Faculty Bibliography

Myeloproliferative neoplasms (MPNs) are a spectrum of clonal hematologic malignancies, characterized by an acquired somatic mutation in hematopoietic stem cells (HSC). Consequent constitutive activation of the JAK/STAT signaling pathway ultimately leads to HSC clonal expansion, a heightened inflammatory state, and aberrant trafficking of the malignant stem cells to sites of extramedullary hematopoiesis. While polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF) are distinct disease entities, each with their own diagnostic criteria, risk stratification, and molecular profiles, they share a common pathogenesis and exist on a spectrum, with overlapping clinical features, propensity for thrombohemorrhagic events, and risk for transformation to acute leukemia. Interferon alpha (IFN-α) has both anti-proliferative and immunomodulatory effects on MPN HSCs, and therefore is an effective treatment modality for PV, ET, and MF. In this review, we discuss the rationale for IFN-α use in MPNs, examine the evidence supporting its use, and convey practical considerations.

Idasanutlin is a small molecule inhibitor that restores p53 activity, triggering apoptosis. Two trials (phase 1/2) of idasanutlin therapy in polycythemia vera patients that were intolerant or refractory to hydroxyurea resulted in substantial clinical and molecular responses. Here the long term outcomes of these patients are reported.

INTRODUCTION/UNASSIGNED:negative myeloproliferative neoplasm (MPN) driven by recurrent acquired somatic mutations in hematopoietic stem cells and characterized by progressive bone marrow fibrosis, cytopenias, and extramedullary hematopoiesis. Janus kinase inhibitors (JAKi) improve splenomegaly and MF symptom burden but without achieving molecular remission or clear disease course modification. Novel therapies targeting epigenetic dysregulation through bromodomain and extra-terminal domain (BET) proteins have emerged as a key therapeutic approach, aimed at reducing pro-inflammatory and oncogenic transcription to deepen clinical responses in combination with JAKi therapy. AREAS COVERED/UNASSIGNED:This review summarizes the biology, preclinical data, and emerging clinical data in the development of novel BET inhibitor (BETi). Trials assessing the efficacy of pelabresib, ABBV-744, INCB057643, BMS-986158, and OPN-2853 are detailed herein. EXPERT OPINION/UNASSIGNED:BET protein inhibition is a promising therapeutic target complementing JAK inhibition by co-targeting inflammatory pathways, fibrosis, and clonal proliferation. Pelabresib is a pan-BETi furthest in development demonstrating clinical benefit with ongoing trials. Research into novel pan-and selective-BETis both as monotherapy and in combination with JAKis or other mechanism-based therapies is ongoing. Whether BETi therapy in MF will ultimately deliver substantial anti-clonal activity to modify disease biology and meaningfully impact clinical outcomes is yet to be determined.

Myelofibrosis (MF) is a chronic myeloproliferative neoplasm characterized by progressive cytopenias, splenomegaly, and constitutional symptoms. The hallmark of MF pathophysiology is constitutive activation of JAK/STAT signaling, which, in the majority of cases, is associated with an acquired mutation in one of three driver mutations, JAK2, CALR, or MPL. Our growing understanding of the molecular biology of MPNs has resulted in regulatory approval of four JAK inhibitors (JAKi), which have demonstrated efficacy in improving symptom burden and reducing spleen size. Despite clear benefits of JAKi therapy, including evidence of improved survival, these therapeutic interventions have not established an ability to modify disease in terms of resolution of bone marrow fibrosis or molecular remissions. Therefore, recent emphasis has been on the development of novel therapies with informed targets outside of the JAK/STAT signaling pathway. Moreover, combination approaches utilizing JAK and non-JAK targeting agents underscore the potential for disease modification along with deeper and more durable clinical responses. Emerging combination strategies and their clinical development will be reviewed here, including investigations that pair JAKi therapy with BCL-2 family inhibitors, BET inhibitors, restored p53 cell death signals, telomerase inhibitors, PIM1 kinase inhibitors, and mutant CALR targeted therapies. While several combination clinical trials suggest improved spleen and symptom responses and the possibility of disease modification, toxicity profiles and optimal sequencing remain areas of active investigation.

Treatment of NSCLC KRAS G12C mutant tumors with the allele-selective sotorasib and adagrasib inhibitors is invariably associated with acquired resistance. The MUC1-encoded oncogenic M1C protein is necessary for self-renewal of NSCLC KRAS mutant cells. We report that treatment of NSCLC KRAS G12C cells with sotorasib induces M1C expression by a STAT1-dependent pathway. In turn, M1C drives the sotorasib resistant phenotype by NF-κB-mediated induction of the epithelial-mesenchymal transition (EMT) and a mucinous gene program. Targeting M1C→NF-κB signaling (i) suppresses EMT and mucin genes, and (ii) reverses sotorasib resistance. Of translational relevance, treatment with a M1C antibody-drug conjugate (ADC) is effective against two sotorasib-resistant NSCLC KRAS G12C cell lines and two patient-derived tumor xenograft models. Analysis of patients with NSCLC KRAS G12C tumors treated with sotorasib/adagrasib and overexpressing MUC1 associates with decreases in overall survival. These findings identify M1C as a key effector of sotorasib resistance and as a target for treatment of patients with refractory NSCLC KRAS G12C mutant tumors.

