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Small Cell Lung CancerPhase 2NCT04553133

PF-07104091 as a Single Agent and in Combination Therapy

A Phase 2 study testing PF-07104091 monotherapy dose escalation, PF-07104091 + palbociclib + fulvestrant and PF-07104091 + palbociclib + letrozole in people with Small Cell Lung Cancer and Ovarian Cancer, run by Pfizer at 22 sites in 4 countries.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
Search all trials

Trial summary

To assess the safety and tolerability of increasing doses of PF-07104091 and to estimate the Maximum Tolerated Dose (MTD) and/or select the Recommended Phase 2 dose (RP2D) for PF-07104091 as a single agent in participants with advanced or metastatic small cell lung, breast and ovarian cancers. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
PF-07104091 monotherapy dose escalation, PF-07104091 + palbociclib + fulvestrant and PF-07104091 + palbociclib + letrozole
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
157 participants
Where
22 sitesin 4 countries
Study dates
16 Sep 2020to 31 Dec 2026
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Participants with HR-positive HER2-negative advanced or metastatic breast cancer (received at least two prior lines in the advanced or metastatic setting including one prior line of combined CDK4/6 inhibitor and endocrine therapy and no more than two prior lines of cytotoxic chemotherapy)
  • Participants with locally recurrent/advanced or metastatic TNBC who have received up to 2 prior lines of chemotherapy in the advanced or metastatic setting
  • Participants with advanced platinum resistant epithelial ovarian cancer (EOC)/fallopian tube cancer/primary peritoneal cancer (PPC) (histologically or cytologically proven) who have received at least 1 systemic anti-cancer therapy containing a platinum analog
  • Participants with cytological diagnosis of advanced/metastatic SCLC
  • Participants with or cytological diagnosis of advanced/metastatic NSCLC
  • Participants with HR-positive HER2-negative advanced or metastatic breast cancer (second line plus setting) (histologically or cytologically proven).
Show all 10Show fewer
  • Participants entering the study in the expansion cohort have at least one measurable lesion as defined by RECIST version 1.1 that has not been previously irradiated
  • Performance Status 0 or 1
  • Adequate bone marrow, hematological, kidney and liver function
  • Resolved acute effects of any prior therapy to baseline severity

Who cannot join

  • Participants with known symptomatic brain metastases requiring steroids
  • Participants with any other active malignancy within 3 years prior to enrollment
  • Major surgery within 3 weeks prior to study entry
  • Radiation therapy within 3 weeks prior to study entry.
  • Systemic anti cancer therapy within 4 weeks prior to study
  • Prior irradiation to >25% of the bone marrow
Show all 23Show fewer
  • Participants with active, uncontrolled bacterial, fungal, or viral infection, including HBV, HCV, and known HIV or AIDS related illness
  • Active COVID-19/SARS-CoV2 infection
  • Baseline 12 lead ECG that demonstrates clinically relevant abnormalities that may affect participant safety or interpretation of study results
  • Any of the following in the previous 6 months: myocardial infarction, long QT syndrome, Torsade de Pointes, arrhythmias, serious conduction system abnormalities, unstable angina, coronary/peripheral artery bypass graft, symptomatic CHF, New York Heart Association class III or IV, cerebrovascular accident, transient ischemic attack, symptomatic pulmonary embolism, and/or other clinical significant episode of thrombo embolic disease.
  • Anticoagulation with vitamin K antagonists or factor Xa inhibitors is not allowed.
  • Hypertension that cannot be controlled by medications
  • Participation in other studies involving investigational drug(s) within 2 weeks prior to study entry.
  • Known or suspected hypersensitivity to active ingredient/excipients in PF 07104091.
  • Active inflammatory gastrointestinal disease, chronic diarrhea, known diverticular disease or previous gastric resection or lap band surgery.
  • Participants with advanced/metastatic, symptomatic, visceral spread, that are at risk of life threatening complications in the short
  • Participants with an indwelling catheter that has an external component such as those used for drainage of effusion(s) or central venous catheter that is externally
  • Previous high dose chemotherapy requiring stem cell rescue
  • Known abnormalities in coagulation such as bleeding diathesis, or treatment with anticoagulants precluding intramuscular injections of goserelin (if applicable).
  • Current use or anticipated need for food or drugs that are known strong CYP3A4/5 or UGT1A9 inhibitors or inducers
  • Current use or anticipated need for drugs that are known sensitive UGT1A1 substrates with narrow therapeutic
  • Serum pregnancy test positive at screening
  • Other medical or psychiatric condition

Trial locations and contacts

22 sites in 4 countries.

