Gollob JA et al. (2007) Phase II trial of sorafenib plus interferon alfa-2b as first- or second-line therapy in patients with metastatic renal cell cancer. J Clin Oncol 25: 3288–3295

Interferon (IFN)-α2b and sorafenib are modestly effective against renal cell carcinoma (RCC) when either agent is used alone. In a phase II trial, Gollob et al. evaluated the efficacy of combined IFN-α2b and sorafenib in 40 patients with metastatic RCC. The researchers found that 33% of patients responded to the combined treatment, an outcome that compares favorably with the 5–10% response obtained with either agent alone.

Patients received a median of 3 cycles of therapy (range <1–8.5 cycles). Partial tumor regression was observed in 11 patients (28%), a complete response in 2 patients (5%), 18 patients (45%) had stable disease and 5 patients (12%) had progressive disease. The observed regression generally occurred after 1–2 cycles; lungs and lymph nodes were the most common sites of response, although good responses were also observed in the pleura, liver and pancreas. Dose reductions because of toxicity were required in 65% of patients, and 28% discontinued therapy because of toxicity after a median of 2.5 cycles. Incidence of some toxic effects was higher with the combined therapy than would be expected for either agent alone, and 2-week breaks between cycles were necessary to allow chronic therapy.

The authors conclude that the combination of sorafenib and IFN-α2b seems more effective against metastatic RCC than either agent alone; a phase III trial is required to confirm this effect.