is on the asset pages: Olanzapine (Zyprexa)'s landscape · Quetiapine (Seroquel XR)'s landscape