Head-to-head evidence
Olanzapine (Zyprexa) vs Quetiapine (Seroquel)
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)
Marketed by Cheplapharm Arzneimittel GmbH and partners
NCT00305422 · Phase 3 · completed
The study was randomized and double-blinded with an active risperidone comparator, but its small sample of 45 participants limits the strength of the evidence. The primary comparison was not reported, and the primary focus included cognitive and functional brain-activation measures rather than a clearly specified hard clinical endpoint.
Next expected readout: June 2028 · NCT05603104 (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)'s landscape