After disease progression on EGFR tyrosine kinase inhibitor (TKI) therapy, patients with EGFR-mutated NSCLC who are then treated with platinum-based chemotherapy (PBC) obtain only limited clinical benefit with transient responses. Therapies with greater efficacy and tolerable safety profiles are needed in this setting. The receptor tyrosine kinase HER3 is widely expressed in NSCLC, and increased expression is associated with poor treatment outcomes. In the U31402-A-U102 phase I trial, HER3-DXd showed promising antitumor activity with manageable safety in heavily pre-treated patients with EGFR-mutated NSCLC across a range of tumor HER3 expression levels and EGFR TKI resistance mechanisms. HERTHENA-Lung02 is the first phase III trial to evaluate the safety and efficacy of HER3-DXd versus PBC in patients with progression on a third-generation EGFR TKI. Clinical Trial Registration: NCT05338970 (clinicaltrials.gov); 2021-005879-40 (EudraCT Number).
Keywords: EGFR-activating mutation; HER3-DXd; antibody–drug conjugate; non-small-cell lung cancer; patritumab deruxtecan.
In some patients with non-small-cell lung cancer, changes (or mutations) in the DNA sequence can alter a protein called EGFR and allow tumors to grow and survive. Drugs called EGFR tyrosine kinase inhibitors (EGFR TKIs for short) are used to treat these tumors by interfering with the abnormal EGFR protein. Treatment with these drugs can work well at first, but some tumors never respond, and for tumors that do respond, the cancer eventually becomes resistant to the EGFR TKI and the drug stops working. Platinum-based chemotherapy is often prescribed after an EGFR TKI stops working; however, platinum-based chemotherapy can provide only temporary control of the tumor growth. Most patients with non-small-cell lung cancer have a protein called HER3 on the surface of their tumor cells. A new drug candidate called patritumab deruxtecan (HER3-DXd) finds tumor cells and attaches to the HER3 protein on their surface. HER3-DXd then moves inside the cancer cells, where a novel antitumor payload is released and kills the tumor cells. This article describes the phase III clinical trial HERTHENA-Lung02 (NCT05338970) that compares the benefit of HER3-DXd to platinum-based chemotherapy for patients who have non-small-cell lung cancer with the abnormal EGFR protein and whose disease stopped responding or never responded to EGFR TKI therapy.