Beamion LUNG-1, a Phase Ia/Ib trial of the HER2-specific tyrosine kinase inhibitor, zongertinib (BI 1810631), in patients with HER2-driven tumors: outcomes according to HER2 aberration type

Abstract Introduction/Objective Beamion LUNG-1 (NCT04886804) is an ongoing, Phase Ia/Ib trial evaluating the novel HER2- specific tyrosine kinase inhibitor, zongertinib, in patients with HER2 aberration-positive solid tumors (Phase Ia) and HER2 mutation-positive NSCLC (Phase Ib). Here, we report data from Phase Ia according to HER2 aberration type. Methods/Case Report Phase Ia enrolled patients with HER2 aberration-positive (by local assessment: gene mutations, rearrangements, amplification, or overexpression) advanced/metastatic solid tumors. Patients received escalating doses of zongertinib BID (≥15 mg) or QD (≥60 mg), guided by a Bayesian model with overdose control. The primary endpoint of Phase Ia was maximum tolerated dose (MTD) based on dose-limiting toxicities (DLTs). Results (if a Case Study enter NA) At data cut-off (January 29, 2024), 83 patients received zongertinib (BID n=17; QD n=66). Three patients had DLTs during the MTD evaluation period (G3 decreased platelets, G3 diarrhea, G4 neutropenia); the MTD was not reached. Treatment-related adverse events (TRAEs; all/G3/G4/G5) were reported in 76%/8%/1%/0% of patients. Confirmed investigator-assessed ORR/DCR rates in evaluable patients/patients with NSCLC (n=74/n=41) were 35%/85% and 44%/93%; median duration of response was 12.7/15.8 months, respectively. Based on preliminary data, 43 patients were HER2 mutation-positive (TKD/non-TKD/unknown n=36/n=6/n=1; A775_G776insYVMA n=16; G778dupGSP insertions n=3; S310F n=2); 23 patients overexpressed HER2 (2+/3+); 17 had HER2 amplification; 3 patients had NRG1 fusions. ORR/DCR rates (regardless of confirmation) in patients with TKD mutation-positive, A775_G776insYVMA-positive, non-TKD mutation-positive, G778dupGSP-positive and S310F- positive tumors were 64%/97%, 69%/94%, 20%/100%, 33%/100% and 50%/100%, respectively. ORR/DCR rates (regardless of confirmation) in patients with HER2 overexpressing tumors (+/- amplification) were 39%/83%. Of the 3 patients with NRG1 fusions, one had a partial response and two had stable disease. Conclusion In this preliminary analysis, zongertinib showed promising activity across a broad range of tumor types with different HER2 aberrations, including aberrations that have historically been difficult to treat. Updated data will be presented.