Aptevo Therapeutics Inc. announced a clinical update for the company?s Phase 1b Expansion trial evaluating APVO436 in the treatment of acute myeloid leukemia. Preliminary data observed to date includes one complete remission. A high-risk AML patient treated in Cohort 1 with a combination of chemotherapy plus APVO436 achieved a complete remission after one cycle of therapy. The chemotherapy regimen included the standard leukemia drugs Mitoxantrone, Etoposide, and Cytarabine. The patient tolerated treatment without evidence of overt toxicity. The overarching goal of the Phase 1b expansion phase study is to determine if APVO436 treatments can improve the quality of remission in high-risk AML patients by reducing the residual chemotherapy-resistant measurable residual disease burden. The quality of remission will be assessed using multiparameter flow cytometry methods for quantitative MRD assessment in a centralized laboratory. MRD, previously known as minimal residual disease, in AML refers to leukemia cells that are present at very low numbers but can be detected using highly sensitive flow cytometric or genomic methods. A recent systematic review of the clinical significance of MRD in over 10,000 AML patients has demonstrated that achievement of MRD negativity is associated with superior leukemia-free survival and overall survival. Therefore, MRD status has emerged as an attractive and clinically meaningful end point that may allow for accelerated evaluation of novel therapies in AML as well as an increased likelihood of responses as both CRS as well as responses are inversely correlated with the leukemia burden of the patients. If successful, deepening the remission to an MRD-negative remission using this strategy could translate into an improved overall survival in AML.