Phase I/II trial of carboplatin and paclitaxel chemotherapy in combination with intravenous oncolytic reovirus in patients with advanced malignancies

Purpose: Reovirus type 3 Dearing (RT3D) replicates preferentially in Ras-activated cancers. RT3D shows synergistic in vitro cytotoxicity in combination with platins and taxanes. The purpose of this phase I/II study was to assess RT3D combined with carboplatin/paclitaxel in patients with advanced cancers. Experimental Design: Patients were initially treated in a dose-escalating, phase I trial with intravenous RT3D days 1 to 5, carboplatin [area under curve (AUC) 5, day 1] and paclitaxel (175 mg/m ², day 1) 3-weekly. RT3D was escalated through three dose levels: 3 × 10 ⁹, 1 × 10 ¹⁰, and 3 × 10 ¹⁰ TCID ₅₀ in cohorts of three. Primary endpoints were to define the maximum tolerated dose and dose-limiting toxicity and to recommend a dose for phase II studies. Secondary endpoints included pharmacokinetics, immune response, and antitumor activity. A subsequent phase II study using the 3 × 10 ¹⁰ TCID ₅₀ dose characterized the response rate in patients with head and neck cancer. Results: Thirty-one heavily pretreated patients received study therapy. There were no dose-limiting toxicities during dose-escalation and most toxicities were grade I/II. Overall effectiveness rates were as follows: one patient had a complete response (3.8%), six patients (23.1%) had partial response, two patients (7.6%) had major clinical responses clinically evaluated in radiation pretreated lesions which are not evaluable by Response Evaluation Criteria in Solid Tumors (RECIST), nine patients (34.6%) had stable disease, and eight patients (30.8%) had disease progression. Viral shedding was minimal and antiviral immune responses were attenuated compared with previous single-agent data for RT3D. Conclusions: The combination of RT3D plus carboplatin/paclitaxel is well tolerated with evidence of activity in cancer of the head and neck. A randomized phase III study is currently open for recruitment.