TILs May Predict Pembrolizumab Response in Triple-negative Breast Cancer

Share this content:
The results of the study demonstrate that increased TIL levels may be associated with a greater response to pembrolizumab monotherapy in patients with mTNBC, especially in the first-line setting.
The results of the study demonstrate that increased TIL levels may be associated with a greater response to pembrolizumab monotherapy in patients with mTNBC, especially in the first-line setting.
The following article features coverage from the European Society of Medical Oncology (ESMO) 2017 Congress in Madrid, Spain. Click here to read more of Cancer Therapy Advisor's conference coverage.

Patients with metastatic triple-negative breast cancer (mTNBC) likely to respond to pembrolizumab monotherapy may be identified by high levels of tumor infiltrating lymphocytes (TIL), according to data presented at the European Society of Medical Oncology (ESMO) 2017 Congress in Spain.1

For this study, researchers analyzed data from the KEYNOTE-086 phase 2 study (ClinicalTrials.gov Identifier: NCT02447003), in which patients with mTNBC received pembrolizumab monotherapy regardless of PD-L1 expression (cohort A) or when determined to be PD-L1-positive (cohort B). Response to therapy was evaluated every 9 weeks for 1 year and every 3 months thereafter.

Of the 222 enrolled patients, 193 had evaluable tumor samples; 146 samples were collected from metastatic sites and 47 were collected from primary breast cancer tumors. Higher median TIL levels were observed in cohort B compared with cohort A (17.5% [6.2% -57.5%] vs 5% [1%-10%]; Wilcoxon rank sum P < .001), and in lymph node compared with non-lymph node samples (10% [5%-50%] vs 5% [2%-15%]; P = .01).

The overall response rate (ORR) in patients with greater than median TIL levels was 6% vs 2% in patients who had less than median TIL levels in cohort A, and was 39% vs 9% in cohort B. The median TIL levels in responders and non-responders were 10% (7.5%-25%) and 5% (1-10%), respectively, in cohort A, and 50% (5%-70%) and 15% (5%-37.5%), respectively, in cohort B.

In the combined cohorts, a significantly improved ORR (odds ratio 1.26; 95% CI, 1.03-1.55; P = .01) and disease control rate (odds ratio 1.22; 95% CI, 1.02-1.46; P = .01) was observed in patients with higher TIL levels.

RELATED: CDK4/6 Inhibitors in Breast Cancer Treatment: Recent Research, Safety Profiles, Acquired Resistance, Next Steps

The results of the study demonstrate that increased TIL levels may be associated with a greater response to pembrolizumab monotherapy in patients with mTNBC, especially in the first-line setting.

Read more of Cancer Therapy Advisor's coverage of the European Society of Medical Oncology (ESMO) 2017 Congress by visiting the conference page.

Reference

  1. Loi S, Adams S, Schmid P, et al. Relationship between tumor infiltrating lymphocyte (TIL) levels and response to pembrolizumab (pembro) in metastatic triple-negative breast cancer (mTNBC): results from KEYNOTE-086. Presented at: European Society of Medical Oncology (ESMO) 2017 Congress; Madrid, Spain: September 8-12, 2017. Abstract LBA13.

Related Resources

You must be a registered member of Cancer Therapy Advisor to post a comment.

Sign Up for Free e-newsletters

Regimen and Drug Listings

GET FULL LISTINGS OF TREATMENT Regimens and Drug INFORMATION

Bone Cancer Regimens Drugs
Brain Cancer Regimens Drugs
Breast Cancer Regimens Drugs
Endocrine Cancer Regimens Drugs
Gastrointestinal Cancer Regimens Drugs
Gynecologic Cancer Regimens Drugs
Head and Neck Cancer Regimens Drugs
Hematologic Cancer Regimens Drugs
Lung Cancer Regimens Drugs
Other Cancers Regimens
Prostate Cancer Regimens Drugs
Rare Cancers Regimens
Renal Cell Carcinoma Regimens Drugs
Skin Cancer Regimens Drugs
Urologic Cancers Regimens Drugs