A pilot feasibility study of TNFerade™ biologic with capecitabine and radiation therapy followed by surgical resection for the treatment of rectal cancer

Objective: The purpose of this pilot study was to evaluate the feasibility and tolerability of weekly intratumoral TNFerade™ injections combined with concurrent capecitabine and radiotherapy in the treatment of patients with locally advanced rectal cancer. Methods: Patients with T3, T4, or N+ rectal cancer received radiotherapy to a total dose of 50.4-54 Gy in combination with capecitabine 937.5 mg/m² p.o. b.i.d. TNFerade™ at a dose of 4 × 10¹⁰ particle units was injected into the rectal tumor on the first day of radiotherapy and weekly for a total of 5 injections. Surgery was performed 5-10 weeks after the completion of chemoradiation. Results: Nine patients were enrolled in this pilot trial. The stage was cT2 in 2 patients, cT3 in 6 patients, cT4 in 1 patient, N- in 7 patients and N+ in 2 patients. Eight patients completed all treatments. Grade 3 hematologic toxicity was observed in 2 patients. There was no toxicity directly attributable to the injection procedure. A complete pathologic response was observed in 2 of 9 patients. Conclusions: This study demonstrates the feasibility of weekly intratumoral TNFerade™ injections during chemoradiotherapy for locally advanced rectal cancer. Pathologic responses with this combination compare favorably to published rates.