# Pfizer: Phase 3 study in Early Breast Cancer, Estrogen Receptor Positive (ER+), Human Epidermal Growth Factor Receptor 2 Negative (HER2-) (3800 participants)

**Score:** 100/100

| Field | Value |
|---|---|
| Sponsor | Pfizer |
| Sponsor type | Industry (pharma, biotech, medtech) |
| Study | A Study of a Medicine Called Atirmociclib in Combination With Giredestrant in Adult Participants With ER-positive, HER2-negative Early-stage Breast Cancer |
| NCT ID | NCT07890597 |
| Phase | Phase 3 |
| Status | not yet recruiting |
| Conditions | Early Breast Cancer; Estrogen Receptor Positive (ER+), Human Epidermal Growth Factor Receptor 2 Negative (HER2-) |
| Intervention types | drug, other |
| Target enrollment | 3800 |
| Posted | 2026-10-22 |
| Planned start | 2026-12-01 |
| Event | Newly registered study |
| Event date | 2026-10-22 |

## Why this score
- Posted in the last two weeks.
- Industry sponsor (buys outsourced services).
- Phase 3: multi-site, larger budget.
- 3800 participants planned.
- Not yet recruiting: vendors still being chosen.

Source: ClinicalTrials.gov (U.S. National Library of Medicine) API v2 (https://clinicaltrials.gov/study/NCT07890597). Last refreshed: 2026-11-04T06:04:38.232Z.
From public ClinicalTrials.gov registrations. Sponsor and study level only: we never list investigators, contacts or participants. A registration describes a planned study and can change. Status changes are read from each study's current status, actual dates and latest posted update, not a full change history, so an update can be a correction rather than a new change. Verify on ClinicalTrials.gov.