Evaluation of Novel Targets, Including CC-Chemokine Receptor 4, in Adult T-Cell Acute Lymphoblastic Leukemia/Lymphoma

Context.-Unlike B -cell acute lymphoblastic leukemia/ lymphoma (ALL/LBL), there have been few therapeutic advances in T -cell ALL (T-ALL)/LBL, an aggressive ALL/LBL subtype. Objective.-To perform a focused tissue array study to elucidate tumor markers of therapeutic potential in T-ALL/LBL. Design.-Using immunohistochemistry, we evaluated expression of leukemic antigens of interest, specifically CCchemokine receptor 4 (CCR4), among others, on available remnant diagnostic material, including tumor tissue slides obtained from formalin-fixed, paraffin -embedded preserved tissues. Results.-Our analysis identified, for the first time, expression of CCR4 in T-ALL/LBL in 11 of 27 cases (40.7%) and confirmed common expression of BCL2, CD38, and CD47, as reported previously. We also identified the expression of CD123 in 4 of 26 cases (15.4%), whereas BCL6 and PDL1 were expressed in a small number of T -ALL/ LBL cases. The potential novel target CCR4 was significantly more common in the Pre/Pro-T immunophenotypic subtype, 6 of 9 (66.7%, P 1/4 .01). No additional differences in clinical and epidemiologic variables were noted among positive or negative CCR4 cases. Conclusions.-These findings support preclinical and clinical testing of therapies targeting CCR4, CD47, BCL2, CD38, and CD123 in T-ALL/LBL, and may help guide the development of targeted clinical trials in T-ALL/LBL, a rare disease in urgent need of novel therapies.