Hogan, William J.

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 .

BACKGROUND: Pulmonary function test (PFT) impairments are common after allogeneic hematopoietic stem cell transplantation. The prognostic significance of these declines on outcomes is not well understood. The objectives were to determine the frequency of declines in pulmonary function (FVC, FEV 1 , and diffusing capacity for carbon monoxide [D LCO ]) in the early post-transplantation period; and to determine the prognostic significance of these declines on mortality or development of bronchiolitis obliterans syndrome. METHODS: This was a retrospective cohort study conducted at Mayo Clinic, Rochester, Minnesota. PFTs were obtained at baseline and at day +100. Competing risk survival models were developed, which accounted for pre-transplantation pulmonary function and relapse status. RESULTS: Between January 1, 2005, and December 31, 2020, 1,145 subjects underwent allogeneic hematopoietic stem cell transplantation and had a pre-transplantation PFT performed. Of these, 900 (78.6%) survived to day 100 and had post-transplantation PFTs performed (median [interquartile range] 97 [94–103] d). A decline of ≥10% in FEV 1, FVC, or D LCO was seen in 401 of 900 subjects (44.5%). Declines of ≥20% in FEV 1 (hazard ratio 1.65, 95% CI 1.07–2.56; P = .02), FVC (hazard ratio 1.72, 95% CI [1.11–2.67]; P = .02), and D LCO (hazard ratio 1.46, 95% CI 1.04–2.07; P = .028) were all associated with reduced survival when compared with those with < 10% decline in PFT measures. These findings were independent of pre-transplantation pulmonary function or relapse status. Bronchiolitis obliterans syndrome was diagnosed in 118 subjects (10.3%), and there was no relationship between early PFT decline and a subsequent diagnosis of bronchiolitis obliterans syndrome. The subjects who received myeloablative conditioning with cyclophosphamide plus total body irradiation or cyclophosphamide plus fludarabine plus total body irradiation were more likely to have lower spirometry values after hematopoietic stem cell transplantation. The subjects who received reduced intensity conditioning or nonmyeloablative conditioning with fludarabine plus total body irradiation were more likely to have higher post–hematopoietic stem cell transplantation FEV 1 , FVC, and D LCO . CONCLUSIONS: An absolute decline of ≥20% in FEV 1 , FVC, or D LCO were associated with reduced survival independent of pre-transplantation pulmonary function or relapse status. In contrast to previous work, early declines in PFT measures were not associated with future development of bronchiolitis obliterans syndrome.

AbstractBackgroundMyeloid neoplasms (myelodysplastic syndrome [MDS], myelofibrosis, and chronic myelomonocytic [CMML]) are aggressive hematological malignancies for which, despite recent approvals, novel therapies are needed to improve clinical outcomes. The hedgehog (HH) pathway is one of the main pathways for cancer stem cells survival and several HH inhibitors (HHi) are approved in clinical practice.MethodsSonidegib (SON), an oral HHi, was tested in this phase 1/1b trial in combination with azacitidine (AZA, 75 mg/m2 days ×7) in patients with newly diagnosed and relapsed/refractory (r/r) chronic MN or acute myeloid leukemia (AML).ResultsSixty‐two patients (28 [45%] newly diagnosed) were treated in this study, including 10 patients in the dose‐finding component and 52 patients in phase 1b. SON 200 mg oral daily on days 1–28 each cycle was deemed the recommended dose for phase 1b. Out of 21 rrAML patients, two achieved response (one complete response/one morphologic leukemia‐free state) with no responses seen in seven r/r MDS/CMML patients. In newly diagnosed AML/MDS, response was seen in six (three had complete remission, two had morphological leukemia‐free status) of 27 patients. Median overall survival was 26.4 and 4.7 months for newly diagnosed MDS and AML, respectively. Safety was satisfactory with common (>20%) side effects including fatigue, constipation, nausea, cough, insomnia, and diarrhea. Only 7% of patients died in the study, and none of the deaths were deemed related to treatment.ConclusionsOur study shows that AZA + SON are a safe combination in a patient with MN. Similar to other hedgehog inhibitors, this combination yielded limited response rate in patients with myeloid neoplasms.

Abstract Acute graft-versus-host disease (GVHD), a serious complication of allogeneic hematopoietic cell transplantation (HCT), frequently involves the skin. Since clinicopathologic features of GVHD can mimic those of certain drug eruptions, accurate diagnosis can be challenging. We aimed to develop a tissue-based molecular assay to improve differentiation of GVHD from vacuolar interface drug eruption in the post-HCT period. After identifying 62 putative tissue-based biomarkers using unbiased molecular methods, we incorporated 26 into a quantitative RT-PCR assay. We tested skin biopsy specimens showing vacuolar interface changes attributable to either acute GVHD (n=67) or drug reaction (n=17), as classified by meticulous review of clinical features and course. Data were incorporated into clinical-molecular fusion diagnostic models. Significant differences in the expression of several genes, including MX1, MNDA, OAS, LIMA1, GSTM5, and SPP1, were detected between the two diagnostic groups (p<0.05). The optimal fusion model, which incorporated quantitative expression of MX1, MNDA, OAS, and GSTM5, as well as the clinical feature of diarrhea, imparted high diagnostic accuracy (receiver operating characteristic area-under-curve: 0.89). This novel tissue-based diagnostic molecular assay and fusion model demonstrates potential to improve distinction of GVHD from drug eruptions in the post-HCT setting. Multicenter validation studies are required.