Resimmune, an anti-CD3ε recombinant immunotoxin, induces durable remissions in patients with cutaneous T-cell lymphoma

Abstract

Resimmune is a second-generation recombinant immunotoxin composed of the catalytic and translocation domains of diphtheria toxin fused to two single chain antibody fragments reactive with the extracellular domain of CD3ε. We gave intravenous infusions of Resimmune 2.5 - 11.25 μg/kg over 15 minutes to 30 patients (25 with cutaneous T-cell lymphoma, 3 with peripheral T-cell lymphoma, 1 with T-cell large granular lymphocytic leukemia and 1 with T-cell prolymphocytic leukemia) in an inter-patient dose escalation trial. The most common adverse events were fever, chills, hypotension, edema, hypoalbuminemia, hypophosphatemia, and transaminasemia. Among the 25 patients with cutaneous T-cell lymphoma, there were nine responses for a response rate of 36% (95% CI, 18%-57%) including four complete remissions (16%, 95% CI, 5%-36%). The durations of the complete remissions were 72+, 72+, 60+ and 38+ months. There were five partial remissions lasting 3, 3, 3+, 6+ and 14 months. Of 17 patients with a modified skin weighted assessment tool score <50, 17 patients with stage IB/IIB, and 11 patients with both a score <50 and stage IB/IIB, nine (53%), eight (47%), and eight (73%) had responses, respectively. Further studies of Resimmune in patients with low tumor burden, stage IB-IIB cutaneous T-cell lymphoma are warranted. This trial is registered at clinicaltrials.gov as #NCT00611208.

Figure 1.

A serum concentration disposition curve of Resimmune. Each time point was calculated from results of patients #1–6, 9, 10, 16 and 18. Error bars indicate standard deviation. A one phase decay model was used to calculate the serum half-life of Resimmune (35.69 min).

Figure 2.

Reduction of mSWAT scores over time. Changes of % initial mSWAT score for patients #2, 3, 6, 7, 8, 15, 23, 25 and 28.

Figure 3.

Photographs of patient #15 before treatment and 1 month after treatment.