A Phase I, Open-Label, Dose Confirmation, Escalation, and Expansion Trial of BI 1810631 as Monotherapy in Patients With Advanced or Metastatic Solid Tumors With HER2 Aberrations

Background: BI 1810631 is a human HER2-selective tyrosine kinase inhibitor that covalently binds to both wild-type and mutated HER2 receptors, including exon 20 insertion mutations, whilst sparing EGFR signaling. This phase Ia/Ib, open-label, non-randomized study will determine the safety, maximum tolerated dose (MTD), pharmacokinetics (PK), pharmacodynamics, and preliminary efficacy of BI 1810631 in patients with HER2 aberration-positive solid tumors (NCT04886804). Patients and Methods: In phase Ia, patients with histologically/cytologically confirmed HER2 aberration-positive advanced/metastatic solid tumors will receive BI 1810631 orally twice daily (BID) or once daily (QD) at escalating doses. Starting dose level is 15 mg BID; QD schedule will begin after one dose level above estimated therapeutic dose of BI 1810631 is determined safe by the Dose Escalation Committee. Dose escalation will continue until MTD/recommended phase II dose and preferred phase Ib schedule for each schedule is determined. In phase Ib, patients with HER2 tyrosine kinase domain (TKD) mutation-positive non-small cell lung cancer (NSCLC) who have previously received ≥1 line of systemic therapy will be enrolled initially, with possible inclusion of additional NSCLC cohorts in the future, including untreated patients. The primary endpoints will be MTD based on number of dose-limiting toxicities (DLTs)/number of patients with DLTs (phase Ia) and objective response (phase Ib). Secondary endpoints include PK parameters (phase Ia/Ib); duration of response, disease control, duration of disease control, and progression-free survival (phase Ib). Conclusions: BI 1810631 could be an effective and tolerable EGFR-sparing oral treatment for patients with HER2 mutation-positive NSCLC, including exon 20 insertion mutations. ClinicalTrials.gov identifier: NCT04886804.