Head-to-head evidence
Quetiapine (Seroquel XR) vs Risperidone (Risperdal)
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
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)
Risperidone (Risperdal)
Marketed by Johnson & Johnson
NCT00253136 · Phase 3 · completed
The study randomized 458 participants to double-blind risperidone or placebo, with change in the clinical PANSS score as the primary endpoint. Because the registry does not report whether this endpoint was met, the trial provides a well-controlled design but no assessable result.
Next expected readout: December 2026 · NCT06482554 (registry estimate)
The full competitive landscape for each asset (every same-race competitor with aligned evidence, sortable) is on the asset pages: Quetiapine (Seroquel XR)'s landscape · Risperidone (Risperdal)'s landscape