Tagrisso Shows Notable Tumor Shrinkage in Clinical Trial

  • Patients with stage II to IIIB non-small cell lung cancer (NSCLC) with an epidermal growth factor receptor (EGFR) gene mutation had better outcomes when treated with Tagrisso (generic name: osimertinib) before surgery compared to chemotherapy alone, according to research presented at 2025’s American Society of Clinical Oncology (ASCO) conference.
  • The promising data indicates that adding the the drug, a targeted therapy known as a tyrosine kinase inhibitors (TKI), before surgery leads to significantly higher rates of tumor shrinkage than chemotherapy.

Patients with stage II to IIIB non-small cell lung cancer (NSCLC) with an epidermal growth factor receptor (EGFR) mutation saw better results when treated with the targeted drug osimertinib (brand name: Tagrisso) before surgery, either by itself or combined with chemotherapy, compared to just chemotherapy alone.

This treatment led to a significantly higher rate of tumor shrinkage before surgery, according to new research published in the Journal of Clinical Oncology and presented at the 2025 American Society of Clinical Oncology (ASCO) annual meeting.

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“Tagrisso is one of the very effective EGFR targeting agents used widely in cases of advanced/stage IV EGFR+ lung cancer,” Dr. Balazs Halmos, director of the Multidisciplinary Thoracic Oncology Program at Montefiore Health Systems, tells SurvivorNet Connect.

The new research highlights the drug’s potential in earlier-stage disease — and when given in the neoadjuvant setting.

What Did The Data Show?

In the recently published study, 358 stage II to IIIB lung cancer patients with resectable lung cancer that had the EGFR mutation were randomly assigned to receive osimertinib and platinum-based chemotherapy, osimertinib as a monotherapy (single drug treatment), or placebo plus platinum-based chemotherapy before surgery.

Patients on the osimertinib-plus-chemotherapy and the osimertinib monotherapy regimen saw a significant reduction in tumor cells after treatment (major pathological response, MPR) compared to chemotherapy alone.

The osimertinib-plus-chemotherapy group had an MPR rate of 26% and the osimertinib alone group had 25% — while the placebo group had an MPR of just 2%.

The data also indicated patients receiving the targeted therapy before surgery had better event-free survival.