Abstract 1430: In vivo PoC study and design for Phase I clinical study of SJP1604, a nucleolin-targeted therapeutic agent to treat entire population of relapsed/refractory acute myeloid leukemia patients

SJP1604 (APTA-16) is an aptamer-drug conjugate (APTA-DC) specifically targeting nucleolin, which is highly expressed only on the cell membrane of acute myeloid leukemia (AML) cells including relapsed/refractory aute myeloid leukemia (R/R AML). We previously presented the outstanding anti-leukemic activity of SJP1604 on AML cells including drug-resistant AML cells while standard chemotherapies showed no efficacy in vitro and in vivo. Therefore, we were able to conclude that only SJP1604 exhibits excellent resistance overcoming efficacy regardless of genetic defects of AML cells. Additionally, we recently identified that SJP1604 markedly eradicated AML cell engraftment with decreasing expression level of nucleolin protein in the bone marrow cells of MOLM-13 xenograft mouse model. These findings demonstrate that SJP1604 contributes to anti-leukemic effects through the regulation of nucleolin protein. We also figured out that nucleolin as a clinical biomarker was significantly highly expressed on AML and R/R AML patient-derived bone marrow cells. In particular, nucleolin expression is highly overexpressed in the bone marrow cells of entire population of R/R AML patients. Upto recent, considered as one of the major targeted therapeutics for AML, FLT3 inhibitors can target 25-30% of AML patients only. Therefore, our results mentioned above are very noteworthy finding showing the high potential of SJP1604 to be further developed as the first innovative targeted therapy to treat entire population of R/R AML patients. Herein, we show a phase I clinical trial design of SJP1604 to perform an open-label, first-in-human, dose escalation study to evaluate the safety, tolerability, pharmacokinetics and anti-tumor activity in patients with R/R AML. Citation Format: Jihyun Um, Dohyeong Lee, So Hee Kim, Eun-Hye Huh, Yongbin Park, Sung Hwan Moon, Soo Jin Lee, Je-Hwan Lee, Min-Hyo Ki. In vivo PoC study and design for Phase I clinical study of SJP1604, a nucleolin-targeted therapeutic agent to treat entire population of relapsed/refractory acute myeloid leukemia patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1430.