Sufficient and Timely Autologous Stem Cell Harvest After Chemoimmunotherapy with Alemtuzumab In Combination with Bi-Weekly CHOP as First Line Treatment In Systemic Peripheral T-Cell Lymphomas (PTCL): a Feasibility Analysis From the First Randomized Trial In Systemic PTCL (ACT trial)

Abstract 2395

While already tested in T-PLL, the impact of chemo-immunotherapy with alemtuzumab in combination with bi-weekly CHOP on autologous stem cell harvest (ASCH) has not yet been analysed in the context of first line treatment of primary systemic peripheral T-cell lymphoma (PTCL). We therefore evaluated the feasibility of ASCH in the first 23 patients of the ongoing international multicenter ACT-1 study, the first, and so far only, randomized trial in primary systemic PTCL. The ACT trials (ACT-1 + ACT-2) test the addition of alemtuzumab to CHOP followed, in younger patients (ACT-1), by high-dose therapy with autologous stem cell transplant (HDT+ASCT). The aims of the analysis were: (i) feasibility of ASCH in alemtuzumab + CHOP (A-CHOP) treated patients as compared to patients not receiving the antibody, but otherwise treated and managed in the same way, and (ii) comparison of ASCH counts in the two treatment arms.

By July 2010, 20 patients, 11 in the standard treatment (arm A) and 9 in the experimental treatment (arm B) cohort, had undergone induction therapy and had been primed for subsequent ASCH according to local guidelines. Histological subtype distribution in the two treatment groups showed: PTCL not otherwise specified N=4 (arm A) and N=5 (arm B), angioimmunoblastic N=5 (arm A) and N=4 (arm B), extranodal NK/T-cell, nasal type N=1 (arm A), hepatosplenic N=1 (arm A). Pre-therapeutic evidence of bone marrow involvement was present in 4 (arm A) and 2 (arm B) patients, respectively. Of the original 23 patients, three did not undergo stem-cell harvest due to progressive disease (1 pt), patient's decision (1 pt), and pre-therapeutic CNS involvement (1 pt). Among the 20 harvested patients, ASCH failure was experienced in three patients (standard arm N=1 and experimental arm N=2; p=0.57). In two patients (one in each treatment cohort) a suboptimal stem cell yield could be optimized by the use of plerixafor according to local guidelines. A comparison of stem cell counts (CD34+ cells × 10⁶/kg body weight) from the two treatment cohorts showed a trend towards moderately lower stem cell yields in alemtuzumab-treated patients (3.34 CD34+ cells × 10⁶/kg body weight in arm B vs 6.54 CD34+ cells × 10⁶/kg body weight in arm A, p=0.03).

In conclusion, the addition of alemtuzumab to bi-weekly CHOP in the setting of first-line therapy of primary systemic PTCL does not significantly impair ASCH prior to upfront autologous stem cell transplant.