Related Experiment Video
Updated: May 28, 2026
Studying Triple Negative Breast Cancer Using Orthotopic Breast Cancer Model
Published on: March 20, 2020
Dasatinib as a single agent in triple-negative breast cancer: results of an open-label phase 2 study
Richard S Finn1, Carmelo Bengala, Nuhad Ibrahim
1Department of Medicine, Division of Hematology, Oncology, Geffen School of Medicine, UCLA Medical Center, Los Angeles, California 90095, USA. rfinn@mednet.ucla.edu
Purpose:
Dasatinib is a potent, oral SRC-family kinase inhibitor with preclinical antiproliferative, antimetastatic, and antiosteoclastic activity suggesting dasatinib sensitivity in triple-negative, or basal-like, breast cancer cell lines. This phase 2 trial assessed efficacy and safety of single-agent dasatinib in patients with advanced triple-negative breast cancer (TNBC).
Experimental Design:
Female patients with measurable, locally advanced or metastatic TNBC initially received dasatinib 100 mg twice daily (BID); to improve tolerability, the protocol was amended and subsequent patients received 70 mg BID. Primary endpoint was Response Evaluation Criteria in Solid Tumors-defined objective response rate (ORR); secondary endpoints included progression-free survival (PFS), disease control rate (DCR), safety, and limited pharmacokinetics.
Results:
Of the 44 treated patients, 43 were response evaluable. ORR was 4.7%: two patients had confirmed partial responses lasting 14 and 58 weeks, respectively. Of 11 patients with stable disease, two continued for more than 16 weeks, thus protocol-defined DCR was 9.3%. Median PFS was 8.3 weeks (95% CI: 7.3-15.3). Five patients discontinued before first tumor assessment. No grade 4 adverse events (AE) were reported; grade 3 AEs occurring in more than 5% of patients were fatigue (9.1%), diarrhea, pleural effusion, and dyspnea (all 6.8%). Laboratory abnormalities were uncommon. Dasatinib at 100 mg BID was not well tolerated; rates of treatment interruption, dose reduction, and serious AEs were lower with dasatinib 70 mg BID.
Conclusions:
Single-agent dasatinib has limited activity in unselected patients with TNBC. Dasatinib 70 mg BID was better tolerated than 100 mg BID. Future studies will investigate dasatinib in other breast cancer settings, including chemotherapy combinations.
Insights
Single-agent dasatinib showed limited effectiveness in advanced triple-negative breast cancer (TNBC). A lower dose of dasatinib (70 mg BID) was better tolerated than the higher dose (100 mg BID) in patients.
Area of Science:
- Oncology
- Pharmacology
Background:
- Triple-negative breast cancer (TNBC) is an aggressive subtype with limited targeted therapy options.
- Dasatinib, a SRC-family kinase inhibitor, demonstrated preclinical activity against TNBC cell lines.
Purpose of the Study:
- To evaluate the efficacy and safety of single-agent dasatinib in patients with advanced TNBC.
- To assess objective response rate (ORR), progression-free survival (PFS), and disease control rate (DCR).
Main Methods:
- Phase 2 trial involving female patients with measurable, locally advanced or metastatic TNBC.
- Dasatinib administered at 100 mg twice daily (BID), later amended to 70 mg BID for improved tolerability.
- Primary endpoint: ORR. Secondary endpoints: PFS, DCR, safety, and pharmacokinetics.
Main Results:
- The objective response rate (ORR) was 4.7% (2 partial responses).
- Disease control rate (DCR) was 9.3% (2 patients with stable disease >16 weeks).
- Median PFS was 8.3 weeks; grade 3 adverse events included fatigue, diarrhea, pleural effusion, and dyspnea. The 70 mg BID dose was better tolerated.
Conclusions:
- Single-agent dasatinib exhibits limited clinical activity in unselected patients with advanced TNBC.
- Dasatinib 70 mg BID demonstrated improved tolerability compared to 100 mg BID.
- Future research may explore dasatinib in combination therapies or other breast cancer settings.
