Immunotherapy: New Options for Breast Cancer Patients
By Antoinette Tan, MD, MHSc, chief, breast medical oncology
Immunotherapies have revolutionized care for several types of solid tumors, but progress using this type of approach against breast cancer has been elusive. Unlike melanoma or lung cancer cells, breast cancer cells look very similar to normal tissue and don’t automatically trigger an immune response. This makes it harder to coax immune cells into attacking breast cancer cells. But the tide is turning.
Recent studies indicate that one type of checkpoint inhibitor – the programmed death-1 (PD-1) inhibitor – can shrink tumors, stabilize disease and extend survival in some patients with triple-negative breast cancer (TNBC). At Levine Cancer Institute (LCI), we’re building on this progress via clinical trials that bring PD-1 inhibitors to patients with early stage and metastatic TNBC as well as metastatic, HER2-negative breast cancer.
Goal: Reduce Recurrence
One of our top breast cancer research priorities is to make progress against the TNBC subtype. Findings from the KEYNOTE-086 trial offer an encouraging sign: Of 52 TNBC participants who received the PD-1 inhibitor pembrolizumab as their first treatment for advanced disease, 23 percent saw tumors shrink by more than 30 percent, while the treatment stabilized disease in another 17 percent of patients. While these numbers are small, they signal that there may be ways to build on pembrolizumab’s potential.
Soon, we will open a large, Phase III trial that investigates whether pembrolizumab can reduce relapse rates for TNBC, which carries an especially high rate of recurrence. The trial will compare outcomes of patients with TNBC who receive one year of pembrolizumab after neoadjuvant therapy to outcomes among patients with TNBC who don’t receive pembrolizumab.
We’re hopeful that this treatment approach can help more patients with TNBC survive without relapse – a key milestone because the risk of recurrence is high in this subgroup. I provide a more in-depth look at the diagnosis, assessment, treatment and follow up care of patients with TNBC in my recently published book, "Triple-Negative Breast Cancer: A Clinician’s Guide."
Combining Immunotherapy and Chemotherapy
Results from another trial, KEYNOTE-028, showed that pembrolizumab was active in ER-positive, HER2-negative metastatic breast cancer. Of 25 participants who received pembrolizumab for their advanced disease, 12 percent saw tumors shrink by more than 30 percent, while the treatment stabilized disease in another 16 percent of patients. This has created interest in evaluating immunotherapy in other types of breast cancer.
It has been widely hypothesized that combining immunotherapy and chemotherapy might make breast cancers more responsive to immunotherapy. I am spearheading a pilot trial, called PePPy, Pilot Study of Paclitaxel Plus Pembrolizumab in Patients with Metastatic HER2-Negative Breast Cancer, to investigate whether this combination therapy is tolerable and what the appropriate timing of drugs might be.
One cohort of patients receives both drugs simultaneously upfront. The other cohort first receives two cycles of paclitaxel, followed by paclitaxel plus pembrolizumab.
Only available at LCI, the trial's primary aim is to evaluate whether the regimen is safe and tolerable, and whether the sequencing of the immunotherapy and chemotherapy matters. We also hope to see signs that this combination stabilizes tumor growth or causes regression.
An Immunotherapy Leader
These trials are just a fraction of the immunotherapy trials currently open at LCI. We’re home to the region’s oldest, most experienced immunotherapy program, which gives us the expertise to match your patient with the right therapy. It also means we’re very familiar with immunotherapy’s unique side effects, enabling us to make this treatment as safe and effective as possible.
Contact Us
For more information on PePPy, call Wendy Vandermolen, clinical trials research nurse at 980-442-2347. For additional questions, call 704-512-7878.