PT - JOURNAL ARTICLE AU - Koch, Raphael AU - Christie, Amanda L. AU - Crombie, Jennifer L. AU - Palmer, Adam C. AU - Plana, Deborah AU - Shigemori, Kay AU - Morrow, Sara N. AU - Van Scoyk, Alexandria AU - Wu, Wenchao AU - Brem, Elizabeth A. AU - Secrist, J. Paul AU - Drew, Lisa AU - Schuller, Alwin G. AU - Cidado, Justin AU - Letai, Anthony AU - Weinstock, David M. TI - Biomarker-driven strategy for MCL1 inhibition in T-cell lymphomas AID - 10.1182/blood-2018-07-865527 DP - 2019 Feb 07 TA - Blood PG - 566--575 VI - 133 IP - 6 4099 - http://www.bloodjournal.org/content/133/6/566.short 4100 - http://www.bloodjournal.org/content/133/6/566.full SO - Blood2019 Feb 07; 133 AB - We outline a biomarker-driven treatment strategy for targeting MCL1 in TCL.AZD5991 shows promising activity as both a single agent and in combination with CHOP-based therapy.There is a Blood Commentary on this article in this issue.There is a pressing need for more effective therapies to treat patients with T-cell lymphomas (TCLs), including first-line approaches that increase the response rate to cyclophosphamide, adriamycin, vincristine, and prednisone (CHOP) chemotherapy. We characterized the mitochondrial apoptosis pathway in cell lines and patient-derived xenograft (PDX) models of TCL and assessed the in vitro efficacy of BH3 mimetics, including the BCL2 inhibitor venetoclax, the BCL2/BCL-xL inhibitor navitoclax, and the novel MCL1 inhibitor AZD5991. The abundance of antiapoptotic BCL2 family members based on immunoblotting or RNA transcript levels correlated poorly with the activity of BH3 mimetics. In contrast, the functional approach BH3 profiling reliably predicted sensitivity to BH3 mimetics in vitro and in vivo. We used BH3 profiling to select TCL PDX that were dependent on MCL1. Mice xenografted with these PDX and treated with AZD5991 had markedly improved survival. The combination of AZD5991 and CHOP achieved synergy based on survival improvement beyond a mathematical “sum of benefits” model. Thus, MCL1 inhibition is a promising strategy as both a single agent and in combination with chemotherapy for patients with TCL and functional dependence on MCL1.