Isolated limb perfusion with the tumor-targeting human monoclonalantibody-cytokine fusion protein L19-TNF plus melphalan and mild hyperthermia in patients with locally advanced extremity melanoma.

BACKGROUND: L19-TNF is a tumor-targeting immunocytokine composed of the human L19 antibody binding to extra domain B (ED-B) of fibronectin of newly formed blood vessels, and of human TNF. This exploratory trial evaluates safety and clinical activity of L19-TNF plus melphalan-containing isolated limb perfusion (ILP) in extremity melanoma patients. METHODS: Seven and 10 patients received 325 µg and 650 µg of L19-TNF, respectively, during the ILP. Patients were studied for safety, tolerability, and clinical activity of this experimental L19-TNF ILP procedure. RESULTS: Non-hematologic toxicity of L19-TNF ILP was very low, but severe myelosuppression was seen in four patients. Although L19-TNF was administered at a TNF-equivalent dose of only 3.13 and 6.25% of the approved TNF (Beromun®) dose of 4 mg, L19-TNF ILP induced objective responses in 86 and 89% of patients, respectively, including a complete response (CR) in 5/10 patients treated with L19-TNF ILP at 650 µg that was durable at 12 months in four patients. No CR was seen at 325 µg of L19-TNF. CONCLUSIONS: ILP with L19-TNF had a favorable safety and a promising activity profile at a dose of 650 µg of L19-TNF, supporting the exploration of higher L19-TNF doses and a Phase II trial comparing L19-TNF ILP with standard melphalan-containing ILP.