22 sites in 4 countries

United States17 sites

  • Massachusetts General Hospital

    Boston, Massachusetts, 02114

  • UVA Breast Care Center

    Charlottesville, Virginia, 22911

  • Medical Oncology & Hematology Associates DBA Mission Cancer and Blood

    Clive, Iowa, 50325

  • Des Moines Oncology Research Association

    Des Moines, Iowa, 50309

  • Medical Oncology & Hematology Associates DBA Mission Cancer and Blood

    Des Moines, Iowa, 50309

  • Medical Oncology & Hematology Associates DBA Mission Cancer and Blood

    Des Moines, Iowa, 50314

  • Memorial Sloan Kettering Cancer Center (IDS Pharmacy)

    Long Island City, New York, 11101

  • Norton Hospital

    Louisville, Kentucky, 40202

  • Norton Cancer Institute, St. Matthews Campus

    Louisville, Kentucky, 40207

  • Norton Cancer Institute, Audubon

    Louisville, Kentucky, 40217

  • Norton Brownsboro Hospital

    Louisville, Kentucky, 40241

  • Norton Cancer Institute, Brownsboro Campus

    Louisville, Kentucky, 40241

  • Memorial Sloan Kettering Monmouth

    Middletown, New Jersey, 07748

  • Laura & Isaac Perlmutter Cancer Center - NYU ACC

    New York, New York, 10016

  • NYU Langone Medical Center (Tisch Hospital)

    New York, New York, 10016

  • Dana-Farber Cancer Institute - Chestnut Hill

    Newton, Massachusetts, 02459

  • White Plains Hospital

    White Plains, New York, 10601

Other trials in United States

Bulgaria2 sites

  • Complex Oncology Center - Plovdiv EOOD

    Plovdiv, 4004

  • Complex Oncology Center - Shumen

    Shumen, 9700

Other trials in Bulgaria

China2 sites

  • Fudan University Shanghai Cancer Center

    Shanghai, Shanghai Municipality, 200032

  • Tianjin Medical University Cancer Institute & Hospital

    Tianjin, Tianjin Municipality, 300060

Other trials in China

Argentina1 site

  • Centro de Investigaciones Medicas y Desarrollo LC

    Buenos Aires, Buenos Aires F.D., 1113

Other trials in Argentina

About this study

Official title: 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

To assess the safety and tolerability of increasing doses of PF-07104091 and to estimate the Maximum Tolerated Dose (MTD) and/or select the Recommended Phase 2 dose (RP2D) for PF-07104091 as a single agent in participants with advanced or metastatic small cell lung, breast and ovarian cancers.

Read the detailed description

Study C4161001 is a Phase 1, open label, multi dose, multi center, dose escalation, safety, pharmacokinetic (PK) and pharmacodynamic study of PF-07104091 in adult patients with advanced or metastatic small cell lung cancer (SCLC), advanced platinum resistant epithelial ovarian cancer/fallopian tube cancer/primary peritoneal cancer, locally recurrent/advanced or metastatic triple negative breast cancer (TNBC), HR-positive HER2-negative advanced or mBC, advanced or metastatic non-small cell lung cancer (NSCLC). This two part study will assess the safety and tolerability of increasing dose levels of PF-07104091 in Part 1, and establish the recommended Phase 2 dose (RP2D) in Part 2.

Being tested
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)
Keywords
Hormone receptor-positive human epidermal growth factor receptor 2 negative breast cancer, Cyclin-Dependent Kinase 2 Inhibitor, PF-07104091, palbociclib, letrozole, cyclin-dependent kinase, Ibrance
Medical subject headings
Small Cell Lung Carcinoma, Ovarian Neoplasms, Breast Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PF-07104091 monotherapy dose escalationDrug

    PF-07104091 will be administered orally

  • PF-07104091 + palbociclib + fulvestrantDrug

    PF-07104091 will be administered orally in combination with palbociclib and fulvestrant

  • PF-07104091 + palbociclib + letrozoleDrug

    PF-07104091 will be administered orally in combination with palbociclib and letrozole

  • PF-07104091 monotherapy dose expansion (ovarian)Drug

    PF-07104091 will be administered orally

  • PF-07104091 monotherapy dose expansion (SCLC)Drug

    PF-07104091 will be administered orally

  • PF-07104091 + Fulvestrant (post CDK4/6)Drug

    PF-07104091 will be administered orally in combination with fulvestrant

  • PF-0704091 + Fulvestrant (post CDK4/6)Drug

    PF-07104091 + fulvestrant (post 4/6) dose expansion

Study groups in NCT04553133
Study groupRoleWhat they receive
PF-07104091ExperimentalCDK2 monotherapy dose escalation
Receives: Drug: PF-07104091 monotherapy dose escalation
PF-07104091 + palbociclib + fulvestrantExperimentalCDK2 + palbociclib + fulvestrant
Receives: Drug: PF-07104091 + palbociclib + fulvestrant
PF-07104091 + palbociclib + letrozoleExperimentalCDK2 + palbociclib + letrozole
Receives: Drug: PF-07104091 + palbociclib + letrozole
PF-07104091 monotherapy dose expansion (SCLC)ExperimentalPF-07104091 monotherapy dose expansion (SCLC)
Receives: Drug: PF-07104091 monotherapy dose expansion (SCLC)
PF-07104091 monotherapy dose expansion (ovarian)ExperimentalPF-07104091 monotherapy dose expansion (ovarian)
Receives: Drug: PF-07104091 monotherapy dose expansion (ovarian)
PF-07104091 + fulvestrant (post CDK4/6) dose expansionExperimentalPF-07104091 + fulvestrant (post CDK4/6) dose expansion
Receives: Drug: PF-0704091 + Fulvestrant (post CDK4/6)
PF-07104091 + fulvestrant (post CDK 4/6) dose escalationExperimentalCDK2+ fulvestrant (post CDK 4/6) dose escalation
Receives: Drug: PF-07104091 + Fulvestrant (post CDK4/6)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Dose Escalation: Number of participants with Dose-limiting toxicities (DLT) during first cycle

