Mitoxantrone hydrochloride liposome injection in the treatment of recurrent/metastatic head and neck cancers: A multicenter, open-label, single-arm, phase Ib study.

e18028 Background: Mitoxantrone is an anthraquinone antibiotic antitumor agent, and mitoxantrone hydrochloride liposomes have been approved for the treatment of relapsed or refractory peripheral T-cell lymphoma (PTCL) in China. The current study aimed to evaluate the safety and efficacy of mitoxantrone hydrochloride liposome in patients (pts) with recurrent/metastatic head and neck cancers. Methods: This study is a multicenter, open-label, single-arm, phase Ⅰb study. The pts with histologically confirmed diagnosis of head and neck squamous cell carcinoma (including nasopharyngeal carcinoma) were enrolled. Mitoxantrone hydrochloride liposome was administered at 20 mg/m2 by an intravenous infusion, every 21 days (q3w, 1 cycle) until disease progression, intolerable toxic reaction, death, or withdrawal by investigator or patient decision (a maximum of 8 cycles). The primary objective was to determine the safety of mitoxantrone hydrochloride liposome. Secondary objective was to assess the efficacy of mitoxantrone hydrochloride liposome in the treatment of recurrent/metastatic head and neck squamous cell carcinoma. Efficacy assessment was performed every 2 cycles after dosing as per RECIST v1.1. Results: From July 8, 2021 through November 5, 2021, 34 pts with median age of 48 years (range 20-69 years) were enrolled, including 23 with nasopharyngeal cancer and 11 with non-nasopharyngeal cancer (5 with tongue cancer, 2 with hypopharynx, 2 with tonsil cancer, and 1 each with larynx and gum cancer). The most common treatment-emergent adverse events (TEAEs) were white blood cell decreased (41.2%), anemia (41.2%) and lymphocyte count decreased (29.4%). TEAEs were generally Grade (G) 1-2; 13 pts reported G3 TEAE. The summary of all-grade TEAEs (≥ 10%) are shown in the table below. Nineteen pts had undergone at least 1 efficacy evaluation (including 18 pts with nasopharyngeal cancer and 1 with non-nasopharyngeal cancer). The overall objective response rate (ORR) was 42.1% (8/19) and disease control rate (DCR) was 78.9% (15/19). ORR for nasopharyngeal cancer was 38.9% (7/18) and DCR was 77.8% (14/18). One case of hypopharyngeal cancer was evaluated as partial remission (PR). Conclusions: The preliminary data of mitoxantrone hydrochloride liposome has showed manageable safety and evidence of efficacy in pts with recurrent/metastatic head and neck squamous cell carcinoma. An expanded sample size is still needed for further validation in the future study. Clinical trial information: NCT04902027. [Table: see text]