Epratuzumab (humanised anti-CD22 antibody) in primary Sjögren's syndrome: an open-label phase I/II study.

This open-label, phase I/II study investigated the safety and efficacy of epratuzumab, a humanised anti-CD22 monoclonal antibody, in the treatment of patients with active primary Sjögren's syndrome (pSS). Sixteen Caucasian patients (14 females/2 males, 33-72 years) were to receive 4 infusions of 360 mg/m2 epratuzumab once every 2 weeks, with 6 months of follow-up. A composite endpoint involving the Schirmer-I test, unstimulated whole salivary flow, fatigue, erythrocyte sedimentation rate (ESR), and immunoglobulin G (IgG) was devised to provide a clinically meaningful assessment of response, defined as a > or = 20% improvement in at least two of the aforementioned parameters, with > or = 20% reduction in ESR and/or IgG considered as a single combined criterion. Fourteen patients received all infusions without significant reactions, 1 patient received 3, and another was discontinued due to a mild acute reaction after receiving a partial infusion. Three patients showed moderately elevated levels of Human anti-human (epratuzumab) antibody not associated with clinical manifestations. B-cell levels had mean reductions of 54% and 39% at 6 and 18 weeks, respectively, but T-cell levels, immunoglobulins, and routine safety laboratory tests did not change significantly. Fifty-three percent achieved a clinical response (at > or = 20% improvement level) at 6 weeks, with 53%, 47%, and 67% responding at 10, 18, and 32 weeks, respectively. Approximately 40%-50% responded at the > or = 30% level, while 10%-45% responded at the > or = 50% level for 10-32 weeks. Additionally, statistically significant improvements were observed in fatigue, and patient and physician global assessments. Further, we determined that pSS patients have a CD22 over-expression in their peripheral B cells, which was downregulated by epratuzumab for at least 12 weeks after the therapy. Thus, epratuzumab appears to be a promising therapy in active pSS, suggesting that further studies be conducted.

Multicenter phase II trial of immunotherapy with the humanized anti-CD22 antibody, epratuzumab, in combination with rituximab, in refractory or recurrent non-Hodgkin's lymphoma.

PURPOSE: A multicenter, single-arm study examining efficacy and toxicity of epratuzumab combined with rituximab was conducted in patients with recurrent or refractory non-Hodgkin's lymphoma. PATIENTS AND METHODS: Sixty-five patients were enrolled; 34 patients with follicular lymphoma (FL), 15 patients with diffuse large B-cell lymphoma (DLBCL), and 16 patients with other lymphomas. The patients had received a median of two prior therapies (range, 1 to 4); 23% had received rituximab. Epratuzumab was given at 360 mg/m2 intravenously over 60 minutes followed by infusion of 375 mg/m2 rituximab, weekly for 4 consecutive weeks. RESULTS: Combination therapy was well tolerated without greater toxicity than rituximab alone. The objective response (OR) rate was 47% (30 of 64) in assessable patients (46%; 30 of 65 in all patients), being highest in FL (64%; 21 of 33) and DLBCL (47%; seven of 15), and with 24% (eight of 33) and 33% (five of 15) achieving complete response (CR) or complete response unconfirmed (CRu) in these two groups, respectively. Two of six patients with marginal zone lymphoma responded to treatment (one CR). There was a trend for the response rates to be higher in patients with low prognostic index scores (statistically significant with respect to the Follicular Lymphoma International Prognostic Index score in FL patients), with 12 FL patients and three DLBCL patients in groups 0 to 1 having OR (CR/CRu) rates of 83% (33%) and 100% (100%), respectively. The median duration of response was 16 months for FL, with five patients currently progression free for 18 months to 30 months, and 6 months for DLBCL, with two patients currently progression free for 12 months and 18 months. CONCLUSION: Epratuzumab combined with rituximab was well tolerated, demonstrating promising antilymphoma activity that warrants additional study.