Prevention of amivantamab infusion related reactions with extended pre-infusion day oral steroid therapy.

Abstract

e21083 Background: Initial results with amivantamab (ami) in CHRYSALIS-1, and ami and lazertinib (laz) regimen in CHRYSALIS-2 showed encouraging efficacy in patients whose disease progressed after standard-of-care chemotherapy, and osimertinib (osi) and platinum-based chemotherapy respectively. Infusion related reactions however were frequent; 65% all grades in both studies and 2%/7% respectively had >Grade 3 infusion related reactions. An on-going trial (NCT05663866) utilising dexamethasone (dex), montelukast and methotrexate to minimise ami infusion related reactions might be unacceptable to many patients; a simpler method would be more ideal. Ami has been available in Singapore since the third quarter of 2021. Laz is not commercially available in South Asia as at Jan 2023. Methods: A single medical oncologist in private practice in Singapore managing advanced lung cancer patients collated this cohort of 7 consecutive patients treated from August 2021 to Jan 2023 with ami. Infusion day pre-medication and infusion protocol were according to the ami product insert. All patients were EGFR mutation positive and treatment-refractory with KPS <2. All who were on EGFR Tyrosine Kinase Inhibitors (TKI) concomitant with ami had tolerated these agents before and upon rechallenge of the TKI. Oral dex 8mg BD for three days (starting two days before ami) was implemented for patients 5-7 after observing patients 3-4 with >Grade 3 infusion related reactions. Fisher exact test evaluated the statistical significance of the difference in the incidence rate of infusion related reactions between the patients who did and did not receive pre-infusion day steroids. Results: 0/5 and 2/2 patients with and without pre-infusion day steroids respectively had infusion related reactions (p = 0.0476). Both reactions were > Grade 3. Patient 4 did not have any infusion related reactions from Doses 2 to 6 once pre-infusion day dex was given. Conclusions: Premedicating with oral dex 8mg BD for 3 days starting 2 days prior to ami was able to prevent all-grades infusion related reactions. This approach should be confirmed in a larger study given the ease of such an intervention to make ami infusion safer. [Table: see text]