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Recruiting Phase 2 NCT05491226

NCT05491226 Reinvigorating TNBC Response to Immunotherapy With Combination Myeloid Inhibition and Radiation

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Clinical Trial Summary
NCT ID NCT05491226
Status Recruiting
Phase Phase 2
Sponsor Stephen Shiao
Condition TNBC - Triple-Negative Breast Cancer
Study Type INTERVENTIONAL
Enrollment 35 participants
Start Date 2023-11-17
Primary Completion 2026-12-01

Eligibility & Interventions

Sex Female only
Min Age 18 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
PembrolizumabRadiation TherapyAxatilimab

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

In Phase 2, researchers evaluate early signs of effectiveness. You may be randomized to receive the active treatment or a comparator. Monitoring continues closely.

This trial targets 35 participants in total. It began in 2023-11-17 with a primary completion date of 2026-12-01.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

This is an open-label prospective, single institution, Phase II study of pembrolizumab in combination with radiation therapy and CSF-1R inhibition in patients with high-risk TNBC. The primary objective is to assess the pathologic complete response (pCR) rate where pCR is defined as the absence of invasive disease in the breast and lymph nodes at the time of standard of care (SOC) treatment. Secondary objectives include evaluating the change in tumor infiltrating lymphocytes (TILs), safety and tolerability of the combination, progression-free survival, event-free survival, overall survival, and node clearance.

Eligibility Criteria

Inclusion Criteria: * Female patients diagnosed with high-risk triple negative breast cancer (TNBC) with intent for neoadjuvant therapy. * Low tumor-infiltrating lymphocyte (TIL) score, defined as stromal TIL (sTIL) ≤40%; or node-positive; or combined positive score (CPS) \< 10 or PD-L1 tumor positivity \<1%. * Written informed consent obtained from subject and ability for subject to comply with the requirements of the study, including consent for research blood draws and use of available archived tissue. * Age ≥ 18 years of age on day of signing informed consent. * Histologically or cytologically-confirmed TNBC (defined as ER \<1%, PR\<1%, her-2-neu 0-1+ by IHC or FISH-negative). * If an archived tumor tissue is unavailable, be willing to provide tissue from a newly obtained core or excisional biopsy of a tumor lesion. Newly-obtained is defined as a specimen obtained up to 6 weeks (42 days) prior to initiation of treatment on Day 1 of RT. * Have a performance status of 0 or 1 on the ECOG Performance Scale. * Demonstrate adequate organ function. * Female subject of childbearing potential should have a negative serum or urine pregnancy test or documentation of absence of pregnancy by a gynecologist within 14 days of initiating first dose of pembrolizumab (1 week lead-in) for eligibility verification. * Female subjects of childbearing potential should be willing to comply to the contraceptive guidance in Appendix 12.2 during the treatment period through 120 days after the last dose of study medication. Subjects of childbearing potential are those who have not been surgically sterilized or have not been free from menses for \> 1 year. Exclusion Criteria: * Evidence of metastatic disease. * Has received prior radiotherapy within 2 weeks of start of study intervention. * Is currently participating and receiving study therapy or has participated in a study of an investigational agent and received study therapy or used an investigational device within 4 weeks of the first dose of treatment. * Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of trial treatment. * Has a known history of active TB (Bacillus Tuberculosis). * Hypersensitivity to pembrolizumab or any of its excipients. * Has had a prior anti-cancer monoclonal antibody (mAb) within 4 weeks prior to study Day 1 or who has not recovered (i.e., \> Grade 1 or at baseline) from adverse events due to agents administered more than 4 weeks earlier. * Has had prior chemotherapy or targeted small molecule therapy within 2 weeks prior to study Day 1 or who has not recovered (i.e., \> Grade 1 or at baseline) from adverse events due to a previously administered agent. Note: Subjects with ≤ Grade 2 neuropathy are an exception to this criterion and may qualify for the study. * Has a known additional malignancy that progressed or required treatment in the last 5 years. Exceptions include basal cell carcinoma of the skin or squamous cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer. * Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis. Subjects with previously treated brain parenchymal metastases may participate provided they are stable (without evidence of progression by imaging for at least four weeks prior to the first dose of trial treatment and any neurologic symptoms have returned to baseline), have no evidence of new or enlarging brain metastases, and are not using steroids for at least 7 days prior to trial treatment. This exception does not include carcinomatous meningitis, which is excluded regardless of clinical stability. * Has active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment. * Has known history of/active, non-infectious pneumonitis requiring treatment with steroids or has history of/active interstitial lung disease. * Has an active infection requiring systemic therapy. * Has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the treating investigator. * Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial. * Is pregnant or breastfeeding, or expecting to conceive within the projected duration of the trial, starting with the pre-screening or screening visit through 120 days after the last dose of trial treatment. A WOCBP who has a positive urine pregnancy test within 2 weeks prior to start of study treatment (first dose of pembrolizumab). If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required. Note: Negative urine or serum pregnancy test is also conducted within 72 hours prior to C1D1 for study procedures but if screening pregnancy test is done within 72 hours of C1D1, it is not required to be repeated.. * Has a known history of Human Immunodeficiency Virus (HIV) (HIV 1/2 antibodies). * Has a known history of active Hepatitis B (e.g., HBsAg reactive) or known active Hepatitis C (e.g., HCV RNA \[qualitative\] is detected). * Has received a live vaccine or live-attenuated vaccine within 30 days of planned start of pembrolizumab. Administration of killed vaccines is allowed. * Has had an allogenic tissue/solid organ transplant.

Contact & Investigator

Central Contact

Clinical Trial Recruitment Navigator

✉ cancer.trial.info@cshs.org

📞 310-423-2133

Principal Investigator

Stephen L Shiao, MD, PhD

PRINCIPAL INVESTIGATOR

CSMC

Frequently Asked Questions

Who can join the NCT05491226 clinical trial?

This trial is open to female participants only, aged 18 Years or older, studying TNBC - Triple-Negative Breast Cancer. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT05491226 trial and what does that mean for participants?

Phase 2 trials evaluate whether the treatment shows signs of effectiveness while continuing to monitor safety. More participants are enrolled than in Phase 1 to help refine the treatment protocol.

Is NCT05491226 currently recruiting?

Yes, NCT05491226 is actively recruiting participants. Contact the research team at cancer.trial.info@cshs.org for enrollment information.

Where is the NCT05491226 trial being conducted?

This trial is being conducted at Los Angeles, United States.

Who is sponsoring the NCT05491226 clinical trial?

NCT05491226 is sponsored by Stephen Shiao. The principal investigator is Stephen L Shiao, MD, PhD at CSMC. The trial plans to enroll 35 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: April 2026  ·  Data Methodology