Abstract
Introduction Amivantamab, an EGFR-MET bispecific antibody, is approved for multiple indications in EGFR-mutated advanced NSCLC as monotherapy or combined with other agents. Intravenous amivantamab is associated with a 67% infusion-related reaction (IRR) rate. Methods The phase 2 SKIPPirr study (NCT05663866) enrolled participants with EGFR-mutated (exon 19 deletion or exon 21 L858R) advanced NSCLC after progression on osimertinib and platinum-based chemotherapy who received intravenous amivantamab plus oral lazertinib (amivantamab-lazertinib), a third-generation tyrosine kinase inhibitor. Aiming to mitigate IRRs, four independent prophylactic approaches were evaluated using Simon's two-stage design with an expansion stage if a cohort passed both stages: oral dexamethasone 4 mg twice daily given on cycle (C) 1 day (D) -1 (two doses); oral dexamethasone 8 mg twice daily given on C1D-2, C1D-1, and the morning of C1D1 (five doses); oral montelukast 10 mg once daily given on C1D-4, C1D-3, C1D-2, C1D-1, and C1D1 (five doses); subcutaneous methotrexate 25 mg (one dose) given anytime between C1D-7 and C1D-3. The primary end point was C1D1 IRR incidence. Results As of June 24, 2024, 68 participants were treated across all cohorts. The dexamethasone 8 mg cohort passed stages 1 and 2 proceeding to the expansion stage, with 24 additional participants treated. At C1D1, nine of 40 participants (22.5%) experienced IRRs, resulting in an approximately threefold decrease versus historical data (67.4%). By the end of C3, 10 of 41 participants (24.4%) in the dexamethasone 8 mg cohort experienced IRRs (grades 1-2, except one grade 3 on C2D1). Amivantamab-lazertinib's safety and efficacy were consistent with previous reports. Conclusions Prophylaxis with 8 mg oral dexamethasone meaningfully reduced IRRs and can be readily implemented in clinical practice. (c) 2025 The Authors. Published by Elsevier Inc. on behalf of International Association for the Study of Lung Cancer. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
