NCT03272334: Breast-47

A Phase I/II Study of Anti-CD3 x Anti-HER2/Neu (Her2Bi) Armed Activated T Cells (ATC) and Pembrolizumab Combination Therapy in Women With Metastatic Breast Cancer

Active, enrolled Phase 1/Phase 2 Results posted Last updated 6 February 2026

What this trial tests

Phase 1/Phase 2 trial testing HER2 BATs with Pembrolizumab in Metastatic Breast Cancer in 22 participants. Participants enrolled and being followed up; not accepting new ones.

Timeline

29 December 2017

Primary endpoint
30 November 2024

1 January 2031

Quick facts

Lead sponsor	University of Virginia
Phase	Phase 1/Phase 2
Status	Active, enrolled
Study type	INTERVENTIONAL
Allocation	non randomized
Design	sequential
Masking	none
Primary purpose	treatment
Enrollment	22
Start date	29 December 2017
Primary completion	30 November 2024
Estimated completion	1 January 2031
Sites	1 location across United States

Drugs / interventions tested

• HER2 BATs with Pembrolizumab — full drug profile →

Conditions studied

• Metastatic Breast Cancer — all drugs for Metastatic Breast Cancer →

Sponsor

University of Virginia

Who can join

18 and older, female only, with Metastatic Breast Cancer. Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

• Dose Limiting Toxicities (Escalation and Expansion Cohorts)
  Time frame: From start of study treatment until 3 weeks after last dose of study treatment, assessed over about 10 weeks.
  Maximum tolerated dose will be based on number of dose limiting toxicities in each schedule/arm

Sponsor's own description

This proposal uses HER2Bi armed activated T-cells (HER2 BATs) to target breast cancer in combination with pembrolizumab (PBZ) in women with metastatic breast cancer (MBC). Phase I will determine a safe dose of the combination of PBZ and HER2 BATs in 3 to 18 patients. In the phase II portion, an additional 12 patients will be treated at the selected dose to further evaluate the safety and preliminary efficacy.

Study treatment includes a combination of 8 infusions of BATs using a previously established schedule and one to three infusions of PBZ (200 mg per dose). PBZ will be added to 8 infusions of BATs in 3 schedules: #1) after the 8th BATs infusion; #2) after the 4th and 8th BATs infusions; and then, #3) before the 1st and after the 4th and 8th BATs infusions.

Publications & conference data

8 peer-reviewed publications reference this trial (live from Europe PMC):

1. Targeting HER2-positive breast cancer: advances and future directions.
   Swain SM, Shastry M, Hamilton E. · · 2023 · cited 703× · PMID 36344672 · DOI 10.1038/s41573-022-00579-0
2. Overcoming Challenges for CD3-Bispecific Antibody Therapy in Solid Tumors.
   Middelburg J, Kemper K, Engelberts P, Labrijn AF, et al · · 2021 · cited 122× · PMID 33466732 · DOI 10.3390/cancers13020287
3. Bi-specific and tri-specific antibodies- the next big thing in solid tumor therapeutics.
   Runcie K, Budman DR, John V, Seetharamu N. · · 2018 · cited 120× · PMID 30249178 · DOI 10.1186/s10020-018-0051-4
4. Emerging Targeted Therapies for HER2-Positive Breast Cancer.
   Mercogliano MF, Bruni S, Mauro FL, Schillaci R. · · 2023 · cited 95× · PMID 37046648 · DOI 10.3390/cancers15071987
5. Interaction of host immunity with HER2-targeted treatment and tumor heterogeneity in HER2-positive breast cancer.
   Griguolo G, Pascual T, Dieci MV, Guarneri V, et al · · 2019 · cited 91× · PMID 30922362 · DOI 10.1186/s40425-019-0548-6
6. Overcoming the challenges associated with CD3+ T-cell redirection in cancer.
   Singh A, Dees S, Grewal IS. · · 2021 · cited 82× · PMID 33469153 · DOI 10.1038/s41416-020-01225-5
7. Management of patients with advanced-stage HER2-positive breast cancer: current evidence and future perspectives.
   Marra A, Chandarlapaty S, Modi S. · · 2024 · cited 79× · PMID 38191924 · DOI 10.1038/s41571-023-00849-9
8. Immune cell engagers in solid tumors: promises and challenges of the next generation immunotherapy.
   Fucà G, Spagnoletti A, Ambrosini M, de Braud F, et al · · 2021 · cited 41× · PMID 33508733 · DOI 10.1016/j.esmoop.2020.100046