Liposomal doxorubicin plus nab-paclitaxel with/without chemoradiotherapy in head and neck adenoid cystic carcinoma: single-arm phase II study

Given no standard therapies, this single-arm, open-label, multicenter phase II study was conducted in unresectable locally advanced or recurrent/metastatic adenoid cystic carcinoma of the head and neck (LA or R/M ACCHN). Patients received chemotherapeutic nanomedicines (20 mg/m 2 liposomal doxorubicin plus 120 mg/m 2 nab -paclitaxel on days 1 and 8) for three 21-day cycles. Subsequently, patients eligible for radiotherapy received concurrent chemoradiotherapy (cCRT; helical tomotherapy or intensity-modulated radiotherapy and nab -paclitaxel), whereas those ineligible for radiotherapy continued 2–3 cycles of original chemotherapy. Between May 27, 2021, and November 13, 2024, 31 enrolled patients were evaluable for efficacy and safety. The primary endpoint objective response rate (ORR) was 90.3% (95% CI, 74.2–98.0%), with 15 (48.4%) complete responses and 13 (41.9%) partial responses, meeting the prespecified primary endpoint. The median duration of response was 18.5 (95% CI, 0–45.8) months. With a median follow-up of 15.7 months by data cutoff (June 25, 2025), the median progression-free survival (PFS) was 25.7 (95% CI, 6.5–44.8) months; the 1-year PFS was 77.1%. The median overall survival (OS) was not reached (NR), with a 1-year OS of 90.0%. Patients who received cCRT had a prolonged PFS (NR vs. 12.8 months) and OS (NR vs. 21.2 months) compared to those who did not. Grade 3 treatment-related adverse events (TRAEs) occurred in 8 (25.8%) patients. No ≥grade 4 TRAEs or treatment-related deaths occurred. This study demonstrated tumor responses among the highest reported to date, with a manageable safety profile in unresectable LA or R/M ACCHN. Chemotherapeutic nanomedicines, especially sequential cCRT for appropriate patients, may represent an effective and safe option.