BACKGROUND:Coronary microvascular dysfunction (CMD) is a mechanism of ischemia with nonobstructive coronary arteries (INOCA) diagnosed by invasive coronary function testing (CFT). It is unknown whether CMD reflects a systemic microcirculatory disorder. Sidestream darkfield (SDF) microscopy permits noninvasive imaging of red blood cells (RBCs) in the sublingual microcirculation. OBJECTIVES/OBJECTIVE:We sought to evaluate whether SDF microscopy identifies sublingual microvascular abnormalities in patients with INOCA due to CMD. METHODS:Adults with INOCA underwent CFT for CMD, defined by abnormal coronary flow reserve <2.5 or index of microcirculatory resistance ≥25. Sublingual SDF microscopy was performed to determine the endothelial glycocalyx perfused boundary region (PBR), RBC filling percentage (%RBC), and perfused microvascular density (PMVD). RESULTS:A total of 135 participants with INOCA (mean age 59.3 ± 12.1 years, 80% female) underwent CFT and sublingual SDF microscopy. CMD was present in 63 participants (46.7%). The median PBR was 1.96 (IQR: 0.4), median %RBC was 72.6 (IQR: 8.0), and median PMVD was 406 (IQR: 141). No differences in sublingual PBR, %RBC, and PMVD were observed by CMD status. No correlations between sublingual parameters and continuous measures of coronary flow reserve or index of microcirculatory resistance were observed. CONCLUSIONS:Noninvasive SDF microscopy did not identify sublingual microvascular abnormalities in INOCA patients with CMD.

OBJECTIVES/OBJECTIVE:The COVID-19 pandemic highlighted an urgent need to more efficiently identify patients at highest risk for developing respiratory failure. We investigated whether plasma levels of lung injury biomarkers are associated with progression to respiratory failure among adults hospitalized with COVID-19 pneumonia without respiratory failure at admission. DESIGN/METHODS:This was a nested case-control study of COVID-19 patients enrolled in the Accelerating COVID-19 Therapeutic Interventions and Vaccines-3 (ACTIV-3)/Therapeutics for Inpatients with COVID-19 (TICO) platform trial who were on less than 20 L/min supplemental oxygen at enrollment. We compared baseline measurements of lung injury biomarkers between participants who progressed to respiratory failure or died by study day 10 (cases) and matched controls who did not progress to respiratory failure or death. Cases and controls were matched 1:1 on age, baseline oxygen requirement, immunomodulator use, and study arm. SETTING/METHODS:Hospitals enrolling in the ACTIV-3/TICO trials. PATIENTS/METHODS:Four hundred five cases and 405 matched controls. INTERVENTIONS/METHODS:None. MEASUREMENTS AND MAIN RESULTS/RESULTS:Baseline levels of plasma interleukin (IL)-6, IL-8, IL-18, tumor necrosis factor receptor, angiopoietin-2, soluble receptor for advanced glycation end-products (sRAGE), C-reactive protein (CRP), and surfactant protein D (SPD) were compared between cases and controls using matched logistic regression. Forward variable selection was used to identify biomarkers that were independently associated with progression to respiratory failure or death in a multivariate model. All lung injury biomarkers with the exception of SPD were significantly associated with progression to respiratory failure or death, with sRAGE demonstrating the highest odds ratio (OR) for each doubling of biomarker level (OR, 1.85; 95% CI, 1.61-2.12). In multivariate regression analysis, sRAGE, IL-6, and CRP were independently associated with progression, with sRAGE as the biomarker with the strongest association. CONCLUSIONS:Baseline levels of plasma lung injury biomarkers are significantly associated with progression to respiratory failure or death among hospitalized COVID-19 patients without respiratory failure at admission. These findings support the potential utility of measuring lung injury biomarkers in patients hospitalized without respiratory failure and should be tested in more heterogeneous patient groups including non-COVID-19 cohorts.

[This corrects the article DOI: 10.7759/cureus.113024.].

PURPOSE/UNASSIGNED:To examine the correlation between hydroxychloroquine levels with real body weight and ideal body weight dose and identify patient characteristics at risk for subtherapeutic or supratherapeutic dosing. METHODS/UNASSIGNED:A retrospective chart review of 181 patients with lupus (429 unique hydroxychloroquine whole blood levels) was performed. Hydroxychloroquine levels <100 (indicating medication noncompliance) were excluded (n = 26). Summary statistics, linear regression of hydroxychloroquine level and real body weight/ideal body weight, and odds ratios (ORs) for factors associated with supratherapeutic (>2000 ng/mL) or subtherapeutic (<750 ng/mL) hydroxychloroquine levels were calculated. RESULTS/UNASSIGNED:, respectively. CONCLUSIONS/UNASSIGNED:All dosing schedules show variability in hydroxychloroquine levels. Ideal body weight may correlate more strongly with hydroxychloroquine level than real body weight. Under real body weight-based guidelines, obesity may increase the risk for supratherapeutic hydroxychloroquine levels, and low weight may increase the risk for subtherapeutic levels.