AACR 2020 – Immunotherapy combo boosts response in HER2- breast cancer


  • Deepa Koli
  • Univadis
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Takeaway

  • Immunotherapy durvalumab+olaparib followed by chemotherapy shows superior pathologic complete response (pCR) rate in patients with HER2-negative (HER2-) breast cancer, including those with estrogen receptor-positive (HR+) tumors and triple-negative breast cancer (TNBC).

Why this matters

  • Lead author said, “results provide further evidence for the clinical value of immunotherapy in early-stage breast cancer.”

Study design

  • Results from one arm of the ongoing phase 2, Investigation of Serial Studies to Predict Your Therapeutic Response Through Imaging and Molecular Analysis 2 (I-SPY 2) trial. 
  • 73 women with high-risk, HER2- breast cancer received durvalumab+olaparib with paclitaxel followed by doxorubicin+cyclophosphamide.
  • 299 patients in the control group received paclitaxel followed by doxorubicin+cyclophosphamide.
  • Funding: William K. Bowes Jr Foundation; others. 

Key results

  • 21 patients with TNBC and 52 patients with HR+ tumors received durvalumab and olaparib.
  • Durvalumab and olaparib increased pCR rates compared with control patients in:
    • HER2- group: 37% vs 20%
    • TNBC group: 47% vs 27%
    • HR+/HER2- group: 28% vs 14%
  • No new safety signals were reported.
  • Immune-related grade 3 adverse event rate was 19% in the durvalumab, olaparib group vs 1.6% in the control group.

Expert commentary

Pamela N. Munster, MD, from the University of California, San Francisco commented, “the signal of a better pCR rate among patients in the ultra-high Mammaprint group may allow selection of patients with HR-positive disease who may benefit from immunotherapeutic agents and/or PARP inhibitors.”

Since AACR 2020 is a virtual meeting, registered users can watch this session and allpresentations online.