Phase II study of cisplatin and imatinib in advanced salivary adenoid cystic carcinoma

Patients with adenoid cystic carcinoma of the salivary glands show over-expression of KIT in a high proportion of cases. Options for systemic treatment are limited in locally advanced and metastatic disease. We explored the efficacy of imatinib and cisplatin combined in this group of patients. A Gehan's two-stage, phase II trial was conducted on 28 patients. Those with progressive, locally advanced, and metastatic disease with an over-expression of KIT were treated with single agent imatinib 800 mg daily for two months, followed by a combination of imatinib 400 mg daily and cisplatin 80 mg/m2 at four-weekly intervals for six cycles. This was followed by maintenance single agent imatinib 400 mg daily until the disease progressed. Response was monitored using fluorodeoxyglucose positron emission tomography (FDG-PET) and morphological imaging using computed tomography, magnetic resonance, and chest radiographs (CT/MRI/CXR). Morphological imaging showed partial response in three of 28 patients, and five patients showed a response on FDG-PET. In addition, 19 patients had useful stabilisation of disease. The median time to progression and overall survival was 15 months (range 1–43) and 35 months (range 1–75), respectively. The combination of imatinib and cisplatin was reasonably well tolerated. This combination may provide stabilisation in locally advanced and metastatic adenoid cystic carcinoma of the salivary glands.