Interim safety and efficacy of BP1001 in a phase II acute myeloid leukemia (AML) study.

Abstract

6511 Background: Oncogenic tyrosine kinases induce AML progression via the growth factor receptor bound protein-2 (Grb2). BP1001, a liposome-incorporated Grb2 antisense oligonucleotide,enhanced cancer cell sensitivity to chemotherapy, such as decitabine (DEC) and venetoclax (VEN). A multi-center open-label Phase II study was initiated to assess whether the BP1001 + DEC + VEN combination provides higher response rates than historically reported responses of DEC + VEN in newly diagnosed AML (including secondary AML) (cohort 1) or refractory/relapsed (R/R; cohort 2) AML patients (pts) considered unsuitable for intensive chemotherapy. Per protocol, when 19 evaluable pts are enrolled in each cohort, interim analysis will be performed to determine which cohort has ≥5 complete responses and will continue with enrollment. Methods: BP1001 was given, beginning on Day 4, at 60 mg/m2 IV, 2x weekly for a total of 8 doses over a 28-day cycle. DEC was given IV on days 1 to 5 at 20 mg/m2. VEN was given PO at 100 mg on day 1, 200 mg on day 2, and 400 mg from day 3 to day 14 or 21. Eligible pts were considered unsuitable for or refused intensive chemotherapy and had ECOG performance status of 0-2. Interim analysis was performed on Jan 24, 2024 on pts enrolled between July 28, 2020 and December 26, 2023. Evaluability for efficacy was defined as: completion of at least 4 cycles of combination therapy, documented Progressive Disease (PD) or any drug toxicity at any time, or CR/CRi/CRh prior to 4 cycles. Results: In Cohort 1, 31 newly diagnosed pts were enrolled; 20 evaluable pts (9 male: 45%) with a median age of 75 years (range, 69 - 84), treated with at least 1 cycle of BP1001 + DEC + VEN, had adverse-risk (n=12, ELN 2017 classification) or secondary AML (sAML; n=7) evolved from MDS (n=4), CMML (n=1) or treatment-related AML (n=2). Fifteen pts (75% of evaluable; 54% of enrolled) achieved CR/CRi/CRh; 2 pts achieved partial remission (PR) and 2 achieved stable disease (SD). In Cohort 2, 38 R/R pts were enrolled; 23 evaluable pts (13 male: 57%) with a median age of 63 years (range, 24 - 89), treated with at least 1 cycle of BP1001 + DEC + VEN, had adverse-risk (n=13) or sAML (n=5). Twelve pts (55% of evaluable; 32% of enrolled) achieved CR/CRi/CRh; 1 pt achieved PR, 8 achieved SD and 1 had treatment failure. Among the evaluable pts of both cohorts, adverse events were consistent with those expected with DEC, VEN and/or AML, including fatigue (72%), anemia (60%) and neutropenia (49%), while the most frequent serious adverse events were febrile neutropenia (26%) and sepsis (5%). Conclusions: BP1001 + DEC + VEN has been safely administered to pts without drug-related toxicity. Since >5 responses are observed in both cohorts, the study will continue with enrollment up to 98 and 54 evaluable pts in cohorts 1 and 2, respectively. Efficacy data are encouraging in a challenging population of frontline adverse-risk, sAML and R/R pts. Clinical trial information: NCT02781883 .