Citations

Abstract We surveyed the performance of ponatinib, as salvage therapy, in a real-world setting of chronic phase chronic myeloid leukemia (CML-CP). Among 55 consecutive patients (median age 49 years) with relapsed/refractory CML-CP, 35 (64%) had failed ≥ 3 tyrosine kinase inhibitors (TKIs), 35 (64%) were pre-treated with nilotinib, and 14 (28%) harbored ABL1T315I. At start of ponatinib (median dose 30 mg/day), 40 patients were already in complete hematologic (CHR), 4 in complete cytogenetic (CCyR), 3 in major molecular (MMR) remission, while 8 had not achieved CHR (NR). Ponatinib improved the depth of response in 13 (33%), 3 (75%), 2 (66%), and 4 (50%) patients with CHR, CCyR, MMR, and NR, respectively (p = 0.02). At a median follow-up of 42 months, 13 (23%) deaths, 5 (9%) blast transformations, and 25 (45%) allogeneic transplants were recorded. Five/10-year post-ponatinib survival was 77%/58% with no significant difference when patients were stratified by allogeneic transplant (p = 0.94), ponatinib-induced deeper response (p = 0.28), or a post-ponatinib ≥ CCyR vs CHR remission state (p = 0.25). ABL1T315I was detrimental to survival (p = 0.04) but did not appear to affect response. Prior exposure to nilotinib was associated with higher risk of arterial occlusive events (AOEs; 11% vs 0%; age-adjusted p = 0.04). Ponatinib starting/maintenance dose (45 vs 15 mg/day) did not influence either treatment response or AOEs. Our observations support the use of a lower starting/maintenance dose for ponatinib in relapsed/refractory CML-CP but a survival advantage for deeper responses was not apparent and treatment might not overcome the detrimental impact of ABL1T315I on survival. The association between prior exposure to nilotinib and a higher risk of post-ponatinib AOEs requires further validation.

TPS7089 Background: Chronic myelomonocytic leukemia (CMML) is a myelodysplastic/myeloproliferative overlap neoplasm (MDS/MPN) that can be further divided into MD (WBC < 13 x 109/L) and MP (≥13 x 109/L) subtypes. MP-CMML is enriched in RAS pathway mutations ( NRAS, CBL, KRAS, PTPN11 and NF1), has a shorter median survival (19 vs 36 months), has a higher rate of acute myeloid leukemia (AML) transformation (40% vs 10%) and has a unique transcriptomic and epigenetic composition. These RAS pathway mutations promote selective PLK1 overexpression, a mitotic checkpoint kinase. Given the relative inefficacy of hypomethylating agents (HMA) in MP-CMML and previously demonstrated in vitro and in vivo efficacy data for PLK1 inhibition on MP-CMML with RAS pathway mutations, we designed a phase 1 clinical trial testing the safety of onvansertib, a novel, orally bioavailable, PLK1 inhibitor in relapsed/refractory MP-CMML. Methods: This is an investigator-initiated, prospective, open-label, phase I study of onvansertib in MP-CMML relapsed/refractory (RR) or intolerant to existing therapies including HMA and hydroxyurea. The primary endpoint is characterization of safety. Secondary endpoints include efficacy as defined by the 2015 MDS/MPN International Working Group criteria, volumetric spleen response and symptom response via assessment with MPN-SAF-TSS. Inclusion criteria include MP-CMML RR following hydroxyurea or at least 4-cycles of HMA or intolerance of treatment with either, platelets ≥ 20,000/m3 and Cockcroft-Gault creatinine clearance ≥ 60 mL/min/m2. Hydroxyurea may continue for the first 28 days on study. Onvansertib will be given orally on days 1 through 21 of a 28-day cycle with a Bayesian optimal interval design to assess the safety and recommended phase II dose. Exploratory end points include targeting efficacy, impact of PLK1 and KMT2A expression and interactions with ASXL1 and TET2 mutations. Twenty-five patients will be enrolled at Mayo Clinic in Minnesota, with enrollment open since November 2022. Clinical trial information: NCT05549661 .

1535 Background: Ambulatory management of select patients with febrile neutropenia (FN) may substantially decrease patients’ burden of illness and improve their quality of life, and is recommended by American Society of Clinical Oncology (ASCO) guidelines. However, in the United States, inpatient management remains the universal standard. We hereby report the health care utilization associated with the DEFeNDR remote patient monitoring (RPM) program, which leverages technology and virtual centralized nurse monitoring to facilitate ambulatory management of FN as an alternative to hospital-based care. Methods: Adult patients with cancer hospitalized with FN were assessed daily for eligibility to participate in the DEFeNDR program. Eligibility criteria included MASCC score >21 (per ASCO guidelines), and clinical judgment of the attending provider. Patients receiving cellular therapy (CAR-T, BMT) in the prior 100 days were excluded. Eligible patients agreeing to participate in the 30-day program were provided a kit containing cellular-enabled, pre-connected devices to facilitate monitoring, including twice-daily vital signs and electronic symptom questionnaires. Data were EHR-integrated in real-time and embedded decision trees facilitated alerts for adverse trends. RPM nurses responded to alerts and escalated care as indicated by pre-specified care pathways. Program assessment was performed at 20 weeks after full implementation. The primary outcome was the mean proportion of evaluable days spent inpatient (mPEDI) within 30 days of eligibility compared between those who participated in the program vs. those who declined. Results: 35 patients were offered participation in the DEFeNDR program. Of these, 17 participated and 18 declined. Baseline characteristics are provided. Participating patients experienced mPEDI of 6.9% (Standard Error [SE], 3.7%), compared with 17.7% (SE, 3.6%) for patients who declined participation. Due to small sample size, this difference (10.8%) did not reach statistical significance (Wilcoxon Rank Sums p-value, 0.15). 30-day mortality did not differ between groups. Mean inpatient days were also lower for patients participating in the program. Additionally, when readmitted, patients participating in RPM experienced a trend toward shorter length of stay and lower rates of intensive care unit utilization. Conclusions: A trend towards decreased burden of inpatient care is evident among patients participating in the DEFeNDR program. Further studies are warranted to assess comparative effectiveness of this model vs usual care.[Table: see text]