Ocular toxicity
Most patients had at least one treatment-related adverse event (96.5% SD985, 96.4% PC), and grade 3 or higher event rates were similar between groups (52.8% SYD985, 48.2% PC). The most frequently reported adverse events for trastuzumab duocarmazine were ocular toxicity, with conjunctivitis reported in 38.2%, and keratitis in 38.2%, with fatigue at 33.3%; for physician’s choice these were diarrhea (35.8%), nausea (31.4%) and fatigue (29.9%). Interstitial lung disease pneumonitis was reported for 7.6% (5.2% grade 1-2) of patients treated with trastuzumab duocarmazine, including two grade 5 events.
Eye toxicity led to discontinuations in 20.8% of trastuzumab duocarmazine patients, dose modifications in 22.9%, with dose modifications for interstitial lung disease/pneumonitis in 5.2% of trastuzumab duocarmazine patients. Six fatalities (2.1%) were reported in the trastuzumab duocarmazine group, with four attributed to treatment. Assessment of health-related quality of life showed no significant difference between groups.
Dr. Manich outlined risk mitigation strategies. Patients with prior keratitis were excluded and patients were given prophylactic lubricating eye drops and regular eye exams by ophthalmologists. Treatment was discontinued if grade 3 or higher keratitis developed, and was delayed if grade 3 conjunctivitis developed until it reduced to grade 2. Also, patients with prior pneumonitis were excluded and CT lung scans were evaluated for lung changes. New or worsening respiratory symptoms triggered a full diagnostic workup. Treatment was discontinued for grade 2 or higher pneumonitis and delayed until resolution for grade 1 pneumonitis.
TULIP was funded by Byondis. Dr. Saura disclosed numerous financial interests including support from AstraZeneca and Daiichi Sankyo.