Sorafenib in combination with gemcitabine plus cisplatin chemotherapy in metastatic renal collecting duct carcinoma: A prospective, multicentre, single-arm, phase 2 study

Background: Collecting duct carcinoma (CDC) is a rare type of renal cancer with a poor prognosis. As there are no standard guidelines for the management of metastatic CDC (mCDC), we evaluated the efficacy and safety of combined therapies of sorafenib, gemcitabine, plus cisplatin in patients with mCDC. Materials and methods: A prospective, multicentre, single-arm, open-label, phase 2 trial (ClinicalTrials.gov identifier NCT01762150) that enrolled 26 mCDC patients with no prior systemic chemotherapy. Patients were treated with sorafenib (400 mg orally, twice daily) combined with chemotherapy (gemcitabine 1000 mg/m ² , intravenously for 30–60 min on days 1 and 8, plus cisplatin 25 mg/m ² , intravenously on days 1–3, repeated every 28 days for 4 cycles), until disease progression, unacceptable toxicity, or study discontinuation for any other reason. The primary end-points were progression-free survival (PFS) and 6-month PFS rate. Results: The 6-month PFS rate was 65%, and the median PFS was 8.8 months (95% confidence interval [CI]: 6.7–10.9) with a median overall survival of about 12.5 months (95% CI: 9.6–15.4). The objective response rate was 30.8%, and the disease control rate was 84.6%. The treatment was generally well tolerated. Major grade 3/4 toxicities included leucopenia (26.9%), thrombocytopenia (23.1%), anaemia (11.5%) and palmar-plantar erythrodysesthesia (7.7%). Conclusions: Though the combination of sorafenib and chemotherapy demonstrated a similar outcome as that of the previously reported regimens in patients with mCDC, this combination may be a suitable option for patients who have low Eastern Cooperative Oncology Group performance status or less metastatic sites.