Abstract 25P
Background
Agent targeting HER2 is promising and is the best studied therapy in patients with HER2-positive salivary duct carcinoma (SDC). RC48-ADC (Disitamab Vedotin) is a novel humanized anti-HER2 antibody-drug conjugate (ADC). But the efficacy and safety of RC48-ADC is still unknown in metastatic SDC with HER2-positive.
Methods
Eligible patients from Zhejiang Cancer Hospital were 35∼76 years old, with confirmed, histologically HER2-expression (IHC1+, 2+, 3+), metastatic SDC. Patients had at least one line of systemic chemotherapy. Patients received RC48-ADC at 1.5 or 2 mg/kg, every two weeks. Clinical efficacy and safety were assessed.
Results
This study enrolled HER2-expression metastatic SDC patients from June 2022 to Dec 2022. 10 mSDC patients (8 males, 2 females) were enrolled. 90% patients had received ≥2 lines systemic chemotherapy. 80% patients had visceral metastases. As of 05 Jan 2023 (data cutoff), 1 patient received CR, 4 patients received PR, 4 patients received SD, and only 1 patient received PD. The overall confirmed DCR was 90%. Most common treatment-related AEs were hypoaesthesia (70%), asthenia (60%), Leukopenia (30%), decreased appetite (20%), alopecia (10%). The grade≥3 TRAEs only included hypoaesthesia (30.0%) and neutropenia (10%).
Conclusions
RC48-ADC showed continuously a promising efficacy with a manageable safety profile in HER2-expression mSDC patients who had failed at least one line systemic chemotherapy.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.