    Number of participants with DLTs, which are typically Grade 3 or higher adverse events will be summarized by dose level

    Measured: 28 days

  2. To evaluate incidence of treatment emergent adverse events and laboratory abnormalities

    Type, incidence, severity, timing, seriousness and relationship to study treatment of adverse events and any laboratory abnormalities will be summarized by dose level

    Measured: From baseline until end of study treatment or study completion (approximately 2 years)

  3. Evaluate pulse rate that is out of normal range and changes in pulse rate as compared to baseline

    Identify pulse rate readings that are outside the normal range. The number and percentage of participants who experienced significant pulse rate change from baseline will be summarized by dose level

    Measured: From baseline until end of study treatment or study completion (approximately 2 years)

  4. Evaluate blood pressure that is out of normal range and changes in blood pressure as compared to baseline

    Identify systolic and diastolic readings that are outside the normal range. The number and percentage of participants who experienced significant blood pressure change from baseline will be summarized by dose level

    Measured: From baseline until end of study treatment or study completion (approximately 2 years)

  5. To evaluate heart rate corrected QT interval and changes in corrected QT interval as compared to baseline

    Determine the effect of the drug on QT prolongation. The number and percentage of participants who experienced QT interval prolongation will be summarized by dose level

    Measured: From baseline until end of study treatment or study completion (approximately 2 years)

  6. To evaluate the preliminary antitumor activity of PF-07104091 as a single agent and in combination with palbociclib and in combination with letrozole or fulvestrant or fulvestrant alone by objective response rate (ORR) in dose expansion

    Percentage of participants with a best overall response of complete response (CR) or partial response (PR) using RECIST 1.1

    Measured: From baseline through disease progression or study completion (approximately 2 years)

Secondary outcomes (7)

  1. Maximum plasma concentration (Cmax) of PF-07104091 after a single dose and multiple dose

    Peak concentration of PF-07104091 during selected cycles

    Measured: Day 1 and Day 15 of Cycle 1 (each cycle is 28 days)

  2. Time to maximum plasma concentration (Tmax) of PF-07104091 after a single dose and multiple dose

    Time to peak concentration of PF-07104091 during selected cycles

    Measured: Day 1 and Day 15 of Cycle 1 (each cycle is 28 days)

  3. Area under the concentration versus time curve from time zero to the last quantifiable time point prior to the next dose (AUClast) of PF-07104091

    AUC of PF-07104091 will be calculated at selected cycles

    Measured: Day 1 and Day 15 of Cycle 1 (each cycle is 28 days)

  4. Area under the curve of PF-07104091 with or without food

    AUC of PF-07104091 in plasma and whether absorption of the drug is affected when taken by food

    Measured: From baseline through time to event on study or study completion (approximately 2 years)

  5. Maximum plasma concentration of PF-07104091 with or without food

    Peak concentrations of PF-07104091 in plasma and whether absorption of the drug is affected when taken by food

    Measured: From baseline through time to event on study or study completion (approximately 2 years)

  6. To document any preliminary evidence of antitumor activity of PF-07104091 as a single agent and in combination with palbociclib and in combination with letrozole or fulvestrant or fulvestrant alone by objective response rate (ORR) in dose escalation

    Percentage of participants with a best overall response of CR or PR using RECIST 1.1

    Measured: From baseline and every 8 weeks through disease progression or study completion (approximately 2 years)

  7. To document any preliminary evidence of antitumor activity of PF-07104091 by time to event endpoints

    Time from first assessment of event endpoint to last assessment of using RECIST 1.1

    Measured: From baseline through time to event on study or study completion (approximately 2 years)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted17 Sep 2020
  2. Study start16 Sep 2020
  3. Primary completion31 Dec 2026 (estimated)
  4. Study completion31 Dec 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Sequential
Masking
None (open label)
Enrolment
157 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04553133
Sponsor's protocol ID
C4161001
Other IDs
2024-515492-34-00
Status last verified
May 2026
First submitted
21 Aug 2020
Last updated
6 May 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing PF-07104091 monotherapy dose escalation, PF-07104091 + palbociclib + fulvestrant and PF-07104091 + palbociclib + letrozole in people with Small Cell Lung Cancer and Ovarian Cancer, run by Pfizer at 22 sites in 4 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 23 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 6 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 22 sites in United States, Bulgaria, China, Argentina. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Dose Escalation: Number of participants with Dose-limiting toxicities (DLT) during first cycle (time frame: 28 days). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04553133.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 May 2026; AzTrials last refreshed its copy on 26 Oct 2026.

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