# PF-07104091 as a Single Agent and in Combination Therapy

Source: https://onco.cc/trials/nct04553133/  
OnCo record `nct04553133` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A phase 2 trial of Palbociclib, Fulvestrant, Letrozole in small-cell lung cancer and ovarian cancer, run by Pfizer, active and no longer recruiting.

## Summary

PF-07104091 as a Single Agent and in Combination Therapy is a phase 2 interventional study registered as NCT04553133 by Pfizer, with 157 participants enrolled, started 2020-09-16 and due to reach its primary completion in 2026-12-31. Interventions recorded: PF-07104091 monotherapy dose escalation, PF-07104091 + palbociclib + fulvestrant, PF-07104091 + palbociclib + letrozole, PF-07104091 monotherapy dose expansion (ovarian), PF-07104091 monotherapy dose expansion (SCLC). Conditions listed: Small Cell Lung Cancer, Ovarian Cancer, Breast Cancer. No results are recorded here; the registry entry is the source.

## Fields

- Kind: Trial
- Status: active
- Last checked: 2026-09-16
- Tags: ctgov-ingest
- Registry id: NCT04553133
- Phase: 2
- Setting: PHASE 1/2A DOSE ESCALATION, FINDING AND EXPANSION STUDY EVALUATING SAFETY, TOLERABILITY, PHARMACOKINETICS, PHARMACODYNAMICS AND ANTI TUMOR ACTIVITY OF PF-07104091 AS A SINGLE AGENT AND IN COMBINATION THERAPY
- Sponsor: Pfizer
- Enrolled: 157

## Sources

- ClinicalTrials.gov NCT04553133: https://clinicaltrials.gov/study/NCT04553133

## Connected records

- cancers: [Ovarian cancer](https://onco.cc/cancers/ovarian/), [Small-cell lung cancer](https://onco.cc/cancers/sclc/)
- drugs: [Fulvestrant](https://onco.cc/drugs/fulvestrant/), [Letrozole (and other aromatase inhibitors)](https://onco.cc/drugs/letrozole/), [Palbociclib](https://onco.cc/drugs/palbociclib/)
- companies: [Pfizer (incl. Seagen)](https://onco.cc/companies/pfizer/)

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JSON: https://onco.cc/api/v1/entities/nct04553133.json