CHICAGO (FRONTLINE MEDICAL NEWS) – Adding the monoclonal anti-CD52 antibody alemtuzumab to CHOP (A-CHOP) increased response rates in elderly patients with peripheral T-cell lymphomas but did not improve their survival, based on the final results from 116 patients treated in the international ACT-2 phase III trial .

Complete responses were seen in 43% of 58 patients given CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) and in 60% of 58 patients given A-CHOP in the trial. However, trial participants did not significantly differ in event-free survival and progression-free survival at 3 years.

Further, overall survival at 3 years was 38% for the patients given A-CHOP and 56% for the patients given CHOP. The poorer overall survival was mainly the result of treatment-related toxicity, Dr. Lorenz H. Trümper reported at the annual meeting of the American Society of Clinical Oncology.

The estimated 3-year disease-free survival is 25% for elderly patients with peripheral T-cell lymphomas. Previous phase II trials had indicated that alemtuzumab was active in primary and relapsed T-cell lymphoma, prompting the study of adjuvant alemtuzumab in combination with dose-dense CHOP-14 in patients with previously untreated peripheral T-cell lymphoma, he said.

Although the treatment protocol demanded stringent monitoring for cytomegalovirus and Epstein-Barr virus and anti-infective prophylaxis, there were more grade 3 or higher infections in the A-CHOP group (40%) than the CHOP group (21%). The higher infection rates were attributed to higher rates of grade 3/4 hematotoxicity in patients given A-CHOP. Grade 4 leukocytopenia was seen in 70% with A-CHOP and 54% with CHOP; grade 3/4 thrombocytopenia was seen in 19% given A-CHOP and 13% given CHOP, according to Dr. Trümper of the University of Göttingen, Germany.

For the study, 116 patients from 52 centers were randomized to receive either six cycles of CHOP or A-CHOP given at 14-day intervals with granulocyte-colony stimulating factor (G-CSF) support. Initially, patients received a total of 360 mg of alemtuzumab (90 mg given at each of the first four cycles of CHOP). After patient 39 was enrolled, the dose was reduced to 120 mg (30 mg given at each of the first four cycles of CHOP). Median patient age was 69 years, and 58% of the trial participants were men.

Treatment was completed as planned in 79% of the CHOP patients and in 57% of the A-CHOP patients.

The study was sponsored by the University of Göttingen. Dr. Trümper is a consultant or adviser to Hexal and Janssen-Ortho, and receives research funding from Genzyme, the maker of alemtuzumab ( Lemtrada ), as well as other drug companies.

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