Zongertinib Shows 77% Response Rate in First-Line Treatment of HER2-Mutant Lung Cancer
Key Insights
A phase II trial of zongertinib as first-line treatment for advanced HER2 (search)-mutant lung cancer achieved a 77% overall response rate, with 8% of patients experiencing complete tumor disappearance.
The targeted therapy demonstrated disease control in 96% of patients, offering a new treatment option for the 4% of lung cancer cases driven by HER2 (search) mutations.
Results presented at ESMO Congress represent the first study of zongertinib as initial treatment, with a phase III trial planned to compare against standard chemotherapy.
A novel targeted therapy for lung cancer patients with HER2 (search) genetic mutations has demonstrated remarkable efficacy in a first-line treatment setting, with 77% of patients experiencing tumor shrinkage in a phase II clinical trial. The drug zongertinib showed complete tumor eradication in 8% of patients and partial tumor reduction in 69% of patients, according to findings presented at the European Society for Medical Oncology (search) (ESMO) Congress in Berlin.
Addressing an Unmet Medical Need
The study targeted patients with HER2 (search)-mutant lung cancer, a subset representing up to 4% of the more than 49,000 lung cancer cases diagnosed annually in the UK. HER2 mutations occur in both smoking-related and non-smoking-related lung cancers, yet no targeted therapy has previously been available for these patients.
"Previously there has been no targeted therapy for these patients and they're often put on intense treatment plans with chemotherapy with a lot of side effects," said Professor Sanjay Popat, Professor of Thoracic Oncology at The Institute of Cancer Research, London, and consultant medical oncologist at The Royal Marsden NHS Foundation Trust, who presented the findings.
Trial Design and Patient Population
The global study enrolled 74 patients aged between 35 and 88 across 85 sites worldwide. All participants had advanced lung cancer with HER2 (search) mutations and had received no prior treatment for their advanced disease. Patients took zongertinib as a daily oral medication.
The trial represents the first investigation of zongertinib as a first-line treatment, building on earlier research that tested the drug in patients who had undergone other treatments.
Clinical Outcomes and Disease Control
The primary efficacy results demonstrated substantial clinical activity across the patient population. Overall, 96% of patients achieved disease control with zongertinib as their initial treatment. The 77% overall response rate comprised 8% complete responses and 69% partial responses.
"These initial findings show that by directly switching off the abnormal HER2 (search) mutant lung cancer with zongertinib, we have a new opportunity to improve patient outcomes and also enable them to have a better quality of life," Professor Popat explained.
Patient Experience and Quality of Life
The clinical benefits extended beyond tumor response to improved patient quality of life. Susan Gasson, a 74-year-old London patient who participated in the trial, experienced significant improvement compared to her previous treatments.
"My initial treatment for my lung cancer consisted of surgery, chemotherapy and radiotherapy which left me with a lot of side effects. However, despite the treatment, my cancer returned," Gasson said. "I have been on the trial drug for over two years, my cancer has shrunk, and the side effects have been minimal, allowing me to have a much better quality of life."
Next Steps in Development
The promising phase II results have paved the way for a definitive phase III trial, where zongertinib will be directly compared against standard treatments such as chemotherapy. This randomized controlled trial will provide the regulatory evidence needed to establish zongertinib's role in the treatment paradigm for HER2 (search)-mutant lung cancer.
Professor Popat characterized the study results as "highly significant" and representing "new hope for lung cancer patients with the HER2 (search) genetic mutation," highlighting the potential for this targeted approach to transform treatment outcomes for this previously underserved patient population.