Head-to-head evidence
Clozapine 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
Clozapine
Marketed by HLS Therapeutics Inc.
NCT00250575 · Phase 3 · completed
The study was open-label, single-arm, and had no placebo or active comparator; all 43 participants received clozapine. Its primary measures focused on hematological tests, blood-related adverse events, and monitoring-system compliance rather than a clinical symptom endpoint, and no results are posted.
Next expected readout: April 2027 · NCT04580134 (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: Clozapine's landscape · Quetiapine (Seroquel XR)'s landscape